Sugar
Sugar-sweetened beverages (SSBs) featured article
Sugar-sweetened beverages (SSB) include commonly consumed products such as soda, sports drinks, and energy drinks; coffee, tea, and water with added sugars; and some fruit juices, although not all nutrition experts agree on fruit juice’s inclusion as an SSB. While the consumption of SSBs has declined in recent decades, they remain a leading contributor to sugar intake among people living in the United States.
While the over-consumption of sugar from any source is harmful for health, SSBs present a physiologically unique risk to health due to a converging set of factors. Because they contain no supporting food matrix to slow absorption, SSBs are rapidly absorbed by the gut and cause blood sugar spikes. Sugars from fruits and vegetables are packaged with a matrix of fiber and micronutrients that reduce the rate of digestion. This slow digestion and absorption reduces blood sugar spikes and supports better glycemic control. Additionally, many SSBs [exceed the recommended maximum...
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Dr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
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Sugar-sweetened beverages (SSBs)
Sugar, typically sucrose or high-fructose corn syrup, dissolved in water defines sugar-sweetened beverages, increasing energy density and glycemic burden.
News & Publications
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Artificial sweeteners like sucralose are marketed as healthier alternatives to sugar, but they may send mixed signals to the brain. A recent study found that sucralose increased hunger and altered activity in the part of the brain that regulates appetite, with effects differing by body weight.
Researchers asked 75 young adults—some with a healthy weight and some with overweight or obesity—to drink a beverage sweetened with either sucralose (often marketed as Splenda), sucrose (table sugar), or plain water on three separate occasions. Afterward, the researchers measured the participants' blood glucose levels, collected their self-reported hunger ratings, and conducted brain scans to examine activity and connectivity in key regions involved in appetite control.
Compared to sugar, sucralose increased blood flow to the hypothalamus and promoted stronger feelings of hunger. Sucralose also heightened hypothalamic activity more than water but didn’t influence hunger. Only sugar elevated blood glucose levels, an increase linked to reduced activity in the hunger-regulating regions of the brain.
Interestingly, the brain’s response to sucralose differed based on body weight: In people with a healthy weight, sucralose enhanced connections between the hypothalamus and areas involved in attention and decision-making. In those with overweight, sucralose diminished connections to brain regions that process bodily sensations. And those with obesity exhibited little to no change in these neural connections. Compared to water, both sweeteners elicited distinct patterns of brain activity depending on weight status.
These findings suggest that sucralose interferes with the brain’s normal appetite-regulating signals by mimicking sweetness without delivering the expected rise in blood sugar. This mismatch appears to increase hunger and alter brain connectivity in ways that vary depending on body weight. Artificial sweeteners also affect the gut microbiome. Learn more in this clip featuring Dr. Eran Elinav.
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Sugar-sweetened beverages are linked to 9.8% of new type 2 diabetes cases and 3.1% of new cardiovascular disease cases globally. www.nature.com
Sugar-sweetened beverages contribute to weight gain and increase the risk of severe health concerns, such as type 2 diabetes and cardiovascular disease. A recent study revealed that in 2020, sugar-sweetened drinks were linked to 2.2 million new cases of type 2 diabetes and 1.2 million new cases of cardiovascular disease globally.
Researchers utilized the Global Dietary Database to assess the global, regional, and national effects of type 2 diabetes and cardiovascular disease associated with sugar-sweetened beverage consumption in 184 countries, comparing data from 1990 to 2020. They also considered factors such as age, sex, education, and whether people lived in urban or rural areas to provide further context for the findings.
They found that sugar-sweetened beverages were associated with 9.8% of new type 2 diabetes cases and 3.1% of new cardiovascular disease cases in 2020. The burden was greatest in Latin America and the Caribbean, where sugar-sweetened beverages accounted for 24.4% of type 2 diabetes cases and 11.3% of cardiovascular disease cases. Sub-Saharan Africa also experienced a marked increase in type 2 diabetes and cardiovascular disease related to sugar-sweetened beverages over the past three decades.
These findings suggest that sugar-sweetened beverages have deleterious effects on human health and underscore the need for targeted interventions to reduce their consumption. Learn more about sugar-sweetened beverages in our overview article.
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Drinking more than eight sugar-sweetened drinks a week increases the risk of cardiovascular diseases by up to 31%. pubmed.ncbi.nlm.nih.gov
It’s no surprise that sugar-sweetened drinks can contribute to weight gain, dental problems, and metabolic impairments. But emerging evidence suggests they can also harm your heart. A recent study found that consuming more than eight sugar-sweetened drinks weekly increases the risk of various cardiovascular diseases by as much as 31%.
Researchers investigated links between sugar intake and cardiovascular disease among nearly 70,000 people. They asked participants about their sugar intake from various sugar-sweetened foods and drinks. Then, using national disease registers, they ascertained the incidence of various cardiovascular diseases, including ischemic and hemorrhagic stroke, myocardial infarction (heart attack), heart failure, aortic stenosis (narrowing of the aorta), atrial fibrillation (abnormal heart rhythm), and abdominal aortic aneurysm (ballooning of the major blood vessel in the abdomen).
They found that the risk of developing cardiovascular disease varied according to disease type and sugar source. However, drinking more than eight sugar-sweetened beverages weekly carried the greatest risk, increasing a person’s chances of ischemic stroke by 19%, heart failure by 18%, atrial fibrillation by 11%, and abdominal aortic aneurysms by 31%.
The investigators posited that sugar in beverages is readily metabolized, increasing its potential for harm. Learn more about the health effects of sugar-sweetened beverages in our overview article.
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Adding sugar to tea or coffee increases the risk of premature death by up to 11 percent. www.ncbi.nlm.nih.gov
Tea and coffee provide many health benefits, but for some people, the beverages are often a source of added sugar. A recent study found that adding sugar to tea or coffee increased the risk of premature death by 6 percent; adding sugar to coffee alone increased the risk by 11 percent.
Researchers tracked the health of more than 2,900 men enrolled in the Copenhagen Male Study over thirty years. The men provided information about their tea and coffee consumption and whether they added sugar to these beverages.
The researchers found that about a third of the men added sugar to their tea or coffee. Those who did were about 6 percent more likely to die prematurely from any cause than those who didn’t add sugar. Adding sugar to coffee alone increased the risk of dying early by about 11 percent.
The findings from this large, epidemiological study suggest that adding sugar to tea or coffee increases the risk of dying early, negating some of the longevity benefits often ascribed to the two beverages.
Sugars are natural components of the human diet, found in fruits, vegetables, and dairy products. However, the refined sugar typically added to beverages like tea or coffee is a highly processed product derived from sugar cane or sugar beets. It undergoes rapid metabolism in the body, causing insulin and blood sugar levels to skyrocket. Nearly 75 percent of adults in the US get about one-tenth of their daily calories from added, refined sugar. Learn more about the effects of sugar on human health in this episode featuring Dr. Rhonda Patrick.
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Increased intake of sugar-sweetened drinks raises cardiovascular disease risk by 18 percent with each additional serving, regardless of physical activity. ajcn.nutrition.org
Sugar-sweetened beverages encompass a wide variety of drinks, including soft drinks/sodas, sports drinks, energy drinks, and coffees. People who are physically active often consume sugar-sweetened sports drinks to replenish the electrolytes lost during exercise. While this can be beneficial during prolonged, intense physical activities, the added sugar content in many sports drinks might not be necessary for routine exercise or for people engaging in moderate physical activity. A recent study found that for every additional serving of sugar-sweetened beverages consumed daily, the risk of cardiovascular disease increased by 18 percent for physically active people and 12 percent for those who were inactive.
The study involved more than 105,000 adults enrolled in the Nurses' Health Study and the Health Professionals Follow-up Study who were healthy at the time of enrollment. Researchers gathered information from the participants regarding their physical activity, cardiovascular health, and consumption of sugar-sweetened beverages.
They found that participants who consumed more than two servings of sugar-sweetened beverages per day were 21 percent more likely to develop cardiovascular disease than those who rarely or never consumed them. For each additional serving of sugar-sweetened beverages consumed daily, the risk of cardiovascular disease increased by 18 percent for people who met physical activity guidelines and by 12 percent for those who did not, indicating that physical activity did not compensate for high sugar-sweetened beverage consumption. Participants who did not meet physical activity guidelines and consumed two or more servings per week of sugar-sweetened beverages were 47 percent more likely to develop cardiovascular diseases than those who were physically active and rarely or never drank them.
These findings suggest that consuming sugar-sweetened beverages markedly increases a person’s risk for cardiovascular disease. Furthermore, physical activity does not offset this risk. Learn more about the health effects of sugar-sweetened beverages in our overview article.
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Genetic differences drive the preference for sweet foods. www.sciencedaily.com
Whether a person prefers sweets over savory foods is related to their genetic makeup, a 2017 study found. These genetic differences may also drive alcohol consumption and tobacco use, the research showed.
Researchers analyzed the genetic makeup of more than 6,500 people to determine if they carried a particular gene variant of FGF21 – a hormone produced in the liver – called rs838133. Then they asked the participants about their sweet preferences, alcohol consumption, and tobacco use.
They found that participants who had the rs838133 variant were nearly 20 percent more likely to eat more sweet-tasting foods compared to the other participants. Those who had the rs838133 variant were also more likely to consume alcohol or smoke tobacco.
Next, the researchers asked 86 lean, healthy people about their sweet preferences and then, after a 12-hour fast, measured their FGF21 levels. They found that FGF21 levels in participants who had a low preference for sweets were 51 percent higher compared to those who had a high preference for sweets.
These findings suggest that FGF21 influences eating behaviors, curbing the appetite for sweets in some people. Other research suggests that FGF21 also moderates alcohol consumption, but it does it via different pathways. Taken together, these findings suggest that FGF21 release serves as a means to protect the liver from damage. Learn how exercise promotes the release of FGF21, thereby reducing cravings for alcohol.
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Sugar-sweetened drinks linked to increased visceral fat www.sciencedaily.com
Sugar-sweetened beverage intake increases visceral fat.
Subcutaneous fat is stored just beneath the skin. Commonly associated with a “pear” shape, subcutaneous fat may protect against some diseases. Visceral fat, on the other hand, is stored in the abdominal cavity close to internal organs such as the liver, pancreas, and intestines. An excess of visceral fat, often referred to as central obesity or abdominal obesity, is commonly associated with an “apple” shape and an increased risk of developing many chronic diseases. Findings from a 2016 study suggest that sugar-sweetened beverage intake increases visceral fat deposition.
Sugar-sweetened beverages include commonly consumed products such as soda, sports drinks, energy drinks, and other beverages that contain added sugars. Many sugar-sweetened beverages exceed the recommended maximum daily added sugar intake of 25 grams in a single serving. They are the leading contributor to sugar intake among people living in the United States.
The investigation involved 1,160 participants enrolled in the Third Generation of the Framingham Heart Study who underwent repeated computed tomography scans (approximately six years apart) to assess the amount of fat in their abdominal region, including subcutaneous fat and visceral fat. Participants provided information about their dietary intake, physical activity, overall health, and whether they smoked. Investigators categorized the participants according to their sugar-sweetened beverage or diet soda intake, ranging from non-consumers (drinking none to less than one serving per month) to daily consumers (drinking one or more servings per day.
They found that sugar-sweetened beverage intake was associated with visceral fat gain in a dose-dependent manner, with daily consumers gaining 29 percent more visceral fat over a six-year period than non-consumers. These findings held true even after accounting for the participants' age, gender, physical activity, body mass index, and other factors. Drinking diet soda was not associated with visceral fat gain.
These findings suggest that drinking sugar-sweetened beverages increases visceral fat, potentially contributing to an increased risk of chronic disease. Learn more about sugar-sweetened beverages in our overview article.
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Omega-3 prevents memory and learning impairment caused by high-fructose diets in mice www.sciencedaily.com
From the article:
Gomez-Pinilla and study co-author Rahul Agrawal, a UCLA visiting postdoctoral fellow from India, studied two groups of rats that each consumed a fructose solution as drinking water for six weeks. The second group also received omega-3 fatty acids in the form of flaxseed oil and docosahexaenoic acid (DHA), which protects against damage to the synapses – the chemical connections between brain cells that enable memory and learning.
[…]
The animals were fed standard rat chow and trained on a maze twice daily for five days before starting the experimental diet. The UCLA team tested how well the rats were able to navigate the maze, which contained numerous holes but only one exit. The scientists placed visual landmarks in the maze to help the rats learn and remember the way.
Six weeks later, the researchers tested the rats' ability to recall the route and escape the maze. What they saw surprised them.
“The second group of rats navigated the maze much faster than the rats that did not receive omega-3 fatty acids,” Gomez-Pinilla said. “The DHA-deprived animals were slower, and their brains showed a decline in synaptic activity. Their brain cells had trouble signaling each other, disrupting the rats' ability to think clearly and recall the route they’d learned six weeks earlier.”
The DHA-deprived rats also developed signs of resistance to insulin, a hormone that controls blood sugar and regulates synaptic function in the brain.
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Sugar may drive inflammatory bowel disease through the promotion of mucin-consuming microbes. www.science.org
Inflammatory bowel disease (IBD) is an umbrella term for two chronic inflammatory conditions that affect the digestive tract – ulcerative colitis and Crohn’s disease. Symptoms of IBD include diarrhea, rectal bleeding, abdominal pain, fatigue, and weight loss. Evidence indicates that dysbiosis, an imbalance in the types and numbers of microbes in the gut, contributes to the pathogenesis of IBD. And now, findings from a recent study suggest that eating a high-sugar diet promotes dysbiosis and the development of IBD.
The study involved normal mice and mice that are genetically predisposed to develop colitis. The authors of the study gave a subset of both groups of mice a 10 percent glucose solution (comparable to a sugar-sweetened soft drink) for one week. They gave the normal mice a chemical that causes colitis. Then they measured the inflammatory responses, disease severity, and gut microbial composition in both groups of mice and compared them to mice that did not receive the sugar solution.
They found that, prior to the mice developing colitis, the sugar did not trigger gut inflammation. However, both groups of mice developed worse symptoms of colitis after drinking the glucose solution. In addition, both groups exhibited higher numbers of bacteria that break down the mucus layer of the gut (specifically, Akkermansia muciniphila and Bacteroides fragilis), contributing to mucus layer destruction, increasing gut permeability. The number of beneficial bacteria in the animals' guts decreased, however.
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Specialized cells in the gut differentiate between sugar and artificial sweeteners. www.eurekalert.org
The ability to detect sweetness – whether from sugar or artificial sweeteners – relies on the activity of specialized proteins in the mouth and nasal passages called taste receptors. However, researchers have found that mice that don’t have taste receptors can tell the difference between sugar and artificial sweeteners – and prefer sugar. Findings from a recent study suggest that the capacity to differentiate between sugar and artificial sweeteners is due to the activity of unique cells call neuropods.
Neuropods are enteroendocrine cells – specialized cells that line the gut and sense the presence of food. Located primarily in the duodenum (the upper portion of the intestine), neuropods form synapses (neural connections) with the vagus nerve, a cranial nerve that regulates multiple aspects of the body’s internal functions, including those in the gut. The presence of sugar in the gut causes neuropods to release glutamate, a type of neurotransmitter, facilitating communication via the gut and brain.
The researchers first determined whether neuropods' response to sweetness is specific to sugar, using organoids derived from the intestinal tissues of mice and humans. Organoids are three-dimensional tissue cultures produced from stem cells. They mimic the structure and activity of the organ from which they are derived. The researchers exposed the organoids to sugar or sucralose (an artificial sweetener) and found that sugar promoted the release of glutamate, but sucralose did not.
Then they determined whether the preference for sugar (over artificial sweeteners) arises in the brain or the gut using optogenetics. Optogenetics is a research technique that allows scientists to switch a neuron’s activity on or off using light and genetic engineering. When they turned the neuropod cells in the gut of a living mouse on or off, they found that when the neuropod cells were off, the mouse no longer showed a clear preference for sugar.
These findings suggest that neuropod cells in the gut drive responses to and preferences for sugar. They may further explain why artificial sweeteners often don’t curb the desire (or craving) for sugar. Sugar is ubiquitous in the Western diet and is especially abundant in sugar-sweetened beverages. Learn about the health effects of consuming sugar-sweetened beverages in our overview article.
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Shorter sleep duration promotes the intake of added sugars and carbohydrates. www.sciencedaily.com
Sleep is essential for maintaining optimal physical health. Evidence suggests that adults who don’t get enough sleep have a greater risk of developing many chronic diseases and tend to overeat. Findings from a recent study suggest that teens consume more sugar when they don’t get enough sleep.
Sleep patterns change markedly during the adolescent years, driven by shifts in circadian rhythms and subsequent sleep latency – the tendency to fall asleep later in the evening than adults or young children. Social and behavioral factors play roles, as well, as teens often participate in evening social events and exert autonomy over their bedtimes. Consequently, most teens get fewer than the recommended eight hours of sleep per night.
The study involved 93 healthy adolescents between the ages of 14 and 17 years. The participants experienced two sleep conditions, each lasting five nights. In the “healthy sleep” condition, they had 9.5 hours of sleep opportunity; during the “short sleep” condition, they had 6.5 hours of sleep opportunity. The participants wore sleep trackers and provided information about the types, quantities, and timing of foods they ate while experiencing each sleep condition.
The trackers revealed that, on average, the participants slept more than two hours longer when they experienced the healthy sleep condition. When participants experienced the short sleep condition, they tended to consume more carbohydrates, added sugars, and sweet drinks, and fewer fruits and vegetables than when they experienced the healthy sleep condition. The increase in added sugars was particularly concerning, because added sugars are associated with weight gain. Interestingly, the patterns of higher consumption emerged late at night – after 9 p.m.
These findings suggest that teens who don’t get enough sleep consume more sugars late at night, potentially promoting weight gain and driving other health problems, such as obesity or diabetes. Learn more about the harmful effects of eating sugars in this podcast featuring Dr. Rhonda Patrick.
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Drinking sugar-sweetened beverages increases risk of death from any cause among women with breast cancer. pubmed.ncbi.nlm.nih.gov
Obesity and metabolic disease are risk factors for developing breast cancer; however, they are highly modifiable with lifestyle changes. Sugar-sweetened beverages are the leading contributor of added sugars in the American diet and consuming them in excess greatly increases the risk of developing obesity and type 2 diabetes. Results of a long-term study show that sugar-sweetened beverage consumption among women with breast cancer increases the risk of death from any cause.
As adipose tissue accumulates fat, it becomes dysfunctional and can contribute to breast cancer growth by reducing glucose sensitivity and producing hormonal (e.g., estrogen) and inflammatory (e.g., interleukin-6) pro-cancer signals. Sugar-sweetened beverages contribute to the development of obesity and diabetes by providing large quantities of empty calories and spiking blood glucose and insulin levels due to the rapid absorption of sugar. Although previous research has established the mechanisms by which sugar overconsumption encourages cancer growth, few studies have examined the long-term effects of sugar-sweetened beverage consumption on cancer survival.
The authors examined data from more than 10,000 participants of the Nurses' Health Study (1980-2010) and Nurses' Health Study II (1991-2011), large-scale prospective studies that collected information regarding health and lifestyle from female nurses. Participants completed food frequency questionnaires, which provide a list of specific foods and ask participants to report how often they have consumed that food over the past year, upon entrance to the study and every four years thereafter until 2015. The researchers reviewed only data collected following breast cancer diagnosis.
Compared to non-consumers, participants who consumed three or more 8-ounce servings of sugar-sweetened beverages per week experienced a 35 percent increased risk of death due to cancer and 28 percent increased risk of death due to any cause. Participants consuming between one and three servings per week experienced a 31 percent increased risk of cancer-related death and 21 percent increased risk of death due to any cause compared to non-consumers. The data revealed no association between breast cancer risk and the consumption of beverages sweetened with non-nutritive (i.e., artificial) sweeteners.
In this long-term follow-up study, sugar-sweetened beverage consumption increased the risk of death among women with breast cancer, especially in women consuming more than three servings per week.
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Sugar-sweetened beverage consumption in the United States has decreased in recent decades, hopefully translating into lower rates of obesity and cardiovascular disease, both associated with excess sugar consumption. Although the cardiometabolic effects of added sugars in adults have been well-documented, the effects of sugar sweetened beverages on brain function, especially in children, is under-investigated. Findings of a new report show an association between sugar-sweetened beverage consumption and poorer cognitive performance in children.
Executive function refers to a set of high-level cognitive skills, such as complex reasoning, goal-oriented activity, and self-regulation, that begin development during gestation and continue throughout childhood. Previous research has demonstrated that excess sugar consumption causes neuroinflammation, decreased hippocampal function, and poorer spatial learning ability in adolescent rats, but not adult rats. While it is plausible that excess sugar consumption causes similar effects in children, this area is under-investigated, especially in less developed countries such as China.
The researchers recruited more than 6,000 children (ages, 6 to 12 years) who were enrolled at one of five participating school districts in Guangzhou, China. Parents of these children completed questionnaires about their child’s sugar-sweetened beverage (e.g., soda, fruit juice, energy drinks) consumption, executive function (e.g., emotion regulation, organizing, memory), and other demographics and lifestyle information (e.g., socioeconomic status, parental education, parental smoking status, exercise habits). The researchers categorized children as consuming zero, one, or two or more eight ounce servings of sugar-sweetened beverages per week.
Compared to non-consumers, children who consumed even one serving of sugar-sweetened beverages per week had worse scores on all executive functioning subscales including behavior regulation and metacognition. This trend was even stronger in children consuming two or more servings per week, with a 45 percent increased chance of poor behavior regulation and 70 percent increased chance of poor metacognition compared to non-consumers. These relationships were not altered when taking sex, age, and BMI into account.
In this large observational study, consumption of just one serving of sugar-sweetened beverages per week was associated with worse executive function in children. The authors noted that interventional trials are needed to establish the causal mechanisms of this relationship.
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High fructose diets promote survival of intestinal cells and improve nutrient absorption – possibly promoting cancer. www.cancer.gov
Since the introduction of high fructose corn syrup in the 1960s, fructose consumption has tripled worldwide. Excess sugar consumption degrades health by contributing to obesity and promoting cancer initiation and progression. Findings of a recent report elucidate the mechanisms by which fructose improves survival of and nutrient absorption by intestinal cells.
Fructose absorption begins in the epithelium (i.e., skin-like cells) of the small intestine, which measures approximately 320 square feet in surface area (about the size of a small studio apartment). This massive surface area is arranged like shag carpet, with structures called “villi” that protrude from the intestine wall. The longer the villi, the greater the surface area and number of intestinal epithelial cells available to absorb nutrients, such as fat or iron. Previous research has shown that fructose can lead to excessive intestinal epithelial growth (called hyperplasia) and cancer; however, the effects of fructose on non-cancerous intestinal epithelial cells is unknown.
The investigators gave mice access to normal drinking water or drinking water with 25 percent high-fructose corn syrup (soda contains about 10 percent) for four weeks. Then they fed mice either a normal diet with no fructose, a high-fat diet with no fructose, or a high-fat diet with sucrose, which contains 50 percent fructose and 50 percent glucose. The researchers measured nutrient composition of the feces and examined the intestinal epithelium for changes.
Mice consuming high-fructose corn syrup in their drinking water showed a 25 to 40 percent increase in intestinal villus length compared to mice consuming normal drinking water. As villus length increased, weight gain and dietary fat absorption also increased. Mice consuming a high-fat diet and fructose gained more weight and had longer intestinal villi than mice consuming a high-fat diet with no fructose, despite consuming and expending the same amount of calories. These mice had less fat in their feces, suggesting an increase in nutrient absorption. The researchers found that intestinal epithelial cells isolated from mice consuming fructose were better able to withstand low-oxygen conditions (called hypoxia), which is a common cause of intestinal cell death.
The authors concluded that high fructose diets increase intestinal villi length and nutrient absorption capacity. These findings provide greater insight into the pathogenesis of intestinal cancer.
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Allulose reduces blood sugar and insulin levels. drc.bmj.com
Foods with a high glycemic index, such as sugar-sweetened soft drinks, desserts, and white bread products, contain sugars that are rapidly absorbed into the bloodstream, causing hyperglycemia (high blood glucose). Regular consumption of high glycemic foods may lead to insulin resistance, type 2 diabetes, and obesity. Low-calorie sweeteners (i.e., artificial sweeteners) such as allulose have a low glycemic index and can be used in place of sugar to reduce the intake of calories and high-glycemic carbohydrates; however, the effects of allulose in addition to sugar require further investigation. Findings published in a new report show that allulose significantly reduces glucose and insulin levels following sugar consumption.
Allulose is a rare sugar that can be found in small amounts in some fruits and grains and is sold as a low-calorie sweetener. Allulose is an epimer of fructose, meaning its chemical structure is very similar to fructose, giving it a nearly identical taste and texture; however, allulose provides only 0.4 calories per gram, compared to 4 calories per gram of fructose. A meta-analysis of previous research found that small doses of allulose improved glucose and insulin regulation; however, additional randomized controlled trials are needed, especially in Western populations and in people without type 2 diabetes.
The researchers recruited 30 participants (average age, 33 years) without type 2 diabetes and asked them to follow an individualized diet plan that provided 50 to 65 percent of calories from carbohydrates for up to eight weeks. Participants completed five study visits with one to two weeks between visits. At each visit, the researchers gave participants a beverage containing 50 grams of fructose (the amount in about 16 ounces of sugar-sweetened soda) with escalating doses of allulose (0, 2.5, 5, 7.5, or 10 grams). They measured glucose and insulin levels in the blood 0, 30, 60, 90, and 120 minutes after beverage consumption.
Allulose consumption reduced plasma glucose levels among participants in a dose-dependent manner, meaning as the dose of allulose increased from 0 to 10 grams, glucose levels at each time point decreased. The relationship between allulose and lower glucose levels was statistically significant at the 30-minute time point when either 7.5 or 10 grams of allulose was added to the fructose beverage. Compared to consuming a fructose beverage with no added allulose, the 10-gram dose of allulose also significantly decreased insulin levels 30 minutes after beverage consumption.
These findings demonstrate that allulose decreased glucose and insulin levels when added to a high-sugar beverage in healthy young people without diabetes. The authors suggested that future studies explore more of the mechanisms underlying these results.
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Time-restricted feeding reduces weight gain and cholesterol in male mice. www.sciencedaily.com
A Western diet pattern, characterized by a low intake of fruits and vegetables and a high intake of sugar and processed foods, promotes the development of obesity and metabolic disease. Time restricted eating has been shown to decrease weight and improve metabolic health in humans. However, factors such as age and sex modulate both susceptibilty to obesity and likelihood of responding to weight-loss treatments. Authors of a new report found that male mice experienced greater metabolic benefit from time-restricted feeding than females.
Time-restricted eating, the practice of limiting food intake to an 8- or 12-hour window, is an emerging therapy for the treatment and prevention of metabolic diseases. Much of the research about time-restricted eating in humans is based on research of time-restricted feeding in mice, which has elucidated many of the cellular mechanisms related to [time-restricted eating’s benefits.](https://journals.physiology.org/doi/full/10.1152/ajpregu.00775.2005) These two terms distinguish which population, humans or non-human animals, is practicing time-restricted food intake.
The prevalence of obesity is on the rise in the industrialized world, a problem compounded by an increasing average age in the same populations. The accumulation of extra fat throughout life puts a person at greater risk of metabolic disease as they age. Females are more likely to gain and retain fat mass than males; however, pre-menopausal females tend to have lower rates of type 2 diabetes and cardiovascular disease due to the protective effects of estrogen. Previous research in humans has demonstrated weight loss and improved metabolic health with time-restricted eating; however, additional research is needed to understand the sex- and age-dependent effects of time-restricted eating.
The researchers used male and female mice of two ages: three months old (equivalent to 20-year-old humans) and 12 months old (equivalent to 42 year-old-humans). They fed mice a chow diet representative of a Western diet pattern with 17 percent of calories from sugar (human equivalent of about 25 ounces of soda per day) and 45 percent of calories from fat including lard and soybean oil. Current dietary guidelines recommend limiting solid fats such as lard). Half of the mice had 24-hour access to food while the other half only had restricted access, limited to just nine hours per day. Mice continued their diet for a total of 12 to 13 weeks. After 10 weeks, the researchers measured changes in the animals' body weight, glucose sensitivity, serum cholesterol, fatty liver, muscle performance, and immune response when challenged with bacterial endotoxin.
Although mice in the time-restricted feeding group consumed the same amount of food as mice with constant access to food, time-restricted feeding resulted in 15 percent less weight gain in young male mice and 23 percent less weight gain in older male mice. Time-restricted feeding did not significantly prevent weight gain in female mice. Male mice also experienced a greater reduction in serum cholesterol with time-restricted feeding compared to females. Both older male and female mice had lower rates of insulin resistance and fatty liver while on time-restricted feeding. This protection was likely due to changes in gene expression that increased glucose uptake by and decreased glucose output from the liver. In young male mice, time-restricted feeding preserved muscle mass, function, and performance, but not in young females. Finally, when challenged with bacterial endotoxin, older mice practicing time-restricted feeding were significantly more likely to survive septic shock than mice with 24-hour access to food, demonstrating better health and resilience.
Time-restricted feeding improved survival of septic shock and provided protection against insulin resistance and fatty liver in both sexes; however, male mice experienced greater reductions in body weight and serum cholesterol and maintained greater muscle mass and performance compared to female mice. The authors noted that their research is of particular interest considering the increased risk of severe COVID-19 illness in those with poor metabolic health.
- [Link to full publication.](https://pubmed.ncbi.nlm.nih.gov/34407415/)
- Learn more about the effects of time-restricted feeding and its effects on obesity, muscle mass, and heart health from expert Dr. Satchin Panda in this episode of the Found My Fitness podcast.
- Visit our topic article on time-restricted feeding to learn even more.
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Excess sugar intake induces mitochondrial dysfunction. www.sciencedaily.com
Hyperglycemia, which occurs when glucose levels in the blood rise to dangerous levels, is a hallmark of diseases such as metabolic syndrome and type 2 diabetes. The effects of hyperglycemia are well documented and include cellular damage, inflammation, and pro-cancer effects; however, few studies have elucidated the cellular mechanisms of hyperglycemia. Findings of a new report suggest mitochondrial damage explains the connection between hyperglycemia and disease.
Glucose is consumed in the diet from simple sugars and starches. Glucose transport proteins, which move glucose from the bloodstream into cells, are expressed in the heart, skeletal muscle, adipose tissue, and brain among others. TXNIP is a protein that binds to glucose transporters, preventing the movement of glucose into cells. Mice who do not produce the TXNIP protein, called knockouts, experience uncontrolled glucose transport into cells. Glucose metabolism produces damaging compounds called reactive oxygen species, which attack the delicate lipid membranes in mitochondria, the cell structures that produce energy.
Brown adipose tissue is particularly vulnerable to the effects of hyperglycemia. This fatty tissue produces heat in response to cold temperatures, while white adipose tissue is mainly for energy storage. Brown adipose tissue appears brown because it has a higher density of mitochondria, which may make these cells more susceptible to damage from hyperglycemia, especially in cold temperatures.
The investigators compared normal mice with those that did not express the TXNIP protein in their brown adipose tissue. After exposing both groups of animals to cold temperatures (40°F, 4°C) for four hours, the researchers measured their body temperatures using a thermal camera and performed an in vitro study to examine the cellular integrity of mitochondria and their ability to produce energy from multiple common fuel sources.
These experiments revealed that TXNIP knockout mice had lower body temperatures after cold exposure than normal mice, suggesting that their brown adipose tissue was less effective at producing heat under stress conditions. Their mitochondria also showed signs of membrane damage and reduced concentration of polyunsaturated fats, which indicated that they were significantly more stressed due to reactive oxygen species produced during cold exposure compared to mitochondria in normal mice. TXNIP knockout mice had lower expression of genes related to energy metabolism and heat production.
Interestingly, the researchers found that severely restricting the TXNIP-deficient animals’ glucose intake by feeding them a ketogenic diet for five weeks mitigated the stress-induced deficit in mitochondrial function and reversed the detrimental changes to the polyunsaturated fat content of their mitochondrial membranes.
These findings indicate that excess sugar intake creates mitochondrial dysfunction, which contributes to poor health. A ketogenic diet reversed the effects of hyperglycemia on mitochondrial function.
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Consuming sugar-sweetened beverages increases the risk of early-onset colorectal cancer among young women. www.sciencedaily.com
Colorectal cancer cases and death rates in the United States have been declining since the 1980s, likely due to increased awareness and screening, which typically begins at age 50. However, the number of colorectal cancer cases in young adults – those between the ages of 20 and 49 years – is increasing. Findings from a recent study suggest that consumption of sugar-sweetened beverages increases the risk of early-onset colorectal cancer among young women.
Dietary factors play critical roles in colorectal cancer risk. Consumption of plant-based foods has been shown to decrease colorectal cancer risk. For example, ellagic acid, a bioactive compound present in walnuts and pomegranates, breaks down in the gut to yield urolithins, a class of compounds that exert anti-inflammatory and anti-cancer effects. Conversely, evidence suggests that consumption of red meat increases colorectal cancer risk by 20 to 30 percent.
The participants in the present study included approximately 95,000 women who were part of the Nurses Health Study II, a prospective cohort study comprised of female nurses living in the United States during the period spanning 1991 and 2015. The nurses ranged in age between 25 and 42 years and were cancer-free when they enrolled in the study. Every two years, the women provide information about their demographics, lifestyles, and overall health, including whether they have been diagnosed with colorectal cancer. Every four years, they complete food frequency questionnaires that include questions about their dietary patterns. A subset of approximately 41,000 women provided information about their beverage intake during their teen years.
The authors of study found that 109 of the women in the study group developed early onset colorectal cancer. Women who drank two or more servings of sugar-sweetened beverages per day during adulthood were more than twice as likely to develop early onset colorectal cancer than women who consumed less than one serving per week. This risk was dose-dependent, with a 16 percent higher risk per daily beverage increase. If the women drank sugar-sweetened beverages during their teen years, their risk increased 32 percent for each serving per day increase. Replacing sugar-sweetened beverages with artificially sweetened beverages or milk decreased their risk of early onset colorectal cancer by 17 to 36 percent.
These findings suggest that consuming sugar-sweetened beverages during adolescence and adulthood markedly increases a woman’s risk of developing colorectal cancer. Dietary modifications that include consumption of artificially sweetened beverages or milk appears to reduce risk.
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Added sugars decrease metabolic health, survival, competitive ability, and reproduction in mice at human-relevant doses. www.sciencedaily.com
Average sugar consumption in the United States has increased 50 percent since the 1970s, due in part to the use of high fructose corn syrup in beverages and other processed foods. The mechanisms by which added sugars lead to metabolic diseases such as obesity, type 2 diabetes, cardiovascular disease, and fatty liver disease have been explored in research using mouse models; however, the dose of sugar used in these animal studies is usually much larger than what is normally consumed by people. Authors of this report investigated the effects of human-relevant doses of added sugars on health and behavior in mice.
Mouse models are a useful tool in research because mice can be kept in environments where their exposure to light, food, socialization, and other environmental inputs is completely controlled, minimizing variation between mice when exposed to a dietary intervention. However, these highly controlled environments, combined with large doses of experimental foods, often limit the generalizability of mouse research for human health. Organismal performance assays, which use seminatural conditions to put experimental animals in direct competition with each other, more accurately measure survival, competitive ability, and reproduction (common measures of evolutionary fitness) in response to environmental exposures.
The investigators fed one group of mice a diet containing 25 percent of calories from a 1:1 mixture of fructose and glucose, the same ratio of sugars found in beverages and processed foods containing high fructose corn syrup. They fed a second group of mice a control diet in which the added sugars were replaced with cornstarch and fiber. Both groups of mice consumed their respective diets and lived in controlled environments for 26 weeks before entering the organismal performance assay, upon which all mice consumed the high-sugar diet. The researchers observed mice as they competed for territory, resources, and mates for 26 to 32 weeks.
Female mice fed a high sugar diet prior to entering the organismal performance assay were twice as likely to die than female mice fed a normal diet. Male mice fed a high sugar diet controlled 26 percent less territory and produced 25 percent less offspring compared to mice fed a normal diet prior to entering the organismal performance assay. A high-sugar diet increased fasting cholesterol levels and decreased glucose tolerance.
The authors concluded that a high sugar diet decreased survival, competitive ability, and reproduction in mice and led to metabolic dysfunction. This study was the first to use organismal performance assays in combination with an environmental intervention and the first to demonstrate the negative health effects of added sugars in mice at human-relevant doses.
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Fructose-containing beverages increase free fatty acid production in the liver, a marker of metabolic disease risk. www.sciencedaily.com
Metabolic diseases, such as type 2 diabetes, cardiovascular disease, and non-alcoholic fatty liver disease (NAFLD), represent a major public health burden. Dietary factors such as excess sugar intake are associated with greater metabolic disease risk; however, it is unclear how different types of sugars (e.g., glucose, fructose, or sucrose) differentially impact metabolic health. In this report, researchers investigated the effects of sugar-sweetened beverages on fatty acid synthesis, blood triglycerides, and hepatic insulin resistance in healthy males.
Following the consumption of glucose, the pancreas secretes insulin into the bloodstream so that insulin-sensitive organs such as the liver, skeletal muscle, and adipose tissue can transport glucose into their cells. Excess sugars are converted to fats in the liver via a process called de novo lipogenesis and then stored in adipose tissue; however, as fat levels in adipose tissue rise (i.e., overweight and obesity), fat accumulates in the liver leading to the development of NAFLD. Fructose, the main sweetener found in sugar-sweetened beverages, does not require insulin to be absorbed and is preferentially taken up by the liver, accelerating NAFLD development independent of weight gain.
The authors recruited 94 healthy lean males (average age, 23 years) and assigned them to consume beverages sweetened with moderate amounts of either glucose, fructose, or sucrose (a sugar that contains both glucose and fructose) in addition to their normal diet for seven weeks. The beverages contained an amount of sugar found in about two cans of non-diet soda. The researchers assigned a fourth group of participants to consume their normal diet with no added sugar-sweetened beverages. They assessed fatty acid and triglyceride synthesis by the liver and whole-body fat metabolism.
Daily consumption of beverages sweetened with fructose and sucrose, but not glucose, led to a twofold increase in the production of free fatty acids in the liver. Fructose intake did not increase triglyceride production in the liver or whole-body fat metabolism. Participants from all four groups consumed about the same amount of calories, and while body weight tended to increase for all groups, this relationship was only statistically significant for the group consuming glucose-sweetened beverages. Glucose and insulin tolerance did not change with sugar-sweetened beverage consumption.
The investigators concluded that consumption of beverages sweetened with fructose and sucrose increased free fatty acid production in the liver. While they did not observe changes in other metabolic markers such as insulin tolerance, they hypothesized that the alterations in fat production by the liver pave the way for metabolic disease development.
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Testosterone levels drop in response to glucose consumption regardless of weight status or glucose tolerance. pubmed.ncbi.nlm.nih.gov
Hypogonadism, a disorder in which dysfunction of the ovaries or testes results in the diminished production of sex hormones, is a growing concern, demonstrated by a marked increase in prescriptions for testosterone replacement. Previous research has reported lower serum testosterone in males with type 2 diabetes and metabolic disease. To expand on this observational research, investigators aimed to determine the effects of a glucose challenge on testosterone levels.
Testosterone levels change in response to food intake, which activates the secretion of messenger molecules from the hypothalamus that affect the reproductive organs. While some studies have reported a decrease in serum testosterone in response to glucose intake, others have found an increase in serum testosterone in response to a dose of insulin. The mechanisms underlying the relationship between glucose intake and testosterone levels have yet to be illuminated.
The authors conducted their investigational study with a group of 74 healthy males (19 to 74 years old) of varying weight status who had not been diagnosed with type 2 diabetes. The researchers administered an oral glucose tolerance test in which participants consumed 75 grams of glucose, which is roughly the amount of sugar in two cans of sugar-sweetened soda, and had their blood drawn before consuming the glucose (baseline) and at 30, 60, 90, and 120 minutes afterward. The researchers also collected blood for the measurement of testosterone and other hormones, including luteinizing hormone, which stimulates testosterone production.
At baseline, 57 percent of the participants had normal glucose tolerance, 30 percent had impaired glucose tolerance, and 13 percent met the criteria for a diagnosis of type 2 diabetes. Glucose intake resulted in lower serum testosterone at all time points following glucose consumption, with an average maximum decrease of 25 percent from baseline levels. The authors reported no changes in plasma concentrations of luteinizing hormone or cortisol and a significant decrease in plasma levels of the hormone leptin. Finally, they reported no differences in testosterone response between men of varying glucose tolerance or weight status.
The investigators concluded that a challenge of 75 grams of glucose significantly decreased serum testosterone levels, although the mechanisms that drove the decrease are still unclear, given that no changes in luteinizing hormone were found.
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Sugar-sweetened beverage consumption is associated with lower testosterone levels in younger adult males. www.ncbi.nlm.nih.gov
Sugar-sweetened beverages are the largest source of added sugar in the American diet. The over consumption of sugar-sweetened beverages is linked to insulin resistance and to multiple diseases including obesity, type 2 diabetes, cardiovascular disease, and gout. One group of investigators aimed to determine the relationship between sugar-sweetened beverage consumption and serum testosterone.
Testosterone is essential for masculine development during puberty and reproductive capacity in adult males. Epidemiological evidence has revealed higher serum testosterone levels in males without diabetes compared to males with diabetes and in active males compared to sedentary males. Previous clinical research has reported a relationship between sugar-sweetened beverage consumption and decreased sperm motility and fertility; however, its relationship with testosterone has not yet been demonstrated.
The authors reviewed data from the 2011-2012 National Health and Nutrition Examination Survey, a large-scale survey research project that tracks the health and nutrition of adults and children in the United States over time. Research staff for this project administer an interview to participants to collect dietary and demographic information and medical, dental, and laboratory tests to collect physiologic measures.
The investigators of this report specifically chose a sample of younger males (between ages 20 and 39 years) because this is the period when fertility is highest. They categorized participants (545 males total) into four levels of sugar-sweetened beverage consumption with participants in the lowest level consuming 137 calories of sugar-sweetened beverages or less per day and the highest consuming 442 calories or more per day.
Ninety percent of participants had a normal testosterone level, defined as greater than 231 nanograms per deciliter. Participants in the highest level of sugar-sweetened beverage consumption were more than twice as likely to have low serum testosterone. After taking into account other factors, including age, race/ethnicity, poverty/income, tobacco and alcohol consumption, and physical activity the authors also found that participants with overweight and obesity were nearly four times more likely to have low serum testosterone compared to lean males, independent of sugar-sweetened beverage consumption.
This report demonstrates that sugar-sweetened beverage consumption and higher body mass index were both associated with lower testosterone levels in males. These associations were independent of each other and not due to other demographic and lifestyle factors.
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Sugar exposure reduces production of sex hormone-binding globulin, a predictor of metabolic health. www.sciencedaily.com
Obesity and metabolic disease are associated with reduced fertility and alterations in several markers of reproductive health, including plasma concentrations of sex hormone-binding globulin. Low levels of sex hormone-binding globulin are common in those with obesity and are predictive of cardiovascular disease and type 2 diabetes risk, although it is unclear how glucose and insulin regulation affect sex hormone-binding globulin levels. A group of investigators recently performed a series of experiments with the aim of identifying mechanisms of sugar metabolism and sex hormone-binding globulin production.
Sex hormone-binding globulin, which is produced by liver, transports sex hormones in the blood and regulates their uptake by sensitive tissues. Hepatocyte nuclear factor-4α, also produced by the liver, stimulates sex hormone-binding globulin production and increases serum testosterone by decreasing its half-life. De novo lipogenesis, the process by which the liver converts excess sugar into fatty acids, suppresses hepatocyte nuclear factor-4α activation and sex hormone-binding globulin production.
In the first experiment, the researchers used transgenic mice whose genomes had been altered to express the human sex hormone-binding globulin gene. They fed these mice a diet high in either sucrose, glucose, or fructose (three types of simple sugars) for one week and measured blood levels of sex hormone-binding globulin. In a second experiment, the researchers exposed human liver cells to varying amounts of insulin and to high concentrations of either glucose or fructose and measured gene expression. Finally, they exposed the same type of liver cells to varying concentrations of glucose and fructose and to the fatty acid palmitate and measured gene expression.
After five days a high fructose diet reduced sex hormone-binding globulin levels in the mice by fructose 80 percent. Sex hormone-binding globulin levels decreased by 40 percent on a high glucose diet and 50 percent on a high sucrose diet. Insulin exposure did not affect sex hormone-binding globulin production in mice. In liver cells, glucose and fructose exposure over five days reduced sex hormone-binding globulin accumulation by 50 percent. This change corresponded to a three- to fourfold reduction in the expression of hepatocyte nuclear factor-4α. Additionally, glucose or fructose exposure over five days resulted in a two- to threefold increase in palmitate production (due to de novo lipogenesis), which corresponded to reductions in sex hormone-binding globulin. Finally, exposure to varying amounts of palmitate over five days reduced hepatocyte nuclear factor-4α expression and sex hormone-binding globulin production.
The authors of this comprehensive study concluded that excess sugar intake resulted in increased de novo lipogenesis, which led to a suppression of hepatic HNF-4α activity, which in turn attenuated sex hormone-binding globulin expression. This work provides a detailed explanation of why sex hormone-binding globulin is a sensitive biomarker of metabolic syndrome and why simple sugars, especially fructose, decrease fertility.
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High sugar intake increases cancer risk. academic.oup.com
Current dietary guidelines for people living in the United States recommend limiting calories from sugar intake to less than 10 percent of total daily calories. Despite these recommendations, evidence indicates that some people living in the United States consume as much as 23 percent of their daily calories in the form of added sugars. Findings from a recent study suggest that high dietary sugar intake increases a person’s risk for cancer.
Cancer is the second leading cause of death in the United States. Unlike normal cells, cancer cells preferentially rely on glycolysis (the breakdown of sugar) to produce energy. This altered metabolism, widely recognized as a hallmark of cancer, promotes cell proliferation and cancer metastasis.
The authors of the study drew on data from more than 101,000 participants enrolled in NutriNet-Santé, an ongoing observational cohort study based in France. Participants completed online 24-hour dietary records detailing their usual consumption of more than 3,500 food and beverage items. The authors of the study performed statistical analyses to identify associations between sugar intake and cancer risk, taking into account known risk factors, such as socioeconomic status, body size, lifestyle, medical history, and nutritional factors.
They found that higher dietary sugar intake increased the overall risk of developing cancer 17 percent. The risk of breast cancer increased 50 percent with high sugar intake. These findings suggest that reducing dietary sugar intake decreases a person’s risk of developing cancer and highlight the importance of policies and interventions to reduce intake.
The effects of sugar extend to longevity, as well. In fact, consumption of sugar-sweetened beverages is associated with dramatically accelerated telomere shortening – equivalent to as much as five years of a person’s life. Watch this clip in which Dr. Elissa Epel discusses the harmful effects of what she calls a “toxic lifestyle,” one that includes the consumption of sugary drinks.
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Aerobic exercise counters the harmful effects of consuming regular sugar-sweetened beverages on endothelial function. journals.physiology.org
Sugar-sweetened beverages (SSBs) are among the leading contributors to sugar intake among people living in the United States. Consumption of a single SSB induces acute endothelial dysfunction – the inability of the cells that line the blood vessels to maintain vascular tone and regulate blood flow and inflammation. A recent study found that exercise counteracts the harmful effects of regular SSB consumption in healthy young men.
High sugar intake is associated with several chronic diseases, including diabetes, kidney disease, and cardiovascular disease. Some evidence suggests that consumption of sugar-sweetened beverages is associated with abnormal blood lipid levels.
The study involved 22 healthy young men who were not regular exercisers. Three times a day for seven days, the men drank a beverage containing 75 grams of glucose (a type of sugar) – roughly equivalent to consuming a typical, large-sized sugar-sweetened soft drink. They ate their regular diet throughout the study period. On five of the seven days, half of the participants engaged in a 45-minute supervised exercise protocol on an exercise bike at 60 to 65 percent of their maximal heart rate.
The authors of the study found that the young men’s endothelial function was impaired in the non-exercising group following a week of SSB consumption, compared to their baseline function. However, the subjects who engaged in regular aerobic exercise did not experience impairments in endothelial function, suggesting that exercise offset some of the deleterious effects of regular sugar consumption.
Interestingly, sauna use elicits many of the beneficial effects of exercise. In fact, some evidence suggests that waon therapy, a form of thermal treatment commonly used in Japan, improves endothelial function in patients with ischemic heart disease. Read more about the benefits of waon and other thermal treatments in this overview article about sauna use.
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A gut-brain axis specific to glucose drives sugar preference, potentially explaining sugar cravings. www.sciencedaily.com
Sugar provides necessary energy in the human diet, but excess sugar consumption is associated with weight gain and metabolic disorders. The average person living in the United States consumes approximately 100 pounds of sugar per year. Findings from a recent study suggest that our preference for sugar has its origins in the brain.
The authors of the study gave mice water that was sweetened with either sugar or acesulfame, an artificial sweetener commonly used in diet drinks and foods. At first, the mice chose to drink both solutions, but after two days, the mice chose the sugar-sweetened water only.
The researchers analyzed the brain activity of the mice when they drank the two solutions and found that a particular region of the brain responds to sugar – an area called the caudal nucleus of the solitary tract, which is located in the brain stem. They discovered that signals originating in the gut travel along the vagus nerve to this region of the brain to create a gut-brain-axis specific to glucose and similar molecules. Intake of these molecules stimulates even greater consumption, setting up an environment conducive to overconsumption.
Identification of this neural pathway provides insights into human consumption of sugar and might inform the development of new strategies to reduce intake.
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Sugar-sweetened beverages linked to lipid imbalance, which increases cardiovascular disease risk. www.sciencedaily.com
Sugar-sweetened beverages are among the leading contributors to sugar intake among people living in the United States. Examples of sugar-sweetened beverages include regular soda (not sugar-free), sports drinks, energy drinks, and coffees, teas, and waters that contain added sugars. Data from a new study indicate that sugar-sweetened beverage consumption is associated with dyslipidemia.
Dyslipidemia is a condition in which blood levels of lipids (such as cholesterol or triglycerides) are abnormal. It is recognized as one of the primary risk factors for cardiovascular disease. Most dyslipidemias are characterized by high plasma cholesterol or triglycerides (or both), or low HDL cholesterol. Nearly half of all adults living in the United States have some form of dyslipidemia.
The study involved more than 6,700 people enrolled in two different cohorts of the Framingham Heart Study. At various time points during the study, the participants provided complete medical histories, underwent physical exams, and completed lab tests to assess total cholesterol, HDL cholesterol, and triglyceride levels. They also completed questionnaires about their lifestyles and diet, including beverage intake. Participants were followed for an average of 12.5 years.
The data revealed that consuming more than 12 ounces of sugar-sweetened beverages per day increased the risk of having high triglycerides by 53 percent and having low HDL cholesterol by 98 percent. Consuming low-calorie sweetened beverages (e.g., “diet” drinks) or up to 12 ounces of 100 percent fruit juice was not associated with dyslipidemia.
These findings suggest that consumption of sugar-sweetened beverages increases the risk of dyslipidemia and underscores the role of nutrition in reducing risk factors that contribute to cardiovascular disease.
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Sugar binges increase risk of inflammatory bowel disease. www.sciencedaily.com
Approximately 3 million people living in the United States have inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis. The Western diet – a dietary pattern that is high in unhealthy fats and refined sugar, and low in fiber – has been implicated in the pathogenesis of IBD. A new study suggests that even short-term exposure to a high sugar diet increases susceptibility to ulcerative colitis.
The study involved mice that were fed either regular mouse chow or a diet that was high in sugar (approximately 50 percent sucrose). After two days, the mice were treated with dextran sodium sulfate, a chemical that induces colitis. The mice were then assessed for changes in the diversity of their gut microbiota, disease severity, gut permeability, and short-chain fatty acid (SCFA) concentrations. Increased gut permeability (also known as “leaky gut”) – a condition in which gaps form between the tight junctions of the endothelial cells that line the gut – allows pathogens to leak through the intestinal wall and pass directly into the bloodstream, promoting inflammation. Short-chain fatty acids are products of microbial fermentation that dampen inflammation in the gut.
The mice that ate the high sugar diet exhibited decreased diversity among their gut microbiota, increased gut permeability, and lower concentrations of SCFAs. They were much more likely to develop colitis than the mice that ate the regular chow. These findings suggest that even short-term exposure to a high sugar diet can influence susceptibility to IBD.
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Maternal sugar consumption, particularly from sugar-sweetened beverages, was associated with poorer childhood cognition including non-verbal abilities www.sciencedaily.com
Maternal sugar consumption, particularly from sugar-sweetened beverages, was associated with poorer childhood cognition including non-verbal abilities to solve novel problems, poorer verbal memory, poorer fine motor, and poorer visual-spatial/visual-motor abilities in childhood.
The study also found that substituting diet soda for sugar-sweetened soda during pregnancy was also linked to negative effects. However, children’s fruit consumption (but not fruit juice) had beneficial effects and was associated with higher cognitive scores.
As with any observational study, it is difficult to establish causation. However, the data was adjusted for a variety of other health and socioeconomic factors which does strengthen the data.
Here is the long list of the health/lifestyle factors that the data were adjusted for: maternal age, pre-pregnancy BMI, parity, education, smoking status during pregnancy, maternal prenatal fish intake (the mean of the first and second trimesters), household income at enrollment, and the child’s sex and race/ethnicity,child’s birth weight, maternal marital status, intelligence, depression during pregnancy, pre-pregnancy physical activity levels, Western or prudent dietary pattern (calculated without fruits and sugar beverages), breastfeeding duration, paternal age and education, and HOME-SF score.
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A small trial including 20 people were given either sourdough whole-grain bread or refined white bread to eat for one week. After a two-week break, each participant switched bread types for another week.
The study found very surprising results. Consuming either bread type improved cholesterol levels and improved markers of inflammation. The glycemic response was also dependent on the person’s gut microbiome composition and not bread type. This was surprising considering that fiber slows digestion and normally lowers the glycemic response. The bacterial strains that affected the glycemic response were Coprobacter fastidiosus and Lachnospiraceae bacterium, the latter of which has previously been associated with the development of type 2 diabetes.
More research needs to be done before any definitive conclusions can be made but this study just highlights the potential importance of the gut microbiome in the glycemic response to food. Here is a link to the full study.
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People that consumed 2 sugary drinks a day are more likely to have poorer memory and smaller overall brain volume. www.sciencedaily.com
People that drank two or more sugary beverages of any kind per day were more likely to have poorer memory, smaller overall brain volume, and a significantly smaller hippocampus. Researchers also found that higher intake of diet soda, at least one per day, was associated with smaller brain volume.
In a second study, researchers looked at whether participants had suffered a stroke or been diagnosed with dementia due to Alzheimer’s disease. Interestingly, there was no association between sugary beverage intake and stroke or dementia. But people who drank at least one diet soda per day were nearly 3 times as likely to develop stroke and dementia.
While no of this data proves causation, there is a growing body of research showing that excess refined sugar does increase inflammation which crosses the blood-brain barrier and acceleration brain aging. Regarding the diet soda, there have been studies linking artificial sweeteners to disruption of the gut microbiome which also causes inflammation which can lead to brain aging.