Testosterone
Episodes
In this clip from Modern Wisdom, Dr. Rhonda Patrick discusses how added sugar impacts testosterone, brain function, and overall metabolic health.
Dr. Rhonda Patrick discusses fish oil and Afib risk, hyperbaric oxygen therapy, supplements for kids, and curcumin's impact on testosterone.
In this clip, Dr. Peter Attia presents his unique approach for addressing low testosterone.
-
In this clip from Modern Wisdom, Dr. Rhonda Patrick discusses how added sugar impacts testosterone, brain function, and overall metabolic health.
-
Dr. Rhonda Patrick discusses fish oil and Afib risk, hyperbaric oxygen therapy, supplements for kids, and curcumin's impact on testosterone.
-
In this clip, Dr. Peter Attia presents his unique approach for addressing low testosterone.
-
Rhonda Brain Diet Aging Hormones Omega-3 Fasting Memory Testosterone Dementia Development Skin CocoaDr. Rhonda Patrick explores taurine's longevity role, cocoa flavanols, training adaptations, and oral hyaluronic acid in a Q&A.
-
Dr. Stuart Phillips discusses how exercise and nutrition influence skeletal muscle-protein turnover and muscle maintenance throughout the lifespan.
-
In this clip, Dr. Roger Seheult explains how vitamin D is a misnomer and how it fulfills many critical roles in the body.
-
In this clip, Dr. Rhonda Patrick describes the effect of sex hormones on immune function.
-
COVID-19 Vitamin D Nutrition Exercise Microbiome Sleep Vitamin C Omega-3 Inflammation Immune System Virus Micronutrients Vitamin E Vaccine Genetics Testosterone Estrogen Zinc Fiber AutoimmunityCOVID-19 Q&A Part 2: Rhonda Patrick, Ph.D. answers subscriber questions in a multi-part series.
-
In this clip, Tim Ferriss outlines the biomarkers that he measures routinely to make sure his health is on-track while following a ketogenic diet
-
In this clip, Tim Ferriss describes the biomarkers that he tracks to fine-tune his health and mental well-being.
-
Dr. Rhonda Patrick makes her seventh appearance on the Joe Rogan Experience.
Topic Pages
-
Sugar-sweetened beverages (SSBs)
Sugar-sweetened beverage–induced hyperglycaemia and hyperinsulinaemia inhibit GnRH pulsatility, decreasing Leydig-cell testosterone synthesis.
News & Publications
-
Obstructive sleep apnea may have a suppressive effect on serum testosterone levels in men, independent of BMI and age. (2021) onlinelibrary.wiley.com
Sleep apnea increases the risk of low testosterone.
Men with sleep apnea are more likely to have low testosterone levels, according to a 2021 study. Men with severe apnea are at the greatest risk of low testosterone.
Researchers reviewed the findings of 18 studies involving more than 1,800 men that examined links between sleep apnea and male testosterone levels. Then they analyzed a subset of the studies after matching the men’s age, body mass index, and severity of their sleep apnea.
They found that the men with sleep apnea were more likely to have low testosterone levels, even after considering their age and body mass index. However, the subset analysis revealed that this relationship was only notable for those with severe apnea.
Sleep apnea is a common, but serious, sleep disorder characterized by brief moments of paused or shallow breathing. People with sleep apnea are at greater risk of high blood pressure, stroke, abnormal heart rhythms, heart failure, diabetes, weight gain, and heart attacks.
This review identifies links between sleep apnea and testosterone levels. It also underscores the importance of diagnosing and treating sleep apnea, particularly among men whose apnea is more severe.
-
Intense aerobic exercise modulates testosterone levels. Testosterone is the primary male sex hormone. It plays critical roles in reproductive health and contributes to bone and muscle mass accretion. A recent review summarizes the effects of aerobic exercise on testosterone levels.
Aerobic exercise can be defined as physical activity that increases aerobic metabolism – the body’s energy-producing processes that require oxygen. Examples of aerobic exercise include walking, running, swimming, dancing, and other activities that increase heart rate and respiration. Exercise intensity – the physiological demand it creates on the body – is a critical modulator of exercise-induced changes in testosterone concentrations. Intensity is often captured as a percentage of a person’s maximal oxygen consumption (VO2max).
The reviewers highlighted the findings of studies that focused on exercise intensity and testosterone response. In one study, investigators assessed changes in testosterone after low, moderate, or high intensity aerobic exercise on an exercise bike and found that only high-intensity exercise increased testosterone. Another group of investigators found that exercise intensity was the critical determinant in whether testosterone levels increased, especially if the number of repetitions remained constant. The group conducted another study in which runners using a treadmill experienced incremental increases in exercise intensity, ranging from 60 to 100 percent of the runner’s VO2max. They found that the runners' testosterone levels began to increase when the runners reached 90 percent of their VO2max and remained high at 100 percent VO2max. About one hour post exercise, the runners' testosterone returned to baseline levels. The reviewers also described research demonstrating that duration and hydration status influence testosterone levels, as well.
The findings presented in this review suggest that intense aerobic exercise promotes increases in testosterone levels, ultimately influencing reproductive and musculoskeletal health. Learn about other beneficial health effects of aerobic exercise in our overview article
-
EPA and DHA supplementation increases serum testosterone levels in males with overweight and obesity. pubmed.ncbi.nlm.nih.gov
Long-chain omega-3 fatty acids, such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), increase serum testosterone levels in mice, although the mechanisms that drive these benefits are unclear. While omega-3 fatty acids improve cellular function, omega-6 fatty acids serve as precursors to pro-inflammatory cytokines, such as arachidonic acid, which damage cells. Findings from a recent report detail the effects of long-chain omega-3 fatty acids and omega-6 fatty acids on serum testosterone levels in adults with overweight and obesity.
Omega-3 fatty acids are essential nutrients found in the oils of fatty fish, such as salmon. In humans, they increase cellular membrane flexibility, which improves cellular function. Omega-6 fatty acids are the primary fats in most vegetable oils, such as corn oil. In excess, omega-6 fatty acids can be harmful to health. Leydig cells, located in the testicles, produce testosterone when stimulated with luteinizing hormone. Evidence from studies in mice suggest that long-chain omega-3 fatty acids incorporate into the plasma membranes of Leydig cells increasing their responsiveness to luteinizing hormone and increasing testosterone synthesis..
The authors recruited 22 males with overweight and obesity who did not have type 2 diabetes to participate in the study. Participants consumed either fish oil (providing 860 milligrams of DHA and 120 milligrams of EPA per day) or a placebo (1 gram of corn oil per day) for 12 weeks. They provided blood samples for the analysis of sex hormones and metabolic markers and completed questionnaires about health, diet, dietary supplement use, and other lifestyle factors.
Fish oil supplementation significantly increased serum testosterone concentrations, even after taking into account age and body mass index. This increase in testosterone occurred with an increased concentration of omega-3 fatty acids in the membranes of red blood cells, an indicator of the membrane composition of Leydig cells. The researchers reported an even stronger association between increased testosterone and decreased omega-6 fatty acid concentration in red blood cell membranes. They also noted improvements in insulin sensitivity among the supplemented group compared to the placebo group.
These findings demonstrate that long-chain omega-3 fatty acid supplementation increased serum testosterone levels in males with overweight and obesity. The authors noted that their report is a secondary analysis of a larger clinical trial and that future research with a larger sample of participants is prudent.
-
Fish oil supplementation improves testicular function in young males without infertility. jamanetwork.com
Evidence suggests that sperm quality in males over the past 50-70 years has declined, likely due to a combination of dietary and lifestyle factors and exposure to endocrine-disrupting chemicals. For example, diets rich in processed meats, full fat dairy, and sugar-sweetened beverages are associated with poor sperm quality, whereas diets rich in vitamins, minerals, and unsaturated fats improve sperm quality and fertility. Results of a recent observational study demonstrate the effects of fish oil supplementation on sperm quality and testicular function in healthy young males.
Infertility affects 15 percent of couples, with male and female reproductive dysfunction contributing equally to infertility rates. Previous epidemiological research has revealed an association between fish consumption and better sperm quality in males seeking infertility treatment. Fish and fish oil supplements are an excellent source of omega-3 fatty acids, a type of polyunsaturated fat with numerous anti-inflammatory and health-promoting properties. Two previous randomized, controlled trials have reported increased antioxidant capacity and decreased DNA fragmentation in the sperm of males experiencing infertility who were supplemented with omega-3 fatty acids. However, the effects of supplementation in men without infertility is unknown.
The investigators recruited more than 1,600 male participants (average age, 19 years) who presented for a physical examination for military service in the Netherlands. Participants volunteered to provide a blood sample for the measurement of sex hormones and a semen sample. Finally, they answered a questionnaire about health, lifestyle, diet, and dietary supplement use over the previous three months.
Only 5.8 percent of the participants had consumed fish oil supplements in the previous three months and only 3.1 percent consumed fish oil supplements for more than 60 days over the previous three months. Participants who supplemented with fish oil less than 60 days had increased sperm volume and testicle size compared to those who did not supplement. Participants who supplemented for more than 60 days had even greater sperm volume and testicle size. Participants who supplemented with fish oil also had a 20 percent lower concentration of follicle-stimulating hormone and a 16 percent lower concentration of luteinizing hormone, an indication of better testicular cell function and greater capacity for sperm production.
The authors concluded that fish oil supplementation improves testicular function in males without infertility, even after taking into account the intake of other dietary supplements. Because this study did not take dose into account, randomized clinical trials are needed to further examine this relationship.
-
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.
-
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.
-
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.