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Bone

Episodes

Posted on October 21st 2024 (8 months)

Dr. Rhonda Patrick discusses her supplement stack, avoiding microplastics, creatine for brain health, and mRNA vaccine autoimmunity risks.

Posted on October 4th 2023 (over 1 year)

In this clip, Dr. Martin Gibala examines how different HIIT exercises influence bone growth and joint issues.

Posted on September 19th 2023 (over 1 year)

Dr. Martin Gibala discusses HIIT's health benefits and describes common HIIT protocols.

Topic Pages

  • Red light therapy (photobiomodulation)

    Photobiomodulation elevates osteoblastic cytochrome-c-oxidase activity, upregulating ATP-dependent signaling cascades that stimulate proliferation and matrix mineralization.

News & Publications

  • Even a minor fall can cause a life-altering fracture for women with osteoporosis. Stronger bones can mean the difference between maintaining independence and facing long-term disability. A recent study found that combining high-intensity interval training (HIIT) with daily vitamin D supplements more than doubled the gains in bone mineral density compared to each intervention alone.

    Researchers enrolled 120 sedentary women aged 30 to 50, all diagnosed with osteoporosis. They randomly assigned participants to one of four groups: a control group, a vitamin D group (800 IU per day), an exercise-only group (16 weeks of HIIT), and a combined group that did both. Before and after the intervention, researchers measured bone mineral density of the hips and spine and markers of bone turnover in the blood.

    They found that the group combining HIIT and vitamin D supplementation showed the greatest improvements in bone mineral density at the hips and lumbar spine, with a 3.2% improvement in hip bone mineral density, surpassing the 1.5% increase in the HIIT-only group and the 1.2% increase in the vitamin D-only group. Blood levels of calcium and osteocalcin increased the most in the combined group, while bone-specific alkaline phosphatase (a marker of bone breakdown) decreased. Improvements in bone mineral density were linked to higher calcium and osteocalcin levels and lower body mass index.

    These findings suggest that pairing HIIT with vitamin D supplements boosts bone strength in women with osteoporosis, helping to slow or even reverse bone loss during midlife. Learn more about the effects of HIIT on bone density in this clip featuring Dr. Martin Gibala.

  • Cannabinoids are bioactive compounds found in the Cannabis sativa plant – the source of hemp and marijuana. Evidence suggests they help treat addiction, prevent seizures in certain seizure disorders, and reduce inflammation. A new study in mice shows that cannabinoids relieve pain as effectively as non-steroidal anti-inflammatory drugs (NSAIDs) while also promoting bone fracture healing.

    Researchers studied the effects of cannabidiol (CBD) and cannabigerol (CBG) on bone healing in mice that had experienced a fractured tibia (a lower leg bone). They injected the mice with cannabinoids (CBD or CBG) or NSAIDs (indomethacin or celecoxib) daily for four weeks and assessed the animals' pain throughout the study duration. At the end of the study, they examined the animals' tibias to assess healing.

    They found that CBD and CBG helped manage pain in mice with bone fractures as effectively as NSAIDs. However, the cannabinoids also promoted fracture healing. In the early healing stage, they increased the number of periosteal bone progenitors (cells that later help form bone tissue). In the later healing phase, the cannabinoids accelerated the absorption of minerals to strengthen the new bone, making it functionally healthy.

    These findings indicate that cannabinoids CBD and CBG may be useful alternatives to NSAIDs in an animal model of bone fracture. As their name suggests, NSAIDs block inflammation, an important early step in bone healing. Taking NSAIDs increases a person’s risk for many complications, including gastrointestinal bleeding and cardiovascular events, such as stroke or heart attack. NSAIDs also block some of the beneficial effects of exercise. Learn more in this episode featuring Dr. Charles Raison.

  • Hip fractures can lead to a decline in self-reliance, diminished quality of life, and feelings of depression. However, some research suggests that consuming fish and omega-3 fatty acids influences a person’s risk of experiencing a hip fracture. A 2019 meta-analysis and systematic review found that higher fish and omega-3 intake reduces the risk of hip fracture by as much as 12 percent.

    Researchers reviewed the findings of 10 studies involving nearly 300,000 people. Seven of the studies followed people over time (prospective), and three compared groups with and without fractures (case-control).

    They found that people who consumed more fish had a lower risk of hip fractures, even when combining the results from prospective and case-control studies. They found the same protective effect for those who consumed higher omega-3s in their diets. Notably, the protective effect of fish and omega-3 intake remained only when considering larger prospective studies (involving 10,000 participants or more) or studies that included body mass index as a factor.

    These findings suggest that dietary intake of fish and omega-3s might promote bone health and reduce the risk of hip fractures. Other studies have proposed mechanisms by which omega-3s exert their beneficial effects. For example, one study found that DHA inhibits osteoclast formation and subsequent bone resorption by inhibiting the production of TNF-alpha, a pro-inflammatory molecule. A separate study demonstrated that resolvin, a byproduct of omega-3 metabolism, promotes bone preservation under inflammatory conditions and influences the PI3K-AKT pathway, a major signaling pathway implicated in many human diseases, including osteoporosis.

  • Previous research has shown that creatine supplementation increases bone mass. But a recent trial in postmenopausal women found that creatine had little effect on bone mineral density. It did, however, improve aspects of bone quality.

    Researchers studied the effects of creatine monohydrate supplementation on the bone health of 237 postmenopausal women. Half of the participants took creatine (0.14 grams per kilogram of body weight of creatine, ~10 grams for a 160-pound female) daily for two years, while the other half took a placebo. All the participants engaged in a walking and resistance training exercise program. The researchers measured the women’s bone mineral density and other aspects of bone before and after the two-year intervention.

    They found that the creatine supplements had no significant effects on the women’s bone mineral density of the femoral neck, total hip, or lumbar spine compared to the placebo. However, creatine did improve aspects of their bone quality. Women who took creatine showed improvements in the section modulus (how resistant the bone is to bending and breaking) and the buckling ratio (how well the bone can withstand compression and maintain its shape without collapsing) at the narrow part of the femoral neck.

    Creatine is a nitrogen-containing compound that is produced in the liver and kidneys and is stored in the brain and muscles. It plays essential roles in the recycling of ATP and is widely used as a dietary supplement to build and maintain muscle mass.

    These findings suggest that supplemental creatine in conjunction with exercise did not affect bone mineral density in postmenopausal women, but it did improve certain aspects of bone quality. However, robust data support resistance training as a means to build bone mass. Learn more in this episode featuring Dr. Brad Schoenfeld.

  • A new study shows that having low bone density may increase a person’s risk for cerebral small vessel disease – a driver of dementia. People with the lowest bone density in their upper femur were twice as likely to develop dementia over a ten-year period than those with the highest bone density.

    Researchers categorized nearly 1,200 people over the age of 50 years according to their small vessel health status and bone density. They also measured serum bone turnover markers and microRNAs related to cerebral small vessel disease and bone metabolism.

    They found that cerebral small vessel disease scores increased as bone mineral density decreased. They also found that levels of microRNA-378f, a non-coding RNA molecule that inhibits bone formation, were higher among participants with low bone density.

    In older adults, dementia and low bone mineral density often coincide. In addition, physical inactivity and poor nutrition, common among people with dementia, can accelerate bone loss. Scientists don’t fully understand the extent to which bone loss is present before the onset of dementia, however. (Read more about bone health in the two reviews presented below.)

    The findings from this study suggest that bone and brain health are closely linked, possibly via a bone-brain axis that regulates brain health. However, whether bone loss causes cerebral small vessel disease and subsequent dementia remains unclear. The findings also highlight the importance of maintaining bone health throughout the lifespan. Learn how resistance exercise helps increase bone density in this clip featuring Dr. Brad Schoenfeld.

  • Omega-3 fatty acids may help reduce bone loss, a 2010 study showed. When astronauts – who often experience bone loss after periods of weightlessness – consumed omega-3s during short-duration space missions, they experienced less bone loss.

    Researchers investigated the effects of omega-3s on bone in various settings that induce or replicate weightlessness-related bone loss: cells in culture, astronauts returning from short-duration shuttle missions, and healthy people who experienced 16 days of ground-based bed rest.

    They found that in cultured cells, omega-3s inhibited the activity of nuclear factor-κB (NF-κB), a signaling molecule that is involved in the pathogenesis of bone loss. When astronauts experienced even short-term weightlessness during space missions, they had elevated NF-κB levels, but those who consumed higher quantities of omega-3s during the missions experienced less bone loss than those who consumed less. Finally, when healthy people who experienced prolonged bed rest were given supplemental omega-3s, they experienced less bone loss than those who did not take omega-3s.

    These findings suggest that omega-3s reduce bone loss in settings of weightlessness or bed rest, with relevance for people on earth who are at risk for bone loss. Resistance training helps support bone health, too. Learn more in this clip featuring Dr. Brad Schoenfeld.

  • People who follow vegan diets generally have weaker bones than omnivores, a new study shows. However, vegans and omnivores who practice resistance training have comparable bone strength.

    The study included 88 healthy adults. About half had followed a vegan diet for five years or more, while the other half had followed an omnivorous diet. Participants provided information about their dietary intake and exercise practices, and researchers assessed their bone microarchitecture – a measure of bone strength.

    They found that, overall, vegans had altered microarchitecture compared to omnivores. However, the bone microarchitecture of vegans and omnivores who practiced resistance training was comparable, suggesting that resistance exercise compensated for dietary differences between the two groups. Interestingly, aerobic exercise alone did not confer a protective effect on bone microarchitecture.

    These findings suggest that resistance training protects against bone loss associated with vegan diets. Aerobic exercise did not appear to confer protection, however.

    Vegan diets are rich in plants and plant-based proteins. People who follow vegan diets often experience more bone loss over time than those who follow an omnivorous diet. Evidence suggests that plant-based proteins – when consumed in sufficient quantities – can support muscle hypertrophy in resistance training, which would in turn support bone health. Learn more in this episode featuring Dr. Stuart Phillips.

  • A new study shows that hydrolyzed collagen strengthens knee tendons in female soccer players. Those who took supplemental collagen experienced an 18 percent gain in knee tendon stiffness, potentially reducing their risk for injury during play.

    The study involved 17 elite teenage female soccer players. Half of the players consumed a hydrolyzed collagen supplement plus vitamin C three times a week for ten weeks. The other half consumed a placebo. Both groups participated in a training regimen designed to strengthen the knee and thigh muscles. A team of researchers measured various parameters of the players' knee tendon thickness and strength before and after the intervention.

    They found that the players who consumed the supplemental hydrolyzed collagen experienced an 18 percent increase in their knee tendon stiffness. However, they experienced little change in tendon thickness, suggesting that the increase in stiffness was due to changes in the tendon’s material properties subsequent to collagen intake.

    Female soccer players are more likely to experience knee injuries than male players, due in part to greater knee joint laxity. These findings suggest that supplemental hydrolyzed collagen support training regimens to bolster knee strength in female athletes.

    Hydrolyzed collagen is a mixture of peptides derived from the protein collagen. Evidence suggests that supplemental hydrolyzed collagen consumption improves skin aging, decreases arthritis-induced pain, increases bone mineral density, and decreases hypertension. Learn more about hydrolyzed collage in our overview article.

  • Growth hormone improves bone density and reduces the risk of fractures in women with osteoporosis, according to a 2015 study. Women who received growth hormone were half as likely to experience a fracture over a 10-year period than women who did not.

    The study involved 80 women (50 to 70 years old) who had osteoporosis and were taking estrogen-based hormone replacement therapy. Researchers randomly assigned the women to receive daily injections of either a low or high dose of growth hormone for three years or a placebo for 18 months. All the women took daily vitamin D and calcium supplements for the study’s duration. The researchers measured the women’s body composition and bone mass at regular intervals.

    They found that women who received growth hormone injections showed marked improvements in their bone mineral density and bone mineral content compared to those who received the placebo. Over the 10-year period, the number of fractures among the women who received growth hormone dropped from 56 percent to 28 percent, whereas fractures among those who received the placebo increased from 8 percent to 32 percent.

    Growth hormone, a peptide hormone produced in the pineal gland, promotes growth in childhood and adolescence. During middle age, growth hormone production decreases. Some evidence suggests that because growth hormone is secreted at night (during sleep), not getting enough sleep may hinder growth hormone release, exacerbating age-related bone loss. Learn how body temperature can influence how well you sleep at night in this clip featuring Dr. Matthew Walker.

  • Plant-derived estrogen-like compounds found in dietary supplements are not as effective at reducing bone loss as claimed, a 2009 study showed. When compared to conventional therapies such as hormones or anti-osteoporosis drugs, the plant-based treatments were roughly four to five times less effective at reducing bone loss.

    Over a period of 50 days, 11 postmenopausal women received six different treatments: soy cotyledon (the first leaves to appear on the plant), soy germ, kudzu (a plant used in traditional and folk medicine), red clover, risedronate (a drug used to treat osteoporosis), and estrogen combined with progesterone. Researchers measured the women’s bone loss after each treatment.

    They found that the different treatments reduced bone loss to varying degrees: estrogen combined with progesterone, 24 percent; risedronate, 22 percent; soy cotyledon, 9 percent; soy germ, 5 percent. Red clover and kudzu had only marginal effects on reducing bone loss. Bone loss is a common feature of aging, especially among post-menopausal women.

    Estrogen preserves bone health and is commonly prescribed as a treatment for women with osteoporosis. However, estrogen therapies and many common anti-osteoporosis drugs carry health risks. Plant-derived estrogen-like compounds, often referred to as phytoestrogens, are often touted as viable alternatives to conventional therapies.

    This study demonstrates that plant-based therapies are less effective at reducing bone loss than hormonal or pharmaceutical therapies. They also underscore the importance of building bone mass in early life. Resistance exercise has been shown to preserve and even increase bone mass in postmenopausal women. Learn more about the effects of resistance training on bone health in this episode featuring Dr. Brad Schoenfeld.

  • Plant-based estrogen supplements aren’t as effective at maintaining bone health as claimed.

    Plant-derived estrogen-like compounds found in dietary supplements are not as effective at reducing bone loss as claimed, a 2009 study showed. When compared to conventional therapies such as hormones or anti-osteoporosis drugs, the plant-based treatments were roughly four to five times less effective at reducing bone loss.

    Over a period of 50 days, 11 postmenopausal women received six different treatments: soy cotyledon (the first leaves to appear on the plant), soy germ, kudzu (a plant used in traditional and folk medicine), red clover, risedronate (a drug used to treat osteoporosis), and estrogen combined with progesterone. Researchers measured the women’s bone loss after each treatment.

    They found that the different treatments reduced bone loss to varying degrees: estrogen combined with progesterone, 24 percent; risedronate, 22 percent; soy cotyledon, 9 percent; soy germ, 5 percent. Red clover and kudzu had only marginal effects on reducing bone loss. Bone loss is a common feature of aging, especially among post-menopausal women.

    Estrogen preserves bone health and is commonly prescribed as a treatment for women with osteoporosis. However, estrogen therapies and many common anti-osteoporosis drugs carry health risks. Plant-derived estrogen-like compounds, often referred to as phytoestrogens, are often touted as viable alternatives to conventional therapies.

    This study demonstrates that plant-based therapies are less effective at reducing bone loss than hormonal or pharmaceutical therapies. They also underscore the importance of building bone mass in early life. Resistance exercise has been shown to preserve and even increase bone mass in postmenopausal women. Learn more about the effects of resistance training on bone health in this episode featuring Dr. Brad Schoenfeld.

  • From the article:

    “Previous studies have shown that giving oral estrogen combined with progesterone as birth control pills is not effective in increasing bone density in girls with anorexia nervosa,” Misra said. “However, the impact of giving estrogen in a more natural, or physiological, form has not been previously studied in girls with anorexia nervosa.”

    This National Institutes of Health-funded study explored, over an 18-month period, the effect of physiological estrogen replacement on bone accrual rates in 110 female patients with anorexia nervosa. These patients and 40 healthy-weight girls as controls were between ages 12 to 18 years, a common time for anorexia nervosa to start and also an important time for building optimal bone mass, Misra said.

    […] Those girls with mature bone received either placebo or a full adult dose of estrogen (100 micrograms of estradiol) given via a skin patch. This transdermal form is a natural form of estrogen, Misra said. Girls receiving estrogen also received cyclic progesterone pills to reduce the risk of endometrial cancer.

    Girls with anorexia nervosa whose bones were immature received incremental low doses of oral estrogen, ranging from 3.75 to 11.25 micrograms of estradiol. These low, natural levels mimic estrogen levels seen in early puberty and avoid accelerating fusion of the growth plates, which would otherwise limit height potential, Misra said. Healthy-weight controls received no treatment other than calcium and vitamin D supplements, which all subjects received.

    Using dual-energy X-ray absorptiometry (DEXA) bone density scans, the researchers assessed bone mineral density at the lumbar spine (lower back), hip and whole body. Physiological estrogen administration caused a significant increase in bone density at the spine and hip, compared with placebo, as found on DEXA Z-scores, the authors reported. However, Misra said that estrogen did not result in a complete “catch-up” to normal bone density measures. Girls with anorexia nervosa still had lower bone density than healthy-weight controls did.

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  • From the article:

    Our laboratory recently discovered that bone matrix is maintained by a protein called Sema3A, which is secreted by osteocytes. This led us to suspect that there might be a mechanistic relationship between estrogen and Sema3A."

    Sema3A does indeed appear to be linked to estrogen: the researchers found that blood serum levels of the protein decrease in premenopausal women as they get older – and drop even further once women reach menopause. But how, at the biological level, are estrogen and Sema3A related? And what is Sema3A doing in bone tissue?

    […]

    “When we genetically removed Sema3A from the osteoblast lineage cells (including osteocytes) of mice, we found that intravenous estrogen no longer prevented bones from deteriorating after an ovariectomy,” lead author Mikihito Hayashi describes. “In addition, we found that Sema3A sets off a chain of signaling events that promote the survival of osteocytes in these mice. This suggests that Sema3A serves as a key mechanistic link between estrogen and bone maintenance.

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  • From the publication:

    Bone fracture due to osteoporosis is an important issue in decreasing the quality of life for elderly men in the current aging society. Thus, osteoporosis and bone fracture prevention is a clinical concern for many clinicians. Moreover, testosterone has an important role in maintaining bone mineral density (BMD) among men. Some testosterone molecular mechanisms on bone metabolism have been currently established by many experimental data. Concurrent with a decrease in testosterone with age, various clinical symptoms and signs associated with testosterone decline, including decreased BMD, are known to occur in elderly men. However, the relationship between testosterone levels and osteoporosis development has been conflicting in human epidemiological studies. Thus, testosterone replacement therapy (TRT) is a useful tool for managing clinical symptoms caused by hypogonadism. Many recent studies support the benefit of TRT on BMD, especially in hypogonadal men with osteopenia and osteoporosis, although a few studies failed to demonstrate its effects. However, no evidence supporting the hypothesis that TRT can prevent the incidence of bone fracture exists. Currently, TRT should be considered as one of the treatment options to improve hypogonadal symptoms and BMD simultaneously in symptomatic hypogonadal men with osteopenia.

  • From the publication:

    Bone fracture due to osteoporosis is an important issue in decreasing the quality of life for elderly men in the current aging society. Thus, osteoporosis and bone fracture prevention is a clinical concern for many clinicians. Moreover, testosterone has an important role in maintaining bone mineral density (BMD) among men. Some testosterone molecular mechanisms on bone metabolism have been currently established by many experimental data. Concurrent with a decrease in testosterone with age, various clinical symptoms and signs associated with testosterone decline, including decreased BMD, are known to occur in elderly men. However, the relationship between testosterone levels and osteoporosis development has been conflicting in human epidemiological studies. Thus, testosterone replacement therapy (TRT) is a useful tool for managing clinical symptoms caused by hypogonadism. Many recent studies support the benefit of TRT on BMD, especially in hypogonadal men with osteopenia and osteoporosis, although a few studies failed to demonstrate its effects. However, no evidence supporting the hypothesis that TRT can prevent the incidence of bone fracture exists. Currently, TRT should be considered as one of the treatment options to improve hypogonadal symptoms and BMD simultaneously in symptomatic hypogonadal men with osteopenia.

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  • From the article:

    Marielle H. Emmelot-Vonk, M.D., of University Medical Center Utrecht, the Netherlands, and colleagues conducted a randomized, placebo-controlled study to assess the effects of testosterone supplementation on functional mobility, cognition, bone mineral density, body composition, lipids, quality of life, and safety parameters in older men with testosterone levels less than 13.7 nmol/L (less than the average level in this age group) during a period of six months. The trial, conducted from January 2004 to April 2005, included 207 men between the ages of 60 and 80 years. Participants were randomly assigned to receive 80 mg of testosterone undecenoate or a matching placebo twice daily for six months.

    The researchers found that during the study, lean body mass increased and fat mass decreased in the testosterone group compared with the placebo group but these factors were not accompanied by an increase of functional mobility or muscle strength. Cognitive function and bone mineral density did not change. Insulin sensitivity improved but high-density lipoprotein cholesterol (the “good” cholesterol) decreased. By the end of the study, 47.8 percent in the testosterone group vs. 35.5 percent in the placebo group had the metabolic syndrome (a strong risk factor for cardiovascular disease and type 2 diabetes, a group of several metabolic components in one individual including obesity and dyslipidemia). This difference was not statistically significant.

    Quality-of-life measures did not differ aside from hormone-related quality of life in the testosterone group. Adverse events were not significantly different in the two groups. Testosterone supplementation was associated with an increase in the concentrations of blood creatinine, a measure of kidney function, and hemoglobin and hematocrit, two red blood cell measures. No negative effects on prostate safety were detected (some reports have suggested that testosterone therapy could increase the risk of development or progression of prostate disease or cancer).

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  • From the article:

    Low-trauma fractures occurred in 113 men during follow-up with the risk of fracture significantly higher in those with low testosterone levels. “Twenty-five men experienced multiple incident fractures,” the authors note. “A total of 149 incident fractures were reported, including 55 vertebral, 27 hip, 28 rib, six wrist and 16 upper and 17 lower extremity fractures.”

    “After adjustment for sex hormone binding globulin (a blood protein), serum testosterone and serum estradiol levels were associated with overall fracture risk,” according to the authors. “After further adjustment for major risk factors of fractures (age, weight or bone mineral density, fracture history, smoking status, calcium intake and sex hormone binding globulin), lower testosterone was still associated with increased risk of fracture, particularly with hip and non-vertebral fractures.”

    Although low levels of estradiol and testosterone were associated with a higher risk of fracture in men over 60, only the effect of testosterone was independent of other risk factors, the authors conclude.

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  • From the article:

    Thirteen older men between 60 – 85 years have thusfar participated in the study. Testosterone levels ranged between 200-500 nanograms (ng) of testosterone per deciliter of blood (dL) at the time of enrollment. (Normal limits are considered 250-800.) Each was enrolled in one of three double-blinded groups: (1) those receiving continuous weekly intramuscular injections of testosterone (100 mg testosterone-enanthate) for the entire five month period (TE; n=4); (2) those receiving weekly testosterone every other month (one month of weekly testosterone/one month of weekly placebo; MO; n=4); or (3) those receiving a weekly placebo for the entire five month period (PL; n=5).

    The participants visited the clinic weekly for either scheduled treatment injections or placebos. Volunteers received a baseline whole-body Dual Energy X-Ray Absorptiometry (DEXA) scan at the beginning and end of the study. Dietary records were obtained and analyzed at month zero, month three and month five. Fasting blood samples were collected at regular intervals throughout the study to examine serum markers of bone metabolism.

    Preliminary Study Results

    – testosterone administration appears to reduce bone turnover, perhaps closing the gap between resorption and formation

    – thus far, the impact on bone mineral density are unclear but may become more apparent as the study progresses.

    – the effects of testosterone on long-term bone metabolism are unclear, but are expected to have at least a protective effect on existing bone mass over time by preventing unwanted increases in bone turnover that are frequently associated with osteoporosis. Osteoporosis is often associated with high bone turnover (increases in bone resorption as well as in bone formation) which results in decreased BMD.

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  • From the article:

    Researchers found that testosterone treatment improved bone density and estimated bone strength, as determined by quantitative computed tomography (CT). The treatment also increased hemoglobin concentrations, corrected the anemia of men who had no other identifiable cause of anemia and corrected the anemia of men who had an identifiable cause, such as iron deficiency. While these conclusions proved testosterone to be beneficial to the participants, testosterone treatment did not improve memory or any other measure of cognitive function.

    […]

    In the cardiovascular trial, researchers assessed coronary artery plaque buildup by CT angiography. That assessment showed more plaque buildup in men treated with testosterone than in men treated with placebo. Nonetheless, in all 788 men in the TTrials, the number of major adverse cardiovascular events was similar in the men treated with testosterone as in the men treated with placebo. However, Snyder added, “treating 788 men for one year is far too few to draw conclusions about the clinical significance of the increase in coronary artery plaque volume and the cardiovascular risk of testosterone treatment.”

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  • From the article:

    Researchers from the Morrison laboratory discovered that forces created from walking or running are transmitted from bone surfaces along arteriolar blood vessels into the marrow inside bones. Bone-forming cells that line the outside of the arterioles sense these forces and are induced to proliferate. This not only allows the formation of new bone cells, which helps to thicken bones, but the bone-forming cells also secrete a growth factor that increases the frequency of cells that form lymphocytes around the arterioles. Lymphocytes are the B and T cells that allow the immune system to fight infections.

    When the ability of the bone-forming cells to sense pressure caused by movement, also known as mechanical forces, was inactivated, it reduced the formation of new bone cells and lymphocytes, causing bones to become thinner and reducing the ability of mice to clear a bacterial infection.