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This past week, I came across several testosterone-related research papers, just published this past month. Each study looked at different aspects of how testosterone affects our health, so rather than writing separate articles for each, I thought I’d include them all in a single article with a brief summary. This way, I suspect almost everyone who reads it will find something relevant.
In no particular order, here are five new findings on how testosterone impacts our health.
Low-Carbohydrate Diet, Testosterone and Erectile Function in Men
Becoming overweight or obese is the most effective way to squash a man’s libido and sabotage testosterone production. And when you lower testosterone, you tend to make him look and think more feminine. With the extreme prevalence of overweight and obesity in American culture, it’s little wonder that we’re seeing such high rates of male sexual dysfunction, depression, and apathy.
In this study, 18 men were divided into two groups. Six men were put in a control group, and 12 were assigned a low-carbohydrate diet.1da Silva Schmitt, C., da Costa, C.M., Souto, J.C.S. et al. The effects of a low carbohydrate diet on erectile function and serum testosterone levels in hypogonadal men with metabolic syndrome: a randomized clinical trial. BMC Endocr Disord 23, 30 (2023). https://doi.org/10.1186/s12902-023-01278-6
For those on the low-carbohydrate diet:
- The percentage of men with low testosterone symptoms decreased from 78.6% to 21.4%
- All men before the study had testosterone levels less than 300 ng/dL, and after the diet, half had testosterone levels greater than 300 ng/dL, the cutoff point for medically diagnosed hypogonadism
- Systolic blood pressure decreased
These results add to the plethora of research that shows low-carbohydrate and/or high-protein diets improve body composition, even without the need to count calories, and that improving men’s body composition improves testosterone production and libido. Here are a couple of articles you might like to read:
- Low-Carb vs Low-Fat vs High-Protein: Which diet is best?
- Visceral Fat: How to Lower Belly Fat with Diet, Lifestyle, and Supplements
Non-Alcoholic Fatty Liver Disease, Testosterone and Body Fat in Men
Dietary choices can cause the same kind of liver disease as alcoholism does. It’s called non-alcoholic fatty liver disease (NAFLD), and is often found in those with type II diabetes or metabolic syndrome. As you should expect, excessive dietary carbohydrate consumption is the primary cause. A loss of muscle mass from a sedentary lifestyle or lack of strength training exacerbates the problem because as you lose muscle, you lose the capacity to properly store carbohydrates.
The prevalence of low testosterone and non-alcoholic fatty liver disease was assessed in just over 1000 men with type II diabetes.2Yang, L.J., Zhou, J.Z., Zheng, Y.F. et al. Association of non-alcoholic fatty liver disease with total testosterone in non-overweight/obese men with type 2 diabetes mellitus. J Endocrinol Invest (2023). https://doi.org/10.1007/s40618-023-02006-6 They found that the men with higher testosterone levels were less likely to have developed NAFLD and that this relationship was stronger in normal-weight men with type II diabetes than in overweight or obese men.
Although treating a patient with exogenous testosterone might improve liver health,3Aksam A. Yassin, Mustafa Alwani, Riadh Talib, Yousef Almehmadi, Joanne E. Nettleship, Khalid Alrumaihi, Bassam Albaba, Daniel M. Kelly & Farid Saad (2020) Long-term testosterone therapy improves liver parameters and steatosis in hypogonadal men: a prospective controlled registry study, The Aging Male, 23:5, 1553-1563, DOI: 10.1080/13685538.2020.1867094 the testosterone therapy doesn’t deal with the cause of the fatty liver or type II diabetes. The men’s diet and lack of a consistent strength training program should be the first line of therapy, but that’s a lot less profitable than treating with testosterone, so many clinics start with testosterone treatment instead.
Polycystic Ovary Syndrome, Insulin Resistance and Body Composition in Women
Polycystic Ovary Syndrome (PCOS) affects 4-20% of the female population.4Deswal R, Narwal V, Dang A, Pundir CS. The Prevalence of Polycystic Ovary Syndrome: A Brief Systematic Review. J Hum Reprod Sci. 2020 Oct-Dec;13(4):261-271. doi: 10.4103/jhrs.JHRS_95_18. Epub 2020 Dec 28. PMID: 33627974; PMCID: PMC7879843. Women with PCOS have elevated testosterone, which causes them to carry more of their body fat in the midsection as opposed to the thighs and triceps. This “central obesity” makes them more likely to develop insulin resistance and heart disease.
Women with and without PCOS were compared in their levels of insulin resistance.5Zhang H, Wang W, Zhao J, Jiao P, Zeng L, Zhang H, Zhao Y, Shi L, Hu H, Luo L, Fukuzawa I, Li D, Li R, Qiao J. Relationship between body composition, insulin resistance, and hormonal profiles in women with polycystic ovary syndrome. Front Endocrinol (Lausanne). 2023 Jan 9;13:1085656. doi: 10.3389/fendo.2022.1085656. PMID: 36699018; PMCID: PMC9869160. The researchers found:
Women with PCOS experienced greater insulin sensitivity impairment than did the normal population for every equal increase in BFP (body fat percentage).
This was an important finding because about half of the women with PCOS are at a normal weight. They might not realize that they have some level of insulin resistance, which would make a low-carbohydrate diet and a good exercise program crucial to avoid becoming overweight or obese in the future.
Because they are more likely to have insulin resistance and can gain body fat easier, I usually recommend that women with PCOS train with weights only twice per week and perform aerobic exercise four to five times per week. This is different from the recommendations I make for other women or for men. They also have a much easier time maintaining muscle than other women, which is why the lower frequency of resistance training and higher volume of cardiovascular exercise is appropriate.
The Effects of Inositols on Polycystic Ovary Syndrome
Because PCOS causes insulin resistance, doctors often treat women with PCOS with metformin. Like most pharmaceuticals, metformin can cause side effects like nausea, diarrhea, vomiting, and gas.6Fulghesu AM, Romualdi D, Di Florio C, Sanna S, Tagliaferri V, Gambineri A, et al. Is there a dose-response relationship of metformin treatment in patients with polycystic ovary syndrome? Results from a multicentric study. Hum Reprod. 2012;27(10):3057–3066. doi: 10.1093/humrep/des262. Inositols, which are part of the vitamin B complex, can also improve insulin sensitivity, doing so without metformin’s side effects.
Researchers recently performed a systematic review to assess the efficacy of inositol in people with PCOS. According to their findings, “inositols have a beneficial effect on all aspects of PCOS.”7Greff D, Juhász AE, Váncsa S, et al. Inositol is an effective and safe treatment in polycystic ovary syndrome: a systematic review and meta-analysis of randomized controlled trials. Reprod Biol Endocrinol. 2023;21(1):10. Published 2023 Jan 26. doi:10.1186/s12958-023-01055-z
They found that supplementing with inositol:
- reduced total and free testosterone and androstenedione
- increased sex hormone binding globulin (SHBG)
- normalized menstrual cycle length
- lowered fasting glucose and insulin levels
- lowered body weight
The doses in the studies reviewed ranged from 1000-4000 mg per day.
I would also add that berberine has recently shown much promise in supporting the health of women with PCOS as well.
Testosterone Levels and Risk of Myocardial Infarction in Men and Women
I’ve written previously about how low testosterone levels predispose men to more severe COVID-19 outcomes, and higher levels protect them. In addition, a COVID-19 infection has been shown to lower testosterone levels in men and women. Is it possible that the vaccine could also suppress testosterone? I have not seen a single study assessing this, but based on the similarities between the effects of a COVID infection and the side effects of the vaccines, I wouldn’t be surprised.
What does this have to do with myocardial infarction? The vaccine and infection cause issues with heart function, albeit the vaccine seems problematic more in young and healthy men whereas the infection is more problematic in older men and women. But heart problems are common in both groups.
The research showing the association between testosterone levels and heart problems in COVID patients led researchers to looking at people’s testosterone levels just prior to myocardial infarction.8Faresjö, Åshild et al. “Decreased Testosterone Levels Precede a Myocardial Infarction in Both Men and Women.” The American journal of cardiology vol. 186 (2023): 223-227. doi:10.1016/j.amjcard.2022.10.004 They found a consistent pattern of reduced testosterone levels in the month preceding a heart attack.
This finding would also lend credence to the idea that stress can cause heart attacks. When under high levels of chronic mental or physical stress, you secrete excessive levels of cortisol. High cortisol levels blunt testosterone production, which could open the door to a heart attack.
Most men and women would benefit from enhancing their testosterone levels by eating a higher-protein, lower-carb diet, strength training three to five times per week, and getting at least eight hours of sleep each night.
Doing so can make you look and feel better, but in the interest of not dying, research shows it can also help you avoid a heart attack.
There is an exception, though…if you’re a woman with PCOS, the frequency of strength training should be reduced, and carbohydrate intake significantly limited.
If you’re interested in more testosterone-related content, check out the following blog posts: