A new study conducted at the University of Worcester has revealed that a low-fat diet decreases testosterone levels by between 10 and 15%.
Testosterone is the hormone most associated with masculinity, and although it is also important to women’s bodies and their health, the increased levels of testosterone in the male body are responsible for the host of traits that make men men, rather than women.
Body hair, muscle mass, bone density, strength, aggression, dominance and competitiveness – increases in all of these things are associated with increased testosterone in men.
Having a less-than-optimal testosterone level can have serious effects on a man’s health. Athletic performance and mental and sexual health will all be affected, and a man with low testosterone will also be at higher risk of heart disease, diabetes and Alzheimer’s disease, among other chronic diseases.
There are many external influences that have been blamed for decreases in testosterone levels, but the low-fat diet model appears to have a direct impact.
A Low Fat Diet Decreases Testosterone
The University of Worcester study combined a systematic review and meta-analysis. The results of six controlled studies with a total of 206 participants were considered. These studies first put men on a high-fat diet (40% fat), and then transferred them to a low-fat diet (20% fat), and found that it decreases testosterone by 10-15% on average.
Worst of all was the transition to a low-fat diet combined with vegetarianism, which decreases testosterone by up to 26%.
British strongman Eddie Hall should not transition to a low-fat vegetarian diet –
unless, of course, he’s looking to flatline his gains
Low-Fat Diet Decreases Testosterone More in Some Over Others
The authors also noticed an ethnic component to the research, with a stronger effect for European and North American men (i.e. a larger decrease in testosterone on low-fat diets). The reasons for this variation are not immediately clear, and would reward further research; although such research regularly proves controversial.
Evaluating their results, the authors considered other studies that showed similar results, particularly studies showing that high consumption of monounsaturated fats, such as those found in olive oil, avocados, and nuts, can boost testosterone production.
Polyunsaturated vegetable oils, by contrast, should be avoided at all cost. Elsewhere, we have discussed in detail their dreadful health effects, which mainly result from their chemical instability and high proportion of Omega 6 fatty acids.
Butter: delicious and, believe it or not, also very good for you
Modern Society Decreases Testosterone Levels
The issue of saturated fat consumption, however, is more vexed, largely because of decades of anti-saturated-fat messaging, including the claim, which now looks increasingly spurious, that increased saturated fat and therefore cholesterol consumption is directly correlated with increased risk of heart disease and death. Indeed, studies have shown that saturated fat and cholesterol have extremely beneficial pro-hormone effects, including increasing testosterone levels. [R] [R]
Studies such as the University of Worcester study are helping us better to understand an increasingly worrying trend of the past fifty years: the precipitous decline of men’s testosterone levels. The average man today has considerably less testosterone than a man of the same age even a single generation ago.
A 2007 study in the Journal of Clinical Endocrinology and Metabolism showed a significant reduction in the testosterone levels of men since the 1980s. A 60-year-old American man in 2004, for example, had 17% less testosterone than a 60-year-old American man in 1987. These findings were corroborated in a study of Danish men, who displayed a two-digit decline between the 1920s and the 1960s.
This decline is linked to a worrying collapse of male fertility (sperm counts), with one expert predicting that by 2045 the majority of men may no longer be able to reproduce, a scenario sometimes dubbed ‘spermageddon’.
Professor Shanna Swan. Her new book Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development and Imperiling the Future of the Human Race is out now.
In her new book, Count Down, Profressor Shanna Swan points the figure of blame at xenoestrogens in particular, industrial chemicals that mimic the effects of the female hormone estrogen in the human body. We have already devoted articles to xenoestrogens and to phytoestrogens, plant chemicals that also have estrogenic effects.
Studies like the University of Worcester study remind us that diet is also a very significant part of the equation. Dietary habits have changed considerably over the last century, and the demonisation of dietary fat, especially saturated fat, by the scientific community and media – often for less than honest reasons – must rank as one of the most prominent dietary trends during that period. Indeed, the notion of a low-fat diet for health almost certainly did not exist before the second half of the twentieth century.
The University of Worcester study is also likely to dismay proponents of plant-based diets who claim that vegetarianism or veganism can be just as healthy or even healthier than meat-eating.
For more information on other foods known to decrease testosterone levels, check out our article on the subject.
In advance of our new book Reclaim Your Masculinity, we have been running a whole series of articles on testosterone. First of all you’ll want to know how to know if you have low testosterone, then you should try our articles on 10 ways low testosterone can ruin your life, how low testosterone can ruin your mental health, five foods that boost testosterone and five foods that lower it, and the testosterone booster you’ve never heard of.
We are also looking to start selling home kits for testing your testosterone levels. Watch this space!