The vegan diet is associated with many things and if you listen to certain sections of the media, many of them are negative. Equally, there are many false myths about being vegan and various clichés built out of differing levels of truth. A rumour/myth/cliché/fact/piece of fake news (we’ll tell you which over the course of this article!) that you might not have heard is that a vegan diet can increase testosterone levels in the human body.
That might seem counterintuitive to those who wrongly associate the vegan diet with being low in muscle-building protein and still think of outdated stereotypes of vegans as underweight hippies who only eat lentils. However, it is sure to be of interest to the many great vegan bodybuilders and top vegan sports stars who know full well that a vegan diet is perfectly capable of powering physical excellence.
In this article, we’ll look at the claim that a vegan diet can increase testosterone levels. We’ll also explain what testosterone is, what it does and whether or not having elevated levels of it would be a good thing or not.
Does a Vegan Diet Increase Your Testosterone Levels?
There is lots of conflicting information around this subject, which is characterised by a feature at Livestrong that states, “The nutritional content and health effects of vegan diets can both boost and lower testosterone levels.” Clear as pre-coronavirus Delhi skies.
However, whilst this seemingly self-contradictory statement may be confusing, it is quite easily explained. As we explain in our feature on the health benefits of going vegan, there is no single entity that can be called “a vegan diet”. A person can be vegan and eat nothing but vegan Easter eggs, whilst another adherent of a plant-based diet may be a on a raw vegan diet and consume more or less only raw, unprocessed plants. Equally, one vegan could be drinking 10 bottles of vegan Champagne a week and knocking back Red Bull, whilst another person sticks to water and green tea.
These people are all on very different “vegan diets” and so unsurprisingly would expect to have very different health outcomes. Mrs Easter Egg might well have a lot of fun but she sure won’t be healthy and over time she could be sure she would accumulate a range of nutritional deficiencies and health problems. The same can probably be said for the vegan knocking back the sugar and alcohol-packed drinks.
Simply not consuming animal products is actually only a small part of what constitutes someone’s whole diet. Given one vegan diet can vary so much in nature to another, it should be no surprise that there is no simple answer to the issue of veganism and testosterone.
Why Might a Vegan Have Higher Testosterone?
Livestrong, who we class among the more reliable sources out there but far from a complete authority, say that, “as long as you eat a balanced diet that includes adequate amounts of carbohydrates, protein, and zinc, eating a vegan diet should not lower your testosterone levels.” Whilst scaremongers claim the vegan diet is lacking in a whole host of ways, the fact is that a well-planned vegan eating regimen can easily provide everything needed for optimum health.
Such a diet and indeed the vegan diet in general, such as it exists (by which we mean looking at the overall health and biomarkers of vegans as a group), results in lower body mass index and a reduced risk of obesity. Given a chemical process called aromatisation can turn testosterone stored in fat into the female hormone oestrogen, it is certainly possible that vegans, through their (generally) lower fat levels, might have higher levels of testosterone.
A study published by a branch of the United States National Library of Medicine stated the following in its abstract:
Observational studies between men from different dietary groups have shown that a vegan diet is associated with small but significant increases in sex-hormone-binding globulin and testosterone concentrations in comparison with meat-eaters.
The issue with hormones, such as testosterone, is that the body is very adept at regulating them and keeping them within a particular range in order to preserve health. Indeed, this is mainly why aromatisation takes place. This makes the picture more complex and makes it far harder to determine a direct correlation between a given diet or lifestyle and differences in testosterone.
Hormone Levels & BMI
However, the aforementioned study, initially published by Cambridge University and titled The effects of diet on circulating sex hormone levels in men, states that:
Another well-established determinant of hormone levels is BMI (kg/m2). There is a 20 ± 30% reduction in testosterone concentration between clinically-obese men (BMI 30 kg/m2) compared with lean men (BMI < 20 kg=m2).
They list an impressive range of sources to support this assertion and whilst they state that, “the mechanisms underlying the hormonal changes that occur with an increasing BMI are
not fully understood”, there seems no doubt at all that there is a link. This study assesses a wide range of ways in which diet might impact on testosterone, many of which are beyond the scientific scope of this piece. However, the conclusion does give us much to consider.
They state that, “An increase in BMI is associated with a substantial fall in the concentrations of testosterone”. They then go on to argue that, “In comparison with these factors, the effects of diet on circulating sex hormone levels appear to be small” and that “[in] conclusion, the data available have not demonstrated that variations in dietary composition have any long-term important effects on circulating sex hormone levels in men.”
There simply wasn’t evidence to support a hypothesis that how a person’s diet was made up, in terms of their fibre, fat, carb and protein intake, and also in terms of whether they consumed animal products or not, affected their overall testosterone. The study also suggested that this may be due to the body’s impressive ability of self-regulation, or, to use their words, the “efficient homeostatic control of bioavailable testosterone by negative feedback.”
The Link Between Testosterone & BMI
Based on current evidence the biggest reason that vegans might have higher levels of testosterone is because of the likelihood that they will have a lower BMI. However, as we have already said, this is a very complex picture with lots of interrelated factors. Moreover, as explained by the Harvard Medical School, there are various different measurements of testosterone, including total (T), sex hormone binding globulin (SHBG) and free testosterone (F).
These are slightly different metrics, with different roles to play and studies comparing hormone levels may not necessarily be comparing like with like. There remains much we don’t know and whilst BMI is the biggest contributing factor to testosterone levels, it may not be the only one.
Research published in the British Journal of Cancer looked at 233 vegan men, 226 omnivores and 237 vegetarians. It concluded that:
SHBG was significantly higher in the vegans than in the meat eaters, leading to a corresponding increase in T in order to maintain constant levels of FT, a pattern which has been found in previous smaller observational studies (Key et al, 1990; Pusateri et al, 1990).
The differences in SHBG concentrations between dietary groups were reduced but not eliminated by adjusting for differences in BMI, suggesting that nutritional factors specific to a vegan diet may be important determinants of circulating SHBG levels, over and above their effect on BMI.
In short, this conclusion tell us that BMI is a key factor but not the only factor. Good news for a vegan eating lots of healthy greens, nuts and legumes but perhaps less so for those who favour sugary treats and other unhealthy, yet still vegan, items.
Do Vegans Have a Lower BMI?
All of what we have said thus far assumes that vegans are generally slimmer than non-vegans, but is that true? Well, leaving aside those plant-based eaters for whom the only “plant” they eat is chocolate, in general it is true that vegans do have a lower BMI than those on diets involving animal products.
All of the studies, along with many others, report that and the data from the British Journal of Cancer can be seen in the table below:
|Weight (in KG)
Those figures apply to a relatively small sample size and do not account for age but there are many studies giving similar numbers.
Study Comparing the BMI Between Meat Eaters & Vegans
One of the largest investigations of this issue was published in the International Journal of Obesity and studied 37,875 people. It looked at four different groups of people: meat-eaters, those who ate fish, vegetarians and vegans. It concluded that:
Age-adjusted mean BMI was significantly different between the four diet groups, being highest in the meat-eaters (24.41 kg/m2 in men, 23.52 kg/m2 in women) and lowest in the vegans (22.49 kg/m2 in men, 21.98 kg/m2 in women).
This issue seems largely beyond doubt and aside from the impact such a reduced BMI has on testosterone, it would be remiss to ignore its bearing on health and longevity. For all the scaremongering one sees in the media about vegans being short of choline or iron there are many, many benefits to a vegan diet, with a lower BMI crucial to a lower risk of so many diseases and illnesses.
Why a Vegan Diet Might Reduce Testosterone
Despite fairly strong evidence suggesting vegans actually might have higher testosterone (note the phrasing: we are not saying that a vegan diet in itself causes the increased levels), there are many information sources suggesting the exact opposite.
Whilst, as already said, there is no reason for a well-balanced vegan diet to lead to lower testosterone, there are some micronutrients that are essential to helping the body maintain levels within the right range. Whilst there are many excellent vegan supplements and vitamins that can help with certain nutritional deficiencies, the most natural and efficient way to get all the vitamins and minerals you need is through your diet.
Unfortunately, there are no scientifically proven “testosterone heroes”, nutritionally speaking, and respected bodies, such as the NHS, do not directly link any vitamins or minerals with testosterone production. That said, there are some studies and anecdotal evidence to suggest certain nutrients can help.
Examine, a genuinely independent, educational group that look at nutrition and supplementation, list vitamin D, zinc and magnesium as the best nutrients to look out for. However, they also point out that such supplementation is only likely to work if you have a vitamin or mineral deficiency, and equally that this is only likely to improve your testosterone if it is low to start with.
What Is Testosterone?
Testosterone is a naturally occurring anabolic steroid that is the main male sex hormone. In men, it is primarily released into the system from the testicles and, in women, to a much lesser extent, it is secreted by the ovaries. Men have about seven times as much testosterone as women and it plays a major role in the development of a man’s reproductive system, as well as helping men develop greater muscle mass and grow bodily hair.
Women also need testosterone and are actually more sensitive to it and whilst it has a range of functions naturally and uses therapeutically (including helping transgender men), it is mainly men without any health or medical issues that are concerned with it.
Whilst some men (and women too) may have hypogonadism – clinically low levels of testosterone – this is relatively rare. It is perhaps more common for men who are concerned with athletic performance or physical conditioning to take an interest in their testosterone levels, in particular in raising them. Once again, it is worth pointing out that women too may seek to have more testosterone.
Whilst resistance training increases testosterone, this is something of a positive feedback loop and it is very much the case that raised levels of this hormone also make it easier for both men and women to increase their bone and muscle mass, and strength.
Testosterone & Athletic Performance
South African superstar Caster Sementa has been at the centre of an ongoing controversy and debate due to her naturally high levels of the hormone. The Guardian newspaper reported, “Boosting testosterone levels significantly improves female athletic performance, according to one of the first randomised controlled trials.” It went on to say that, “The latest research confirmed that testosterone significantly increases endurance and lean muscle mass among young women, even when given for a relatively short period.”
Should I Want Higher or Lower Levels of Testosterone?
Once again, the issue of testosterone in terms of its use as a performance enhancing drug, for either men or women, is very complex. To answer the question posed in this section, regarding whether higher or lower levels of testosterone are good, in general the vast majority of people do not need to give this a second thought. Most people have readings in the normal zone and the body carefully regulates this.
There are countless articles and features about increasing your testosterone levels and the natural ways you can supposedly do this, as well as supplements that can help. Whilst there are many valid medical reasons for seeking to do this, in general, most people looking into this subject are doing so because they want to add an extra inch or so to their biceps or an extra 20kg on their bench press.
If you have concerns about a genuine health issue, consult your doctor. As we discuss below, most claims about products that boost testosterone levels are false, or certainly unsubstantiated. Whilst a vegan diet will save the lives of many animals, help improve the health entire planet and probably help you to be fitter and leaner, its direct impact on your testosterone reading is unlikely to be significant.
Ultimately the body, designed by God or evolution or whatever else you want to believe in, is a miracle of engineering. Whilst far from infallible, it can take a lot of strain and a lot of mistreatment and still manage to pull through. From the way it can control temperature to the toxin-cleaning role of the liver, the body has a mechanism to maintain its own “normal”.
When it comes to testosterone, the same is also true and whilst diet and other factors can influence levels, the body’s regulatory systems generally do all they can to keep testosterone levels fairly steady. That means that for most healthy individuals their testosterone levels cannot be altered very much, especially not just by diet.
Unless you have a particular medical condition, as is almost always the case in relation to general health, the best cause of action is the simplest and most boring: eat a healthy diet including a wide range of plants and maintain a weight and BMI within the recommended range. For more unexciting advice, we return to Examine, who correctly assert that,
When it comes to increasing your testosterone, quality sleep, physical activity, and weight management come first. A few supplements can help sustain healthy testosterone levels, but most supplements marketed as testosterone boosters don’t work, though some can make you believe they do by boosting your libido.
There seems to be some evidence to suggest that vegans do have slightly higher testosterone levels than non-vegans. However, this is not down to the vegan diet per se, or at least not in any hugely significant way and is more down to the fact that vegans tend to have a lower BMI and on average are younger than non-vegans.