Before I went vegan, I heard all the standard things about testosterone plummeting without meat.
And then after I went vegan, I heard anecdotes about the opposite – that testosterone actually goes up.
Since those opinions are rarely backed up by any real logic or research, I typically ignore them.
But since this is an interesting topic, I decided to find out for myself what studies say on how veganism affects testosterone.
For now, I’ve only found 2 studies that focus on this topic, which limits how much we can conclude. I’ll add more to this page over time if they become available.
Study 1: Hormones and Diet
This is a study published in the British Journal of Cancer, which looked at testosterone levels in 233 vegan men, 237 vegetarians, and 226 meat-eaters (all in the UK).
The findings were interesting:
Vegans had higher testosterone levels than vegetarians and meat-eaters, but this was offset by higher sex hormone binding globulin, and there were no differences between diet groups in free testosterone, androstanediol glucuronide or luteinizing hormone.
When it comes to building muscle and libido, free testosterone is what matters most.
So even though vegans had higher total testosterone (which I found a bit surprising), that extra bit is tied up by sex hormone-binding globulin (SHBG) and isn’t bio-available.
Study 2: Testosterone in Male Vegans and Omnivores
This study, published in the British Journal of Nutrition, measured total testosterone and calculated free testosterone in 51 vegan males, and 57 omnivores. Not the biggest sample, but decent.
There were 2 interesting conclusions.
…the vegans had 7% higher total T (P = 0.250), 23% higher SHBG (P = 0.001), 3% lower free T (P = 0.580)…
Once again, vegans had higher total testosterone, but also more SHBG. Overall, the vegans had 3% lower free testosterone.
Before you freak out either way! Look at those “P” values beside each result.
In statistics, you usually look for a P value of 0.05 or less, which only the SHBG met. The difference in total and free testosterone are essentially meaningless.
However, the authors were able to find statistically significant differences in a subset of the participants:
In a subset of eighteen vegans and twenty-two omnivores for whom 4 d diet records were available, there were statistically significant correlations between T and polyunsaturated fatty acids (r 0.37), SHBG and fat (r 0.43 for total fat, 0.46 for saturated fatty acids and 0.33 for polyunsaturated fatty acids), and SHBG and alcohol (r–0.39).
SHBG is “bad” for those seeking higher free testosterone. It’s not surprising that drinking alcohol raises SHBG.
However, the relationship between fat (both saturated and polyunsaturated fatty acids) and SHBG is also interesting. Getting too much of those types of fats could reduce your free testosterone. But that’s a topic for another day.
Can We Make Any Conclusions?
Those are 2 pretty good studies looking at diet and testosterone levels.
While we would need more to conclude anything specific, I think we can say that vegans may have higher total testosterone, but when it comes to free testosterone, there isn’t a significant difference between vegans and omnivores.
If you’re looking to increase your free testosterone levels, I’d recommend looking to lifestyle factors rather than diet.