Do vegans have higher testosterone levels?

Question

Do vegans have higher testosterone levels than non-vegans?

^{cf. "Does eating soy lower testosterone?"}

_{There are studies that show fasting increases T levels, too.}

Answer 1

This Allen & Key (2000) paper reviews multiple previous studies looking at testosterone levels of vegans compared to meat-eaters. Only one study had a large enough sample size to actually show a "small but significant" increase in SHBG* and testosterone levels in vegan men compared to men who eat meat. However, none of the studies showed any lasting health impacts as a result of this difference, which could be attributed to negative feedback loops where our bodies naturally compensate small changes in hormone production to maintain consistent levels.

Concomitant with an increase in SHBG concentration among vegans compared with meat- eaters is the small increase in testosterone concentration (Key et al. 1990a; Pusateri et al. 1990; Allen et al. 2000), although Allen et al. (2000) was the only study large enough to detect signficant differences (P<0.􏰁05). One small study reported no differences in testosterone concentration between dietary groups (Deslypere & Vermeulen, 1984)

*SHBG stands for Sex Hormone Binding Globulin which is a protein produced by your liver that binds to our sex hormones, including testosterone. Source linked here.

In summary, yes, there is some evidence that vegan men may have slightly higher testosterone levels than men who eat meat. But it isn't a major health concern and further studies that aren't just observational would help answer this question with more accuracy.