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.
In other words, vegans have higher total, but not free/unbound, testosterone.
basal testosterone (1.95 ng/ml)
i.e. 195 ng/dl, or 6.8 nmol/l. This is not extraordinary, as it is roughly the 2.5th percentile of normal testosterone for most ages.
It is concluded that the severe cholesterol deficiency of this patient did not impair the capacity of the testes to synthesize testosterone. However, the LH/hCG receptor or its subsequent message was activated neither in vivo nor in vitro.
This supports other evidence, such as the fact that vegans, despite their lower cholesterol, have higher total testosterone.
We show that total testosterone peaks [mean (2.5–97.5 percentile)] at 15.4 (7.2–31.1) nmol/L at an average age of 19 years, and falls in the average case [mean (2.5–97.5 percentile)] to 13.0 (6.6–25.3) nmol/L by age 40 years, but we find no evidence for a further fall in mean total testosterone with increasing age through to old age. However we do show that there is an increased variation in total testosterone levels with advancing age after age 40 years. This model provides the age related reference ranges needed to support research and clinical decision making in males who have symptoms that may be due to hypogonadism.
The remaining question is whether those with high testosterone in old age are the same as those with high testosterone in youth. That is to say, does testosterone diverge proportionally from the mean as one grows older, or are there other factors at play?