Keeping testosterone at a decent level as men age can be a challenge. To do this, for starters, one must ensure adequate nutrition; for example, zinc levels are important. Zinc deficiency, which is surprisingly common, kills T levels; elderly men who received zinc supplements had their T levels double, as did hemodialysis patients. Another nutritional example: there’s a strong correlation of T with the amount of fat in the diet, and interestingly, a negative correlation with the amount of protein.
Beyond ensuring adequate nutrition, here are a couple of things to consider. Note, these were all done in animals, but there appears to be no reason why they wouldn’t work in humans.
Probiotic Microbes Sustain Youthful Serum Testosterone Levels and Testicular Size in Aging Mice. This study found that giving purified Lactobacillus reuteri, a bacteria commonly found in yogurt, resulted in much higher levels of T than in controls. How much higher? From four to eight times higher.
The researchers also found that this effect was due to a decrease in a specific inflammatory cytokine, interleukin-17a. This is important, because it shows that inflammation, which increases with age, has a large effect on T levels. This is probably what accounts for low T in obesity.
Also of interest, the same researchers found that Probiotic Bacteria Induce a ‘Glow of Health’. It’s great for the ladies too.
We found that feeding of probiotic bacteria to aged mice induced integumentary changes mimicking peak health and reproductive fitness characteristic of much younger animals… Aged male animals eating probiotics exhibited increased subcuticular folliculogenesis, when compared with matched controls, yielding luxuriant fur only in probiotic-fed subjects. Female animals displayed probiotic-induced hyperacidity coinciding with shinier hair, a feature that also aligns with fertility in human females.
A different study found that resveratrol doubles T levels and sperm counts in rats. The dose was high at 20 mg/kg body weight, but the human equivalent can be found by dividing the rat dose by 8, which brings it down to a more reasonable ~200 mg for a 75 kg man.
There you have it. Probiotics are found in yogurt – be sure to eat the kind that has no sugar – as well as in supplements; resveratrol is found in wine, but one would need a supplement to get the dosage needed.