Although both groups had similar increases in muscle thickness, lean body mass, and strength measures (1RM squat and bench press), only the KD group experienced a significant increase in TT concentrations. A similar study investigated the differences between KD and Western diets (WD) on body composition, strength, power, and hormonal profiles in resistance-trained men. Results indicated that both groups experienced a significant increase from baseline in both total testosterone (TT) and FT concentrations during all four assessment times (weeks 2, 4, 6, and 8) of the study. Shufelt and colleagues reported that red wine consumption resulted in significantly higher FT concentrations and lower SHBG and E2 concentrations in women. Jeong and colleagues reported four compounds isolated from this plant, including diethyl ether extract, inflexin, ursolic acid, and ursolic acid 3-O-acetate that have significant aromatase inhibitory activity. This species has several reported medicinal uses in south and southeast Asia, such as treatment of rheumatism and back pain, aiding in digestion and alleviating constipation, treating bone fractures and sprains, and other health issues . They are important hormones for various biological processes and are vital for the development and maintenance of secondary male characteristics. Testosterone, together with its potent metabolite, dihydrotestosterone (DHT), are the principal androgens in the circulation of mature male mammals, including humans. If your digestive health is undermining your performance and vitality, we can help you find a knowledgeable gastroenterologist to help. At Obsidian Men’s Health, we don’t just look at your testosterone level in isolation. These investigations have indicated that low energy availability has a deleterious effect on various physiological systems in the body, specifically the endocrine system. Situations of low energy availability are reported in both endurance and strength/power athletes and are especially relevant in sports where competition is based upon weight class . These studies clearly indicate the negative effect that low energy availability has on the hypothalamic-pituitary-gonadal axis. Zinc deficiency can impair testosterone synthesis and has been demonstrated to correlate with reductions in testosterone concentrations 153,154,155. Significant associations were also noted between vitamin D concentrations and circulating testosterone and SHBG concentrations, as well as the free androgen index . Vitamin D receptors are present on the Leydig cells within the testes, where the synthesis of testosterone from cholesterol occurs , suggesting an important role of vitamin D on testosterone synthesis. Some of the symptoms of low testosterone levels include depression, fatigue, and irritability. For men with low testosterone, studies show that treatment can decrease fat mass and increase muscle size and strength. Another study found that hormone therapy only widened healthy arteries but had no effect on angina pain. Newer research in humans is needed to further support the effects of licorice root on testosterone. In particular, spearmint and peppermint—two herbs from the mint family of plants—have been shown to directly affect testosterone. We process personal information and consumer health data to provide you with our products and services and maintain essential website functionality. The popularity of soy protein use among vegan athletes has resulted in a focus on its effect on sport performance and changes in testosterone concentrations. One type of protein that has received considerable attention regarding its effect on circulating testosterone concentrations is soy protein. It has been suggested that increases in testosterone concentrations resulting from a KD are related to the high dietary intake of cholesterol . Several studies have examined the effect of HFD on circulating testosterone concentrations 85,86,87. Cholesterol, a dietary fat component, is one of the building blocks for testosterone production . Effect of low energy availability and energy deficits on circulating testosterone concentrations. Others have reported significant elevations in cortisol, decreases in testosterone, and a lower testosterone/cortisol ratio 24-h following an intense exercise session resulting in an energy deficit exceeding 400 kcal in male athletes .