Testosterone is a steroid hormone secreted in specialized cells in the testes in men and in the ovaries in women. Diet can have both deleterious and beneficial effects on testosterone production.
In skeletal muscle, testosterone is involved in the regulation of protein metabolism, in particular by stimulating protein synthesis, while the effect of this steroid on protein breakdown is unclear. In adipose tissue cells, testosterone inhibits lipid consumption and lipoprotein lipase (LPL) activity, and also stimulates lipolysis by increasing the number of lipolytic β-adrenergic receptors.
Changes due to food intake
Changes in testosterone after intake of isocaloric food (800 kcal (3350 kJ)) with high (57% fat, 9% protein and 34% carbohydrates) and low (1% fat, 26% protein and 73% carbohydrates) fat content were analyzed in healthy men … There was no change in testosterone after a low-fat meal, but about a 30% decrease in total and free testosterone was observed 4 hours after a high-fat meal. This decrease was not associated with changes in other steroids (estrone, estradnol, dihydrotestosterone, luteinizing hormone (LH), relative free testosterone, or sex hormone binding globulin (SHBG) sensitivity. not carbohydrates), causes a decrease in testosterone levels after ingestion.In our laboratory, we also observed significant decreases in total (-22%) and free (-23%) testosterone in healthy men after taking a diet rich in fat.
Another study compared changes in testosterone levels after eating a meal containing proteins of different origins (soy and meat), fats in different amounts (lean and fatty foods), and different origins (animal and vegetable fats).The decrease in testosterone levels was more pronounced after a lean meal that included lean meat (-22%) compared with tofu (-15%); foods that included lean meat (-22%) versus meat cooked with animal fat (-9%); and foods that included meat cooked with vegetable fat (-17%) versus vegetable oil (-9%). Although these results are not entirely consistent with the data described above, according to which only foods rich in fat cause testosterone reduction, this work provides additional evidence that food composition, in particular the content and type of fat, influences changes in testosterone levels in the blood. after taking it. After any meal, testosterone levels decreased and LH levels increased, while the amount of SHBG did not change.
A number of studies have investigated changes in testosterone levels after an oral glucose tolerance test. Most of this research has been done with women. We know of only one study in which the response of testosterone in such conditions in men was studied. It showed a significant decrease in the level of total and free testosterone but the time of an oral glucose tolerance test lasting 2 hours. At the same time, there were no changes in SHBG, but the level of LH increased significantly.
Only men took part in the study discussed above. The presented data from other studies, as a rule, indicate that after an oral glucose tolerance test in healthy women with normal body weight, testosterone levels also decrease, which can to some extent be explained by natural daily fluctuations in hormone levels. A number of studies have examined the changes in androgen levels after a glucose tolerance test in women with polycystic ovary disease since they often have increased levels of androgens and insulin associated with insulin resistance. Insulin stimulates the production of testosterone in the ovaries, therefore, it can be assumed that hyperinsulinemia plays a role in the pathogenesis in women with polycystic ovaries. In women with elevated androgen levels or polycystic ovary disease, testosterone levels tend to decrease after glucose tolerance testing, similar to that in healthy women, unless women have insulin resistance or obesity, then testosterone levels rise.
In general, after a meal, testosterone levels usually decrease, but this depends on the composition, in particular on the fat content. Insulin may play a role in explaining the postprandial variation in testosterone, as insulin and testosterone levels tend to be inversely correlated in men, while there is a positive correlation in women, especially in women with polycystic ovary disease. At the same time, data from studies using artificial hyperinsulinemia at normal glucose levels (euglycemic hyperinsulinemic clamp) questioned the hypothesis according to which insulin is involved in the regulation of changes in testosterone levels after a meal, since it has been shown that a sharp increase in insulin levels does not have any effect on the content of free and total testosterone in the blood of healthy men and women with normal body weight. The mechanism by which a fat-rich diet lowers testosterone concentration after ingestion may be related to an increase in chylomicrons or fatty acids, since the latter are capable of suppressing LH-stimulated testosterone production in isolated Leydig cells. It is possible that certain nutrients may interact with testicular tissue and affect testosterone regulation. Changes in the state of the plasma membrane of testicular cells and the sensitivity of Leydig cells, followed by an increase in testosterone secretion as a result of the consumption of lipids in various combinations, have been demonstrated in experiments on rats.
Changes caused by food intake when exposed to physical activity
Strength training causes a sharp increase in testosterone levels, which peaks shortly after exercise and returns to its original value about 60 minutes after exercise; food intake before and after class affects the nature of these changes. Laboratory tests indicate that consumption of protein and carbohydrate drinks 2 hours before and after completing strength training for major muscle groups causes an increase in testosterone levels immediately after exercise, followed by a rapid drop to values lower than baseline. level. In the study under review, participants followed the same exercise program with a variety of nutritional supplements for three consecutive days. The greatest decrease in testosterone levels after exercise compared with taking placebo was observed in the case of consumption of protein and carbohydrate drinks before and after exercise on each of the three days of the study, which emphasizes the uniformity and reproducibility of changes in hormone levels.
A study of changes in testosterone levels in healthy men was carried out in the case of taking dietary supplements containing only protein, only carbohydrates and a combination of protein and carbohydrates immediately and 2 hours after the end of the session. As in our study, after taking all types of nutritional supplements, testosterone levels dropped below baseline 30 minutes after exercise and remained low for 5-6 hours, while in the case of placebo, it recovered soon after the end of the exercise and remained stable throughout the entire recovery period. Another study compared changes in testosterone levels in the case of a mixed meal, an isocaloric drink of the same composition, and an isocaloric carbohydrate drink immediately and 2, 4, and 7 hours after exercise. Compared with placebo, testosterone levels after strength exercise were lower with any type of food after 0.5; 2.5; 4.5 and 8 hours after class. Only one of the studies found no differences in the nature of changes in the level of free testosterone, induced by the performance of strength exercises, after taking a carbohydrate drink and a placebo during exercise.
Overall, these studies suggest that eating before and after exercise results in lower testosterone levels after exercise compared to fasting. This decrease may be due in part to a weakening of testosterone synthesis/secretion and/or an increase in its metabolic clearance. It has been shown that a decrease in testosterone levels after exercise is not associated with a decrease in LH levels, which excludes a decrease in the rate of testosterone secretion, but there is still a possibility of weakening the sensitivity of the testes to LH. Since food intake after exercise enhances muscle protein synthesis during the recovery period The decrease in testosterone levels may be due in part to increased intake in active skeletal muscle. This hypothesis can be confirmed by recent data obtained in our laboratory, according to which the food-induced decrease in testosterone levels 60 minutes after strength training coincides with an increase in the amount of the androgen receptor in skeletal muscle.