Testosterone is the primary male sex hormone, but it is also functionally important in women, playing a role in bone density, muscle mass, and mood. Sesame seeds, derived from the Sesamum indicum plant, have been a dietary staple for millennia. Researchers are now studying the seeds for their biological activity beyond basic nutrition, focusing on how their complex compounds interact with hormone metabolism pathways. This potential interaction has led to investigations into whether consuming sesame seeds can change circulating levels of testosterone.
Hormone-Modulating Compounds in Sesame Seeds
The potential for sesame seeds to modulate hormones stems primarily from their rich content of lignans, a class of polyphenols, including sesamin and sesamolin. Lignans are classified as phytoestrogens, meaning they are plant-derived compounds with a chemical structure similar to the body’s own estrogen, allowing them to interact with human hormone receptors. Once consumed, the gut microflora converts these plant lignans into biologically active mammalian lignans, specifically enterolactone and enterodiol. Beyond lignans, sesame seeds also contain phytosterols, such as beta-sitosterol and stigmasterol, which have demonstrated anti-androgenic characteristics in laboratory models. This combination of phytoestrogenic and anti-androgenic compounds forms the basis for the seed’s hormonal influence.
Research Findings on Testosterone Levels
Research investigating the direct effect of sesame seed consumption on testosterone levels presents a nuanced picture, often dependent on the study population and the form of testosterone measured. In a human study involving postmenopausal women, daily consumption of 50 grams of sesame seed powder for five weeks significantly increased Sex Hormone-Binding Globulin (SHBG) levels by 15%. This suggests a reduction in the amount of free, biologically active testosterone available to tissues. The same study also reported an 18% decrease in serum dehydroepiandrosterone sulfate (DHEA-S), a precursor hormone that the body converts into more potent androgens. This collective shift—increased SHBG and decreased DHEA-S—indicates a clear anti-androgenic effect. This hormonal modulation may be beneficial for managing symptoms related to high androgen levels in female populations, such as in polycystic ovary syndrome (PCOS). Studies on male subjects are less numerous and sometimes show conflicting results, likely due to the seeds’ high zinc content, a mineral known to support testosterone production. However, laboratory and animal studies have consistently supported the anti-androgenic potential of sesame lignans. For instance, one study using castrated rats showed that sesame seed extract led to a significant reduction in both prostate weight and testosterone levels.
Biological Pathway of Hormone Interaction
The mechanism by which sesame seeds influence testosterone is primarily mediated through the action of lignans on Sex Hormone-Binding Globulin (SHBG). SHBG is a glycoprotein synthesized mainly by the liver that binds to sex hormones, including testosterone and dihydrotestosterone (DHT). Only the small fraction of testosterone that remains “free” can easily enter cells and exert its biological effects. The lignan-derived metabolites, like enterolactone, stimulate the liver to produce more SHBG. When SHBG concentration increases, it captures more circulating testosterone molecules, effectively locking the testosterone and preventing it from interacting with androgen receptors. Consequently, while total testosterone may not always decrease significantly, the level of free testosterone—the active form—is reduced, leading to a net lower androgenic effect. Furthermore, phytosterols such as beta-sitosterol can inhibit the enzyme 5-alpha reductase. This enzyme is responsible for converting testosterone into the more potent androgen, DHT. By mildly inhibiting this conversion, sesame compounds decrease the concentration of DHT, which is linked to conditions like benign prostatic hyperplasia and male pattern baldness. This dual action on SHBG production and enzyme activity illustrates the seeds’ anti-androgenic profile.
Dietary Integration and Considerations
For those considering sesame seeds for their potential hormonal benefits, understanding the appropriate context and quantity is important. The significant hormonal effects observed in studies, such as the increase in SHBG, were typically achieved with a high intake of sesame seed powder, around 50 grams daily. This quantity is substantially larger than routine consumption and represents a concentrated dose. A more common daily consumption for general health is about 1 to 2 tablespoons, or 10 to 20 grams, of seeds or tahini. At this lower, routine level, the hormonal effect is likely much milder and is considered part of a balanced diet. Whole seeds, tahini, and cold-pressed oil contain different concentrations of lignans and phytosterols. Sesame seeds are calorie-dense, and consuming 50 grams daily adds substantial fat and calories that must be accounted for in a person’s overall diet. Anyone seeking to use sesame seeds or their extracts to intentionally modulate hormone levels, especially to address a condition like PCOS or androgen excess, should first consult with a healthcare professional for personalized guidance and monitoring.