Long-chain omega-3 fatty acids, such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), increase serum testosterone levels in mice, although the mechanisms that drive these benefits are unclear. While omega-3 fatty acids improve cellular function, omega-6 fatty acids serve as precursors to pro-inflammatory cytokines, such as arachidonic acid, which damage cells. Findings from a recent report detail the effects of long-chain omega-3 fatty acids and omega-6 fatty acids on serum testosterone levels in adults with overweight and obesity.
Omega-3 fatty acids are essential nutrients found in the oils of fatty fish, such as salmon. In humans, they increase cellular membrane flexibility, which improves cellular function. Omega-6 fatty acids are the primary fats in most vegetable oils, such as corn oil. In excess, omega-6 fatty acids can be harmful to health. Leydig cells, located in the testicles, produce testosterone when stimulated with luteinizing hormone. Evidence from studies in mice suggest that long-chain omega-3 fatty acids incorporate into the plasma membranes of Leydig cells increasing their responsiveness to luteinizing hormone and increasing testosterone synthesis..
The authors recruited 22 males with overweight and obesity who did not have type 2 diabetes to participate in the study. Participants consumed either fish oil (providing 860 milligrams of DHA and 120 milligrams of EPA per day) or a placebo (1 gram of corn oil per day) for 12 weeks. They provided blood samples for the analysis of sex hormones and metabolic markers and completed questionnaires about health, diet, dietary supplement use, and other lifestyle factors.
Fish oil supplementation significantly increased serum testosterone concentrations, even after taking into account age and body mass index. This increase in testosterone occurred with an increased concentration of omega-3 fatty acids in the membranes of red blood cells, an indicator of the membrane composition of Leydig cells. The researchers reported an even stronger association between increased testosterone and decreased omega-6 fatty acid concentration in red blood cell membranes. They also noted improvements in insulin sensitivity among the supplemented group compared to the placebo group.
These findings demonstrate that long-chain omega-3 fatty acid supplementation increased serum testosterone levels in males with overweight and obesity. The authors noted that their report is a secondary analysis of a larger clinical trial and that future research with a larger sample of participants is prudent.
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