Proinflammatory diet inhibits testosterone secretion in men

Men who regularly consume inflammation-inducing foods, such as red meat, processed food, fried foods, and sugar-sweetened beverages, among others, tend to have an increased risk of testosterone deficiency (TD), suggests a study.

“Men adhering to a more proinflammatory diet have a higher risk of TD, indicating the important role of inflammatory diet in male reproductive health,” the researchers said. “Large, well designed prospective research studies are warranted in the future to verify the causal relationship between Dietary Inflammatory Index (DII) and TD.”

Data used in this study were obtained from the 2013–2014 and 2015–2016 National Health and Nutrition Examination Survey. The researchers included males aged ≥20 years who provided a 24-hour dietary intake history and underwent serum sex hormone testing.

The associations between DII and sex hormones were assessed using weighted proportions and multivariable analysis controlling for age, race, energy, smoking status, education level, body mass index, and time of venipuncture.

A total of 4,151 men were included in the analysis; their DII ranged from –5.05 to 5.48, and their mean total testosterone was 419.30±176.27 ng/dl. Men in the highest DII tertile group had lower mean total testosterone than those in the lowest tertile group (410.42±171.97 vs 422.71±175.69; p<0.001). A per-unit increase in DII correlated to a 4.0-percent (95 percent confidence interval [CI], 0.5–7.6) higher odds of TD. [J Urol 2021;206:97-103]

Fully adjusted multivariable analysis revealed a higher likelihood of TD (29.6 percent, 95 percent CI, 3.1–63.0) among men in DII tertile 3 (the most proinflammatory) than those in tertile 1 (p_trend=0.025). Of note, body mass index showed no significant impact on the association of DII with TD and all sex hormone parameters in interaction tests.

“Our results indicated that higher proinflammatory dietary intake was positively associated with TD,” the researchers said. “When we limited the participants to males with obesity, the risk for TD was also significant.”

A recent study found that obese men with impaired reproductive function had higher intake of saturated fat and refined carbohydrates and lower intake of fresh fruit and vegetables. In another research, men with high intakes of mono- and polyunsaturated fats had lower production of serum T after a 5-hour period, which was similar to that in obese men. [Reprod Biol 2019;19:219-224; Nutrients 2019;11:3059]

“Emerging evidence showed that a possible mechanism for our results could be the effect of diet on proinflammatory markers such as interleukin (IL)-1, IL-6, IL-17 and tumour necrosis factor,” the researchers said. “These markers severely impair testosterone secretion by activating inflammation and reactive oxygen species production by interstitial macrophages residing adjacent to Leydig cells.” [Am J Physiol Endocrinol Metab 2018;314:E206-E213]

An earlier study also showed that proinflammatory cytokines, including IL-6, IL-1β, and tumour necrosis factor-α, could modulate the hypothalamic-pituitary-gonadal axis to prevent testosterone secretion. [J Clin Endocrinol Metab 2004;89:3313-3318]

“Our findings suggested that a more anti-inflammatory diet could be a feasible method to reduce the accumulated inflammatory burden, hence leading to an increased testosterone level,” the researchers said.