Everybody makes testosterone, and production slows down as we age. For cisgender men, testosterone’s oft-overemphasized reputation as the root of all things desirably masculine – libido, physical strength, energy, and even confidence – can make this element of aging feel like the ultimate enemy. Men’s wellness spaces are full of tips and products that promise to boost testosterone levels – and it starts, they’ll tell you, with what you eat. But if you’re looking to fill up your diet with foods that increase testosterone and cut out foods that kill testosterone, you may want to take a step back. “There’s no one size fits all model in terms of diet’s effect on testosterone,” says Jake Fantus, MDa clinical assistant professor in andrology at the University of Chicago’s Pritzker School of Medicine.
When it comes to testosterone levels, the body really only has two ranges: enough, and not enough. For healthy, younger cis men with normal levels of testosterone (ranging between 300 and 1,000 nanograms per deciliter of blood), there’s little evidence that diet affects testosterone in any meaningful way. For example, a study Fantus published in 2019 found slightly lower levels of testosterone in men who adhered to low-fat diets, but follow-ups have found that this difference has no bearing on measures such as erectile function. Essentially, when you’re in the “enough” category, having a little more or a little less does not change a whole lot.
For everyone else, Fantus suggests throwing the idea of a singular testosterone-boosting superfood – an idea that commonly pops up online – out the window. Claims made about particular foods may look well-supported by research, but many can be traced back to either a fair amount of conjecture or a misinterpretation of nutritional science.
Consider the cabbage, which is often listed as a food that can indirectly boost testosterone by lowering estrogen. Men’s Health suggests that eating cabbage “rids your blood of girly hormones” thanks to a chemical it contains, known as indole-3-carbinol. They reference a study from Rockefeller University that found increased levels of urinary estrogens when students were given 500 mg of indole-3-carbinol a day – the same amount found in about half a head of cabbage. The findings are real, but here’s what else is true about the study: It’s from 1997, it only had seven male participants, and, perhaps most importantly, the word “testosterone” does not appear once in the paper itself. Not quite worth chowing down on four cabbages per week.
Other testosterone-boosting “superfoods,” such as eggs, are promoted based largely on animal model findings that have yet to be replicated in humans. Some, like cocoa, have only been studied in men who are testosterone-deficient. And there’s a whole group of foods, including oysters, for which the downsides of eating enough for any testosterone-boosting benefit (for oysters, zinc toxicity) greatly outweigh the potential gains.
Some men do not look to testosterone-fueling foods, but specific diets they think can help in the pursuit of a masculine ideal. Fantus, a former personal trainer, has seen friends try out meat-heavy diets to gain muscle, but he worries about the unknown effects of missing certain micronutrients. With a carnivore diet, “You’re like you get all your fat, you get your protein… you probably would not be iron-deficient,” he says. “But the point is, there may be other things going on. And those can cause different types of feedback inhibition – either centrally or locally in a testicle – that could impair your testosterone. ”
For some men with testosterone deficiencies, overall dietary changes (rather than specific foods) actually can affect testosterone levels. Being overweight can cause testosterone deficiency in cis men, Fantus says, and “those people can make lifestyle changes through diet and exercise” that can help raise their testosterone levels via weight loss. These types of dietary changes are best made with the assistance of a physician, and should always include a variety of foods. “With any kind of super restrictive diet, I do not think you’re going to come out on top,” Fantus says.
Fantus sees the discussion surrounding diet and supplements for testosterone production as part of a “huge misunderstanding that patients have about what testosterone does.” Testosterone plays an important role in many systems in the body, but adding more is not necessarily the solution when those systems falter.
“The people that come in are like, ‘I just want my testosterone higher,'” he says of some of his patients. Fantus instead advises focusing on the “endgame,” sharing with your doctor the exact change you want to make or reasons you’re concerned about potentially low testosterone. Because your testosterone level is just a number, and “usually, if I fix somebody’s erections, they do not care about the number anymore.”