Many men worry about whether certain types of foods—specifically those that contain phytoestrogens, like soy—might affect their hormone levels, particularly testosterone.
Adding to the difficulty, most of the foods that have these compounds are healthy and a great addition to any diet, particularly if you’re trying to lose weight.
With conflicting information circulating online about foods that contain phytoestrogens, it's important to understand what the scientific research actually says about these plant compounds and their effects on male hormonal health.
What Are Phytoestrogens?
Phytoestrogens are naturally occurring plant compounds that have a structural similarity to estradiol, one of the body's natural estrogens.
This structural resemblance allows them to interact with estrogen receptors in the body, though typically with significantly weaker effects than estrogens produced naturally in the human body.
These compounds exist in varying concentrations in many different plants. The most common dietary sources include:
● Isoflavones: Found mostly in soybeans and soy-based products (tofu, tempeh, edamame, soy milk), as well as other legumes.
● Lignans: Most concentrated in flaxseeds but also found in sesame seeds, whole grains, and some fruits and vegetables.
● Coumestans: Present in clover, alfalfa sprouts, and split peas.
● Prenylflavonoids: Found in hops (used in beer production).
The concentration of these compounds varies based on growing conditions, processing methods, and food preparation techniques.
Men Need Small Amounts of Estrogen to Stay Healthy
To understand phytoestrogens' potential effects on your body, it's important to recognize that you need to have a small amount of estrogen in your body to be healthy. Estrogen actually has several very important jobs in men’s bodies—you can’t live without it.
Your body naturally produces estrogen in small amounts by converting a small portion of your testosterone into estrogen. You need it to maintain bone density, cognitive function, cardiovascular health, and even sexual function.
Evidence on Phytoestrogens and Testosterone
While there’s been a lot of fear-mongering over the potential “damage” to men’s hormone levels that dietary phytoestrogens could supposedly cause, research has shown for more than a decade that eating foods with phytoestrogens in normal amounts has no measurable effect on healthy men’s testosterone levels.
A 2021 review of 41 different studies concluded that "neither soy foods nor isoflavone supplements alter measures of bioavailable testosterone concentrations in men."
These consistent findings across multiple studies show that eating phytoestrogen-containing foods moderately as part of a balanced diet won’t reduce your testosterone levels or consumption.
When Phytoestrogens Might Be Relevant for Men's Hormonal Health
While most men have nothing to worry about, there are a few situations where phytoestrogens might be a problem for your hormones.
Going Overboard
If you're downing multiple protein shakes with soy isolate every day or drinking liters of soy milk daily for months, you might be getting amounts far beyond what any research has tested.
A few case reports show men who consumed massive amounts of soy foods or supplements experienced hormonal changes, but this isn't something that happens with normal eating patterns.
Existing Hormone Issues
If you already have diagnosed hormone problems, especially low testosterone or high estrogen, you might want to be more cautious.
While research doesn't show strong effects, if your hormones are already out of balance, it makes sense to discuss your diet with your healthcare provider.
Individual Differences
Your gut bacteria play a big role in how your body processes phytoestrogens. About 30–50% of people have gut bacteria that convert certain phytoestrogens into compounds that have stronger effects.
This might explain why some men report feeling sensitive to these foods while others don't notice a thing.
What Actually Affects Your Testosterone More Than Phytoestrogens
Instead of worrying about your occasional tofu stir-fry, focus on these factors that have much stronger effects on your testosterone.
Lack of Sleep
Getting less than 7 hours of sleep regularly can drop your testosterone by 10–15%. That's a much bigger impact than any dietary phytoestrogen. If you're concerned about your hormone health, fixing your sleep should be priority #1.
Excess Fat, Especially Visceral Fat
Having excess body fat, especially visceral fat around your middle, is one of the strongest predictors of lower testosterone.
Fat tissue contains aromatase, an enzyme that converts testosterone to estrogen. If you're carrying extra pounds, focus on losing weight rather than avoiding healthy plant foods.
Chronic Stress
When you're chronically stressed, your body produces more cortisol, which directly suppresses testosterone production. Stress management techniques like meditation, deep breathing, or even just regular time spent doing things you enjoy can help protect your testosterone levels.
Alcohol Has Stronger Effects Than Plants
Regular heavy drinking has well-documented negative effects on testosterone production. Even moderate drinking can impact your hormones more than phytoestrogens. If you're concerned about your testosterone, look at your alcohol intake before eliminating healthy foods.
Smart Approaches to Phytoestrogens
Rather than avoiding nutritious foods entirely, here's how to approach phytoestrogens sensibly.
Variety Is Your Friend
Instead of relying heavily on any single food source, aim for variety in your diet. If you enjoy soy foods, there's no need to avoid them—just don't make them your only protein source every day.
Track Your Personal Response
If you suspect sensitivity to certain foods, keep a simple food journal noting what you eat and how you feel for a few weeks. Your individual response matters more than general studies.
Focus on Whole Foods
Whole food sources of phytoestrogens come packaged with fiber, protein, and other nutrients that support overall health. These are generally better choices than isolated supplements or highly processed foods with added soy protein isolate.
Get Your Hormones Tested
If you're experiencing symptoms that might indicate hormone imbalance (like fatigue, low sex drive, or mood changes), testing is more valuable than dietary guesswork. Comprehensive hormone testing can identify what's actually happening with your hormones.
If You're Experiencing the Symptoms of Low T, We Can Help
The scientific evidence is clear: for most men, moderate consumption of phytoestrogen-containing foods doesn't negatively impact testosterone levels.
However, if you're experiencing symptoms that make you feel like you have high estrogen levels, we can help.
Your next step is to get your hormone levels tested so that we can figure out what's causing your symptoms and what we can do about them.
Learn more about TRT here and how proper hormone balance can optimize your health and well-being. You can also schedule an appointment with a specialist today to discuss getting your levels tested.