Estrogen and testosterone do more than subject you to the vagaries of puberty. Throughout your life, hormones control everything from your metabolism to your moods, your fertility to your body fat. When they go haywire, they can also increase your risk of cancer. 

The good news is that simply adjusting your diet can tune down the risk of everything from menopausal hot flashes to prostate cancer. Even erectile dysfunction may be a simple matter of what’s on the menu.

Diet and breast cancer

Breast cancer strikes one in eight American women every year. For 5 to 10 percent of them, there is a genetic factor, but for many others, it is a hormone-related disease. Postmenopausal women with high levels of estradiol, a form of estrogen, have more than double the risk of developing breast cancer. Estradiol, particularly when it’s not bound to a protein, can easily enter the nucleus of breast cells and damage the DNA inside, creating a cancer cell. It can then act as a fertilizer, stimulating the growth of tumors.

In the mid 20th century, researchers discovered a stunning trend: Women in Japan rarely developed breast cancer. When they did, it was less aggressive than the cancer in American women. The difference? Diet. Japanese women at the time ate mostly rice and vegetables with very little meat or fish. But as more Western foods entered the Japanese diet in the 1970s, researchers saw a clear pattern: Women who ate meat- and cheese-laden meals showed an 83 percent higher risk of developing breast cancer than women who maintained a traditional diet.

Here’s why: Fatty foods, like meat and cheese, increase estrogen levels. Fiber-rich fruits, vegetables, and grains do the opposite. The fiber binds to excess hormones and escorts them out of the body. Further, women who eat vegan diets have higher levels of a protein that inactivates hormones until they are needed, the sex hormone-binding globulin.

Diet and prostate cancer

The hormone and cancer link affects men too. Prostate cancer is common in the United States and Europe but rare in Asian countries. In this case, the culprit appears to be dairy.

Our bodies respond to dairy products by producing insulin-like growth factor-1 (IGF-1). When we’re young, we produce our own IGF-1 to help us grow. In adulthood, the body produces much less—we simply don’t need it anymore. Dairy consumption, however, floods the body with IGF-1 long after we have any use for it. The Harvard Physicians’ Health Study found that men who developed prostate cancer had 10 percent more IGF in their blood than those without cancer, suggesting that it plays a role in the disease.

Looking beyond IGF-1, a 2016 review reported that men who drink the most milk and milk products have a 43 percent higher risk of dying from prostate cancer than men who avoid dairy.

Erectile dysfunction

A plant-based diet can have more immediate benefits as well. Many men who make the switch experience an unexpected side effect: the end of erectile dysfunction (ED). While ED can be caused by prostate surgery or certain medications, like antidepressants, it is most often the result of narrowed arteries that reduce normal blood flow. Narrowed arteries aren’t limited to just one part of the body. A man with ED likely has impaired blood flow to the brain and heart as well, putting him at high risk of heart attack and stroke. Dumping dairy and meat can actually undo that arterial damage.


Many women get a pleasant surprise as well: Plant-based eating is linked to the cessation of bothersome menopause symptoms. For women in the United States and other countries where a  Western diet is prevalent, menopause often comes with hot flashes, night sweats, irritability, depression, and insomnia. It turns out that this is a uniquely Western experience: Women who eat traditional Asian diets with little to no meat and dairy report no such symptoms—unless they switch to a Western diet. Long before menopause begins, a vegan diet can even lessen menstrual cramps.

The game plan

Balancing sex hormones is just one example of the many proven benefits of a plant-based diet, so why isn’t everyone doing it? Changing dietary patterns can be difficult, especially when it involves giving up something you enjoy. That’s why I recommend that you start your journey by adding foods, not removing them.

For the next seven days, try as many new plant-based foods as you can to determine what you like. Don’t give up meat and dairy yet, just enjoy a week of discovering new flavors.

Once you’ve identified foods that you enjoy, start making some simple swaps. Try soy milk in your cereal. For lunch, try a burrito stuffed with beans, veggies, and rice. Dinner might be pasta with a hearty marinara sauce. You can stick with your proven winners from week 1 or experiment with new recipes and flavors. Skip cooking oil—even vegetable oil—and try steaming, roasting, cooking with broths, or using an air fryer instead.

Once you fully eliminate animal foods, give it a three-week trial run. You don’t have to give up skepticism. You don’t have to commit long term. Just try it and see how you feel.

There is vegan junk food

Some plant-based foods are high in fat, and they should be reserved for only occasional consumption. If you’re running errands and have to stop for fast food, you could grab an Impossible Whopper from Burger King, for example. While it’s better than a beef burger, it’s a far cry from healthy. Meat replacements are loaded with fat and salt to make them meat-like. Vegan cheeses are also an occasional treat and not a daily food group.

Know your why

To make it easier to make healthy food choices when temptation strikes, remember your reason for trying a plant-based diet. Whatever you set out to do, you’re likely to get even more benefits. A healthy plant-based diet is like a box of Cracker Jacks: You get it for the popcorn but always get an extra prize in the box. Will your prize be fewer mood swings? Lower cholesterol? Better sex? Try it for three weeks to find out.

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