Estrogen is often called the “female sex hormone” since it’s important for regulating monthly flows and even growing breasts. And while women generally have more estrogen in their bodies, everyone has some estrogen as part of their hormonal balance.
Plants also have phytoestrogens that function similarly to estrogen in your body. While phytoestrogens aren’t fully understood, eating foods rich in these compounds *might* affect your body’s estrogen levels (for better or worse).
Phytoestrogens have stirred up a lot of controversy in the nutrition world.
Since phytoestrogen has a similar structure to the estrogen in the human body, it can bind to estrogen receptors in your body when consumed. This might influence how estrogen functions in your bod and increase your estrogen levels (aka the estrogenic effect).
Although it hasn’t been entirely proven, some researchers think consuming too much phytoestrogen can lead to a hormonal imbalance and health issues.
Some theories link high estrogen in women to lighter or heavier periods, fibrocystic breasts (noncancerous breast lumps), increased breast cancer risk, or fibroids. And men impacted by high estrogen levels may experience fertility problems and erectile dysfunction.
But again, none of this is 10/10 proven.
Some research, including a 2010 review, also suggests that certain types of phytoestrogens have antiestrogenic effects — meaning they may block estrogen’s effects and decrease your levels. Confusing, right?
So, what happens when you eat phytoestrogen foods? Here’s what the science has to say about some specific estrogen food sources.
PSA: It’s not definite that the following benefits come from phytoestrogens alone, since these foods contain other beneficial nutrients as well.
Flaxseed is high in the phytoestrogen lignan. Red flags have been raised regarding high lignan levels and hormone-linked cancers like prostate, endometrial, and breast cancer. But many studies lean toward flaxseed having protective effects against breast cancer.
According to a 2018 review, consuming flaxseed daily may reduce the risk of breast cancer thanks to lignans’ ability to reduce inflammatory markers. But many of the studies on this have been done on animals, and more research in humans is needed before we can draw conclusions about the effects.
Flaxseed may even benefit people with menopausal symptoms such as hot flashes. A small 2015 study found that postmenopausal women who took a flaxseed supplement for 3 months had decreased menopause symptoms.
Soybeans contain phytoestrogens called isoflavones, which are known to increase estrogen levels. The question remains: Is this OK? Or does it come with not-soy-good side effects?
A 2021 review found that research on isoflavones is super conflicting. A high isoflavone diet may help relieve menopause symptoms and lower the risk of coronary heart disease, breast cancer, and colorectal cancer. But more research is needed to confirm those claims.
It’s also believed that isoflavones are more likely to bind with beta estrogen receptors found in the bones, lungs, prostate, bladder, skin, and brain than with receptors found in other areas of the body. This basically means isoflavones *may* be more likely to affect these areas.
This soy-based protein source is a vegetarian fave. Like soybeans, it contains isoflavones, so it brings the same potential benefits that soybeans are linked with.
The main difference is that soybeans tend to contain a higher isoflavone content (about 1.5 milligrams per gram) than soy-derived foods like tofu. But tofu still has the highest isoflavone content of all soy-based products.
While we’re still on the soy train, we’ll mention tempeh, which also has soybeans as its main ingredient. Tempeh is a fermented food that’s formed into a dense cake, which can sometimes include grains and spices.
The fermentation of soybeans adds a whole new level of nutrients and benefits beyond isoflavones.
A 2020 study found that participants who ate a diet rich in fermented soy products for about 15 years had a significantly lower risk of death. But we still need more research to confirm this link.
5. Cruciferous veggies
Some of the veggies in the cruciferous category are:
Not all of them contain the same type of phytoestrogen. Broccoli and cauliflower are on team lignan, while brussels sprouts and cabbage contain coumestrol.
A 2017 study found that eating cruciferous veggies resulted in decreased breast cancer risk in premenopausal women. Eating broccoli and cauliflower raw showed a stronger decrease than eating them cooked, but cabbage had better results when cooked.
6. Dried fruits
This shelf-stable version of fresh fruit is a nutritious on-the-go snack that contains various phytoestrogens. Practically any fruit can be dried, but the ones with the highest phytoestrogens are dates, prunes, and apricots.
A 2020 review of studies even suggested that eating 3 to 5 servings of dried fruit per week might reduce the risk of developing precancerous colorectal polyps, developing prostate cancer, or dying from pancreatic cancer. These results were similar to or better than the results from eating raw fruits.
7. Sesame seeds
This is your sign to prep or order your fave Asian-inspired cuisine. Sesame seeds offer great nutty flavor and a dose of phytoestrogens.
Sesame seeds contain lignans similar to those in flaxseed, but they’re a slightly different form.
A 2012 study in animals found that the lignans in sesame seeds decreased breast cancer tumor size in mice by 23 percent compared with both the control group and the flaxseed lignans. But we need more human studies to know how significant the effect really is.
Be honest: Is there ever a time that you don’t add garlic to your savory meals? In addition to providing a great flavor, this ingredient contains phytoestrogens that are believed to benefit your health.
A 2017 study found that postmenopausal women with osteoporosis who took 2 garlic tablets each day for a month had reduced oxidative stress and reduced effects of osteoporosis. This suggests garlic may prevent estrogen deficiency that occurs in postmenopausal women and help improve calcium absorption.
A 2013 study in postmenopausal women found that 2 weekly servings of peaches or nectarines lowered the risk of breast cancer. A high intake of berries showed a similar result, but no other fruits or vegetables did.
The estrogen effects of berries aren’t well studied, but berries higher in phytoestrogens include:
Beyond their phytoestrogen content, berries are a nutritious pick thanks to the antioxidant resveratrol. According to a 2020 review, resveratrol has been linked with preventing and treating chronic conditions like cardiovascular disease, Alzheimer’s disease, Parkinson’s disease, and diabetes.
11. Wheat bran
Wheat bran is the outer part of the wheat kernel and contains fiber along with the phytoestrogen lignan. It has a sweet, nutty flavor and can be used in baked goods or as a topping for smoothies and oatmeal.
There’s very limited research on wheat bran specifically and how its lignan content benefits the body. But wheat bran is a good source of insoluble fiber, which is believed to affect estrogen levels.
12. Alfalfa sprouts
Adding these little sprouts to a sandwich can take it from “meh” to “yeah!”
Alfalfa sprouts contain the phytoestrogen coumestrol, and a 2011 study noted that sprouts also contain smaller amounts of other phytoestrogens that may boost estrogen levels.
A 2019 study found alfalfa sprouts may also benefit your brain by improving memory and protecting against neurodegenerative diseases. But this isn’t necessarily due to the phytoestrogens alone.
Wait, this isn’t a plant! Dairy products from cows and other animals don’t contain phytoestrogens, but they can contain actual estrogen from those animals. This has caused a lot of concern about how the estrogen may impact humans’ endocrine systems.
Although more research in humans needs to be done, a 2016 study in mice found that the estrogen in cow’s milk had no impact on the hormone levels of the mice. Even estrogen levels more than 100 times higher than you’d typically find in milk didn’t cause any changes.
A 2018 study in humans also found that dairy consumption through adolescent and early adult years had no impact on breast cancer risk.
Don’t yolk around: Are eggs high in estrogen?
We’re all still wondering if the chicken or the egg came first, but what we do know is that eggs contain estrogen. According to a 2020 review, eggs have estrogen because they’re made directly in the ovaries of hens.
The same review notes that egg yolks and other full-fat dairy foods also contain progesterone, another hormone that works with estrogen to develop female characteristics and support fertility.
Research indicates that the pros of phytoestrogens likely outweigh the cons. There’s very weak evidence that complications can actually happen, with most human studies debunking the claims.
Here’s what research says about some of the top concerns regarding phytoestrogen intake:
- Infertility. It’s believed that as long as you aren’t eating phytoestrogen-rich foods literally nonstop, you should have no reproductive issues. Eating 1 to 2 servings of soy foods per day has been deemed safe.
- Breast cancer. Research has linked many of the foods we just discussed with protective properties against breast cancer rather than increased risk.
- Effects on male reproductive hormones. A 2020 study found that men who consumed high amounts of a phytoestrogen in soy foods were actually protected against low sperm concentration and low motility (a decrease in how efficiently sperm moves).
- Decreased thyroid function. A 2018 study found that participants with hypothyroidism did not have decreased thyroid function when consuming 66 milligrams of soy phytoestrogens per day for 8 weeks.
Many nutrient-dense fruits and veggies contain phytoestrogens. Although some researchers believe phytoestrogens can cause hormone-related complications, current research doesn’t seem to support that idea.
If you’re concerned about your estrogen levels, the first step is to set up an appointment with a doctor. They can determine whether treatment or diet changes may be necessary.