Certain plants and seeds, including berries and flaxseeds, contain compounds that function as phytoestrogens.
Estrogen is a hormone that has many functions in the body, including promoting sexual and reproductive development.
While it is present in people of all ages, females of reproductive age usually have higher levels of this hormone.
Estrogen carries out a range of functions, including regulating the menstrual cycle and the growth and development of breasts (1Trusted Source).
Estrogen levels decline during menopause. This can lead to symptoms such as hot flashes and night sweats.
Phytoestrogens, also known as dietary estrogen, are naturally occurring plant compounds that may function similarly to the estrogen the human body produces.
Here are 11 significant sources of dietary estrogens.
How do phytoestrogens affect your health?
Phytoestrogens have a similar chemical structure to estrogen and may mimic its hormonal actions.
Phytoestrogens attach to estrogen receptors in your cells, potentially affecting the function of estrogen throughout your body (2Trusted Source).
However, not all phytoestrogens function in the same way.
Research has found that phytoestrogens have both estrogenic and antiestrogenic effects. This means that some phytoestrogens have estrogen-like effects and increase estrogen levels in your body, while others block the hormone’s effects and decrease estrogen levels (3Trusted Source).
Because of their complex actions, phytoestrogens are a controversial topic in nutrition and health.
While some researchers have raised concerns that a high intake of phytoestrogens may cause hormonal imbalance, most evidence has linked them to positive health effects.
In fact, multiple studies have associated phytoestrogen intake after menopause with decreased cholesterol levels, reduced menopausal symptoms, and a lower risk of osteoporosis and certain types of cancer, including breast cancer (4Trusted Source, 5Trusted Source, 6Trusted Source).
However, some researchers suggest that the beneficial effects may be small, and studies that demonstrate long-term results are still needed (6Trusted Source).
SUMMARY
Phytoestrogens may have either estrogenic or antiestrogenic effects. Most available research links phytoestrogens to a variety of health benefits.
1. Flax seeds
Flax seeds are small golden or brown seeds that have recently gained popularity because of their potential health benefits.
They’re incredibly rich in lignans, chemical compounds that function as phytoestrogens. In fact, flax seeds contain up to 800 times more lignans than other plant foods (7Trusted Source, 8Trusted Source).
Studies suggest that the phytoestrogens found in flax seeds may play an important role in decreasing the risk of breast cancer, especially in postmenopausal women (9Trusted Source, 10Trusted Source).
SUMMARY
Flax seeds are a rich source of lignans, chemical compounds that function as phytoestrogens. Eating flax seeds has been associated with a decreased risk of breast cancer.
2. Soybeans and edamame
Soybeans can be processed into many plant-based products, such as tofu and tempeh. They can also be enjoyed whole as edamame.
Edamame beans are green, immature soybeans that are often sold frozen in their inedible pods.
Both soybeans and edamame have been linked to many health benefits and are rich in protein and many vitamins and minerals (11Trusted Source, 12Trusted Source).
They are also rich in phytoestrogens known as isoflavones.
Soy isoflavones can produce estrogen-like activity in the body by mimicking the effects of natural estrogen. They may increase or decrease blood estrogen levels (13Trusted Source).
Research suggests that soy isoflavones may help make hot flashes less frequent and less severe. Additionally, eating a diet rich in soy early in life may lower breast cancer risk, but this effect has not been demonstrated in low soy diets such as the typical Western diet (14Trusted Source).
Soy isoflavone supplements may also benefit bone health after menopause (14Trusted Source).
The effect of soy isoflavones on human estrogen levels is complex. Ultimately, more research is needed before health experts can draw conclusions.
SUMMARY
Soybeans and edamame are rich in isoflavones, a type of phytoestrogen. Soy isoflavones may affect blood estrogen levels in your body, although more research is needed.
3. Dried fruits
Dried fruits are nutrient-rich, delicious, and easy to enjoy as a no-fuss snack.
They are also a potent source of various phytoestrogens (15Trusted Source).
Dates, prunes, and dried apricots are a few of the dried fruits highest in phytoestrogens (16Trusted Source).
What’s more, dried fruits are chock-full of fiber and other important nutrients that make them a healthy snack (17Trusted Source, 18Trusted Source, 19Trusted Source).
SUMMARY
Dried fruits are potent sources of phytoestrogens. Dried apricots, dates, and prunes are some of the dried fruits with the highest phytoestrogen content.
4. Sesame seeds
Sesame seeds are small, fiber-packed seeds that are commonly incorporated into Asian dishes to add a delicate crunch and nutty flavor.
They are also quite rich in phytoestrogens, among other important nutrients.
Interestingly, a small 2006 study found that the consumption of sesame seed powder may affect estrogen levels in postmenopausal women (20Trusted Source).
Study participants consumed 50 grams of sesame seed powder daily for 5 weeks. This not only increased estrogen activity but also improved blood cholesterol levels (20Trusted Source).
SUMMARY
Sesame seeds are a potent source of phytoestrogens. Regularly eating sesame seeds has been shown to increase estrogen activity in postmenopausal women.
5. Garlic
Garlic is a popular ingredient that adds a pungent flavor and aroma to dishes.
It’s not only touted for its culinary attributes but also renowned for its health properties.
Although studies on the effects of garlic in humans are limited, multiple animal studies suggest that it may influence blood estrogen levels (21Trusted Source, 22Trusted Source, 23Trusted Source).
Additionally, in a small 1-month study in 2012, postmenopausal women who took garlic supplements had lower scores on a blood test for inflammation (24Trusted Source).
This anti-inflammatory effect may offer protection against bone loss related to estrogen deficiency, though more research is needed (24Trusted Source).
SUMMARY
In addition to offering a distinctive taste and health benefits, garlic is rich in phytoestrogens and may help reduce bone loss related to estrogen deficiency. However, more research in humans is needed.
6. Peaches
Peaches are a sweet fruit with yellowish or white flesh and fuzzy skin.
They are not only packed with vitamins and minerals but also rich in phytoestrogens known as lignans (25Trusted Source).
Interestingly, a 2009 analysis of studies suggests that lignan-rich diets may decrease the risk of breast cancer by 15% in postmenopausal females. However, more research is needed to understand the potential benefits (26Trusted Source).
SUMMARY
Peaches are sweet, delicious, and packed with a variety of nutrients. They are rich in lignans, a type of phytoestrogen.
7. Berries
Berries have long been touted for their many impressive health benefits.
They’re loaded with vitamins, minerals, fiber, and beneficial plant compounds, including phytoestrogens.
Strawberries, cranberries, and raspberries are all rich sources (25Trusted Source, 27Trusted Source).
SUMMARY
Many berries — including strawberries, cranberries, and raspberries — are rich in phytoestrogens.
8. Wheat bran
Wheat bran is another concentrated source of phytoestrogens, particularly lignans (28Trusted Source).
The results of an animal study suggest that milling wheat bran into very tiny “micronized” particles could cause it to raise blood estrogen levels more effectively when eaten (29Trusted Source).
But ultimately, more research is needed to understand wheat bran’s effect on circulating estrogen levels in humans.
SUMMARY
Wheat bran is rich in phytoestrogens. More studies are needed to investigate its effects on blood estrogen levels in humans.
9. Tofu
Tofu is made from coagulated soy milk pressed into firm white blocks. It’s a popular plant-based protein source, especially in vegan and vegetarian diets.
It’s also a concentrated source of phytoestrogens, largely isoflavones.
Tofu has one of the highest levels of isoflavone content of any soy product. And while soy milk has lower isoflavone levels, it’s still a good source (30).
SUMMARY
Tofu is made from soy milk condensed into solid white blocks. It’s a rich source of isoflavones, a type of phytoestrogen.
10. Cruciferous vegetables
Cruciferous vegetables are a large group of plants with diverse flavors, textures, and nutrients.
Broccoli, cabbage, and collard greens are all cruciferous vegetables rich in phytoestrogens (31).
Broccoli is rich in secoisolariciresinol, a type of lignan phytoestrogen (32Trusted Source).
Brussels sprouts are rich in coumestrol, another type of phytonutrient that has been found to exhibit estrogenic activity (33Trusted Source).
SUMMARY
Cruciferous vegetables are rich in phytoestrogens, including lignans and coumestrol.
11. Tempeh
Tempeh, a fermented soy product, is a popular vegetarian meat replacement.
It’s made from whole soybeans that have been fermented and pressed into a firm, dense cake.
Tempeh is not only an excellent source of protein, prebiotics, vitamins, and minerals but also a very rich source of phytoestrogens, especially isoflavones (34, 35Trusted Source).
SUMMARY
Tempeh is a common vegetarian meat replacement made of fermented soybeans. Like other soy products, tempeh is rich in isoflavones.
Are phytoestrogens dangerous?
The health benefits of consuming phytoestrogen-rich foods likely outweigh the potential risks, so these foods can be consumed safely in moderation.
However, limited research suggests that a high intake of phytoestrogens may be associated with some risks and complications. These findings are mixed and inconclusive, so more research in humans is necessary.
Thus, it is advisable to be skeptical of any strong conclusions about the dangers of phytoestrogens.
People have raised the following potential concerns about phytoestrogens:
- Infertility: While some research states that phytoestrogens may harm reproductive health, the bulk of it has been conducted on animal models, and strong human studies are lacking. One large study of women trying to become pregnant found no strong links between phytoestrogen intake and pregnancy rates (36Trusted Source, 37Trusted Source, 38Trusted Source, 39Trusted Source).
- Breast cancer: Limited research suggests a link between phytoestrogens and an increased risk of breast cancer. However, some studies have observed the opposite — that high phytoestrogen intake may be linked to a decreased risk. One study suggests that phytoestrogen intake may improve breast cancer survival rates (40Trusted Source, 41Trusted Source).
- Effects on testosterone in men: Contrary to popular belief, studies have shown that phytoestrogen intake has no effect on testosterone or other androgens in men (42Trusted Source).
- Decreased thyroid function: Some research associates intake of soy isoflavones with decreased thyroid hormone production. However, most studies in healthy adults have found no significant effects (43Trusted Source, 44Trusted Source, 45Trusted Source).
While weak evidence from animal studies suggests that phytoestrogens may be linked to these complications, many human studies have not found evidence of this.
Additionally, many studies have associated phytoestrogen intake with potential health benefits, including lower cholesterol levels, reduced menopausal symptoms, and a decreased risk of osteoporosis and breast cancer (4Trusted Source, 5Trusted Source, 6Trusted Source, 46Trusted Source).
SUMMARY
Some animal studies have identified potential health risks associated with phytoestrogen intake, but strong human research is lacking. Conversely, many studies have linked phytoestrogen intake to multiple health benefits and protective effects.
The bottom line
Phytoestrogens are found in a wide variety of plant foods.
To boost your phytoestrogen intake, you can try incorporating some of the nutritious and delicious foods listed in this article into your diet.
In most cases, the benefits of including these phytoestrogen-rich foods in your diet outweigh any potential health risks.