This article explores the health benefits and risks of phytoestrogens. It also lists foods that are high in phytoestrogens.
What are phytoestrogens?
Soy foods, including soybeans, tofu, miso, and tempeh, contain phytoestrogens.
Phytoestrogens or dietary estrogens are naturally occurring compounds found in plants. Many of these plants are already part of a person's diet.
Estrogen is a hormone released in a woman's body that regulates her menstrual cycle. The body's endocrine system is responsible for producing this hormone.
In adolescence, estrogen plays a role in the development of a woman's breasts, armpit hair, and pubic hair. Up until the menopause, estrogen controls a woman's periods.
Foods that contain phytoestrogens include:
- some grains
When a person eats plant-based foods that contain phytoestrogens, they may have a similar effect to estrogen produced by the body. For this reason, phytoestrogens are known as dietary estrogens.
There are phytoestrogen supplements, but getting these from natural food sources is a better choice.
How do phytoestrogens work?
Phytoestrogens imitate estrogen because their chemical structure is very similar to that of estrogen from the body.
When phytoestrogens enter the body, the body's estrogen receptors treat them as if they were estrogen. Phytoestrogens are endocrine disruptors because they are chemicals that disrupt normal hormonal function.
However, phytoestrogens do not bind to estrogen receptors as firmly as estrogen produced by the body, so their effects may be weaker.
Phytoestrogens may help to naturally manage hormone imbalances, making them beneficial for women near menopause.
Phytoestrogens may be beneficial for women looking to rebalance their hormones as they approach menopause.
During perimenopause, which is the period before a woman reaches menopause and stops menstruating, the hormone levels in her body will fluctuate and cause a variety of symptoms.
Perimenopause usually starts in a woman's 40s and lasts until menopause. Symptoms of perimenopause include:
These symptoms can be unpleasant, and some women use hormone replacement therapy to help control them.
Phytoestrogens offer a natural alternative to the synthetic estrogen used in hormone replacement therapies.
Phytoestrogens also have a range of other potential benefits, including:
1. Relieving hot flashes
Phytoestrogens may help to relieve uncomfortable hot flashes. A 2014 study found that phytoestrogens reduced the frequency of hot flashes in menopausal women without any serious side effects.
2. Preventing osteoporosis
Estrogen deficiency after menopause can affect bone health and cause conditions such as osteoporosis.
Hormone replacement therapy (HRT) can help remedy this and promote bone strength, but it may have uncomfortable side effects. Phytoestrogens may be a natural alternative.
A 2011 study found that phytoestrogens did help to combat postmenopausal osteoporosis.
However, researchers noted that there were some potential side effects. As the United States Food and Drug Administration (FDA) do not currently regulate phytoestrogens, the study did not recommend taking them for osteoporosis.
3. Combatting menstrual issues
When a woman's estrogen levels drop, it can affect mood and energy levels.
Some women try to eat foods rich in phytoestrogens during this time to balance their hormone levels and relieve symptoms.
More research is needed to support using phytoestrogens in this way.
4. Treating acne
When women get acne, the cause may be a rise in male hormones (androgens) in their bodies. Phytoestrogens may help to combat acne by rebalancing hormone levels.
A 2017 study partially supports this theory, but more research is needed to prove whether phytoestrogens are an effective acne treatment.
5. Fighting breast cancer
A 2009 study found that consuming soy foods decreased the risk of death and recurrence in women with breast cancer. Soy foods are rich in phytoestrogens.
Another study in 2015 found that phytoestrogens inhibited the growth of breast cancer cells. However, a further 2015 study suggested the role of phytoestrogens in breast cancer survival is complex and depends on what stage of menopause a woman is in.
More research is needed to fully understand whether phytoestrogens could play a useful role in cancer prevention and treatment. Phytoestrogens are not appropriate for all types of cancer. Anyone considering taking phytoestrogens should discuss it with their doctor first.
6. Promoting heart health
Phytoestrogens may support heart health. A 2016 study found that phytoestrogens helped to treat a condition that affects the arteries and improve heart health in postmenopausal women.
Risks and side effects
Studies show phytoestrogens may provide similar benefits to the synthetic estrogen used in hormone replacement therapy.
However, this does not mean that they are safer than synthetic estrogen. They act in a similar way and may carry the same risks. These may include increased risk of:
- problems with reproduction
This 2010 study found that high levels of soy in a woman's diet could affect how her ovaries' function.
It is believed to be healthful to eat a plant-based diet, and many plant foods contain phytoestrogens.
More research is needed to fully understand how phytoestrogens work, as it is not clear whether consuming them in high levels carries any health risks. Unless a person is taking phytoestrogen supplements, it is unlikely they could consume a harmful level, however.
A person should always speak to a doctor before starting to take any new supplements, including phytoestrogen.
The following foods groups are rich in phytoestrogens:
Nuts and seeds
Sunflower seeds, sesame seeds, and flaxseeds contain high levels of phytoestrogens.
The following nuts and seeds are high in phytoestrogens:
- sunflower seeds
- sesame seeds
Certain fruits are rich in phytoestrogens, including:
Certain vegetables are a good source of phytoestrogens, including:
- alfalfa sprouts
- mung beans
Soy and soy products are rich in phytoestrogens. These include:
- miso soup
- miso paste
The following herbs contain phytoestrogens:
- red clover
- licorice root
The following beverages and oils are sources of phytoestrogen:
- red wine
- olive oil
- jasmine oil
Some grains contain phytoestrogens. These include:
- wheat germ
Phytoestrogens are plant-based compounds that mimic estrogen in the body. They have been found to be beneficial in combatting symptoms and conditions caused by estrogen deficiency. This may be of particular benefit to premenopausal and post-menopausal women.
Phytoestrogens may also play a role in fighting cancer. However, much more research is needed to understand this.
The risks of consuming high levels of phytoestrogens are not yet fully understood. Their side effects are likely to be similar to those of synthetic estrogen.