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October 23, 2024
Phytoestrogens, or plant-based estrogens, are an almost mysterious part of nutrition. Natural compounds found in many plants and foods, such as soy, dairy and flaxseeds, they possess a similar chemical structure to estrogen.
An essential hormone for health in all sexes, estrogen is present in higher amounts among females than males. Benefits include supporting fertility, strengthening bones and regulating the metabolism.
Phytoestrogens are a popular food choice for many women because they may affect the body in much the way that estrogen does, including assisting those with low estrogen — which can include women going through perimenopause and menopause. For that effect to occur, it’s important to know that high amounts of phytoestrogens are necessary.
Let’s discuss phytoestrogen foods, their benefits and risks, and how to use them in your weekly diet.
What are phytoestrogens?
The word phytoestrogens comes from the Greek word “phyto,” or plant, and “estrogen,” the hormone that causes fertility in all female mammals. Phytoestrogens have also been termed dietary estrogens because they’re not created by the human endocrine system. They can only be ingested or consumed.
In their natural state, phytoestrogens exist within plants as a natural defense against herbivores. Plants secrete these hormones to modulate the fertility of animals that may eat them to reduce further attacks.
The most well-studied of the types of phytoestrogen compounds are isoflavones, also commonly referred to as soy isoflavones because most are found in soy and red clover. Soy is known as the most phytoestrogen-rich plant found in a typical Western diet, but most foods barely contain any phytoestrogen content.
How do phytoestrogens work? They both mimic estrogen and act as an estrogen antagonist (meaning they behave in the opposite way of biological estrogen). They affect the body by attaching to estrogen receptors. Because they aren’t specifically necessary for a human diet, phytoestrogens can’t be considered actual nutrients.
The body’s ability to absorb phytoestrogens from foods is limited, so you need to eat a fair amount to experience health-changing effects. One has to consume at least 50 milligrams a day of isoflavones, for example to see a health effect. That’s many more times than the average Western intake and higher than even an Asian average intake.
Top foods
Phytoestrogens exist in many foods, supplements and essential oils. Some of the highest concentrations can be found in following:
- Soy products: tofu, tempeh, miso
- Seeds: flaxseeds, sesame seeds
- Grains: oats, barley, wheat germ, barley, rye
- Dairy: yogurt, cow’s milk, butter
- Legumes: lentils
- Fruits: apples, pomegranates, berries, grapes
- Vegetables: yams, carrots, celery, potatoes, broccoli, cabbage, collard greens
- Herbs: turmeric, chaste berry, hops,
- Plants: garlic, alfalfa, licorice root
- Essential oils: jasmine oil, clary sage oil
- Beverages: coffee, tea, red wine, bourbon, beer
Health benefits
1. May reduce cancer risk
Cancers related to hormone production can be treated, in part, by adjusting the hormone levels in the body by eating the right foods. Phytoestrogens have been studied extensively in connection with breast and ovarian cancers, with many positive results.
A 2009 study of over 5,000 women diagnosed with breast cancer showed a significant decrease in death and recurrence of the disease of the patients on a diet rich in non-soy phytoestrogens, a finding that echoed a 1997 questionnaire study of breast cancer patients.
A 2020 review indicated that phytoestrogens in soy help reduce the risk of several types of cancer, including breast, prostate and ovarian cancers.
Regarding breast cancer in particular, it seems that apigenin might be the best of the phytoestrogens in reducing breast cancer cell growth.
The jury is still out on exactly how and when phytoestrogens are most efficient in fighting hormonal cancers. Depending on the state of menopause, individual body makeup and the times at which high levels of soy are part of one’s diet, phytoestrogens may or may not be beneficial for cancer prevention and/or treatment.
2. May reduce menopause symptoms
Menopause is the period of time in which a women transitions from her last menstrual cycle, ending fertility. While childbearing potential ends, menopause doesn’t have to mark the end of vitality and healthy sexuality. The biggest drawback to menopause is the unpredictable change in sex hormone levels, namely estrogen, progesterone and testosterone.
During perimenopause, some physicians suggest beginning to increase phytoestrogen intake to counteract the effects of the hormonal imbalances women begin to experience and balance hormones naturally. Some research indicates a drastic drop in hot flashes, sleep troubles, sexual dysfunction and depression symptoms for women in perimenopause eating a phytoestrogen-rich diet (40 milligrams of soy isoflavones twice a day for 12 weeks).
Another benefit phytoestrogens may offer to menopausal or postmenopausal women is a reduction in bone loss, leading to higher bone density and fewer breaks, when administered in dose-specific measures alongside vitamin D.
3. Support heart health
Phytoestrogens may also improve heart health, specifically in postmenopausal women. They can be used to deal with arteriosclerosis, a disease characterized by fatty buildup within the arteries, and seem to do so by regulating many different hormone and chemical levels within the body.
4. May reduce osteoporosis risk
Lower levels of estrogen can lead to more brittle bones and osteoporosis. While males may also develop osteoporosis, females are more likely to have it earlier in life because of menopause.
A review of 23 studies showed that phytoestrogens may improve bone mineral density among menopausal women, but more studies need to be conducted.
Risk and side effects
While research supports these benefits described above, there are also potential negative effects of phytoestrogens as well, of which you should be aware.
Thyroid function
Some research showed that isoflavones can lead to an underactive thyroid in some people who deal with an iodine deficiency. (Iodine is a nutrient that people need for a properly functioning thyroid.)
Fertility
Exposure to genistein and coumestrol, two specific phytoestrogen compounds, early in life may contribute to fertility issues later in development.
At the same time, research also has indicated that phytoestrogens have no effect on semen quality or infertility risk. More research is needed to see how phytoestrogens affect fertility.
Low testosterone
A 2021 review of 38 clinical trials researched whether or not soy or isoflavones has any impact on testosterone or estrogen levels in males. The review found no evidence.
A 2018 study examined protein supplements and how they impacted testosterone levels in males. While whey protein intake helped increase testosterone levels, but soy protein didn’t impact levels in either level; same story with estrogen.
Conclusions
Phytoestrogens are dietary estrogens because they’re not created by the human endocrine system. They can only be ingested or consumed.
More research is needed about the potential benefits and risks of consuming phytoestrogen foods. At present, they appear to help reduce cancer risk, lower menopause symptoms, support heart health. and reduce osteoporosis risk.
The body’s ability to absorb phytoestrogens from foods is limited, so a significant amount is needed to be consumed in order to experience health-changing effects.
Phytoestrogen foods include soy products, certain seeds and grains, lentils, some fruits and more.
