What are phytoestrogens?
Phytoestrogens are naturally produced chemicals that mimic hormones in the body, also referred to as mild estrogens. Currently, more than 300 plants produce phytoestrogens, in 16 different plant families. While phytoestrogens are much weaker than natural estrogen found in humans and in animals, they may have the potential to produce estrogenic effects.[6][8]
For quite some time, phytoestrogens have found their way into mainstream natural treatment of many medical conditions, including menopausal symptoms in women. Phytoestrogens classified as, er lignans act as estrogens on both bone and cardiovascular tissue as well. For thousands of years, many Eastern areas of the world, including Asian countries have used phytoestrogens as therapeutic agents to both prevent and treat diseases like, osteoporosis and breast cancer. Phytoestrogens are broken down into classifications of isoflavonoids, flavonoids, anthraquinones, triterpenes, lignans, and saponins.[7]
Phytoestrogens—Nature’s Defense
Scientists theorize that certain plants make phytoestrogen to defend against predators, more specifically plant eating animals, or herbivores. Rather than grow thorns or emit toxic odors, these plants produce chemicals that disrupt fertility in animals that feed on them. In this way, plants can prosper. Due to genetic differences in animals however, not every species of herbivore will become infertile as a result of eating phytoestrogens. Some may be resistant, much like bacteria are to certain antibiotics.[8]
What foods contain phytoestrogens?
The majority of phytoestrogens are found in diet. Plant compounds containing the chemicals can be found in a host of foods, herbs, grains and beans.
These include:
Lignans are the byproduct of whole grains, fiber, flax, fruits and vegetables. Isoflavones are derived from legumes and soybeans.[8]
How can phytoestrogens help?
Soy-based phytoestrogens are implicated in the possible treatment of a number of health concerns including, menopausal symptoms, high cholesterol, and coronary heart disease, the condition that causes plaque build-up in coronary arteries.[5][7] Plants rich in phytoestrogens may also help restore tissue damaged from stress or oxidants, as well as relieve vasomotor perimenopausal symptoms such as hot flashes and night sweats. Benefits to the skeletal system are documented, as well as research that indicates that 45mg of phytoestrogens daily helps stabilize hormone levels.[4]Phytoestrogens may even have neuroprotective effects in response to injury.[6][7]
In one study, Asian populations had a lower rate of estrogen fed cancers including breast and endometrial cancer, as well as lower rates of osteoporosis. Other research suggests that phytoestrogens may actually help prevent certain cancers including, breast, colon, prostate, liver, and leukemia. Tumor growth may be inhibited as well.[1]
The History of Phytoestrogens
Historically, scientists have observed measurable differences in the health of populations that regularly consume soy. Regions, such as eastern Asia report lower rates of breast and prostate cancer, cardiovascular disease, and bone fractures. Menopausal women in these areas report fewer vasomotor symptoms such as, hot flashes, and both sexes are found to have a lower incidence of age-related brain disease. Studies also find that disease rates in these populations change over time, as people emigrate from eastern regions to the West, and adopt a Western diet.[2]
How are phytoestrogens detected?
Scientists can detect phytoestrogens in both urine and blood. Adults who eat a vegetarian diet, individuals ingesting dietary supplements containing phytoestrogens, and babies who drink soy-based formulas have the highest concentration of phytoestrogens in the body.[8]
Health and Safety Concerns with Phytoestrogens
Studies have found that a diet rich in isoflavone in the form of soy may actually compromise female reproduction. Soy-rich foods may suppress circulating estrogen and progesterone and can reduce the activity of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).[6] Phytoestrogens may also suppress sexual function and increase anxiety.[7]Some studies report altered ovarian development in animal test subjects, ovulation problems, and fewer pups in a litter, besides infertility.[3]
Individuals with soy allergies, breast cancer, kidney disease, hypothyroidism, or uterine cancer should not take soy supplements, or consume large amounts of soy-based foods without first consulting a physician.[1]
Naturally produced phytoestrogens may provide the additional support some individuals need for optimal health and wellness. Finding the right nutritional balance is essential.
1. A, 2013 (1997) Soy. Available at: http://umm.edu/health/medical/altmed/supplement/soy (Accessed: 9 February 2017).
2. Barrett, J.R. (2006) ‘The science of soy: What do we really know?’, 114(6).
3. CDC (no date) Biomonitoring summary. Available at: https://www.cdc.gov/biomonitoring/Phytoestrogens_BiomonitoringSummary.html (Accessed: 9 February 2017).
4. Foods that contain natural estrogen (no date) Available at: http://enhs.umn.edu/current/5200/estrogen/estrofood.html(Accessed: 9 February 2017).
5. Gibbons, G.H. (2015) Related director’s message. Available at: https://www.nhlbi.nih.gov/health/health-topics/topics/cad (Accessed: 9 February 2017).
6. Patisaul, H.B. and Jefferson, W. (2010) ‘The pros and cons of phytoestrogens’, 31(4).
7. Sunita, P. and Pattanayak, S.P. (2011) ‘Phytoestrogens in postmenopausal indications: A theoretical perspective’, 5(9).
8. Tulane (2014) Phytoestrogens. Available at: http://e.hormone.tulane.edu/learning/phytoestrogens.html (Accessed: 9 February 2017).