What are Phytoestrogens?
Phytoestrogens, also called “dietary estrogens,” are a group of naturally occurring compounds found in plants that function like the primary female sex hormone and have a similar chemical structure to the hormone estrogen. They are not however generated within the endocrine system but consumed by eating phytoestrogenic plants. They can mimic the effects of estrogen in the body and bind to estrogen receptors in cells, although their effects are generally weaker than those of natural estrogen. These phytoestrogens have the ability to cause estrogenic and antiestrogenic effects.
Phytoestrogens and the associated risks are not yet fully understood. Some studies have suggested that high levels of phytoestrogens may be associated with certain health risks, particularly in women with a history of breast cancer.
What Are Complications of Phytoestrogens?
Here are some potential negative health effects of phytoestrogens:
✓ Hormonal imbalances: Phytoestrogens can disrupt the body's hormonal balance, leading to irregular menstrual cycles, decreased fertility, and other hormonal issues.
✓ Thyroid problems: Some phytoestrogens can interfere with the production of thyroid hormones, which can lead to thyroid problems such as hypothyroidism.
✓ Breast cancer: While some studies have suggested that phytoestrogens may reduce the risk of breast cancer, other studies have found that high levels of phytoestrogens may increase the risk of breast cancer, particularly in women with a history of breast cancer.
✓ Male fertility: High levels of phytoestrogens can decrease sperm count and quality, leading to infertility in men.
✓ Allergic reactions: Some people may be allergic to phytoestrogens, leading to allergic reactions such as hives, itching, and swelling.
About Breast Cancer:
Breast cancer is a type of cancer that develops in the cells of the breast. It occurs when the cells in the breast tissue start to grow uncontrollably, forming a lump or mass. Breast cancer can occur in both men and women, but it is more common in women. In the United States, it is estimated that about 2,650 new cases of invasive breast cancer will be diagnosed in men, each year. It is the second most common cancer in women after skin cancer. According to the American Cancer Society, in the United States, it is estimated that a new breast cancer diagnosis is made once every 2 minutes. Additionally, about 1 in 8 women in the United States will develop invasive breast cancer in their lifetime.
Phytoestrogen and Breast cancer:
The link between phytoestrogens and breast cancer prevention has been the subject of numerous studies. Estrogens itself have been implicated in the initiation and promotion stages of breast cancer, and that lifetime exposure to estrogen is a significant risk factor for breast cancer development (Yager and Davidson 2006). Given the carcinogenic properties of endogenous estrogens, the thought is that by reducing the level of phytoestrogen in the body that should be protective against breast cancer development. Soy protein, for example have been known to stimulate the growth of breast cancer cell xenografts implanted in mice. However, the evidence is not consistent, and some studies have found no association between phytoestrogen intake and breast cancer risk. Despite intense investigation, it is unclear whether phytoestrogens are chemoprotective agents or propagator of disease.
About Menopausal Hormone Therapy (MHT)?
Almost 100 years ago, it was felt that estrogen given to post-menopausal women would have multifactorial health benefits. To that end, menopausal hormone therapy (MHT), formerly known as hormone replacement therapy (HRT), was born. MHT was used to treat menopausal symptoms for over 80 years. The first form of MHT was introduced in the 1930s and involved the use of estrogen-only therapy. In the 1960s, progestin was added to the therapy to reduce the risk of uterine cancer in women who had not had a hysterectomy. In the decades that followed, MHT became a common treatment for menopausal symptoms such as hot flashes and vaginal dryness.
The widespread use of MHT declined however, in the early 2000s after the Women's Health Initiative (WHI) study found that the risks of MHT outweighed the benefits for many women. This was a large, randomized, controlled trial that included over 16,000 women aged 50-79 years. The study, which began in 1991 and involved over 16,000 postmenopausal women.
As a result, many healthcare providers became more cautious about prescribing MHT, and many women stopped taking it.
Rationale for beginning MHT in the 1930s included:
➢ Relief from hot flashes and other menopausal symptoms.
➢ Reduced risk of osteoporosis and bone fractures.
➢ Lowered risk of colorectal cancer.
➢ Improved mood and quality of life.
➢ Reduced risk of heart disease (when started within 10 years of menopause in women without a history of heart disease).
What they found instead were:
➢ Increased risk of breast cancer.
➢ Increased risk of stroke.
➢ Increased risk of blood clots.
➢ Increased risk of endometrial cancer (when estrogen is not balanced with progesterone).
➢ Increased risk of gallbladder disease.
➢ Increased risk of dementia (in women over the age of 65).
What Markers Are Used to Diagnose Breast Cancer?
ER positive breast cancer (also known as estrogen receptor positive breast cancer) is a type of breast cancer where the cancer cells have receptors for the hormone estrogen. This means that this particular cancer requires estrogen to grow and divide. The presence of estrogen receptors in breast cancer cells is an important factor in determining treatment options for breast cancer. Hormone therapy drugs, have been used to block the actions of these estrogen receptors and prevent the cancer cells from growing and dividing. It is these same receptors that phytoestrogens can interact with and possibly allowing the cancer the grow. ER positive breast cancer is the most common type of breast cancer, accounting for about 75% of all breast cancer cases. Remember that phytoestrogen is simply a plant-based, oral hormone that functions similarly to animal estrogen, hence phytoestrogen could activate these cancer receptors allowing the cancer to propagate.
What Are Common Phytoestrogen-rich Foods?
❖ Soybeans and soy products: Soy is one of the richest sources of phytoestrogens, particularly a type of phytoestrogen called isoflavones. Soy products include soy milk, tofu, tempeh, and edamame.
❖ Sesame seeds: Sesame seeds and tahini (sesame seed paste) contain phytoestrogens, particularly a type of phytoestrogen called lignans.
❖ Whole grains: Whole grains such as oats, barley, and wheat contain phytoestrogens.
❖ Legumes: Legumes such as lentils, chickpeas, and kidney beans contain phytoestrogens.
❖ Fruits and vegetables: Some fruits and vegetables contain phytoestrogens, particularly a type of phytoestrogen called flavonoids. Examples include apples, and grapes.
❖ Alfalfa sprouts: Alfalfa sprouts contain phytoestrogens, particularly a type of phytoestrogen called coumestans.
❖ Mung bean sprouts: Mung bean sprouts contain phytoestrogens, particularly a type of phytoestrogen called isoflavones.
❖ Tempeh: Tempeh is a fermented soy product that contains phytoestrogens, particularly a type of phytoestrogen called isoflavones.
❖ Red clover: Red clover contains phytoestrogens, particularly a type of phytoestrogen called isoflavones. It is often used in supplements and teas.
❖ Black beans: Black beans contain phytoestrogens, particularly a type of phytoestrogen called lignans.
❖ Hummus: Hummus is made from chickpeas and tahini, both of which contain phytoestrogens.
❖ Beer: Beer contains hops, which contain phytoestrogens.
Bottom Line:
Low doses of phytoestrogens are generally found to stimulate growth of breast cancer cells according to the NIH. Studies have been inconclusive, however and the relationship between phytoestrogens and breast cancer prevention remains uncertain. Until the issue becomes clearer, many doctors recommend that women who take hormonal therapy or who have estrogen-receptor-positive breast cancer avoid phytoestrogens, specifically soy supplements, because they contain high concentrations of phytoestrogens.
Disclaimer: These statements have not been evaluated by the Food and Drug Administration. The contents of this website are based upon the views of Dr. Walker and his experience. This product is not intended as medical advice nor to diagnose, treat, cure or prevent any disease. The information is likewise not to replace the advice of a qualified health care provider. The information provided herein is intended as a sharing of general knowledge only and is not intended to be, nor is it, medical advice or a substitute for medical advice. That being said, please consult your healthcare provider before using supplements or providing supplements to children under the age of 18. If you have or suspect you have, a specific medical condition or disease, please consult your healthcare provider.
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