What is Estrogen (Estradiol)?
Estrogen is a hormone composed of a group of compounds, including estrone, estradiol, and estriol. Although it is the main sex hormone in women, it is also found in lower levels in men in the form of estradiol. The normal reference range for men is 50 to 200 pmol/L ( picomole per liter), which may also be measured in picograms per milliliter (14 to 54 pg/ml). (Raven 2006).
The relationship of estradiol with testosterone is a critical one when it comes to prostate health. Specifically, it is essential for men to maintain the proper balance or ratio of testosterone to estradiol to help prevent prostate enlargement and prostate cancer.
Estradiol also appears to protect the heart. A recent study published in the Journal of the American Medical Association found that men who had chronic heart failure and very low or very high levels of estradiol were at great risk of dying. (Jankowska 2009) Men with low estradiol levels had as much as a 50 percent lower survival compared with men who had mid-range levels of the female hormone. High estradiol levels were also associated with poorer survival.
Causes of Estrogen Dominance in Men
Estrogen dominance in men is the result of an imbalance between testosterone and estradiol. It occurs when testosterone levels are not sufficient to stop or balance the effects of estradiol. Men who carry extra weight/fat have higher estrogen levels because fat cells convert testosterone and androstenedione (a precursor of testosterone) into estrogen. When men develop estrogen dominance, they can actually experience some of the same symptoms that affect women, including weight gain and breast cell growth. Men who develop enlarged breasts have extra estradiol.
Other causes of estrogen dominance include:
- Insulin resistance, which is common among overweight individuals and/or people who have diabetes
- Stress, which raises cortisol levels, a hormone that makes the body less able to utilize its other hormones. Cortisol also increases oxidation and thus damages DNA
- Personal care products (e.g., shampoo, lotions), laundry detergents, water, fertilizers, plastics, and so on.
- Phytoestrogens, which are estrogen-like compounds found in plants. Soybeans and soybean products (e.g., tofu, soy beverages) are sources of phytoestrogens
- BPA (Bisphenol A) exposure
- Pesticides and herbicides in fruits and vegetables
- Hormones in meat and dairy products
- Diets high in animal fat
- Excessive consumption of omega-6 fatty acids (e.g., canola, corn, safflower, and soy oils)
Estrogen dominance (an imbalance of testosterone and estrogen) also stimulates benign prostate hypertrophy (BPH) and prostate cancer. In fact, estrogen dominance is believed to be a major contributing cause of prostate cancer.
Factors That Can Reduce and Inhibit Estrogen
A variety of nutritional and herbal supplements, lifestyle habits, dietary choices, and medications can inhibit the production or reduce the levels of estrogen in the body. Because a hormone balance among testosterone, estrogen, and progesterone is important for prostate health, men should have their hormone levels checked by a physician before taking medications or supplements to alter those levels.
Drugs and Medications
Aromatase inhibitors: Drugs in this category either reduce estrogen levels or reduce the activity of estrogen. Aromatase inhibitors work by inhibiting the action of the enzyme aromatase, which transforms androgens into estrogens in a process called aromatization. Aromatase inhibitors include aminoglutethimide (Cytadren), anastrozole (Arimidex), clomiphene citrate (Clomid), exemestane (Aromasin), human chorionic gonadrotropin (HCG), letrozole (Femara), raloxifene (Evista), tamoxifen citrate (Nolvadex), testolactone (Texlac), and toremifene citrate (Fareston).
Barbiturates: Barbiturates, rifampin, and other medications that stimulate the liver to break down drugs may reduce the amount of estrogen in the bloodstream.
Progesterone: Progesterone is a sex hormone, produced in both women and men that ideally should be in balance with estrogen and testosterone. Progesterone can be taken with or without a prescription to help balance hormone levels, but it should be used only under the guidance of a knowledgeable healthcare practitioner who can identify your hormone levels before determining the best dose of bio-identical progesterone.
Supplements
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Black cohosh: Black cohosh (Actaea racemosa, formerly Cimicifuga racemosa) is believed to contain phytoestrogens, which can help reduce estrogen in the body. Black cohosh is most often used to treat menopausal symptoms. (University of Maryland) Read more on black cohosh |
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Chasteberry: Chastebetty (Vitex agnus-castus), is the fruit of the chaste tree. Studies show chasteberry can reduce estrogen levels while increasing progesterone and prolactin, possibly by inhibiting the release of follicle-stimulating hormone and by stimulating the luteinizing hormone. (Mills 2000; Brown 1994; Merz 1996) Read more on chasteberry |
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Dong quai: Dong quai (Angelica sinensis) is a traditional Chinese medicine herb that is sometimes called the “female ginseng.” Research regarding the impact of dong quai on estrogen suggests it may have estrogen-like effects or it may block estrogen activity in the body. (University of Maryland) Read more on dong quai |
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Genistein: Genistein is a constituent of soybeans that has phytoestrogen properties; that is, it binds with estrogen receptors, preventing natural estrogen activity, and thus may help reduce estrogen in the body. Read more on genistein |
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Indole-3-carbinol/DIM: Indole-3-carbinol (I3C) is a phytonutrient present in high amounts in cruciferous vegetables, and it is also the precursor to another indole and phytonutrient, diindolylmethane (DIM). Although both I3C and DIM promote metabolism of estrogen, DIM is the more active and effective of the two. (Zeligs) Read more on Indole-3-carbinol/DIM |
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Licorice: Licorice (Glycyrrhiza glabra) is reported to reduce estrogen and increase progesterone levels in the body. A constituent of licorice root, glabridin, is similar to estradiol-17beta, a type of estrogen. Research shows that licorice and its constituents may reduce testosterone levels in men. (Armanini 1999) Read more on licorice |
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Omega-3 fatty acids: Omega-3 can also be taken as a supplement (see “Dietary Habits”). Read more on omega 3 and prostate health |
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Pollen extract: Bee pollen contains phytoestrogens that can block estrogen receptors and reduce the effect of estrogen. A recent study demonstrated the anti-estrogen properties of bee pollen in mice. (Saric 2009) Read more on pollen extract |
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Red Clover: Red clover is a plant that contains isoflavones, substances that have an estrogen-like effect and may reduce levels of natural estrogen in the body. Red clover is most often used to treat menopausal symptoms. (University of Maryland) Read more on red clover |
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Sulfur-rich Foods: Foods that are high in sulfur, such as garlic and onions, assist the liver in eliminating toxins and estrogen from the body and thus can reduce levels of the hormone. |
Dietary Habits
Alcohol: Alcohol use can impair liver function, which makes it difficult for the liver to metabolize estrogen properly, resulting in higher levels of estrogen in the body. Alcohol consumption should be limited to no more than one drink daily or eliminated.
Fiber: A high-fiber diet can help decrease blood levels of estrogen. Estrogens are eliminated from the body when they bind to bile acids, which are produced by the liver. Bile acids are moved into the intestinal tract during digestion, and fiber then attaches to and promotes excretion of the bile acids. Because excess estrogen is eliminated from the body via the bowels, stool that remains in the colon allows estrogen to be reabsorbed. Eating high-fiber foods, such as fresh fruits and vegetables, oatmeal, nuts, seeds, and beans can promote elimination. More on fiber and prostate health
Hormones in food: Foods that contain hormones, including meat, poultry, and dairy products, should be avoided. Milk, for example, can contain a high amount of estrogens because cows are frequently milked during pregnancy when estrogen levels are at their highest point. Dairy products made from milk similarly contain hormones. Meat and poultry, unless they are hormone-free, are also sources of hormones. More on foods to avoid for prostate health
Omega-3 fatty acids: Omega-3 fatty acids are a good source of lingans, compounds that interfere with the enzymes that are involved with estrogen production. Specifically, omega-3 fatty acids have a weak estrogen-like effect, and when these substances take the place of the body’s natural much more potent estrogen, then the weaker substances acts as an anti-estrogen. Omega-3 fatty acids are found in certain fatty fish (e.g., tuna, salmon, herring), flax seeds, walnuts, soybeans, kidney beans, and navy beans. More on omega 3
Organic foods: Organic foods should be chosen whenever possible to avoid exposure to substances that can raise estrogen levels. Pesticides and insecticides used on fruits, vegetables, grains, and other crops are a source of estrogens that provoke or imitate estrogen in the body (xenoestrogens).
Lifestyle Habits
Environmental estrogens: Chemicals in the environment can contribute to and raise estrogen levels, so it is best to avoid them as much as possible (see list of environmental estrogen promoters below).
Exercise: Daily physical exercise reduces estrogen production and stress, as well as promotes a healthy circulatory system and stimulates the liver, which helps eliminate estrogen from the body. More on exercise and prostate health
Healthy weight: An enzyme in body fat called aromatase converts testosterone to estrogen. Therefore a high level of body fat can result in a greater amount of testosterone being converted into unwanted estrogen.
Stress: Regular participation in stress-reducing activities can help reduce levels of the stress hormone, cortisol. High amounts of stress raise cortisol levels, which interferes with the body’s ability to maintain hormone balance. Stress reduction can take many forms, including exercise, yoga, deep breathing, meditation, tai chi, visualization, laughter therapy, and others.
Environmental Sources of Estrogen
Estrogen-like substances in the environment that can disrupt the body’s hormonal balance are called xenoestrogens, or estrogen promoters. These substances can accumulate in the body and are difficult to eliminate through the liver.
Here is a general guide to products to avoid and to check for on labels when shopping which have been linked to having an estrogenic effect:
- Pesticides and herbicides used on fruits, vegetables, and other crops
- Insecticides (some ingredients to look for are dieldrin, DDT, endosulfan, heptachlor, lindane, methoxychlor)
- Bisphenol-A (BPA), a plastic derivative used in food cans and plastic-lined packaging and containers that can leach into food and beverages; also used in water bottles
- Artificial scents, such as those in air fresheners
- Vehicle exhaust
- Paints, lacquers, solvents
- Parabens and stearal konium chloride found in creams and cosmetics
- Phenoxyethanol, found in lotions, soaps, shampoos
- Phthalates, in powders, perfumes, and other personal care products
- Nonorganic, commercially raised meat and meat products
- Plastic wraps and plastic containers (especially when used to heat food)
- Detergents
- Dryer sheets, fabric softeners
- 4-methylbenzylidene camphor (sunscreen lotions)
References
Armanini D et al. Reduction of serum testosterone in men by licorice. N Engl J Med 1999; 341(15): 1158
Brown D. Vitex agnus castus clinical monograph. Quarterly Review of Natural Medicine. 1994; 2:111–21.
Merz PG et al. The effects of a special Agnus castus extract (BP1095E1) on prolactin secretion in healthy male subjects. Exp Clin Endocrinol Diabetes. 1996;104:447–53.
Mills S, Bone K. Principles and practice of phytotherapy: modern herbal medicine. Edinburgh: Churchill Livingstone, 2000.
Raven G et al. In men, peripheral estradiol levels directly reflect the amount of estrogens at the hypothalamo-pituitary level to inhibit gonadotropic secretion. J Clin Endocrin Metabol 2006; 91(9): 3324-28
Saric A et al. Antioxidant effects of flavonoid from Croatian Cystus incanus L. rich bee pollen. Food Chem Toxicol 2009 Mar; 47(3): 547-54
University of Maryland Medical Center:
http://www.umm.edu/altmed/articles/dong-quai-000238.htm
