Hormonal balance is vital to a healthy, cancer-free mind and body, but can be disrupted in many ways. Hormone fluctuations occur naturally, such as in puberty, menopause and perimenopause. Hormone imbalance may also be caused by toxins or an unbalanced lifestyle. Understanding the causes of hormone imbalance empowers us to prevent them, and at the same time, feel better, think better, and better prevent breast cancer.
Age, Menopause and Hormone Imbalance
As reproductive functions play out over time hormone levels take a plunge, triggering the onset of menopause and common hormone imbalances associated with the change of life. Unhealthy habits can muddy the midlife picture by speeding the pace of hormonal decline and premature aging.
Adrenal Hormone Balance and Breast Cancer Risk
Hormone balance is deeply connected to the food we eat, the exercise we get, the toxins we absorb, the weight we carry, and the stress levels we put up with. How these multiple factors impact the overall hormone picture is crucial, particularly at midlife when most hormone production is taken over by the adrenal glands. If stress takes center stage in our lives and becomes chronic, cortisol floods the system and total hormone production lags. This forces the body to steal from its own supplies of available progesterone, to make more cortisol, thus depleting this key balancing hormone with obvious implications for estrogen dominance. Prolonged stress tears up our bones, melts our muscles, robs us of strength and energy, lowers our libido and overwhelms our immunities, putting us at serious risk for chronic illness and autoimmune disease.
The bottom line: when our adrenals get run down, we get run down. Supporting them with enough rest, exercise, and good nutrition is vital to maintaining hormone balance and long-term health.
Belly Fat, Insulin Resistance and Breast Cancer Risk
Insulin is the hormone responsible for maintaining normal blood sugar (glucose) levels in the body. The foods we eat break down into glucose, and insulin’s job is to transport that glucose into the cells that turn it into fuel for energy. Insulin resistance arises when the body is flooded with more sugar than it can handle, and attempts to deliver that glucose to the cells are met with resistance. The syndrome goes hand-in-hand with rising rates of obesity and diabetes. What, you might ask, has this to do with breast cancer? The answer boils down to simple physiology. Excess carbohydrates (especially in refined foods and sugars) that are not needed for energy are stored as fat. Increased body fat increases estrogen levels and increased estrogen levels lead to estrogen dominance, which, as we already know, leads to increased risks for breast cancer.
Insulin resistance is linked with many health problems, Type II diabetes, being the most commonly known, but it also leads to an increased risk of breast cancer. Insulin is a growth factor and as we eat more and more carbohydrates and sweets, it rises, and as it does it increases IGF-1 (insulin-like growth factor) which stimulates cancer cells. A 2004 study out of Vanderbilt University suggests that insulin resistance and increased IGF-1 synergistically increase the risk for breast cancer. The study found that women with abnormal levels of both had a three-fold rise in the incidence of breast cancer. Two years earlier, Dr. Pamela Goodwin of Mt. Sinai Hospital in Toronto found that women with early stage breast cancer, who were also insulin resistant (as defined by a high fasting insulin level) had a higher rate of cancer spreading to other organs (metastases), and death, compared to those whose insulin levels were normal. Type 2 diabetes, which is essentially advanced insulin resistance, leads to breast cancer—the long-running Nurses Health Study of over 100,000 nurses bears this out. Although some studies have questioned these findings, a combined analysis of 21 studies published in 2004, backs up the trend.
Insulin resistance and the belly fat that often accompanies it are at epidemic proportions with long-term consequences besides breast cancer: more hypertension, heart attack stroke, and other cancers. Some predictions have the US life expectancy about to decline for the first time in history.
- Throw out the bad carbs—the buns, the chips, the fries, and the doughnuts for whole grains, vegetables and high fiber fruits
- Eat a high protein breakfast and make sure you have some high quality protein at every meal, but don’t go overboard. You can figure out the right amount of protein to eat every day by multiplying your ideal weight by 0.55
- Eat slowly and stop before you are full
- If you are apple-shaped with most of your weight concentrated in your belly and upper body, you may be insulin resistant and might benefit from supplements like chromium and alpha lipoic acid that improve blood sugar and insulin balance
Obesity Increases Breast Cancer Risk
Cancer-causing toxins accumulate in body fat—the more body fat the more room for stored toxins. We can excrete these by losing weight and eating fiber that binds up toxins and escorts them out of the body. Fat cells also contain the enzyme aromatase, which converts testosterone to estrogens. This is why overweight and obese women have more estrogen. The more estrogen produced in the breast tissue, the more chance of stimulating the growth of breast cancer cells. Fat also produces substances called cytokines that are inflammatory in nature. A whole host of diseases including cancers of the breast and prostate are aided and abetted by silent inflammation.
Leptin, another hormone with multiple actions is produced by fat tissue and has been shown to directly stimulate the growth of cancer cells. Its levels rise in people with increased body fat and indirectly trigger more aromatase activity.
Obesity leads to the reduction of SHBG (sex hormone binding globulin) a protein that binds estrogen levels and keeps them out of circulation. When these levels go down, estrogen levels go up, become active, and thus stimulate the growth of breast cancer cells. Over one hundred studies have investigated the links between obesity and breast cancer. Taken as a whole, their findings strongly indicate that overweight or obese women have a 30 to 50% great risk of postmenopausal breast cancer than leaner women. It is known that women who continuously gain weight throughout life have a higher risk of breast cancer.
Estrogen Dominance, Progesterone Deficiency and Breast Cancer
One of the first steps in protecting the health of our breasts and preventing breast cancer, is to recognize its hormonal risk factors and begin to reduce them. According to the experts, almost all risk factors associated with breast cancer are directly or indirectly linked to an excess of estrogen, or estrogen that is not sufficiently balanced with progesterone, as is the body’s accustomed way. Also known as estrogen dominance, the condition was defined by John R. Lee, M.D., as an imbalance between estrogen and progesterone in which estrogen levels can become too high relative to inadequate progesterone levels. Dr. Lee also emphasized that estrogen can become dominant whether levels are within normal range, high, or even low, if progesterone levels are even lower, relatively speaking. This is a common condition during perimenopause when hormone levels are fluctuating, and at menopause when ovarian hormone production ceases altogether. A growing number of experts believe that correcting this fundamental imbalance is at the heart of preventing and treating breast cancer.
Many women have unknowingly been estrogen dominant for years, resigning themselves to tender breasts, heavy bleeding, painful cramps or PMS mood swings and depression as the monthly consequence of “the curse.” But behind this all-too-familiar symptom picture lurks the greater health impact of hormone imbalance. “For women with undetected estrogen dominance,” writes co-author Virginia Hopkins, in the popular John Lee books on menopause, “Being put on synthetic hormones when they reach menopause is like pouring gasoline on a fire in terms of breast cancer risk.”
Hormone Balance in Menopause and Anovulatory Cycles
Of course, there is little mid-life women can do to reverse normal physiology and aging ovaries, although they can diligently guard against undue stress that can speed up the process. But growing numbers of younger women are showing signs of estrogen dominance as a result of anovulatory cycles (failure to ovulate) linked to an unbalanced lifestyle: chronic stress, crash diets, exposure to synthetic hormones used in birth control pills, and growth hormones in feedlot beef and dairy products, as well as xenoestrogens found in numerous personal hygiene and household products.
In any case, there is much women of all ages can do to rebalance progesterone and overall hormone levels to avoid becoming estrogen dominant. First, we can work with a provider to test our hormone levels for imbalances. If testing reveals estrogen dominance, we can take steps to restore the natural equilibrium by rebalancing with bioidenticals—hormones derived from plant compounds that are made to be identical in structure and function to those our body makes naturally.
Does testosterone increase breast cancer risk?
There have been studies which have suggested that testosterone treatment might be connected to increased breast cancer (Arch Intern Med 2006;166(14):1483-9.). However, on closer inspection the women in these studies were being treated with a synthetic testosterone, methyltestosterone, which is the kind of testosterone found in Estratest. Estratest is an HRT product and is prescribed to postmenopausal women with signs of testosterone deficiency. However, methyltestosterone is not the same as the testosterone produced by our bodies, and while it has some of the same actions as testosterone, it also has some very different actions.
But what about natural testosterone, made by our own bodies? Well, we know that one hormone doesn’t exist in isolation in the body. For example, in a study of breast cancer risk and natural hormone levels in postmenopausal women (J Natl Cancer Inst 2003;95(16):1218-26) risk increased as body mass index increased. However, even though testosterone levels were higher in the obese women, their estrogen levels were higher still. Fatty tissue converts testosterone into estrogens, using an enzyme called aromatase, so obese postmenopausal women tend to have higher estrogen levels than lean women. The study found that it was the higher estrogen levels that accounted for the increased breast cancer risk while the higher testosterone levels had a negligible impact on risk. Another study of natural hormone levels and breast cancer risk in postmenopausal women (Br J Cancer 1997; 76(3):401-5) also found that estradiol levels were more strongly associated with breast cancer risk than testosterone. The same investigators had similar results when they studied premenopausal women, in whom high estradiol (the most potent of the estrogens) and low progesterone levels were more often seen than high testosterone levels in women who developed breast cancer. In addition, women with polycystic ovarian syndrome (PCOS), who tend to have higher than normal testosterone levels, do not have a higher rate of breast cancer than women without PCOS. So the testosterone circulating naturally in our bodies certainly does not seem to be the prime culprit in breast cancer risk.
Hormone Replacement Therapy: Fuel on the Fire of Risk
Hormone Replacement Therapies and Breast Cancer Risk Research
Although a number of studies over the years have pointed to elevated breast cancer risks among users of synthetic hormone replacement, the Women’s Health Initiative (WHI) was the first major clinical trial of its kind to study their impact on bodily health. Results revealed greater risk than benefit among HRT users in terms of heart disease, stroke, and blood clots and a 26% increase in breast cancer risk; the trial was abruptly halted. Naysayers were quick to point out that since only one type of hormone replacement was used in the study—PremPro, a synthetic estrogen and progestin combination that was the number one prescribed HRT for women—the results could not be applied to all forms of HRT use. And that further, the average age of women subjects in the WHI was over 60 so the results could not be representative of most women on HRT. These conclusions were swiftly challenged by the Million Women Study published in the prestigious medical journal, The Lancet, [HRT use and Breast Cancer, Cancer 2003;97:1387–92.] which found that, “use of HRT, by women in the UK over the past decade has resulted in an estimated 20,000 extra breast cancers.” Note to WHI naysayers: The women in this study were between 50 and 64 years of age and a full 15,000 of these cancers were associated with any combination of estrogen-progestin.
Breast cancer is a major concern for women of all ages. As we have discussed, excess estrogens may act as initiators of cancer or as promoters of cancer cell growth. There are concerns too about a surplus of estrogen metabolites such as estrone sulphate, the stored form of estrogen in the body, contributing to the overall estrogen burden and the growth of breast tumors. However, not all hormones are equivalent when it comes to breast cancer risk. Estriol, the weakest estrogen may have a protective effect against breast cancer. If we follow natural physiology, and the growing number of studies attesting to its protective benefits, bioidentical vs. synthetic progestin may also help to reduce the risk of developing breast cancer via its balancing effects on estrogen.
Birth Control Pills and Breast Cancer Risk
The use of birth control pills in teenage girls has the potential to raise their risk of breast cancer. It is well established that when girls between the ages of 13 and 18—and to a lesser but still significant degree, up to the age of 21—use birth control pills, their risk of breast cancer can increase by as much as 600 percent. To put it plainly, the earlier a girl begins to use contraceptives, the greater her risk of breast cancer. This may be because the younger the girl, the more undeveloped her breast tissue, and thus the more vulnerable it is to the synthetic hormones contained in the pill. Furthermore, contraceptives work by inhibiting ovulation, which significantly reduces progesterone production and its essential estrogen balancing effects. This is a situation many young women find themselves in: ripe for symptoms of estrogen dominance and vulnerable to long-term risks for breast cancer. (Excerpted from What Your Doctor May Not Tell You About Breast Cancer: How Hormone Balance Can Help Save Your Life.)
Xenoestrogens and Hormone Imbalance
Not found in nature, man-made toxins are estrogen imposters that mimic the effects of the real hormone but overstimulate cellular activity to an uncontrollable extent. The xenoestrogenes wreak havoc on internal balancing mechanisms of the body, raising the estrogen burden and with it, potential risks for breast cancer.
Xenoestrogens are found in feedlot beef and dairy that is pumped up with synthetic growth hormones, in household cleaners and personal care products that contain toxic chemicals, in plastics, acetones (e.g., fingernail polish and removers) and in pesticides, fungicides, herbicides and industrial pollutants. The xenoestrogens are ten to a hundred times more potent than hormones occurring naturally in the body. Like an unexpected guest that overstays its welcome, once xenoestrogens settle in, they are not easily removed.
Xenoestrogens tend to accumulate in body fat such as breast tissue, and play a dangerous role in the initiation and progression of breast cancer. They mimic the actions of estrogens by barging in and knocking naturally occurring estrogens right off the receptor sites of the cell. They are directly toxic to our DNA and are widely acknowledged to be contributing to the rising rate of breast cancer in western countries. After the 1976 banning of organochlorine pesticide use in Israel, breast cancer rates have come down.
To cut down your exposure to these toxins be sure to:
- Choose hormone-free, meat, dairy and wild caught fish vs. farmed varieties
- Avoid produce that has been sprayed with pesticides
- Use glass rather than plastic containers for food. Be sure not to heat or microwave food in plastic bags or containers
- Avoid herbicides and insecticides
- Avoid bleached paper such as coffee filters, tissue paper, napkins, etc.
- Avoid the use of household chlorine containing bleach or use disposable gloves and open all the windows if working with chemicals
- Switch to organic sanitary napkins and tampons
- Reduce use of solvents like nail polish, nail polish remover, etc.