Although menopause itself isn’t associated with a higher risk of breast cancer, there are several links to consider. Whether you haven’t yet entered menopause or are in postmenopause, breast cancer is something many women face, and understanding the risk factors is the first step to a healthy, long life.
Breast Cancer & Hormone Replacement Therapy
The biggest study to date assessing the effects of hormone replacement therapy or HRT was the women’s health initiative (Rossouw et al., 2002). The main findings of this study were that HRT increased breast cancer and cardiovascular risk by increasing thrombosis. Further problems were encountered when progestins were added to estrogen replacement therapy.
Since the Women’s Health Initiative study results were released in 2002, which showed the detrimental effects of hormone replacement therapy (HRT) for women, the public’s and experts’ opinion of estrogen has been one of confusion.
Is estrogen a ¨bad” hormone? No, but it can quickly accumulate when the body isn’t functioning properly, and that’s when the problems begin.
“Excess estrogen” is a difficult concept for many of my clients to understand. They tell me, “oh, my doctor checked my estrogen levels and they are fine.” But our bodies can become overloaded with an excess of estrogen and estrogen-like chemicals in tissues, resulting in impaired fertility, PMS, endometriosis, fibrocystic breasts, miscarriages, problems breastfeeding, and increased risk of estrogen-related cancers.
Besides the health issues listed above, other signs and symptoms of excess estrogen include:
The American College of Obstetricians and Gynecologists (ACOG) and the American Society for Reproductive Medicine (ASRM) released an opinion paper on the topic in October 2013 (1). They concluded that the evidence that links exposure to xenoestrogens and adverse reproductive and developmental health outcomes is sufficiently robust and that reducing exposure is a critical area of intervention for obstetricians, gynecologists, and other reproductive health care professionals.
How Can I Prevent Breast Cancer?
Unfortunately, there is no guarantee that anything you do can prevent you from getting breast cancer. However, there are several things you can do to reduce your risk:
Eat a healthy diet (ancestral eating is best)
Maintain a healthy weight
Exercise regularly, 30 minutes of moderate exercise five times a week at minimum. Aim to move every day if possible.
Limit alcohol consumption
Buy organic fruits and vegetables on the “Dirty Dozen” list, and organic meat and dairy products.
Lose weight. Excess estrogen is stored in fat tissue and excess fat can actually produce estrogen on its own.
Avoid canned food, or choose BPA-free cans.
Limit packaged processed foods. Certain food additives are estrogenic (2).
Limit soy, the most potent estrogenic food, and a known fertility inhibitor (3). Think you don’t eat soy? Yes, you do. The average American, who is definitely not a tofu-eating vegetarian, gets up to 9% of their total calories from soybean oil alone (4). What about the Japanese, you say? Some experts believe their large tea intake protects them from the detrimental effects of soy. Plus, soy is only a small part of their diet. What about meat and dairy and their hormones? Both have a small fraction of the estrogenic compounds of soy, especially when you buy organic/grass-fed/pasture-raised meat and dairy. This deserves a blog post of its own. One day, I promise!
Limit vegetable and seed oils. The accumulation of these oils in the tissues promotes the action of estrogen in a variety of ways, and this effect of this tends to be cumulative and self-accelerating. Use olive oil, butter, or coconut oil.
Avoid fish with high mercury levels like swordfish, shark, tilefish, and king mackerel.
Use natural cleaning products or make your own.
Check your personal care products for ingredients like parabens and phthalates, or check them in the EWG Skin Deep database for endocrine safety.
Adequate protein intake. Estrogen is mainly metabolized in the liver, where it’s made more water-soluble for excretion via urine and stool. Estrogen receptors in the liver are under the control of dietary protein. Government recommendations for protein are for surviving, not thriving. I tend to recommend a moderate protein intake of 25% of your daily calories – that usually equals 80-100g for most women, depending on weight and activity level. An easy way to make sure you’re getting enough without food logging? Include a concentrated protein source (at least 15g) at all of your meals and snacks – don’t skimp out at breakfast and lunch!
Get enough fat-soluble vitamins (A, D, E, K). The American diet is notoriously low in these as I’ve written about in previous posts (5, 6). That’s a shame because all 4 have direct anti-estrogen action. Vitamins A, D, and K are potent inhibitors of aromatase (the enzyme converting testosterone into estrogen) – so they will directly lower the synthesis of new estrogen. Vitamin E will help counteract the effects of the already existing estrogen.