The Definitive Guide to Reducing Your Breast Cancer Risk


They come in all shapes and sizes and are as unique as the women they belong to. They can be a source of food, of pride, of self-consciousness, and even scandal. They are a fundamental part of being female. They are breasts, and for many women, there’s nothing that strikes a chord of fear more than developing breast cancer.

While much of the focus has been on finding a cure for breast cancer, the truth is that there’s plenty you can do to lower your long-term risk of developing breast cancer in the first place, and the sooner you begin taking these steps, the better. The scientific evidence also suggests that it’s never too late to benefit from changes in lifestyle and diet.

The Big Risk Factors for Breast Cancer

Several risk factors stand out for their influence on the risk of developing breast cancer.

Estrogen dominance

For many women, high levels of estrogen, what doctors call estrogen dominance, are a major risk factor for breast cancer. Estrogen is necessary for health and reproduction, but it proliferates tissue, and high estrogen levels can increase the risk of breast cancer by more than four times, according to a report in the Journal of the National Cancer Institute.[1] Some women make several times more estrogen compared with other women,[2] and estradiol is most likely to drive tumor growth, whereas estriol is least likely to.

Hormone-replacement therapy (HRT)

The duration of estrogen exposure also influences breast cancer risk. HRT adds to a woman’s lifetime exposure to estrogen, and studies have clearly shown that HRT boosts the risk of breast cancer.[3],[4] Taking estrogen-only HRT for more than 10 years increases the risk of both breast and ovarian cancer, and taking a combination of estrogen and progesterone HRT can increase the risk of breast cancer by 75 percent. The risk of breast cancer returns to normal two years after ceasing combination HRT.[5] [6]

Cancer genes

Inherited gene mutations account for 2 percent of all breast cancers. The BRCA1 and BRCA2 genes normally program the activity of gene-repair enzymes, as well as for lactation. Although fewer than 0.5 percent of women in the United States inherit mutations in the BRCA, 2.5 percent of Jewish women of eastern European heritage carry these mutations, raising their risk of breast and ovarian cancer.[7] The mutations lead to unstable BRCA genes.


Environmental estrogens, also known as xenoestrogens, can alter normal hormone levels. They tend to feminize male members of species while increasing the estrogen load of women. Soft plastics, particularly those made with bisphenol-A (BPA) are very estrogenic, and when the plastic is warm or hot, estrogenic molecules can migrate to food. Many pesticides are also estrogenic, as are some household cleaning products and cosmetics. Xenoestrogens contribute to a woman’s risk of breast cancer,[8] [9] [10] [11] [12] and a study at Tulane University in New Orleans found that combining just two estrogenic pesticides made them 1,000 times more potent than either by themselves.[13] [14] The cumulative effect of dozens or even hundreds of estrogenic compounds may be far more dangerous.

Diet and Breast Cancer

Poor eating habits can also increase the risk of breast cancer, whereas a healthy diet can decrease the risk of developing the disease.

Sugary foods and beverages

Sugar increases insulin and insulin growth factor-1, both of which can fuel cancer growth. There’s also compelling evidence showing that high intake of soft drinks by prepubescent girls increases the likelihood of early menstruation, which is related to a greater risk of developing breast cancer decades later (because of prolonged estrogen exposure). The take-home message is to avoid, or severely restrict, sugary foods and soft drinks at any age.[15]

Inflammatory diet

High-glycemic diets—think too many sugary and starchy foods—are by their very nature promoters of inflammation and cancer. Chronic inflammation can increase the risk of cancer, and inflammation drives the growth of tumors.[16] [17] A European study created a “dietary inflammation index” in their analysis of the diets of 6,542 middle-age women. After more than 12 years of follow up, a higher inflammatory index, due partly to alcohol intake, increased the risk of breast cancer by 75 percent.[18]

Mediterranean diet

A five-year controlled study found that women eating a Mediterranean diet with extra amounts of olive oil, which is anti-inflammatory, had a 68 percent lower risk of developing breast cancer. Those eating a similar diet with normal amounts of olive oil but extra nuts had a 41 percent lower risk of developing breast cancer.[19] Cutting out nighttime snacking may also reduce the risk of breast cancer recurrence among women diagnosed with and treated for the disease.[20]


Multiple studies have shown that women who eat plenty of vegetables have a lower risk of developing breast cancer, a likely reason the Mediterranean diet, which is rich in vegetables, is protective.[21] [22] [23] Mushrooms in particular seem to have a strong protective effect in postmenopausal women. Research in South Korea found that postmenopausal women who ate the most mushrooms (equivalent to about 1/4 pound a week) had an 83 percent reduction in the risk of breast cancer, likely because mushrooms act as aromatase inhibitors, i.e., they block estrogen production. Other research found that the common white button mushroom was particularly effective as an aromatase inhibitor.[24] Just be sure to always opt for organic to avoid xenoestrogenic pesticides!

Supplements and Breast Cancer

Numerous supplements may reduce the risk of breast cancer, and they work in different ways.

Choline and inositol

Choline is a B vitamin and inositol is a nutrient often classified with the B vitamins. Together they help the body break down estrogen and xenoestrogens. An ideal choice might be lecithin granules, which stimulates the release of bile, one of the ways the body prepares estrogens for excretion. Other research has found that phosphatidylcholine and phosphatidylserine prevent the attachment of estradiol to cell estrogen receptors.[25] Tip: Try at least 250 mg each of phosphatidylcholine, phosphatidylserine, and inositol, preferably in the form of lecithin granules, plus a B-complex supplement. Lecithin has a chewy, nutty flavor, and the granules can be added to yogurt, salads, cereal, or just eaten directly.


Known technically as diindolylmethane (die-in-dole-lyl-meth-ane), DIM regulates healthy estrogen metabolism. The body makes DIM from indole-3-carbinol (I3C), a substance that naturally occurs in broccoli and other cruciferous vegetables. DIM increases levels of “good” estrogens, such as 2-hydroxy estradial and 2-hydroxy estrone, while lowering levels of undesirable forms, such as 16-hydroxy estrone and 4-hydroxy estrone.[26] [27] It is especially helpful in cases of estrogen dominance and ridding the body of xenoestrogens. Tip: Try 100-200 mg of DIM daily.

Vitamin D

This vitamin has broad cancer-preventive benefits. One recent study found that low vitamin D levels increased the likelihood of being diagnosed with breast cancer and, conversely, that high levels were protective.[28] [29] [30]  A study in the journal Anticancer Research found that breast cancer survivors with the highest vitamin D levels had half the death rate of those with low levels.[31] Tip: Have your levels tested annually and aim to maintain levels of 50 ng/mL or higher.


This concentrated extract of turmeric root has broad anti-inflammatory properties, important because inflammation drives the development and proliferation of cancerous tumors. It inhibits inflammation through almost 100 different mechanisms.[32] In terms of breast cancer, curcumin has been shown to inhibit multiple biochemical pathways involved in many cases of breast cancer, including estrogen receptors and human epidermal growth factor receptor 2 (HER2).[33] The MD Anderson Cancer Center in Houston has used curcumin as an adjunct therapy in cancer treatment. Tip: The clinical studies have used dosages from 2 to 8 grams daily. For prevention, try 300 to 750 mg of a standardized curcumin supplement.

Omega-3 fish oil

With its anti-inflammatory effects, it stands to reason that high intake of the omega-3 fats EPA and DHA would reduce the risk of breast cancer. Two studies showed that the omega-3s reduced the risk of breast cancer by as much as one-third, and the greatest benefits occurred when women took fish oil supplements for at least 10 years.[34] [35] One study of 25 women, most with metastatic breast cancer, found that taking large amounts of DHA daily significantly increased survival time, in some cases up to three years.[36] Tip: To reduce risk, take 1,000-2,000 mg of omega-3s daily.


This mineral serves as part of the antioxidant enzyme glutathione peroxidase, and it may lower the risk of cancer among women with the BRCA1 mutation. A team of Canadian and European researchers found numerous cell abnormalities in 26 women with the BRCA1 mutation. After taking selenium supplements for three months, the number of cell abnormalities dropped to normal levels.[37] A follow-up study found half the risk of breast cancer in women taking selenium supplements after just two years.[38] [39] Tip:  Take 200 mcg of selenium daily.

Coenzyme Q10

Many researchers believe that abnormalities in mitochondria (the energy factory of cells) play a major role in cancer. Coenzyme Q10 (CoQ10) plays a key role in normal mitochondrial function. Two different Danish physicians have focused on using high-dose CoQ10 as an adjunct in treating breast and other cancers. Those high doses—300 to 400 mg daily— led to the regression of metastases in women treated for breast cancer and increased survival. [40] [41] [42] Tip: For prevention, consider 100 to 200 mg of either CoQ10 or its ubiquinol form.


Night-shift work increases the risk of breast cancer, possibly by disrupting the body’s production of the hormone melatonin. It’s not surprising then that research increasingly shows that melatonin might protect against breast cancer. Melatonin reduces the production of estrogens in breasts, as well as the enzyme aromatase, which is involved in estrogen synthesis. One recent study reported that melatonin slowed the growth of breast cells and prevented the invasion of cancer cells into surrounding tissues, while at the same time helping to maintain stable genes in normal cells.[43] [44]

While you can never predict what twists and turns your health may take, there’s plenty you can do to reduce your risk of breast cancer, even if you are genetically at high risk. Be proactive by making healthier choices, such as avoiding or limiting your exposure to HRT, xenoestrogens, and foods that promote inflammation and focus on healthy eating habits. Add some of the dietary supplements that have been shown to lower the risk of breast cancer for a well-rounded preventative approach.



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