Nutritional prevention of breast cancer

Breast cancer is the most commonly diagnosed cancer in females. There are several preventative nutritional measures you can implement to reduce your risk of breast cancer, such as enjoying the right foods and avoiding others.  For example, green tea, fruits, and veggies are protective, while alcohol can raise your risk.

Metabolic syndrome has been linked with a 2.6 times higher risk of breast cancer in postmenopausal women.  The syndrome is clinically defined as having three of the following factors: Abdominal obesity, hypertension, high blood sugar, high triglycerides, or low HDL cholesterol.  Excess weight gain causes inflammation, which drives breast cancer growth. Therefore, a healthy diet with good fats and polyphenols, and exercise are essential to lower inflammation caused by fat gain.

Green tea

Green tea is rich in catechins, a group of polyphenols with anticancer effects, and (−)-Epigallocatechin gallate (EGCG) is the most abundant and powerful green tea polyphenol.  Note that black tea contains lower levels of EGCG.

Recent evidence shows that green tea consumption is linked to a statistically significant reduction of breast cancer among women with high green tea intake.  This effect is especially pronounced among females drinking more than 10 cups a day.  Evidence also suggests that high intake of green tea may be linked with a relative risk reduction in stage I and II breast cancer recurrence.

A case-control study showed that higher dietary intake of mushrooms decreased breast cancer risk in pre- and postmenopausal Chinese women, and an additional decreased risk of breast cancer from combining mushrooms and green tea was observed.

Green tea prevents breast cancer by many ways, such as suppression of DNA damage, and inhibiting angiogenesis (the formation of blood vessels that feed tumors).  Green tea also inhibits breast cancer cell proliferation, and the invasion and migration of breast cancer cells, and this results in decreased lung and liver metastasis.

To optimize the effect of green tea you must avoid drinking it at the same time as milk products. Vitamin C enhances absorption of EGCG, so have tea with some fruits.

Mediterranean diet

The Mediterranean diet, with an emphasis on veggies, fruits, whole grains, fish, and olive oil, and with very low amounts of meat, has the potential to prevent breast cancer.

Although more research is needed, a recent study showed that a Mediterranean diet supplemented with extra-virgin olive oil is beneficial in the primary prevention of breast cancer.  Participants were randomly allocated to a Mediterranean diet supplemented with 1 extra litre of extra-virgin olive oil per week, a Mediterranean diet supplemented with mixed nuts, or a control diet (advice to reduce dietary fat).

Women who ate the Mediterranean diet with extra virgin olive oil had a 68% relatively lower risk of developing breast cancer compared to women in the low fat control group.

Olive oil contains polyphenols which might help explain its anticancer effects.

What to avoid

Epidemiological evidence suggests that there is an increased risk of breast cancer with an increased intake of red and processed meat.

Red meat raise IGF-1, a hormone that causes breast cancer cells to grow. High serum IGF-1 is linked with increased all-cause mortality in women with established breast malignancy.

Red meat may also elevate your circulating levels of steroid hormones, and this might cause increased growth of breast cancer cells.

The prudent approach to help you prevent breast cancer is to adopt the Mediterranean diet, avoid red meat, and enjoy green tea.