A comprehensive review by researchers from the Harvard School of Public Health reveals that folic acid and vitamin B-6 can help protect women against breast cancer. While several studies have shown that a diet rich in B-vitamins may help reduce breast cancer risk, this was the first review where the participants’ lifestyle and dietary information was obtained prior to their developing breast cancer. The researchers used data previously compiled in the Nurses Health Study, which began in 1976, and included over 120,000 female nurses.

Specifically, the Harvard researchers compared the lifestyles and diets of 712 nurses who developed breast cancer to 712 nurses who did not. They examined the nurses’ intake of vitamins B-6 and B-12 as well as folic acid—all vitamins required for the formation of healthy DNA.

The researchers found that the nurses who developed breast cancer had a lower intake of dietary folic acid. They concluded folic acid helped protect against breast cancer, and also, based on the data, that sufficient folic acid protected against the increased risk of breast cancer associated with increased alcohol intake. They also found that while B-12 did not offer any protective benefits, B-6 did. Women with a higher intake of B-6 had a lower rate of breast cancer.

Folic acid is a critical nutrient during cell division and growth. Also used to make DNA and red blood cells, folic acid is found mainly in green leafy vegetables, legumes, citrus fruits and fortified breakfast cereals.

The body uses B-6 to form the neurotransmitter serotonin, red blood cells and DNA, as well as for protein and fat metabolism. It can be obtained from meat, poultry and fish as well as potatoes, bananas. Other nutrients that protect against breast cancer include essential fatty acids, flax seed and vitamin C.

Source: Journal of the National Cancer Institute 95(5):373-380