Foods to Prevent Breast Cancer

Every day, almost 600 women and 5 men will be diagnosed with breast cancer in the United States. Breast cancer is the cause of 1% of all deaths in women and 7% of all cancer deaths. Although there are a number of factors contributing to carcinogenesis, which are normally out of our control (genetic, environmental), there are some simple dietary changes which can reduce the risk of many cancers. Here we will look specifically at those which reduce the risk of breast cancer.

Cruciferous Vegetables:

Cruciferous vegetables include: broccoli, cauliflower, mustard greens, cabbage, brussels sprouts, kale, and wasabi. This class of vegetables contain several chemical compounds known to reduce the risk of various types of cancer. They are particularly suited for stopping the growth of tumors of the break, colon, cervix, and lung.

The most powerful of these components is class of compounds called isothiocyanates. These compounds reduce the risk of breast cancer by inhibiting certain enzymes (cytochrome P450) in the body. These cytochrome enzymes interact with chemicals that we regularly are exposed to (such as exhaust fumes and chemicals in burnt food) to produce even nastier chemicals which create mutations in our DNA which can eventually cause cancer. The isothiocyanates found in Cruciferous vegetables prevent those nasty enzymes from producing the DNA damaging compounds and thereby reducing the risk of cancer.

Another useful anti carcinogenic compound is indole-3-carbinol. Normal cells are programed to die after a certain amount of time. When a cell "runs out of time" and dies it is called apoptosis. Unlike normal cells, cancerous cells do not respond to the chemical signals which trigger the cell death. However, indole-3-carbinol has been shown to help make cancer cells responsive to the normal process of apoptosis. This has been specifically demonstrated in breast cancer, prostate cancer, cervical cancer, and pancreatic cancer cells. Limited studies have also shown that indole-3-carbinol may help prevent cancerous tumors from developing the blood vessels necessary to grow.

We could continuing talking for a long time about further beneficial anti carcinogenic chemicals in cruciferous vegetables, but this is beyond the scope of the article.

Too much of a good thing:

Although there are many beneficial compounds in cruciferous vegetables for the prevention of breast cancer, there is a limit to how much you should eat. Cruciferous vegetables contain a type of chemical called glucosinolates which also play a role in preventing cancer. However, this class of chemicals are slightly toxic and are particularly damaging to the thyroid. In excessive quantities they are known to cause thyroid problems such as goiter. Excessive quantities can also cause hormonal imbalances.

How to Eat Them:

Just be reasonable when adding cruciferous vegetables to your diet. One or two servings a day should be fine, especially if you are getting a sufficient amount of iodine from fish or iodine enriched salt. Cooking may slightly reduce the total amount of anti carcinogenic compounds, but may also make them easier to absorb. The bottom line is is that adding them to your diet in which ever way you prefer is fine.

Please remember that preventative measures alone are not sufficient. Regular self exams and doctor visits/mammograms are a must. Although everybody would like to prevent breast cancer, the greatest assets to surviving is early detection and treatment.

Some References:

Hong C, Firestone GL, Bjeldanes LF. Bcl-2 family-mediated apoptotic effects of 3,3'-diindolylmethane (DIM) in human breast cancer cells. Biochem Pharmacol. 2002;63(6):1085-1097.

Howells LM, Gallacher-Horley B, Houghton CE, Manson MM, Hudson EA. Indole-3-carbinol inhibits protein kinase B/Akt and induces apoptosis in the human breast tumor cell line MDA MB468 but not in the nontumorigenic HBL100 line. Mol Cancer Ther. 2002;1(13):1161-1172.

Rahman KW, Sarkar FH. Inhibition of nuclear translocation of nuclear factor-{kappa}B contributes to 3,3'-diindolylmethane-induced apoptosis in breast cancer cells. Cancer Res. 2005;65(1):364-371.