The Office of Dietary Supplements describes how folate, also called vitamin B-9, is a water-soluble vitamin, meaning that this vitamin cannot be stored in the body and excess folate is excreted in the urine. This means that an adequate amount of folate is required for daily health. Folate helps maintain and grow new cells and there is also some scientific evidence that folate helps reduce colon cancer risk.
Folate and Colon Cancer Risk
There is scientific evidence that folate significantly reduces the risk of colon cancer, in people with a family history of the disease, according to the American Cancer Society. This recommendation is based on data from the Nurses Health Study that began in 1976 and followed the health and diet of over 85,000 women for 16 years. This study found that women with a family history of colon cancer had twice the risk of colon cancer, but those that supplemented their diet with 400 mcg of folate cut their risk in half compared to those that took 200 mcg of folate per day.
Folate and Polyps
Polyps are abnormal growths in the intestine that are sometimes the precursors to colon cancer. According to the Harvard School of Public Health, one study involving patients that had a history of developing colon polyps had their diet supplemented with 1,000 mcg of folate per day. Unfortunately, this level of folate did not prevent the formation of further polyps, and may have even caused more polyps to grow. However, the dose of folate was quite high at 1,000 mcg, and the effect of a smaller dose of folate on colon polyps is unknown. The Harvard School of Public Health also hypothesizes that folate may prevent polyps or colon tumors, but may be ineffective in slowing their growth in people who already have them.
Effect of Folate on Cancer Cells
Researchers have a strong hypothesis on how folate reduces colon cancer risk. Folate supports the health of growing cells by helping DNA replicate and genes work properly. Colon cancer occurs when the DNA in the cells of the colon replicates improperly, and certain regulators of cell growth can become unregulated. The American Cancer Society notes that folate likely helps DNA replicate accurately, without the "mistakes" that can ultimately lead to cancer.
Recommendations and Dietary Sources
The Federal Drug Administration, or FDA, reports that the daily recommended intake value of folate is 400 micrograms for adults and children over 4 years of age. The FDA recognizes the value of folate intake and in 1996 required folic acid, the man-made form of folate, to be added to enriched breads, breakfast cereals, flour, rice and pasta, according to the Office of Dietary Supplements. In addition to these fortified foods, natural dietary source of folate include beef liver, spinach, black-eyed peas, Great Northern beans and asparagus.
References
- Office of Dietary Supplements, National Institutes of Health: Folate
- American Cancer Society: Folate Reduces Risk of Colon Cancer For People with Family History
- Harvard School of Public Health: Three of the B Vitamins: Folate, Vitamin B6, and Vitamin B12
- Federal Drug Administration: Guidance for Industry: A Food Labeling Guide
