Adequate intake of the B vitamin folate may lower women's risk of developing colorectal cancer.

An international team of investigators found that women with the highest intakes of folate were 40% less likely than those who consumed the least to develop cancer of the colon and rectum.

Folate is found in foods such as leafy green vegetables. The synthetic form of the vitamin, folic acid, is used to fortify foods such as cereals and other grain products. The vitamin is essential for the production and maintenance of new cells, and adequate intake before and during pregnancy helps guard against certain birth defects.

Researchers suspect that folate and folic acid may also protect against certain cancers by helping with DNA synthesis and repair -- processes that, when disrupted, can lead to cancer.

The investigators found that women who reported the highest folate intakes -- more than 367 micrograms per day -- had the lowest risk of cancers of the colon, rectum or both. The US recommendation for daily folate intake is 400 micrograms.

Still, according to Terry, these findings should contribute to the overall understanding of the role of folate in reducing cancer risk.

International Journal of Cancer 2002;97:864-867