Sufficient levels of folate consumption, the B vitamin, may lower women's risk of developing colorectal cancer, according to recent research published in the International Journal of Cancer 2002;97.
Researchers at the Albert Einstein College of Medicine found that women with the highest intakes of folate were 40 per cent less likely to develop cancer of the colon and rectum than those who consumed the least folate.
Paul Terry and his team examined data collected from 295 women who had taken part in a large study of breast cancer screening in the 1980s.
The researchers 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.
Folate is found in leafy green vegetables, beans and peas, orange juice and liver, and folic acid, the synthetic form of the vitamin, is used to fortify foods such as cereals and other grain products.
Scientists maintain that folate is essential for the production and maintenance of new cells, and therefore adequate intake before and during pregnancy helps to protect against certain birth defects. Researchers also suspect that folate and folic acid may protect against certain cancers by helping with DNA synthesis and repair - processes essential for the prevention of cancer. The US recommendation for daily folate intake is 400 micrograms.
In the study, however, Terry acknowledged that many unknown factors could have influenced the findings. This small study "is not a call for everyone to go out and start popping more folic acid," he said.
For example, it is not certain how much folate and folic acid patients were consuming since the findings were based on dietary questionnaires. In addition, cancer takes a long time to develop, and women in the study may have changed their diets over time, Terry explained.
He also noted that other dietary habits, including alcohol intake, may alter the effects of folate and folic acid on cancer risk.
Nevertheless, Terry maintains that these findings should contribute to the overall understanding of the role of folate in reducing cancer risk.
"Although one study doesn't make a big difference when so many studies have been conducted, we have one more piece of information. In the long run, when people look at all of the studies that have been conducted, they're going to draw a conclusion," he said.
He added that rather than increasing folate intake, the best way to prevent cancer was to "eat a balanced diet, exercise, maintain normal body weight and don't smoke.".