A recent study has demonstrated that high folate intake can lower your risk of colorectal cancer. These findings support previous epidemiologic (analyzing the origin of diseases) studies. The new research also contradicts recent evidence linking high levels of folate with increased risks of some cancers.
"Eat your greens to reduce your risk of colorectal cancer."
This is the first study to look at the association between folate and colorectal cancer risks. This study was conducted following the mandatory folate fortification program started in the US in 1998, which requires wheat flours be fortified with folic acid.
It's also the first study to distinguish between the forms of folate found naturally in food and folic acid, which is used in supplements.
The study involved 99,523 participants in the Cancer Prevention Study II Nutrition Cohort. Victoria Stevens, PhD, Strategic Director of Laboratory Services at the American Cancer Society, led the research team.
Among the participants, 1,023 participants were diagnosed with colorectal cancer between 1999 and 2007, which was after folate fortification began.
Interestingly, there was no change in risks for the first two years (1999 to 2001). But from 2002 to 2007, there was a link between high folate intake and reduced risks of colorectal cancer.
While these findings are important, a causal relationship can't be confirmed. A previous study found that folate supplementation did not impact the recurrence of colorectal adenomas, non-cancerous polyps that can develop into cancer.
The Recommended Daily Intake (RDI) of folate is 400 mcg, according to the National Institutes of Health. Folate is found naturally in leafy vegetables, egg yolks and legumes. Inadequate folate intake has been linked to birth defects, a finding that led to the folate fortification program.
Stevens says additional study is needed to clarify the benefits of folate intake as it relates to colorectal cancer.
The study was published in Gastroenterology.