Folate fortification may lower colon cancer risk

A new analysis suggests that increased intakes of folate following the introduction of fortification in the US were associated with a reduction in the incidence of colorectal cancer.

In the observational study, health data from 525,488 individuals aged between 50 and 71 were collected over the course of about nine years following the introduction of folic acid fortification in the US in 1998 (1). The analysis showed that for people with the highest average intakes of folate or folic acid (at least 900 micrograms per day) the risk of colorectal cancer was 30% lower than for people with the lowest average intakes (less than 200 micrograms per day). In addition, the highest intakes specifically from dietary supplements or the diet were associated with 18% and 19% reductions, respectively. Data revealed that people with the highest folate levels were 30% less likely to develop colorectal cancer.

The researchers noted that colorectal cancer has a long latency period (time between the first exposure to a cancer-causing agent and the clinical recognition of the disease) of between 10 and 20 years, and that additional follow-up time is required before firm conclusions can be drawn.

In the past, some scientists had suggested that folic acid, the synthetic form of folate, may promote the formation of cancers under select circumstances where a person may already have a pre-cancerous or cancerous tumor. However, a recent analysis of data from almost 100,000 men and women from the American Cancer Society indicated that increased intakes of folic acid from fortified foods and dietary supplements are not linked to an increased risk of colorectal cancer (2).

1. Gibson T. M. et al. Increased intakes of folate following the introduction of fortification in the US was associated with a reduction in the incidence of colorectal cancer. American Journal of Clinical Nutrition. Online publication August 2011.
2. Stevens V. L. et al. High levels of folate from supplements and fortification are not associated with increased risk of colorectal cancer. Gastroenterology. 2011; 141(1):98–105.