stylistic:tone, information:extraction, structural:expansion
Cancer

Early after fortification programs were implemented, high intakes were theorized to accelerate the growth of preneoplastic lesions that could lead to cancer, specifically colon cancer. Subsequent meta-analyses of the effects of low versus high dietary folate, elevated serum folate, and supplemental folate in the form of folic acid have reported at times conflicting results. Comparing low to high dietary folate showed a modest but statistically significant reduced risk of colon cancer. For prostate cancer risk, comparing low to high dietary folate showed no effect. A review of trials that involved folic acid dietary supplements reported a statistically significant 24% increase in prostate cancer risk. It was shown that supplementation with folic acid at 1,000 to 2,500 μg/day – the amounts used in many of the cited supplement trials – would result in higher concentrations of serum folate than what is achieved from diets high in food-derived folate. The second supplementation review reported no significant increase or decrease in total cancer incidence, colorectal cancer, other gastrointestinal cancer, genitourinary cancer, lung cancer or hematological malignancies in people who were consuming folic acid supplements. A third supplementation meta-analysis limited to reporting only on colorectal cancer incidence showed that folic acid treatment was not associated with colorectal cancer risk.