The study, published in the Journal of the American Medical Association (JAMA), found that folic acid and other B vitamin supplements were ineffective in preventing cancer. Researchers from Harvard Medical School reviewed data on around 5,500 women over the age of 42 who had cardiac disease or at least three risk factors for heart disease.
The women were then divided into groups at random. Half were given the B vitamin and folic acid supplement, while the other half were given a placebo. The women were then studied for over seven years. Unfortunately for the team no difference was found between the supplement group and the placebo group over the likelihood of developing cancer. It is the longest trial of its kind, and suggests that folic acid and B vitamins do not prevent people from developing cancer.
The findings looked at a broad variety of cancers, but the supplements didn’t make a difference to any of them. The supplement also made no overall difference to mortality levels. The researchers did also suggest that the supplements did not do any damage to the women, either.
Previous studies had suggested that B vitamins could play a role in preventing cancer, but follow-up research has been inconsistent. While some studies have produced moderately positive results, some have even gone as far to suggest that the vitamin supplements did more harm than good in terms of general health and wellbeing.