The Good, The Bad and The Unknown About Folic Acid Fortification

As of this week Australians will be getting a little something extra than just bread in their loaves. In a new government measure all bread-making flour in the country must be fortified with folic acid in an effort to reduce the number of babies born with neural tube defects such as spina bifida. Studies suggests that if daily doses of 400 micrograms of folic acid, a synthetic form of B vitamin folate, are taken by pregnant women three months before conception and during pregnancy, up to 75% of cases of spina bifida could be prevented. According to Food Standards Australia New Zealand (FSANZ), there are approximately 300-350 cases of neural tube defects in Australia, and the agency hopes that the enrichment of commercial bread products will reduce the number of affected pregnancies by up to 14%.

At the outset this certainly seems a worthwhile and necessary measure and the precedents offer much hope for success. In the U.S. mandatory folic acid fortification has been in place for over ten years and a 2008 article in the Harvard Women’s Health Watch states that “in countries that require folic acid fortification, including the United States and Canada, the rate of neural tube defects has fallen by 25% to 50%.”

Folate is naturally found in green leafy vegetables, orange juice, cooked lentils and baked beans amongst other foods but it is rare that women eat enough of these foods on a daily basis to elicit the necessary amount of folic acid. And since everyone loves bread – certainly more than they do taking a handful of supplements every morning – enriching the staple with the nutrient was the obvious choice. Moreover, a significant percentage of pregnancies are unplanned and as such many women don’t consume the recommended amount of folic acid prior to conception. And because a fetus – particularly its spine and brain – develops so quickly in its first weeks and months, by the time most women discover that they are pregnant and start taking supplements, the damage may already have set in. But pregnant or not, these women will still have toast for breakfast, a sandwich for lunch or a roll with dinner, thereby inadvertently filling up on the nutrient.

So far so good; the evidence suggests that Australians are set to benefit from this new mandate. But a comprehensive survey of the most recent scientific studies reveals that folic acid is not entirely benevolent. While the positive link between decreasing rates of NTDs and folic acid remains undisputed, researchers have now discovered cancer risks associated with excessive synthetic folate consumption for both men and women. Once the mandatory fortification measure is implemented in Australia, with grocery lists full of breads, breakfast cereals and snack bars, ingesting more than the recommended 400 micrograms of folic acid will quickly become a reality there just as it has done in the U.S.

The relationship between folic acid and cancer is a complex one. A group of around 30 research papers has shown that folic acid can reduce people’s risk of developing colorectal (colon) cancer by 40% – 60% by playing an essential role in the formation of DNA and the growth of healthy cells. But once cancerous cells have already developed the nutrient actually helps the cancer cells grow in the same way that it helps healthy cells replicate. A 2007 study in the journal Cancer Epidemiology Biomarkers & Prevention notes that rates of colon cancer in North America rose just as fortification began in the late 1990’s. In another study published earlier this year, Chilean researchers in the European Journal of Gastroenterology and Hepatology found the same pattern in Chile since fortification began there in 2000.

But the dangers do not stop there. A more recent analysis of the findings of a 2007 study examining the relationship between folic acid and cancer suggests a link between a high consumption of the nutrient and an increased risk of prostrate cancer. Men in the study who took high doses of folic acid appeared twice as likely to develop prostrate cancer than men who did not take supplements. Still, the researchers were keen to stress was that the study was nowhere near comprehensive enough to allow them to deduce any firm conclusions about a definite link between folic acid and prostate cancer; the suggestion of a relationship was all they were prepared to concede. 

No doubt many healthy antipodean newborns will owe thanks to their mothers’ penchant for processed white, but that their good health may come at the expense of others is perhaps a scenario that the Australian government should seriously reconsider.