Did you know the US sprays its wheat with this?

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Wheat and maize (corn) flour are staple crops consumed widely throughout the world and have been fortified with folic acid in over 80 countries to prevent neural tube defects. And great as it is that pregnant women don’t give birth to children with spina bifida, has anyone looked at the law of unintended consequences, and what it means for the rest of us?

Folic acid, or vitamin B-9, is one of the water-soluble B-complex vitamins that is essential for numerous body functions, including DNA replication and repair as well as cell division and growth. Although folic acid is considered an essential part of your diet and is found in many foods such as flour, grains, rice and pasta, some individuals have an intolerance, or allergy, to folic acid.

In 1996, the Food and Drug Administration (FDA) established a regulation that required manufacturers to add folic acid to enriched flours, breads, rolls, buns, corn grits, cornmeal, farina, rice, pasta and noodle products. 

Although the main reason for adding folic acid to the food supply was to prevent neural tube defects, health experts thought there might be benefits for others besides pregnant women and their children. Folic acid and vitamins B6 and B12 help keep homocysteine in check. Homocysteine is an amino acid that has been associated with heart disease, stroke, dementia, and Alzheimer’s disease when found in the blood at high levels.

The hope was that increased folic acid intake would help reduce homocysteine levels and possibly the risk of cardiovascular disease. Epidemiological and animal studies suggested that it might also help prevent certain forms of cancer, particularly colorectal cancer. In Harvard’s long-term Nurses’ Health Study, for example, women who got adequate folic acid were less likely to develop colon cancer and, among those who drank alcohol, breast cancer.

But when it comes to the secondary benefits of adding folic acid to the food supply, the picture is distinctly mixed. Since fortification was mandated, the average level of folate in the blood of Americans has risen and the average level of homocysteine has fallen. The question is, to what effect? On the plus side, a study published in the journal Circulation (March 14, 2006) found that the rate of stroke deaths fell dramatically in the United States and Canada during the first four years of fortification, compared with the seven preceding years. There was no such improvement (and no fall in the rate of neural tube defects) in England and Wales, where fortification is not mandatory. Stroke mortality has gradually declined since 1990, probably because of wider use of statins, aspirin, and other medications, as well as lifestyle changes. But the authors of the study believe the sharp drop between 1998 and 2002 is probably due to fortification.

However, about the time that fortification was mandated, there was also an uptick in colorectal cancer. Researchers at Tufts University, working with large population-based cancer registries, studied trends in colorectal cancer from 1986 to 2002 in the United States and Canada. The results, published in the July 2007 issue of Cancer Epidemiology Biomarkers and Prevention, showed a 15-year decline that was suddenly reversed in the early fortification years, when average blood levels of folate doubled. As a result, an extra four to six cases of colorectal cancer per 100,000 people per year — a total of 16,500 extra cases — were estimated to have occurred. More here at Harvard Health