Questioning Folic Acid Fortification Following Link With Increased Cancer Rate

Main Category: Colorectal Cancer
Also Included In: Nutrition / Diet
Article Date: 05 Nov 2007 - 1:00 PDT

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Two recent commentaries appearing in the November issue of Nutrition Reviews find that the introduction of flour fortified with folic acid into common foods was followed by an increase in colon cancer diagnoses in the U.S. and Canada. The two new review articles address these recent findings and provide an overview of the existing evidence on folic acid fortification and the associated policy issues.

For nearly a decade, folic acid, a chemical form of a common B vitamin (folate), has been added to wheat flour and other grain products in the U.S. and Canada. This public health measure was enacted after evidence was discovered linking folic acid with a reduced rate of a specific birth defect that affected the development of the spinal cord and central nervous system. During the same period, however, rates of colorectal cancer in the U.S. inexplicably began rising, even as regular colonoscopy check-ups became more common. In Canada, where folic acid supplementation was introduced a bit later, the same trend has been observed.

Dr. Solomons, author of one of the review commentaries, "Food Fortification with Folic Acid: Has the Other Shoe Dropped?" advises that a careful reconsideration of the fortification program is needed. "One size of dietary folic acid exposure does not fit all. It can be beneficial to some and detrimental to others at the same time," comments Solomons.

Since the risk-benefit value of fortification varies according to age, Solomons suggests a reevaluation of the manner in which folic acid to prevent birth defects is delivered to the public. Among other things, targeting women of reproductive age while reducing folic acid levels in foods for which fortification is optional (such as ready-to-eat cereals and commercial drinks), would be worthy of consideration, in the opinion of Solomons.

As a result of noted birth defect reduction, 42 countries have implemented some form of mandatory folic acid fortification. The two commentaries stress the need to carefully consider and balance the risks and benefits associated with introducing such a program.

"Folic acid supplementation wields a double-edged sword," remarks Dr. Young-In Kim, author of "Folic Acid Fortification and Supplementation -- Good for Some but Not So Good for Others," the other commentary review published in the November issue. According to Kim, "It may be beneficial or harmful, depending on the timing of intervention." Exposure to high intakes of folic acid in early life and young adulthood may provide life-long protection from the tendency for cancer formation in different organs, such as the large intestines, whereas such exposures later in life, when cell damage has occurred, can spur on the advance of the tumor.

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These reports are published in a policy feature in the November issue of Nutrition Reviews.

Young-In Kim, M.D., FRCP, is an Associate Professor of Medicine and Nutritional Sciences at the University of Toronto and a staff gastroenterologist at St. Michael's Hospital.

Noel W. Solomons, M.D., is the Co-Founder, Senior Scientist, and Director of the Center for Studies of Sensory Impairment, Aging and Metabolism (CeSSIAM) in Guatemala City, and head of the Task-Force on Diet, Nutrition and Long-term Health of the International Union of Nutritional Sciences.

About Nutrition Reviews

Nutrition Reviews is a publication of the International Life Sciences Institute (ILSI). The journal is devoted to keeping academic researchers, students, and professionals abreast of the latest research in the field with authoritative and critical reviews of significant developments in all areas of nutrition science and policy. Nutrition Reviews is edited by Robert M. Russell, M.D., director of the Jean Mayer USDA Human Nutrition Research Center on Aging and professor of medicine and nutrition at Tufts University. Starting in 2008, Wiley-Blackwell will partner with ILSI in publishing Nutrition Reviews. For more information about the journal, visit http://www.ilsi.org/.

Source: Sean Wagner
Blackwell Publishing Ltd.

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