|CRN Responds to B Vitamin Study
2009/11/18 - Council For Responsible Nutrition (CRN)
In response to the publication of a study, "Cancer Incidence and Mortality After Treatment with Folic Acid and Vitamin B12," published in the Journal of the American Medical Association (JAMA), the Council for Responsible Nutrition (CRN), the leading trade association representing the dietary supplement industry, issued the following statement:
Statement from Andrew Shao, Ph.D., vice president, scientific and regulatory affairs, CRN:
"The real headline of this study (1) should be that smoking increases the risk of lung cancer - the study found that a total of 94 percent of the subjects who developed lung cancer were either current or former smokers. For years, the vast body of scientific evidence has shown that individuals who have smoked at any point in their lives are at a significantly increased risk of developing lung cancer. Most health experts would agree that the number one way to prevent lung cancer is to abstain from smoking.
It is puzzling why patients who were given high-doses of folic acid were more likely to develop lung cancer than those subjects in the control group; however, it is important to point out that these results are inconsistent with the larger body of data and that this effect has not been observed previously. In fact, as the authors themselves point out, "Epidemiological studies have demonstrated no associations between intakes of folate or folic acid and lung cancer risk."
Furthermore, the accompanying editorial (2) notes that "rates for total cancer incidence decreased significantly from 2001 to 2005 and lung cancer incidence has also declined significantly in men over almost two decades and among women from the late 1990's." Given that mandatory folic acid fortification went into effect in the United States in 1998, if high doses of folic acid have a paradoxical effect on lung cancer, then we likely would not have seen these drastic reductions in lung cancer incidence over the past two decades. It is inappropriate at this point to reach firm conclusions based on such limited data, especially in the face of vast evidence showing benefit for folic acid supplementation.
Finally, the original studies were secondary prevention trials (i.e. treatment) involving ischemic heart disease patients - not healthy individuals, and the present publication represents findings from the combined trials on cancer obtained from a secondary analysis - both trials were designed to assess effects on cardiovascular events, not cancer. Therefore, not only is it inappropriate to draw any conclusions from these results, but whatever might be concluded, does not readily apply to the generally healthy population.
Consumers, as well as researchers and healthcare professionals, must not lose sight of the safe, well-established benefits of folic acid supplementation and fortification for women of childbearing age to prevent neural tube defects, as well as other potential benefits of folic acid supplementation, such as for cardiovascular health and cognitive function in the general population. CRN is in agreement with and supports the accompanying editorial in which the authors state that "the findings do not nullify the potential long-term benefits that folic acid fortification may have on population health." The most important message for the scientific community is that research on the cancer preventative effects of diet and micronutrients, including folic acid, should continue. For consumers, the most important message is that they should continue to feel confident in the safety and efficacy of consuming the recommended amounts of folic acid as part of an overall healthy lifestyle."
1 Ebbing M, Bonaa K, Arnese E, et al. Cancer Incidence and Mortality After Treatment with Folic Acid and Vitamin B12. Journal of the American Medical Association (JAMA). 2009;302(19):2119-2126.