CRN Responds to Reader's Digest Article About Vitamins


CRN Counters Reader’s Digest’s Vitamin Myths

Reader's Digest says a daily multivitamin is a waste of money for most people and offers five “truths” about vitamins. However, CRN said the article fails to put the science into perspective, while cherry-picking through the scientific literature.

Douglas MacKay, N.D., vice president, scientific and regulatory affairs, Council for Responsible Nutrition (CRN), said vitamins and other dietary supplements play an important role in helping promote and maintain overall health and wellness. He said vitamins can fill nutrient gaps, help prevent neural tube birth defects, and support heart health, bone health, joint health, digestive health and more.

The Reader’s Digest article, written by Christie Aschwanden  offers five “myths” of vitamins, with the first being multivitamins can make up for a bad diet. She highlighted last year’s Women's Health Initiative study that concluded multivitamin-takers do not have fewer cases of cancer, heart disease or stroke than those who do not take them. She said many foods are now fortified with vitamins, so most Americans will not be deficient. However, Aschwanden did say women of reproductive age should take a multivitamin as insurance in case of pregnancy, mostly for the folate content.

MacKay said while taking a multivitamin does not replace a healthy diet, multivitamins can act as an insurance policy to help get essential nutrients when diets fall short. He noted, according to the National Health and Nutrition Examination Survey (NHANES), many Americans, including children and adolescents, fail to consume recommended amounts of vitamins E, C, D, and A, as well as calcium and magnesium. And data from the National Marine Fisheries Service shows that on average, Americans don’t eat enough fish. In December 2009, he said, the American Dietetic Association issued an updated position paper on nutrient supplementation, which acknowledged additional nutrients from supplements can help some people meet their nutrition needs.

The second myth offered in the Reader’s Digest article is that vitamin C fights colds, noting a 2007, study of more than 11,000 subjects that found vitamin C didn't ward off colds, except among marathoners, skiers and soldiers on subarctic exercises. However MacKay said a meta-analysis showed taking vitamin C may reduce the duration of a cold by 8 percent in adults and more than 13 percent in children, though he pointed out the research is not conclusive.

Next, Aschwanden tackles vitamin pills’ effect on heart disease. She noted an analysis of seven vitamin E trials concluded that it didn't cut the risk of stroke or of death from heart disease. That same study also concluded eight beta-carotene studies that found those supplements produced a slight increase in the risk of death. She further mentions “other big studies” have shown vitamin C does not reduce heart disease and she said research showed B vitamins cut homocysteine levels, but that doesn’t reduce heart problems.

Mackay countered by saying omega-3 fatty acids are widely accepted by healthcare professionals, as well as scientific organizations, for helping reduce inflammation, lowering triglyceride levels and contributing to a healthy heart and blood vessels. He said the American Heart Association states patients with coronary artery disease may need to supplement with omega-3s for heart disease risk reduction.

Aschwanden also wrote vitamins don’t protect against cancer, saying many studies have tried and failed to find a benefit. She noted a recent one that randomly assigned 5,442 women to take either a placebo or a B-vitamin combo over the course of more than seven years. Researchers found all the women experienced similar rates of cancers and cancer deaths.  Mackay noted this same study found following an eating pattern lower in total fat did not significantly reduce the incidence of breast cancer, heart disease or stroke, and did not reduce the risk of colorectal cancer in healthy postmenopausal women, but health professional aren’t discounting previously established evidence and recommendations that a low-fat diet may decrease the risk of heart disease. He said these studies are part of whole body of research that need to be viewed in context.

Mackay added studies have shown dietary supplement use has been associated with decreased risk of chronic diseases in numerous observational studies involving tens of thousands of people, and in some studies the benefit has increased with long-term use. For example, he said, a study published in the February 2010 issue of Cancer Research found that leafy green vegetables, folate and multivitamin use appeared to offer protection against lung cancer. Another study found women with higher intakes of calcium from both food and supplements—up to 1,300 milligrams (mg)/day—appear to have a lower risk of cancer overall, and both men and women with high calcium intakes have lower risks of colorectal cancer and other cancers of the digestive system.

Lastly, she wrote it is dangerous to think vitamin supplements may not help, but they won’t hurt either. She quoted Demetrius Albanes, MD, a nutritional epidemiologist at the National Cancer Institute. He said a study showed beta-carotene pills increased the risk of lung cancer and deaths among male smokers who took the supplement. The article said other studies have raised concerns that taking high doses of folic acid could raise the risk of colon cancer.

The safety of supplement use is well established, said Mackay, who pointed out more than 150 million Americans use dietary supplements each year, and yet for the first full year (2008) that it was mandated by law that companies report serious adverse events to FDA, the agency reported only 672 serious adverse events. He does say it’s wise to engage healthcare professionals in dialogue about the dietary supplements, and it is important to always follow the directions on the label and not take more than is recommended.

Sources:
•    Council for Responsible Nutrition: CRN RESPONDS TO READERS DIGEST ARTICLE
•    Reader’s Digest : 5 Vitamin Truths and Lies