Researchers conducting the Iowa Women's Health Study report in the Archives of Internal Medicine found that women who take certain supplements not only don't live longer, they, in fact, may die sooner.
Researchers Report that Nutritional Supplements Aren't a Ticket to the Fountain of YouthThe Iowa Women's Health Study is an ongoing investigation into the relationships between nutrition, health, and disease begun in 1986 by the Masonic Cancer Center at the University of Iowa. At the beginning of the study, researchers recruited 41,836 women then aged 55 to 69 to participate in nutrition interviews at intake and in five follow-up studies conducted in 1987, 1989, 1992, 1997, and 2004.
Analysts at the School of Public Health at the University of Minnesota, for example, found that heavier women were less likely to suffer hip fractures from osteoporosis. Analysts at the Mayo Clinic found no benefit from antioxidant supplements in preventing lymphoma, but considerable benefit from eating fruits and vegetables, especially broccoli. Another group of researchers at the University of Minnesota School of Public Health found that taking 800 IU of vitamin D a day, but not more, reduced the risk of breast cancer in women in the study—but only for the first 5 years. And, of course, there are no men in the Iowa Women's Health Study.
Is there another way to interpret the findings of this latest study? Are women really putting their lives at risk by taking particular supplements? Here are some alternative explanations of the data.
Read more: Busting Myths about Dietary Supplements
• All of the women in the study were born before 1930. Women of that era tended not to take multivitamins unless they had a specific health condition. Women who have been diagnosed with serious health problems naturally can be expected to have shorter life expectancies.
• Vitamin B6 and folic acid are recommended for people who have already been diagnosed with cardiovascular disease, Alzheimer's, or Parkinson's disease. The nutritional supplements could have lengthened individual lives even if the lifespan of supplement users as a group was shorter.
• About 2% of the population has undiagnosed hemochromatosis or has at least one gene for hemochromatosis, an iron storage disease in which excessive iron accumulation causes pro-oxidant (literally rusting) reactions all over the body. Some women who took iron supplements probably did not know they had this disease.
• Magnesium, zinc, and copper are recommended for people who already have osteoporosis or rheumatoid arthritis. Both conditions are associated with a shorter lifespan.
And, to be fair about the analysis, is it possible that calcium actually shortens lifespans, to the contrary of the data analysis? Women who take calcium supplements, and only calcium supplements, tend to be in good health and want to stay that way. Maybe they'd live even longer if they didn't take calcium—but there is nothing in the data to suggest that conclusion.
And the nothing in the data suggests that having taken nutritional supplements is in any way a cause for fear. You aren't a statistic. You're a human being. The "worst" possibility suggested by the data is that women who take iron supplements—heavily advertised when the women in this group were in the prime of their lives—might have about a 4% greater of dying before the age of 73. If you're past 73, well, don't worry about the Geritol you took in the 1950's. The ill effects would have shown up by now. It's actually a good decision to take specific supplements for specific health concerns. Just don't use them in excess.