Growing evidence continues to undermine the food supplement industry’s mantra that using food supplements can eliminate or at least reduce many of the known and suspected health risks as- sociated with eating the typical modern diet full of refined and processed foods. A diet full of refined grains, sugars and refined oils is often nutrient poor so many Americans buy into the notion that taking a daily multi-vitamin/mineral supplement can some- how make-up for unhealthy food choices and improve health and longevity. Back in 1993 Dr. Kim and colleagues at the Center For Disease control examined data from the NHANES I survey back in the early 1970s from over 10,000 subjects 25-74 years old who answered questions about their supplement use. Dr. Kim then looked at the health and longevity as of 1987. They found the health and longevity of the supplement users did not differ from those who did not take supplements.1 More recently, Drs. Lichtenstein and Russell published an excel- lent article reviewing the case for using supplements or foods to reduce morbidity and mortality.2 However, despite the lack of proven benefits for most supplements and with growing concerns about health risks associated with taking one or several nutrients (especially in doses in excess of the RDI) the use of multi-vitamin/ mineral supplements has contin- ued to grow. At the same time the consumption of refined and processed foods loaded with salt and fatty animal products are increasing associated with more and more serious ills.
This past month yet another study looked at the risk and benefits of supplement use. In this case the data came from the large Iowa Women’s Health Study that followed more than 38,000 women to see what impact various diet and lifestyle choices had on their health and longevity. The mean age of these women was about 62 in 1986. They answered questions about their use of sup- plements back in the 1980s. By 2008, more than 15,500 of these women had died. The researchers found a modest but statistically significant increased risk of dying in those that took a multivitamin supplement. They also found that those women taking supplements of folic acid, vitamin b-6, copper, zinc, magnesium, and especially iron were significantly more likely to die than those not taking those supplements. They did find that those taking a calcium supplement were significantly less likely to die but noted this finding conflicted with data from controlled clinical trials.3 By contrast, data linking the use of iron supplements with cancer and cardio- vascular disease, and perhaps diabetes and dementia is consistent with a growing body of data that iron supplementation is likely dangerous and should be limited only to those with clinically estab- lished iron deficiency. This study found that 66% of the women in this study were taking some type of nutritional supplements with most taking at least one or more of the nutrients associated with an increased risk of dying.
Antioxidant supplements of vitamin E, beta-carotene, and vitamin A have all become popular among Americans hoping they will somehow slow the aging process, mitigate unhealthy diet and lifestyle choices and or help them live longer. Sadly, controlled clinical trials with these supplements have found the supplements not only fail in this mission but actually increase the risk of dying.4,5 Another popular antioxidant, vitamin C, touted as a boost to immune function and risk reducer for everything from colds to cancer, has failed miserably in clinical trials to provide such health benefits.
Bottom Line: The data continues to mount to seriously undermine the widespread belief that taking multi-vitamins and mineral supplements and especially high dose supplements of most vitamins, minerals and herbs not only fails to mitigate the known dangers of the typical modern American diet but more often than not are actually shown to be more likely to increase the risk of dying. Looks like it is wise to choose a diet rich in fruits, vegetables, whole grains, with a little seafood and nonfat dairy rather than supplements to assure not only getting adequate nutrients but also for avoiding the nutritional excesses that promote disease and shorten lives.
By James J. Kenney, PhD, FACN.
1 Kim I, et al. Vitamin and mineral supplement use and mortal- ity in a US cohort. Am J Public Health. 1993;83:546-50
2 Lichtenstein AH, Russell RM. Es- sential Nutrients: Food or Sup- plements. JAMA 2005;294:351- 8
3 Mursu J, et al. Dietary supple- ments and mortality rate in older women. Arch Intern Med 2011;171:1625-33
4 Bjelakovic G, et al. Cochrane Database Sys Rev. 2008:2(2), Miller ER, et al. Ann Intern Med 2005;142:37-46
5 Vivekananthan DP, et al. Lancet. 2003361:2017-23
Stephanie Ronco has been editing for Food and Health Communications since 2011. She graduated from Colorado College magna cum laude with distinction in Comparative Literature. She was elected a member of Phi Beta Kappa in 2008.