According to a new study, nutrition supplements may not be as beneficial as nutrients derived from food for reducing all-cause mortality. In fact, certain supplements taken in excess may actually promote some cancers.
"As potential benefits and harms of supplement use continue to be studied, some studies have found associations between excess nutrient intake and adverse outcomes, including increased risk of certain cancers," remarked Fang Fang Zhang, MD, PhD, Associate Professor at the Friedman School of Nutrition Science and Policy at Tufts University and senior author on the study. "It is important to understand the role that the nutrient and its source might play in health outcomes, particularly if the effect might not be beneficial."
For the study, published in Annals of Internal Medicine, data was collected for the years 1999 to 2010 from the National Health and Nutrition Examination Survey, which was linked to National Death Index mortality data. The participants, 30,899 US adults aged 20 years or older, answered survey questions based on dietary supplement use. The researchers used the surveys to quantify participants' nutrient intake from dietary supplements and foods over the past 30 days. All-cause mortality, cardiovascular disease, and cancer were outcomes that the investigators measured.
After a median follow-up of 6.1 years, a total of 3,613 deaths occurred, including 945 deaths from cardiovascular disease (CVD) and 805 from cancer. Adequate consumption of vitamin A, vitamin K, magnesium, zinc, and copper were linked with reduced all-cause and CVD mortality; however, individuals who consumed these nutrients from food, not supplements, benefited from this reduced risk. Individuals who ingested excess calcium from supplements actually had an increased risk for cancer death.
"Our results support the idea that while supplement use contributes to an increased level of total nutrient intake, there are beneficial associations with nutrients from foods that aren't seen with supplements," commented Dr. Zhang. "This study also confirms the importance of identifying the nutrient source when evaluating mortality outcomes."
For More Information
Chen F, Du M, Blumberg JB, et al (2019). Association among dietary supplement use, nutrient intake, and mortality among US adults: a cohort study. Ann Intern Med. [Epub ahead of print] DOI:10.7326/M18-2478
Image Courtesy of Daniel Brosam