Nutrients from foods, no supplements, related to reducing the risk of death and cancer

According to a new study, a sufficient intake of certain nutrients is associated with a reduction in all-cause mortality when nutrients come from food, but not from supplements. There was no association between the use of dietary supplements and a lower risk of death.

In addition, excessive calcium intake was associated with an increased risk of cancer deaths, which the researchers found associated with additional doses of calcium greater than 1000 mg / day. The study was published on April 9 in Annals of Internal Medicine.

While the potential benefits and harms of using supplements continue to be studied, some studies have shown associations between excessive intake of nutrients and adverse effects, including an increased risk of certain cancers. "said Fang Fang Zhang, MD, Ph.D., associate professor at the Tufts Friedman School of Nutrition Science and Policy and senior author and corresponding author of the study. "It's important to understand the role that the nutrient and its source could play in health outcomes, especially if the effect may not be beneficial."

The study used a nationally representative sample of data from more than 27,000 US adults aged 20 years and older to assess the relationship between dietary supplement use and all-cause mortality, cardiovascular disease, and cardiovascular disease. the cancer. The researchers evaluated whether sufficient or excess nutrient intake was associated with death and whether intake from food versus supplements had an effect on the associations.

For the association between nutrient intake and risk of death, the researchers found:

• Sufficient vitamin K and magnesium intake was associated with a lower risk of death;
• Adequate vitamin A, vitamin K and zinc intakes were associated with a lower risk of CVD death; and
• Excessive calcium intake was associated with a higher risk of cancer death.

When assessing the sources of nutritional intake (food vs. supplement), the researchers found:

• The risk of death associated with adequate vitamin K and magnesium intake was limited to nutrients in foods and not in supplements.
• The lower risk of CVD death associated with adequate vitamin A, vitamin K and zinc intake was limited to nutrients from foods and not supplements; and
• Calcium intake from total supplements of at least 1000 mg / day was associated with an increased risk of death from cancer, but there was no association for cancer. 39 calcium intake from food.

In addition, the researchers found that dietary supplements had no effect on the risk of death in people with low nutrient intake. Rather, the team found indications that the use of vitamin D supplements by people with no evidence of vitamin D deficiency may be associated with an increased risk of all-cause death, including cancer. . Further research on this potential connection is needed.

"Our results support the idea that, while the use of supplements contributes to an increase in total nutrient intake, there are beneficial associations with nutrients from foods that we do not see with the supplements, "Zhang said. "This study also confirms the importance of identifying the source of nutrients when assessing mortality outcomes."

The study used 24-hour dietary recall data from six cycles of two years of the National Health and Nutrition Review Survey, up to 2010. For each nutrient, the daily dose of complement was calculated by combining the frequency with the product information, the amount of ingredient per serving and unit of ingredients. Food intake of nutrients contained in foods was assessed using 24-hour food recalls. Mortality results were obtained for each participant through a linkage to the National Death Index until December 31, 2011, using a probabilistic match.

The authors note some limitations, including the duration of use of dietary supplements studied. In addition, the prevalence and dosage of the use of dietary supplements have been self-reported and are therefore subject to recall bias. Residual confusion may play a role in observed associations.