When’s the last time you had your blood tested for zinc? Maybe… never? That’s because zinc tests are famously inaccurate. But based on a new study published this month, some scientists are saying that tests or no tests, older people need to supplement in large doses.
As we age, it turns out, we become less and less able to absorb zinc. What’s more, our diets may be lacking in it; about 40 percent of older Americans have zinc-deficient diets. The combination can lead to a decline in immune system functioning and an increase in oxidation as well as the inflammation that leads to cancer, heart disease and a host of other ills.
“In zinc deficiency, the risk of which has been shown to increase with age, the body’s ability to repair genetic damage may be decreasing even as the amount of damage is going up.” —Dr. Emily Ho
In fact, in a study conducted with old mice by scientists at the Linus Pauling Institute at Oregon State University and the OSU College of Public Health and Human Science, even the mice whose diets had sufficient zinc showed low zinc levels and high levels of inflammation. When the researchers jacked up the animals’ daily dose to ten times their RDA, those inflammatory markers returned to the levels of a young mouse.
Given these results, a principal investigator in the study, Emily Ho, now recommends that the elderly take their full RDA of zinc, regardless of diet. That’s 11 milligrams a day for men and 8 milligrams for women. The study authors also recommend an FDA rethink of the RDA for older adults, but warn against taking more than 40 milligrams a day. Good dietary sources of zinc are beef, pork, and lamb, with nuts, whole grains, legumes and yeast providing smaller amounts. If you like oysters, be happy: They contain the highest amount of zinc of any food.