Studies Explore Minerals & Your Brain

Studies about food and your brain are revealing the role of iron and zinc in keeping us sharp. In the Information Age, especially, keeping our mental capacities up to par is critical, according to research physiologist Mary J. Kretsch. She is with the Agricultural Research Service’s Western Human Nutrition Research Center in Davis, Calif.

In an early study with men age 27 to 47, Kretsch looked at the relation between iron and the volunteers’ ability to concentrate. She found that a low score for volunteers’ attention span corresponded with a subsequent decline in iron levels in the body. In another study, this one with 14 obese but otherwise healthy female volunteers age 25 to 42, Kretsch and colleagues documented a similar change in ability to focus.

Her studies are the first in healthy adults to link a low attention span with a decrease in body iron levels. Kretsch says the findings suggest that decreased ability to concentrate may be an early indicator of declining iron. She plans followup studies to investigate whether iron supplementation can reverse this cognitive impairment.

Her zinc investigations, using the same men who were volunteers in the iron study, employed a test that evaluated volunteers’ ability to recall specific words. Preliminary results showed that, after only three weeks on a low-zinc regimen, many of the volunteers’ ability to recall the words slowed. The volunteers who slowed the most in this test also had the greatest decrease in blood levels of zinc.

Kretsch says the mental performance tests may prove to be a simple way to identify people who aren’t getting enough zinc or iron, well before any signs show up in biochemical samples such as blood or urine.

ARS is the U.S. Department of Agriculture’s chief scientific research agency.