To function at its best, your brain needs just the right balance of minerals. These inorganic substances—iron, magnesium, zinc, and more—are important constituents of all bodily flu-ids and tissues, including your nerve cells, and are essential to a number of biological and physiological processes.
Both deficiencies in these minerals and excessive amounts are associated with negative changes in brain health and functioning—an important reason why consuming a broad range of nutritious foods rather than relying on mineral supplements is the best way to ensure brain health.
“In the United States, adequate levels of most of these minerals can be obtained by eating a well-balanced, healthy diet, so individuals who are concerned about their mineral intake should evaluate their diets,” says David Mischoulon, MD, PhD, Director of Research and Alternative Remedy Studies at MGH’s Depression and Clinical Research Program. “Taking mineral supplements is generally not necessary unless recommended by your medical care provider. In fact, excessive levels of many minerals may be detrimental to brain health.”
MCI and magnesium
A recent study calls attention to the importance of one key mineral, magnesium, in ensuring brain health among aging individuals. Researchers looked at the daily mineral intake of 1,406 cognitively healthy older adults and followed them over a period of eight years, during which time participants took periodic tests of cognition. The scientists calculated the incidence among participants of mild cognitive impairment (MCI, memory loss that is worse than aver-age for a person’s age and often considered an early stage of Alzheimer’s disease, or AD) and other mild cognitive disorders. At the end of the study, 27 participants had developed MCI, and another 52 had developed other mild cognitive disorders, according to a report published online Feb. 4, 2014 in Frontiers in Aging Neuroscience. After accounting for various health and socio-demographic factors, the researchers found that participants with a higher intake of magnesium had a decreased risk for MCI and mild cognitive disorders compared to participants with lower intake. The results add to evidence from animal research published in 2013 that found that laboratory rats bred to develop AD were less likely to develop brain changes associated with cognitive decline and AD and more likely to retain learning and memory capacities when given magnesium in their drinking water, compared to similar animals that did not get magnesium supplementation.
“This research adds to other investigative work over the past decade or so that suggests that mineral deficiency can negatively affect brain chemistry and ultimately have consequences for brain functioning,” says Dr. Mischoulon. “Its findings are important because they illustrate the possible effects associated with our modern diet, which often lacks regular consumption of mineral-rich foods necessary for brain health. For example, over half of all people in developed countries are thought to have magnesium deficiencies. This suggests that our dietary habits can lead to sub-clinical deficiencies that are hard to detect, but nevertheless affect brain chemistry.
“That’s why it’s important to make sure you’re getting enough of the foods that supply your brain’s requirement for minerals, such as fresh fruits and vegetables, whole grains, nuts, legumes, low-fat dairy products, lean meats, and seafood. If your diet contains few of these healthy foods and includes many fast foods and processed foods, you may be at risk for mineral deficiencies. People who eat restricted diets, such as vegetarians and people with certain medical conditions, may also be vulnerable. If you’re experiencing health problems, be sure to see your medical care provider for a thorough evaluation.”
Six Mighty Minerals
Among the many minerals supplied in a healthy diet, these six are some of the most important for brain health and functioning:
Plays a role in nerve function, and maintaining normal blood pressure. Deficiency may lead to impaired signal transmission between brain cells, cognitive decline, and memory loss. Recommended daily allowance (RDA): 800-1200 milligrams (mg). Sources: Leafy green vegetables, dairy products, almonds, liver, sardines, cereals.
Aids in glucose metabolism. Some evidence that chromium has beneficial effects on mood. Chromium depletion is thought to interfere with the body’s ability to use glucose for energy, raise insulin requirements and possibly increase vulnerability to type 2 diabetes. RDA: 120 micrograms. Sources: Broccoli, grape juice, whole-grain cereals and breads, fresh fruits, nuts, liver, beef.
Involved in the production of oxygen-carrying proteins in the blood. Plays a role in the production of certain neurotransmitters that relay signals among nerve cells, and the formation of fatty myelin sheaths that protect nerve connections. Helps protect cells from oxidant damage and stress. Deficiency causes anemia, fatigue, headache, dizziness, slowed thinking, worse memory performance, problems concentrating, and cardiovascular disorders such as irregular heartbeat that affect the brain. RDA: Under age 50, 15 mg; over age 50, 10 mg. Sources: Liver, dried beans, whole-grain cereals, eggs, fish, wheat germ, spinach and other leafy green vegetables, poul-try, red meat, nuts.
Involved in a variety of chemical reactions, some of which are important to the brain. Plays a role in nerve function, and appears to help protect brain cells from injury. Enhances the brain’s ability to change and respond in the presence of new information. In addition to brain problems suggested by the research discussed above, deficiency may also cause anxiety, headache, and confusion. RDA: 420 mg for men, 320 mg for women. Sources: Whole grains, nuts, tuna, green vegetables, fish, cereals, milk.
Involved in regulation of body fluids; aids in nerve transmission. Deficiency can cause confusion, fatigue. RDA: 2,400 mg Sources: Table salt.
An essential part of more than 200 enzymes, zinc is involved in many chemical reactions within the body and plays an important part in transmission of signals between brain cells in the hippocampus, a key memory region. Deficiency of zinc may be associated with memory problems, mental lethargy, emotional problems. RDA: 15 mg for men, 12 mg for women. Sources: Brewer’s yeast, fish, soybeans, liver, spinach, red meat, egg yolk.