May 3, 2023
Eating foods rich in magnesium, a mineral found in nuts and seeds, leafy greens, whole grains, beans and other foods, may be good for the brain. Scientists in Australia report that adults who tend to get the most magnesium in their diets tend to have less shrinkage in their brains as they age. Greater brain volume is tied to a lower risk of Alzheimer’s disease and other forms of dementia. A magnesium-rich diet was also tied to fewer lesions in the brain’s white matter, which can lower the risk of stroke.
“Our study shows a 41 per cent increase in magnesium intake could lead to less age-related brain shrinkage, which is associated with better cognitive function and lower risk or delayed onset of dementia in later life,” said lead author Khawlah Alateeq, a doctoral candidate from the Neuroimaging and Brain Lab at The Australian National University. “This research highlights the potential benefits of a diet high in magnesium and the role it plays in promoting good brain health.”
For the study, researchers looked at 6,001 men and women who were part of the UK Biobank, a large and ongoing study of thousands of people living in Britain, using medical imaging to track health and disease onset over decades. They ranged in age from 40 to 73.
Participants filled out questionnaires about what they ate over a 16-month period, including information on 200 different foods. The researchers also had detailed information about their health, as well as the results of MRI brain scans that measured the volumes of various areas of their brains.
The researchers found that the more magnesium people tended to get in their diets, the larger their average brain volume. By the time they reached their mid-50s, people who consumed more than 550 milligrams of magnesium each day had a brain volume that was about one year younger than their peers who ate a more typical amount of magnesium, about 350 milligrams a day.
“The study shows higher dietary magnesium intake may contribute to neuroprotection earlier in the aging process, and preventative effects may begin in our 40s or even earlier,” Ms. Alateeq said. “This means people of all ages should be paying closer attention to their magnesium intake.”
The benefits of consuming magnesium-rich foods appeared to benefit women more than men, though men also saw brain benefits. Post-menopausal women also tended to have greater benefits than younger women. The findings were published in the European Journal of Nutrition.
Magnesium plays an essential role in nerve transmission, muscle contraction and other critical body functions. Scientists aren’t sure exactly how magnesium benefits the aging brain, though the mineral can lower blood pressure as well as levels of body-wide inflammation, which have been linked to a lower risk of developing dementia. Magnesium can also help to promote sound sleep, and sleep disturbances have likewise been linked to a higher risk of Alzheimer’s disease.
Earlier research has shown that people with Alzheimer’s disease tend to have lower levels of magnesium in their blood than their cognitively healthy peers. Other studies have also linked higher levels of the nutrient to a lower risk of developing memory problems. Older adults, as well as people with Type 2 diabetes or digestive disorders or those who drink alcohol heavily tended to have lower levels of magnesium.
The Recommended Dietary Allowance for magnesium is 400 to 420 milligrams a day for men and 310 to 320 milligrams a day for women. Foods high in magnesium include pumpkin seeds (168 mg in a 1-ounce serving), almonds (80 mg in a 1-ounce serving), spinach (78 mg in a half-cup cooked), peanuts (63 mg in a quarter-cup serving), soy milk (61 mg per cup), black beans (60 mg per cup cooked), dark chocolate (50 mg per 1-ounce serving), avocados (44 mg per cup), bananas (32 mg per medium banana), and salmon (26 mg in a 3-ounce portion). Many breads and cereals are also fortified with magnesium.
If you are worried you may be deficient in magnesium or want to take magnesium supplements, talk to your doctor first. Magnesium can interact poorly with various medications, and taking high-dose supplements can cause stomach cramps, nausea and digestive upset. Including more leafy green vegetables, legumes, nuts, seeds and whole grains in your diet may be a better option than taking supplements, doctors say.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Khawlah Alateeq, Erin I. Walsh, Nicolas Cherbuin: “Dietary magnesium intake is related to larger brain volumes and lower white matter lesions with notable sex differences.” European Journal of Nutrition, March 10, 2023