High Dietary Magnesium Intake May Help Prevent Dementia

A diet higher in magnesium may lead to less age-related brain shrinkage, particularly in women, according to a recent study.

Published in the European Journal of Nutrition, the study explored the relationship between magnesium intake through food sources and brain volumes and white matter lesions in middle to older-aged people. The investigation was led by Khawlah Alateeq, a PhD candidate at The Australian National University (ANU), and its findings indicated that magnesium-rich foods like spinach and nuts could help reduce the risk of dementia.

“Our study shows a 41 percent 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,” Alateeq said.

The study included more than 6,000 cognitively healthy people in the United Kingdom aged 40 to 73. Over 16 months, participants completed five online questionnaires on the amount of magnesium-rich foods they consumed. Based on their responses, researchers estimated their average daily intake of magnesium. The questionnaire asked about over 200 different foods with various portion sizes, but researchers focused mainly on foods like leafy green vegetables, legumes, nuts, seeds, and whole grains.

Results showed that by the time they reached 55 years old, people who ate a diet high in magnesium had a brain age one year younger than those who ate a normal amount of magnesium. The study defined a high magnesium intake as more than 550 milligrams (mg) per day and a normal magnesium intake as about 350 mg per day.

According to Alateeq, these results suggest that higher dietary magnesium intake may contribute to neuroprotection earlier in the aging process, helping to prevent cognitive decline by age 40 and perhaps even earlier.  

“This means people of all ages should be paying closer attention to their magnesium intake,” said Alateeq.

Interestingly, the study also found that the neuroprotective effects of higher daily magnesium intake were more pronounced in women than in men. Moreover, dietary magnesium appeared to benefit the brain health of post-menopausal women more than pre-menopausal women, which Alateeq said may be due to its anti-inflammatory effects.

Because there is currently no cure for dementia and recent pharmacological treatments have been unsuccessful, to Erin Walsh, PhD, a senior research fellow at ANU and co-author of the study, more focus should go towards prevention.

"Our research could inform the development of public health interventions aimed at promoting healthy brain aging through dietary strategies,” said Walsh.