Dementia is an incurable, debilitating disease that affects millions of people worldwide. While science continues to look for answers to treat the disease, there has been a shift towards prevention. A study has provided new evidence about the link between magnesium intake and brain health.
Previous studies have shown that the intake of dietary magnesium is involved in the biological processes related to brain aging and may help prevent the neurodegeneration that ultimately leads to dementia.
The exact mechanisms underlying magnesium’s neuroprotective effects haven’t been identified clearly, particularly at what point magnesium intake starts affecting brain health. Since lifestyle and diet are modifiable risk factors for dementia, it is important that more is known about the role of magnesium as a preventative agent.
A new study by researchers at the Australian National University has looked at brain volumes and white matter lesions (WMLs) and their association with dietary magnesium. They also examined the association between blood pressure and magnesium and whether there were differences in these associations between men and women.
Brain volume is an important factor to consider because brain shrinkage (atrophy) in people diagnosed with Alzheimer’s disease precedes the appearance of clinical symptoms. Atrophy in the hippocampus, the complex brain structure that plays a role in learning and memory, is an early characteristic of Alzheimer’s disease.
White matter is found throughout the central nervous system but largely in the brain's interior. It’s made up of bundles of millions of nerve fibers that connect to the brain’s gray matter. WMLs are abnormalities that show up as bright spots on MRI scans of the brain. They can reflect normal aging and have no clinical significance, or they can indicate inflammation and damage to the myelin, the insulating sheath around the nerves. It is thought that WMLs are an early sign of neurodegenerative conditions like Alzheimer’s disease and stroke.
The current study included 6,001 participants taken from the UK Biobank. The participants, aged between 40 and 73, had no evidence of neurological disorders. Participants were asked to complete an online questionnaire five times over 16 months and their responses were used to calculate their daily magnesium intake based on 200 foods of different portion sizes.
The researchers found, for the first time, that dietary magnesium was associated with larger brain volumes and lower WMLs, particularly in the gray and white matter. They found that the neuroprotective effect of magnesium was substantial but varied across different brain regions, being particularly strong for the gray matter and hippocampus.
Compared to someone with a normal magnesium intake of around 0.1 oz (350 mg) a day, those that consumed more than 0.2 oz (550 mg) of magnesium daily were found to have a brain age approximately one year younger than their “body age” by the time they reach 55.
“Our study shows a 41% 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 Khawlah Alateeq, lead author of the study.
While the data showed strong associations between dietary magnesium and brain volumes and WMLs across men and women, the possible neuroprotective effects of magnesium only reached significance in women. The effect was stronger in post-menopausal women than in pre-menopausal women, but the researchers point out that this may be due to the anti-inflammatory properties of magnesium. Unexpectedly, the study showed no association between dietary magnesium intake and blood pressure.
Based on the results of their study, the researchers recommend increasing magnesium intake from a younger age to safeguard against neurodegenerative diseases.
“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,” Alateeq said. “This means people of all ages should be paying closer attention to their magnesium intake.”
So, it looks like bananas, green leafy vegetables, avocados, cashews and almonds, legumes, tofu, fatty fish, seeds and whole grains are on the menu. But don’t forget dessert: dark chocolate is also very rich in magnesium.
The researchers hope their findings will generate further research into the benefits of magnesium on brain health and be used to guide public health strategies focused on prevention.
“Our research could inform the development of public health interventions aimed at promoting healthy brain aging through dietary strategies,” said Erin Walsh, co-author of the study.
The study was published in the European Journal of Nutrition.
Source: Australian National University
