A new study published in the journal Neurology suggests that both very high and very low levels of magnesium may put people at risk of developing dementia. Share on Pinterest Cashews, almonds, and bananas are some of the richest sources of magnesium. The first author of the study is Dr. Brenda Kieboom, of the Erasmus University Medical Center in Rotterdam, the Netherlands. Dr. Kieboom and her colleagues measured serum magnesium levels in 9,569 participants aged 64.9 years, on average. The participants did not have dementia at the beginning of the study – that is, between 1997 and 2008. They were clinically followed for 8 years on average, until January 2015. Low serum magnesium levels were defined as equal to or lower than 0.79 millimoles per liter, and high magnesium levels were defined as equal to or above 0.90 millimoles per liter. Magnesium levels were divided into quintiles, or fifths; the researchers examined the association between dementia and serum magnesium using the third quintile as a reference. The researchers adjusted for age, sex, education, risk factors for cardiovascular disease, kidney function, and other comorbidities.
High or low magnesium raises risk by a third Over the follow-up period, 823 people developed dementia. Of these, 662 were diagnosed with Alzheimer’s disease. As for magnesium levels, both those in the high and the low group were significantly more likely to develop dementia compared with those in the middle group. More specifically, participants in both the high- and low-magnesium groups had a 30 percent increase in dementia risk compared with their counterparts in the middle group. The low-magnesium group had 1,771 people, 160 of whom developed dementia. The high-magnesium group comprised 1,748 people, 179 of whom were diagnosed with dementia. In the middle group, 102 of the 1,387 participants developed dementia.