Mental Stimulation May Delay Symptoms of Alzheimer’s, But Not Its Cause

People who stay physically and mentally healthy in middle age may help avert the symptoms of Alzheimer’s disease, but not the underlying cause of the disease changes itself, according to research published in Neurology.

Prashanthi Vemuri, PhD, from the Mayo Clinic in Rochester, Minn., and colleagues found that of the participants who had 14 years of education or more who were carriers of the APOE4 gene — which is linked to Alzheimer’s and affects about 20% of the population — those who kept mentally active in middle age had lower levels of amyloid plaque buildup in the brain compared with those who did not keep mentally active in middle age.

“Recent studies have shown conflicting results about the value of physical and mental activity related to the risk of developing Alzheimer’s disease, and we noticed that levels of education differed in those studies,” said Dr Vemuri in a statement. “When we looked specifically at the level of lifetime learning, we found that carriers of the APOE4 gene who had higher education and continued to learn through middle age had [less] amyloid deposition on imaging when compared to those who did not continue with intellectual activity in middle age.”

To investigate the effect of various characteristics on Alzheimer’s disease biomarker trajectories, the researchers evaluated 393 participants without dementia (70 years and older) from the Mayo Clinic Study of Aging using longitudinal imaging data (brain b-amyloid load via Pittsburgh compound B PET and neurodegeneration via ¹⁸fluorodeoxyglucose (FDG) PET and structural MRI).

Of the 393 participants, 340 were clinically normal and 53 had mild cognitive impairment. The participants were grouped into high levels of education (≥14 years) and low levels of education (<14 years).

Using MRI and PET scans, the researchers searched for biomarkers of Alzheimer’s disease. They also evaluated weekly intellectual and physical activity in middle age with questionnaires.

For the entire group of participants as a whole, the researchers found that education, occupation, and mental and physical activity in middle age appeared to have little to no effect on the rates of amyloid plaque buildup. However, for carriers of the APOE4 gene, those with high education who continued stimulating their minds in middle age had less amyloid plaque deposition in the brain than those with high education who did not continue mental stimulation in middle age.