Mild cognitive impairment is clinically defined as the intermediate stage between normal cognitive functioning and dementia. New research examines whether engaging in mentally stimulating activities can reduce the risk of mild cognitive impairment.
According to several long-term studies, mild cognitive impairment (MCI) affects between 16 and 20 percent of people aged 65 and over.
MCI refers to a loss of cognitive function that is not severe enough to interfere with daily activities, but which is very likely to develop into dementia. Numerous studies suggest that between 20 and 40 percent of people who have MCI go on to develop dementia.
New research led by Dr. Yonas E. Geda, from the Mayo Clinic in Scottsdale, AZ, examined the link between brain-stimulating activities and cognitive functioning in healthy adults aged 70 and over. The researchers also assessed the influence of the apolipoprotein E (APOE) ε4 genotype.
The findings were published in the journal JAMA Neurology.
The team examined 1,929 cognitively healthy seniors who took part in the Mayo Clinic Study of Aging in Olmsted County, MN.
The participants were examined and deemed normal at the beginning of the study. They provided information about their participation in brain stimulating activities during the year preceding their enrolment in the study.
Researchers then clinically followed the participants for approximately 4 years to see how many of them developed MCI. They performed neurocognitive assessments of the seniors at baseline and evaluated them every 15 months. In their statistical analysis, Dr. Geda and team used Cox regression models and adjusted for sex, age, and education.
The team also took blood tests from the participants to determine APOE ε4 genotyping.
The APOE ε4 genotype is a variant in the APOE gene commonly associated with a high risk of late-onset dementia. Existing research has not yet uncovered the mechanism responsible for this association, but it has found links between the gene variant and the buildup of Alzheimer’s-related amyloid plaques.
By the end of the study period, 456 participants (over 23 percent) had developed new-onset MCI. Additionally, 512 participants (or 26.7 percent) were carriers of the APOE ε4 genotype.
The researchers found that brain-stimulating activities significantly decreased the risk of new-onset MCI.
Some of these activities included computer use, crafts, social activities, and playing games. The association between reading books and a decreased risk of MCI almost reached statistical significance.
According to the authors, the findings mean that engaging in brain-stimulating activities even in later life can lower the chances of developing MCI.
Researchers also noted the lowest risk of MCI in those participants who engaged in mentally stimulating activities, but who were not APOE ε4 carriers. Conversely, they found participants who did not engage in cognitively stimulating activities, and who were also carriers of APOE ε4, to have the highest risk of MCI.
The authors point out that their study did not investigate the cause-and-effect mechanism behind the associations, as the study was observational. Dr. Geda and team conclude:
“Performing certain mentally stimulating activities may also lower the risk of incident MCI among APOE ε4 carriers. Future research is needed to understand the mechanisms linking mentally stimulating activities and cognition in late life.”