A healthier lifestyle associated with better cognitive function, independent of Alzheimer's disease pathology

Preventing Alzheimer's disease through lifestyle adjustments and modifications is a hot topic among researchers, and theoretically, if individuals adopted healthier lifestyles, dementia worldwide could be reduced. It is estimated that approximately 40% of cases can be prevented.Researchers whose research was published in JAMA Neurology investigated the effects of lifestyle interventions on cognition in older adults as a preventive measure. Additionally, the authors specifically looked at individuals who died and performed autopsies to assess whether lifestyle factors influenced cognition before death.

This cohort study utilized data from the Rush Memory and Aging Project (Rush MAP), a longitudinal clinicopathological study using autopsy data with up to 24 years of follow-up from 1997 to 2022. Researchers analyzed 754 deaths and individual data on lifestyle factors, cognitive testing near death, and complete neuropathological evaluation at the time of analysis. Of the 754 individuals included, 586 had valid dietary and lifestyle data in addition to cognitive testing and complete anatomical data at the time of analysis. The authors also compared the demographics (age, gender, education, etc.) and genetic characteristics of MAP among study participants.

Dietary intake was assessed with a 144-item food frequency questionnaire (FFQ) in which participants report their usual food intake frequency over the past 12 months. Overall diet quality was calculated by a diet score that does not take into account alcohol intake. In addition to diet, cognitive activity was assessed using a questionnaire measuring participation in seven cognitively stimulating activities (e.g., reading, visiting museums, playing cards, checkers, crosswords, puzzles) within the previous year. Additionally, physical activity was assessed through surveys specifically targeted at older adults. Participants were required to self-report the amount of time they spent completing activities of moderate to vigorous intensity, such as walking, gardening or yard work, swimming, biking, and calisthenics. Finally, mean alcohol consumption was obtained through a self-report survey.

Using these factors, if a participant is in the healthiest 40% of the overall analysis population (equivalent to a diet score higher than 7.5 and a cognitive activity score higher than 3.20), then the participant is It was classified as risk or “healthy.” In addition, the Healthy Lifestyle score includes performance of at least 150 minutes of moderate or vigorous activity per week, light to moderate alcohol intake (up to 15 g/day for women and 30 g/day for men). g/day) were also included. Smoking is prohibited when self-reporting.

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When patients died, their brains were removed and tested for cognitive ability and the presence of Alzheimer's disease. Steps were performed to quantify β-amyloid deposits, phosphorylated tau changes, senile and diffuse plaques, neurofibrillary tangles, and other pathologies. Additionally, immunohistochemistry and staining techniques over specific brain regions were performed to generate composite measures of Alzheimer's disease pathology and associated conditions (atherosclerosis, Lewy body disease, hippocampal sclerosis). etc.) were evaluated. Cognitive function was assessed through 19 tests each year, with each score standardized to the baseline mean, and the standardized cognitive scores from the 19 tests were used to create a composite score for overall cognitive function. it was done. Positive scores indicate high cognitive performance and negative scores indicate low cognitive performance.

The results showed that higher lifestyle scores, or a healthier lifestyle, were associated with better cognitive function before death. Furthermore, the association between lifestyle and cognition is independent of Alzheimer's disease pathology burden, and when β-amyloid burden, phosphorylated tau tangles, or other memory-related brain pathology is included, the relationship between lifestyle and cognition is We show that the strength of the association varies widely. Regression tools.

Furthermore, the study found that although the correlation between lifestyle and cognition was independent of brain pathology, approximately 12% was due to beta-amyloid. The authors argue that this finding supports the role of lifestyle in providing cognitive reserve to maintain cognitive function in older adults despite the accumulation of common brain lesions associated with dementia. It is pointed out that this is supported. Additionally, the researchers believe that further research will analyze the role of duration and lifestyle changes during the study period and how it affects cognition or whether it is independent of pathology. suggests that it should be done.

Furthermore, this analysis suggests that lifestyle may reduce the risk of Alzheimer's disease by reducing the burden of vascular disease. This supports previous findings demonstrating that both diet and physical activity are associated with cognitive performance independent of vascular disease burden. According to the study authors, the link between lifestyle and cognition is a result of the antioxidant and anti-inflammatory effects of each lifestyle factor (such as nutrition and physical activity), as well as cognitive reserve (such as cognitive-based activities). It is said that there is a possibility. May contribute to reducing inflammation and oxidative stress. The study authors believe that further research into specific associations between lifestyle factors and inflammatory markers in the brain is needed to better understand the mechanisms of how lifestyle and pre-mortem cognitive scores are correlated. points out that it is necessary.

Limitations of this study include the reliance on self-reported lifestyle factors, which may lead to inaccurate results, and the possibility that cognitive ability may influence the ability to adhere to certain lifestyle factors (e.g., physical activity). patient population, and the demographics of the patient population are limited. . The study authors also stress that due to the study's observational design, causality of the reported associations cannot be assumed.

reference

Dhana K, Agarwal P, James BD et al Healthy lifestyle and cognition in older adults with common neuropathology of dementia. JAMA New Roll. Published online on February 5, 2024. doi:10.1001/jamaneurol.2023.5491