Association between healthy lifestyle and memory decline in older adults: 10 year, population based, prospective cohort study.
Level 3 - non-randomized controlled study
Prospective cohort study following participants over 10 years
PubMed 36696990 · doi:10.1136/bmj-2022-072691
What was done
A 10-year prospective cohort study (2009–2019) followed 29,072 cognitively normal adults aged 60 years or older across representative regions of China who underwent baseline APOE genotyping. Six lifestyle factors were evaluated: healthy diet (adherence to >=7 of 12 items), regular physical activity (>=150 min moderate or >=75 min vigorous per week), active social contact (>=twice per week), active cognitive activity (>=twice per week), never or former smoking, and never drinking alcohol. Participants were grouped into favourable (4–6 factors), average (2–3 factors), or unfavourable (0–1 factor) lifestyle categories. Memory was assessed using the WHO/UCLA Auditory Verbal Learning Test and global cognition with the MMSE; linear mixed models evaluated trajectories of memory decline.
What was found
Participants had a mean age of 72.23 years, 48.54% were women, and 20.43% were APOE ε4 carriers. Over 10 years, participants with a favourable lifestyle had slower memory decline compared with the unfavourable group (0.028 points/year slower, 95% CI 0.023 to 0.032, P<0.001). Among APOE ε4 carriers, memory decline was slower in the favourable (0.027 points/year, 95% CI 0.023 to 0.031) and average (0.014 points/year, 95% CI 0.010 to 0.019) groups relative to the unfavourable group. In non-carriers, decline was also slower in favourable (0.029 points/year, 95% CI 0.019 to 0.039) and average (0.019 points/year, 95% CI 0.011 to 0.027) groups compared with the unfavourable group. The interaction between APOE ε4 status and lifestyle profile was not statistically significant (P=0.52).
Why it matters
This study shows that adhering to a combination of healthy lifestyle habits is linked to attenuated memory decline in older adults, providing evidence that lifestyle benefits persist regardless of genetic risk from APOE ε4.
Limits
The observational design cannot establish causality. Lifestyle behaviors were self-reported, introducing potential misclassification and recall bias. The study population was restricted to adults in China, which may limit generalizability to other dietary patterns and cultural contexts. Unmeasured residual confounding cannot be excluded.
Cited by
- context Lack of exercise accelerates cognitive decline, particularly in individuals with major genetic risk factors.