A recent study published in the British Medical Journal, confirmed that a combination of healthy lifestyle factors (healthy diet, no smoking/drinking, regular physical exercise, cognitive activities, and active social contact) were associated with a slower rate of memory decline in older people with normal cognitive function. Healthy lifestyle slowed memory loss even in individuals who were genetically susceptible to rapid neurodegeneration and cognitive decline (apolipoprotein [APOE] ε4 gene carriers).
A prospective cohort study enrolled older people with normal cognitive function (n = 29,072; mean age = 72.2 years) and assessed whether adherence to a combination of healthy lifestyle factors, viz., healthy diet (intake 7 out of 12 food items such as fruits, vegetables, fish, meat, dairy products, salt, oil, eggs, cereals, legumes, nuts, and tea), non-/former- smoking, non-alcohol drinking, regular physical exercise (150 min of moderate or 75 min of vigorous activity per week), cognitive activity (writing, reading, playing cards, mahjong, and other games) and active social contact (attending parties, visiting friends)were associated with a slower memory decline.
Based on the number of healthy lifestyle factors, participants were categorized into 3 groups, i.e., favourable group (4–6 healthy factors), average group (2–3 factors), and unfavourable group (0–1 factor). Participants were also categorized as carrier and non-carriers of APOE ε4 gene after APOE ε4 genotyping. Change in memory function was assessed using Auditory Verbal Learning Test (AVLT) during each of the four follow-up visits conducted over a 10-year period. The results are summarized below:
- Among the lifestyle factors, healthy diet strongly influenced the rate of memory decline followed by other factors (see part [A] in the graphic below).
- Participants with favourable and average lifestyles had a slower rate of memory decline compared to the participants with an unfavourable lifestyle (p <0.001; see part [B] in the graphic below).
- Among the genetically susceptible individuals, i.e., APOE ε4 gene carriers (20% of the total participants), favourable lifestyle was associated with better memory performance over time compared with average and unfavourable lifestyles (p <0.001; see part [B] in the graphic below).
- Over the 10-year study period, the probability of progression to mild cognitive impairment and dementia among participants with favourable and average lifestyles was lowcompared with an unfavourable lifestyle.
Clinical implication: This long-term study provides robust evidence that memory loss in ageing population is a potentially modifiable phenomenon, and adopting healthy lifestyle factors can significantly reduce progressive memory decline in the older population. In addition to this, healthy lifestyle might also be beneficial in delaying memory loss in individuals with non-modifiable genetic risk factors, such as the presence of APOE ε4 gene.
(Reference: Jia J, Zhao T, Liu Z, Liang Y, Li F, Li Y, Liu W, Li F, Shi S, Zhou C, Yang H, Liao Z, Li Y, Zhao H, Zhang J, Zhang K, Kan M, Yang S, Li H, Liu Z, Ma R, Lv J, Wang Y, Yan X, Liang F, Yuan X, Zhang J, Gauthier S, Cummings J. Association between healthy lifestyle and memory decline in older adults: 10-year, population based, prospective cohort study. BMJ. 2023;380:e072691. Doi:10.1136/bmj-2022-072691)