Research

"Studies have been conducted to identify factors that might affect memory, including aging, the apolipoprotein E (APOE) ε4 genotype, chronic diseases, and lifestyle patterns. Among these, lifestyle has received increasing attention as a modifiable behaviour because this factor is relatively easily amendable with potential benefits for overall health as well as memory."

ApoE4 is a specific version of the apolipoprotein E (ApoE) gene, which plays a critical role in the transport and metabolism of cholesterol and other lipids in the body. The significance of ApoE4 lies in its association with an increased risk for several age-related diseases, including Alzheimer's disease.

Studies have shown that individuals who carry one copy of the ApoE4 gene are at an increased risk of developing Alzheimer's disease compared to those who carry other versions of the ApoE gene. Individuals who carry two copies of the ApoE4 gene have an even higher risk of developing Alzheimer's disease, and the onset of symptoms can occur at a younger age.

In addition to Alzheimer's disease, ApoE4 has been associated with an increased risk for other age-related diseases, including cardiovascular disease and some types of cancer.

It's important to note that while the presence of the ApoE4 gene increases the risk for these diseases, it is not a guarantee that an individual will develop them. Other factors, such as lifestyle, environmental factors, and overall health, also play a role.

Study Main outcome measures: Participants were followed up until death, discontinuation, or 26 December 2019. Six healthy lifestyle factors were assessed: a healthy diet (adherence to the recommended intake of at least 7 of 12 eligible food items), regular physical exercise (≥150 min of moderate intensity or ≥75 min of vigorous intensity, per week), active social contact (≥twice per week), active cognitive activity (≥twice per week), never or previously smoked, and never drinking alcohol. Participants were categorised into the favourable group if they had four to six healthy lifestyle factors, into the average group for two to three factors, and into the unfavourable group for zero to one factor. Memory function was assessed using the World Health Organization/University of California-Los Angeles Auditory Verbal Learning Test, and global cognition was assessed via the Mini-Mental State Examination. Linear mixed models were used to explore the impact of lifestyle factors on memory in the study sample.

Results: Over the 10 year follow-up period (2009-19), participants in the favourable group had slower memory decline than those in the unfavourable group. APOE ε4 carriers with favourable and average lifestyles exhibited a slower memory decline than those with unfavourable lifestyles. Among people who were not carriers of APOE ε4, similar results were observed among participants in the favourable and average groups compared with those in the unfavourable group. APOE ε4 status and lifestyle profiles did not show a significant interaction effect on memory decline (P=0.52).

Conclusion: A healthy lifestyle is associated with slower memory decline, even in the presence of the APOE ε4 allele. This study might offer important information to protect older adults against memory decline.