Memory can decline as people age, for many reasons – from neurological conditions such as Alzheimer’s disease to physiological conditions such as depression. Now, a new study has found a list of specific things that we can all do on a daily basis to slow our memory decline – from a healthy diet to regular social contact.

Previous studies looked at the effect of a healthy lifestyle on memory loss but the evidence was insufficient, the researchers said. So, to explore this further, the researchers who conducted this study analyzed data from 29,000 adults at least 60 years old with normal cognitive function. The participants had a mean age of 72 years, 51% were men and 20% carried the apolipoprotein E (APOE) gene.

The study started in 2009 and continued for over 10 years. At the start, the researchers measured memory function using the Auditory Verbal Learning Test (AVLT), neuropsychological assessment, and tested participants for the APOE gene, associated with Alzheimer’s. They then did follow-up assessments in 2012, 2014, 2016 and 2019.

“This study might offer important information to protect older adults against memory decline,” the researchers, led by Jianping Jia from Capital Medicine University, wrote in the journal BMJ. “A combination of positive healthy behaviours is associated with a slower rate of memory decline in cognitively normal older adults, including in people with the APOE4 allele.”

Memory loss and daily habits

The researchers calculated a healthy lifestyle score by combining six factors: not drinking alcohol, cognitive activity (writing, reading, etc), active social contact (seeing friends and family), regular exercise and a healthy diet. Based on their score, from 0 to 6, participants were put in three lifestyle groups: favorable, average or unfavorable.

A diet was considered healthy when eating at least seven of the 12 food groups: fruits, vegetables, fish, meat, dairy, salt, oil, eggs, cereals, legumes, nuts and tea. Social contact was considered active when happening at least twice a week, while exercise was considered regular when doing over 150 minutes a week at a moderate intensity.

After considering other economic, social and health factors, the researchers found that each of the six behaviors was linked with a slower-than-average decline in memory over the 10-year period of the study. The strongest effect on slowing memory decline was thanks to a healthy diet, followed then by cognitive activity and physical exercise

Participants with the APOE gene in the favorable and average groups also experienced a slower rate of memory loss. Those with favorable or average lifestyles were almost 90% and almost 30%, respectively, less likely to develop dementia or mild cognitive impairment relative to those with an unfavorable lifestyle.

The APOE group had similar results. The study was observational and had some limitations, such as self-reporting of lifestyle factors or selection bias.

However, the researchers believe their results provide strong evidence that following a healthy lifestyle with a combination of positive behaviors is linked with a slower rate of memory decline. They suggest that further studies could look at the effects of a healthy lifestyle on memory decline across the lifespan, as memory problems can also affect young people.