In a new study published in BMJ, researchers have identified six lifestyle factors that can help patients slow memory decline and dementia risk.

Home- and community-based memory care models

The 6 factors that can reduce your risk of dementia

For the study, researchers in China followed 29,072 older adults over a 10-year period between 2009 and 2019. At baseline, the mean age of participants was 72.23 years, and 48.54% were women.

The 12 risk factors tied to 40% of dementia cases

At the start of the study, participants underwent baseline memory tests, as well as genetic testing for the APOE ε4 gene, which is a major risk factor for Alzheimer's. In total, 20.43% of the participants were carriers of the APOE gene.

In the study, the researchers assessed six healthy lifestyle factors, which participants reported through surveys at baseline and at each follow-up point (2012, 2014, 2016, 2019):

1. Physical exercise, which included at least 150 minutes of moderate exercise or 75 minutes of vigorous exercise per week
2. Diet, which included eating the appropriate daily amounts of at least 7 out of 12 food items (fruits, vegetables, fish, meat, dairy products, salt, oil, etc.)
3. Alcohol, which included never drinking or only drinking occasionally
4. Smoking, which included never having smoked or been a former smoker
5. Cognitive activity, which included activities to exercise the brain, such as reading or playing cards, at least twice a week
6. Social contact, which included socializing with others at least twice a week

Based on their responses, participants were divided into three groups: favorable (four to six healthy factors, average (two to three health factors), and unfavorable (zero to one healthy factor). In total, there were 5,556 participants in the favorable group, 16,549 in the average group, and 6,967 in the unfavorable group.

Overall, the researchers found that participants in the favorable and average groups had a slower rate of memory decline compared to those in the unfavorable group. People who lived a favorable lifestyle were also less likely to develop mild cognitive impairment and dementia compared to those in the other lifestyle groups.

Notably, these results were also true for participants who had the APOE gene.

"These results provide an optimistic outlook, as they suggest that although genetic risk is not modifiable, a combination of more healthy lifestyle factors are associated with a slower rate of memory decline, regardless of the genetic risk," the researchers wrote.

Commentary

According to Carol Brayne, a professor of public health medicine who studies dementia at the University of Cambridge, the study was notable for its size and its long follow-up period. It was also conducted in China, whereas "most publications are based on western high income countries," she said.

Eef Hogervorst, chair of biological psychology at Loughborough University, noted that while some of the study's findings differed from those of other large studies conducted in western countries, they still broadly align with scientific consensus that lifestyle factors can have a significant impact on cognitive function as people age.

The study's findings show that "more is better of these [health lifestyle] behaviors," Hogervorst said. He also said the study's suggestion that a healthy lifestyle can be beneficial even for people with a genetic risk of cognitive decline is "very hope-giving."

"The overall message from the study is a positive one," said Snorri Rafnsson, associate professor of aging and dementia at the University of West London. "Namely, that cognitive function, and especially memory function, in later life maybe positively influenced by regularly and frequently engaging in different health related activities." (Timsit, Washington Post, 1/26; Jia et al., BMJ, 1/25)