New study finds 6 ways to slow memory decline and reduce dementia risk
While researchers have long known that there is a connection between dementia and factors such as social isolation and obesityThe size and scope of the new study adds substantial evidence to a global body of research suggesting that a healthy lifestyle can help the brain age better.
It also suggests that the effects of a healthy lifestyle are beneficial even for people who are genetically more susceptible to memory loss – a finding that is “very hopeful” for the millions of individuals around the world who carry the APOEε4 gene, a major risk factor for Alzheimer’s disease, said Eef Hogervorst, head in biological psychology at Loughborough University, who was not involved in the study.
Memory naturally gradually declines as people age. Some older people can develop dementia, an umbrella term that can include Alzheimer’s disease, and generally describes a deterioration in cognitive function that goes beyond the normal effects of aging. But for many, “memory loss can be just plain old forgetfulness,” write the BMJ study authors — like forgetting the name of a TV show you loved or that boring fact you wanted to look up.
Memory loss is no less damaging because it is gradual, and age-related memory loss can in some cases be an early symptom of dementia. But the good news, the researchers say, is that “it can be reversed or become stable rather than going into a pathological state.”
The BMJ study was conducted in China between 2009 and 2019. Researchers tested more than 29,000 people aged 60 and over, then tracked their progress or decline over time — known as a cohort study population based. Although more than 10,500 participants dropped out of the study over the next decade—some participants died or stopped participating—the researchers still used data collected from those individuals in their analysis.
At the start of the study, researchers conducted basic memory tests as well as testing for the APOE gene. They also surveyed the participants about their daily habits. Participants were classified into one of three groups – favorable, average and unfavorable – based on their lifestyle.
The six modifiable lifestyle factors the researchers focused on include:
- Physical exercise: at least 150 minutes of moderate or 75 minutes of vigorous activity per week.
- Nutrition: Eat adequate daily amounts of at least seven of the 12 foods (fruits, vegetables, fish, meat, dairy products, salt, oil, eggs, cereals, legumes, nuts and tea).
- Alcohol: I never drank or drank occasionally.
- Smoking: I have never smoked or am a former smoker.
- Cognitive activity: Exercising the brain at least twice a week (reading and playing cards or mah-jongg, for example).
- Social contact: Socializing with others at least twice a week (by attending community meetings or visiting friends or relatives, for example).
During the study, the researchers found that people in the favorable group (four to six healthy factors) and the average group (two to three) had a slower rate of memory decline over time than people with unfavorable lifestyles (zero to one healthy factor).
People who live a good lifestyle that includes at least four healthy habits they were also less likely to progress to mild cognitive impairment and dementia.
The results show that “more is better than these behaviors,” Hogervorst says—in other words, the more healthy lifestyle factors you can combine, the better your chances of preserving your memory and preventing dementia.
Significantly, this was true even for people who wore the APOE gene associated with a higher risk of Alzheimer’s disease.
“These results provide an optimistic perspective, as they suggest that although genetic risk cannot be modified, a combination of healthier lifestyle factors is associated with a slower rate of memory decline, regardless of genetic risk,” the study authors wrote.
The study stands out for its size and follow-up over time and because it was conducted in China, while “most publications are based on high-income Western countries,” Carol Brayne, a professor of public health medicine at the University of Cambridge who researches older people and dementia, said. in the email.
However, the study authors acknowledge several limitations, including that people’s self-reports of health behaviors may not be entirely accurate, and that people who participated in the study were more likely to lead healthy lives to begin with.
Some of the study’s findings differ from the results of other large studies conducted in the United States and Europe, Hogervorst says. For example, BMJ research found that the lifestyle factor with the greatest effect on reducing memory loss is a balanced diet. Other studies have shown that diet is less important than physical and mental exercise in old age, says Hogervorst.
Still, the results are consistent with the broad scientific consensus that there is a link between the way we live and our cognitive function as we age—and perhaps more importantly, suggest that it may never be too late to improve your brain health.
“The overall message of the study is positive,” Snorri B. Rafnsson, associate professor of aging and dementia at the University of West London, said in an email. “Namely, this cognitive function, and especially memory function, in later life can be positively affected by regular and frequent engagement in various health activities.”
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