Study identifies six factors linked with lower risk of dementia; expert says 'It may never be too late to improve your brain health'

A new study of more than 29,000 older adults in China has identified six habits "that are linked with a lower risk of dementia and a slower rate of memory decline," Annabelle Timsit of The Washington Post reports. "Eating a balanced diet, exercising the mind and body regularly, having regular contact with others, and not drinking or smoking . . . were associated with better cognitive outcomes in older adults." Specifially, the six modifiable lifestyle factors were:

• Exercise: At least 150 minutes of moderate activity or 75 minutes of vigorous activity per week.
• Diet: Appropriate daily amounts of at least seven of 12 food items (fruits, vegetables, fish, meat, dairy products, salt, oil, eggs, cereals, legumes, nuts and tea).
• Alcohol: Never drank, or drank occasionally.
• Smoking: Never smoked, or a former smoker.
• Cognitive activity: Exercising the brain at least twice a week (examples: reading and playing cards).
• Social contact: Engaging with others at least twice a week (examples: attending community meetings or visiting with friends or relatives).

The study was conducted from 2009 to 2019 and published in the British Medical Journal. "While researchers have long known that there is a link between dementia and factors such as social isolation and obesity, the size and scope of the new study adds substantial evidence to a global body of research that suggests a healthy lifestyle may help brains age better," Timsit writes. "It also suggests that the effects of a healthy lifestyle are beneficial even for people who are genetically more susceptible to memory decline — a 'very hope-giving' finding for the millions of individuals around the world who carry the APOEε4 gene, a major risk factor for Alzheimer’s disease, said Eef Hogervorst, chair of biological psychology at Loughborough University, who was not involved in the study."

Timsit notes, "Memory naturally declines gradually as people age. Some older people may develop dementia, an umbrella term that can include Alzheimer’s, and generally describes a deterioration in cognitive function that goes beyond the normal effects of aging. But for many, 'memory loss can merely be senescent forgetfulness,' write the authors of the BMJ study — like forgetting the name of that TV program you used to love, or that pesky fact you wanted to look up.

"Memory loss is no less damaging for being gradual, and age-related memory decline 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 progress to a pathological state.' . . . At the start of the study, researchers conducted baseline memory tests as well as testing for the APOE gene. They also surveyed participants about their daily habits. Participants were sorted into one of three groups — favorable, average and unfavorable — based on their lifestyle. Over the course of the study, the researchers found that people in the favorable group (four to six healthy factors) and 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 living favorable lifestyles that included at least four healthy habits were also less likely to progress to mild cognitive impairment and dementia. . . . Notably, this held true even for people who carried the APOE gene associated with a higher risk of Alzheimer’s disease.

"Some of the study’s findings differ from the results of other large studies conducted in the United States and in Europe, says Hogervorst. For instance, the BMJ study found that the lifestyle factor with the greatest effect on reducing memory decline was a balanced diet. Other studies have suggested that diet matters less in old age than physical and mental exercise, says Hogervorst. Still, its results align with the broad scientific consensus that there is a link between how we live and our cognitive function as we age — and perhaps more important, suggest that it may never be too late to improve your brain health."