6 science-backed ways to stave off dementia and preserve your memory as you age

• Memory and cognitive function tend to decline as people age.
• According to a recent paper, lifestyle choices can help slow that decline.
• A healthy diet, regular exercise, and an active social life can keep your memory stronger.

A healthy diet, regular exercise, and an active social life can help preserve your memory as you age.

That's according to a study published in The BMJ that followed almost 30,000 people in China for 10 years. Those who had more "healthy lifestyle factors" had slower memory decline than those who did not. Participants were all 60 years or older at the start of the study.

Researchers looked at six factors: a healthy diet, regular exercise, regular social contact, cognitive activities, and abstaining from both smoking and alcohol. 

Here's how the scientists defined each factor:

• A healthy diet: a varied daily diet that included at least 7 out of 12 food categories such as fruits, vegetables, fish, meat, dairy products, salt, oil, eggs, cereals, legumes, nuts, and tea.
• Regular exercise: at least 150 minutes of moderate activity or 75 minutes of vigorous activity each week 
• Regular social contact: visited friends or relatives, attended meetings, or chatted online at least twice a week
• Cognitive activities: played games (like cards or mahjong), read, and wrote at least twice a week
• Abstaining from smoking: never smoked or stopped smoking at least three years ago 
• Abstaining from alcohol: never drank alcohol or drank very occasionally 

People who followed four to six of these habits were categorized into the "favorable group" while those who followed two to three were put in the "average group." Participants with zero or one factor were categorized as the "unfavorable group."

After ten years, researchers found that people who followed healthier habits had slower memory decline than those who didn't. They used a standard test that asks patients to listen to and then recall a list of words to track memory changes over time.

The study also showed that healthy lifestyle habits benefited participants who had a well-known risk factor for Alzheimer's disease and other dementias. This suggests that despite having a higher risk for memory loss, a healthy lifestyle can have a positive effect on slowing memory decline, the authors of the report said. 

Of the six factors that the study looked at, researchers concluded that a healthy diet had the strongest effect on memory, followed by cognitive activity and then physical exercise. 

In an editorial, the study authors said that their research could offer important information that may help protect older adults against memory decline. They added that there needs to be further research on the link between healthy habits and the slowing of memory loss. 

"Prevention is important, given the absence of effective treatments for Alzheimer's disease and related dementias," they said.