The four easy habits that could prevent dementia more than exercise
Aging experts have long advised aging adults to exercise regularly to maintain their cognitive health, but new research points to an even more effective and easy way to prevent dementia.
A Georgetown University study followed more than 20,000 adults over a decade and found that physical activity alone had no significant effect on slowing cognitive decline in people over 50. Walking, jogging, or even vigorous exercise did not move the needle on its own.
The likely reason is that the brain benefits of exercise may be locked in earlier in life. Someone active in their 30s and 40s has likely already reaped the neurological benefits of exercise, such as boosting brain cell growth and reducing the risk of Alzheimer's disease and other forms of dementia. Starting later may be too little, too late.
For adults over 65, the study found frequent cognitive activity became the strongest predictor of slower decline. Reading regularly, writing, playing cards or chess, doing puzzles or using a computer – these habits were tied to markedly better cognitive health predictions and a better chance at preventing dementia, a group of conditions that affects nearly seven million Americans.
Researchers identified four activities that older adults should work into their daily lives to help stave off the onset of dementia. The first recommended habit is keeping the brain active by reading, writing, doing puzzles or playing Scrabble.
The second was partaking in social activities with friends in family. The third was taking part in social organizations such as volunteer groups and the fourth was to do all of these things equally without focusing on one or two.
The protective effect was comparable in size to the cognitive toll of having diabetes. In the same way diabetes accelerates decline, daily mental engagement appears to slow it.
And adults who spread their time across many different activities showed slower cognitive decline. The benefit was nearly as large as the harm caused by smoking, which has long been one of the strongest drivers of cognitive decline.
Middle-aged and older adults who engaging in mentally stimulating activities, including social time with friends and family, saw slower cognitive decline over time (stock)
Researchers drew on national Health and Retirement Study (HRS) data from 2008 to 2020, following 20,817 adults age 50 and older across up to seven waves of interviews, a total of 86,567 observations.
The sample from the Midlife in the United States (MIDUS) added 2,713 adults ranging from their 30s to their 80s, tracked over roughly a decade.
Participants reported how often they engaged in cognitive tasks, like reading, writing, word games or computer use; physical activity, including light, moderate and vigorous exercise; social contact, including time with family and friends; and participation in clubs, religious services and organizations.
Researchers also calculated an activity diversity score – whether people spread their time evenly across all four types of activity or concentrated on just one or two.
The analysis controlled for dozens of variables known to affect activity levels and brain health, including education, smoking, diabetes, high blood pressure, depression, head injury and more.
Between the ages of 55 and 65, people who spread their time evenly across cognitive, physical and social activities showed significantly slower cognitive decline. The benefit of a varied routine, researchers said, was nearly as large as the harm that is done by smoking.
For adults 65 and up, frequent cognitive activity, including reading, writing, puzzles and using the computer, emerged as the strongest predictor of slower decline. By 85, those who stayed mentally engaged had significantly higher cognitive scores than those who did not.
Researchers posited that the protective effect was comparable in size to the cognitive toll of having diabetes, which can accelerate decline at a similar rate.
The graph shows that people who engage in frequent cognitive activities [blue] maintain higher cognitive scores across aging, with the gap between them and the average widening by age 85. The protective effect of mental engagement is roughly as large as the cognitive damage caused by diabetes [red], just in the opposite direction
The above graph shows that people with high activity diversity maintain better cognitive function than average, though the gap stops widening after age 75. The benefit of diversity in midlife is comparable in size to the cognitive damage caused by smoking
The study, published in the journal Innovation in Aging, found that the benefits compound over time. The people who kept their minds active and busy started ahead but also saw a slower decline.
Activity diversity, or, doing a little bit of everything, had the strongest effects in midlife. At 55, high-diversity participants saw a meaningful difference in decline, roughly the equivalent of being one to two points higher on a typical 100-point cognitive test.
By 75, that advantage had nearly doubled, meaning the diverse activity group effectively aged two to three years slower than their peers over that two-decade span.
Physical activity showed no such influences on cognitive health in that time among the middle-aged and older adults.
This could be because the cognitive benefits of exercise may be locked in earlier in life. An active person in their 30s and early 40s likely builds cognitive reserves that support brain development and aging down the line.
But for a person who only starts to become physically active in their 50s and beyond, researchers said they ‘have slim prospects for slowing future cognitive decline.’ Starting to exercise late probably cannot reverse or slow the decline that is already underway.
That does not mean that exercise lacks value at any age. It is essential for heart health, physical function that helps older adults remain independent and quality of life.
But the latest research suggests that one needs to start early and stick with it, not expect that a late-in-life fitness bent will undo decades of neurological wear.
