A study of people in the US suggests those at high genetic risk of dementia are less likely to develop the condition if they improve their lives in seven ways
25 May 2022
People with a high genetic risk for dementia can reduce the likelihood of developing the disorder by living a healthier lifestyle, a study in the US suggests.
Adrienne Tin at Johns Hopkins University in Maryland and her colleagues used data from more than 11,000 people in the US collected between 1987 to 2019. The participants had an average age of 54 at the start of the study and were followed, on average, for 26 years. Of these people, 8823 were of primarily European descent and 2738 were of primarily African descent.
The researchers devised a score for each participant based on seven health factors. These are: to stop smoking, eat a healthy diet, maintain a healthy weight, remain physically active, and to control blood sugar levels, cholesterol levels and blood pressure. The team combined these factors into a single score on a 14-point scale, with 0 being the least healthy and 14 the healthiest.
These factors are promoted by the American Heart Association as a means to maintain good cardiovascular health and are known as “Life’s Simple 7”. Previous studies have shown that improving your health in any of these areas can also reduce the likelihood of developing dementia, says Tin.
In this study, the researchers wanted to see if this was still true for those who are most at risk of developing dementia due to their genetics.
The team used genome-wide association studies to assess each person’s genetic risk for developing dementia, and then used the information to split the participants into groups based on how high their risk was. Those in the highest risk group were 1.5 to 2.7 times as likely to develop the disease as those in the lowest risk group.
The researchers found that people of primarily European descent in the highest genetic risk group could reduce the likelihood of developing dementia by 8 per cent for each point by which they increased their healthy lifestyle score on the 14-point scale.
They also saw similar results for people of primarily African descent, but due to the smaller sample size the researchers can’t be as certain about their conclusions, says Tin. Overall, people of primarily African descent who scored between 9 and 14 in the lifestyle assessment had a 17 per cent lower risk of dementia than those who scored between 0 and 6, the team found.
In the timespan studied, 2234 of the participants developed dementia. “There were no major differences in our findings between African and European ancestry,” Tin says.
“These findings show that it’s particularly advantageous to maintain [these healthy habits] early in life, since our study finds that a higher Life’s Simple 7 score in midlife is associated with lower risk for dementia,” she says.
She says the next step is to determine what social factors may prevent individuals from making their lifestyles healthier.
“These results are very promising,” says Claudia Cooper at University College London. “They show that while none of us can know for certain our starting risk for developing dementia, we can all take steps to reduce it.”
Rosa Sancho at the charity Alzheimer’s Research UK says the results are good news, but notes that because the lifestyle score was taken at the start of the study, it is unclear whether a participant’s healthy habits lasted for the rest of the study.
“Ideally, future studies should also include continually monitoring health habits in the participants to assess long-term effects of a healthy lifestyle,” she says.
Journal reference: Neurology, DOI: 10.1212/WNL.0000000000200520
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