A good diet and ample exercise don't just help your waistline. Healthy lifestyle factors may also help lower your risk of dementia, even if you have a higher genetic risk, according to a study published Sunday in the medical journal JAMA.
This study, along with other research looking at the impact of lifestyle factors on dementia, is being presented at the Alzheimer's Association International Conference this week.
There is no cure for or preventive medicine that can stop dementia and its most common form, Alzheimer's disease. But a growing body of evidence suggests the way you live can potentially lower your risk.
The study found that among people with a high genetic risk, those who maintained a health lifestyle -- meaning they watched their diet, exercised regularly, kept their drinking to a minimum and didn't smoke -- were less likely to develop dementia later in life.
The study looked at 196,383 adults age 60 and older who lived in the UK and found that specifically, 1.13% of those with a healthy lifestyle developed dementia later in life compared with 1.78% of those with a less healthy lifestyle -- a statistically significant difference.
The adults who took part in the study joined it from 2006 to 2010 and researchers followed up with them until 2016 to 2017.
"This research is exciting in that it shows there are actionable things we can do to try to counteract genetic risk for dementia," said Elzbieta KuÅºma, a research fellow at the University of Exeter Medical School who worked on the study. "In our study, adherence to a healthy lifestyle was associated with a reduced risk of dementia regardless of the genetic risk."
There are some limitations to the study. Patients were all of European ancestry and they self-reported their lifestyle.
"While this well-conducted study adds to data suggesting that a healthy lifestyle can help prevent dementia in many people, it is important to remember that some people will develop dementia no matter how healthy their lifestyle," Tara Spires-Jones, UK Dementia Research Institute programme lead, told Science Media Centre.
Spires-Jones, who is also deputy director of the Centre for Discovery Brain Sciences at the University of Edinburgh, was not involved in the new study.
"We need more research into the brain changes that cause the diseases underlying dementia symptoms in order to develop effective preventions and treatments for everyone affected by dementia," Spires-Jones said.
Another study being presented at the Alzheimer's conference found a similar result after looking at data from the Chicago Health and Aging Project and the Rush Memory and Aging Project which followed up with patients after nine years.
People who adopted four or five healthy lifestyle habits -- a healthy diet, at least 150 minutes a week of moderate to vigorous physical activity, light to moderate drinking, no smoking, and engaging in mentally stimulating activity -- reduced their risk of developing Alzheimer's by 60% compared to people who had only one of those healthier behaviors.
People who added just one more of those healthy habits to their lifestyle, regardless of how healthy they were when the study started, saw their risk of Alzheimer's drop by 22%.
Additional studies being presented at the conference also showed that women who were alcoholics significantly increased their risk of dementia later in life. Smoking also seems to be associated with cognitive impairment, even at mid-life.
Earlier research has shown connections to a healthy lifestyle may help prevent some forms of dementia, but scientists still don't quite understand why. Alzheimer's is the sixth leading cause of death in the United States and the number of cases is increasing. While 5.8 million Americans live with Alzheimer's now, scientists project the number will rise to nearly 14 million by 2050.
"While there is no proven cure or treatment for Alzheimer's, a large body of research now strongly suggests that combining healthy habits promotes good brain health and reduces your risk of cognitive decline," said Maria C. Carrillo, the Alzheimer's Association chief science officer. "The research reported today at [the conference] gives us attainable, actionable recommendations that can help us all live a healthier life."