Can a Healthy Lifestyle Reduce Your Dementia Risk Despite Genetics?
Having a family history of Alzheimer’s disease can make any mental lapses a cause for worry.
But does this mean you’re guaranteed to eventually develop the disease?
New findings presented at the annual Alzheimer’s Association International Conference this weekend indicate that simple lifestyle changes can significantly reduce that risk.
The studyTrusted Source, led by the University of Exeter in England and published in the Journal of the American Medical Association (JAMA), concluded that the risk of dementia was significantly lower in people with genetic risk if they followed a healthy lifestyle.
“We know from previous research that both genes and lifestyle are associated with dementia risk. However, this is the first study that comprehensively investigates the combination of the two in relation to dementia. We wanted to find out whether lifestyle may offset genetic risk for dementia,” Elżbieta Kuźma, PhD, a research fellow at the University of Exeter College of Medicine and Health and a joint lead author of the study, told Healthline.
“We looked at a combination of lifestyle factors that have been previously associated with dementia risk,” she added. “We included no current smoking, regular physical activity, moderate alcohol consumption, and healthy diet as healthy behaviors in our healthy lifestyle score and categorized it as favorable, intermediate, and unfavorable. We found that favorable lifestyle reduced the risk of dementia by 32 percent in those with high genetic risk compared to unfavorable lifestyle.”
Jason Krellman, PhD, ABPP-CN, a board-certified clinical neuropsychologist, agreed that lifestyle is a major factor.
“Previous research already shows that smoking increases Alzheimer’s disease risk,” he told Healthline. “The likely reasons for this are oxidative stress or cerebrovascular disease caused by smoking increasing susceptibility to the development of Alzheimer’s pathology in the brain.”
“While moderate alcohol intake may reduce the risk of developing Alzheimer’s disease,” he added, “higher amounts can have the reverse effect, increasing inflammation that ultimately damages heart and brain tissue, making the brain more vulnerable to Alzheimer’s and other disease processes.”
Researchers analyzed data from the UK Biobank of 196,383 adults of European ancestry who were aged 60 and older.
Researchers assessed genetic risk by looking at previously published data to identify known factors for Alzheimer’s disease. Each risk factor was then considered according to how strongly it was associated with the disease.
They identified 1,769 cases of dementia over an eight-year follow-up period.
The participants were grouped by whether they had a high, intermediate, or low genetic risk for developing dementia.
“This research delivers a really important message that undermines a fatalistic view of dementia,” David Llewellyn, PhD, a joint lead study author and an associate professor of neuroepidemiology and digital health at the University of Exeter Medical School, said in a statement. “Some people believe it’s inevitable they’ll develop dementia because of their genetics. However it appears that you may be able to substantially reduce your dementia risk by living a healthy lifestyle.”
According to the National Institute on Aging, there is a strong genetic component to Alzheimer’s disease.
“We’ve identified genetic mutations that carry a very strong risk for the uncommon early-onset form of Alzheimer’s disease, which starts to show symptoms as early as the third decade of life but accounts for less than 10 percent of all [Alzheimer’s] cases,” Krellman said.
The gene found to be the strongest predictor of Alzheimer’s risk is called ApoE, and there are three varieties:
We all carry two copies of this gene, but researchTrusted Source shows that carrying the ApoE4 variety significantly increases Alzheimer’s risk. Having just one copy of ApoE4 can triple your risk.
However, for late-onset Alzheimer’s disease, the most frequent type of dementia that can appear after age 65, there may be multiple genes, lifestyle factors, and even environmentalTrusted Sourcefactors that determine whether you’ll develop the disease.
In another study, researchers at Tianjin Medical University, China, examined whether a lifetime of mental and social activity was linked to both a reduced rate of memory loss and lower risk of developing dementia, despite age-related changes to the brain.
The degree of lifetime mental and social activity is called cognitive reserveTrusted Source.
The researchers found that, despite having degenerative brain disease or Alzheimer’s, there was reduced risk if a senior had high scores in lifespan cognitive reserve.
The lifespan cognitive reserve score combined education, social activities in later life, size of social networks in later life, and mental activity in early-life, midlife, and late-life.
The studyTrusted Source, published in JAMA Neurology, found that seniors who had the highest lifetime cognitive reserve had a 39 percent lower risk of dementia, compared to those with the lowest reserve.
“Social engagement, cognitive stimulation in activities the person enjoys, maintaining a regular schedule of restful sleep, and reducing psychological stress have also been shown to decrease development and severity of [Alzheimer’s] as well as lead to a better overall quality of life,” said Krellman.
According to Krellman, the development and progression of Alzheimer’s and other neurodegenerative diseases are governed by many factors out of a person’s control, such as genetics.
However, he emphasized that “controlling those factors the person can modify, such as diet, activity level, and social engagement, might slow progression of symptoms in some people.”
“Cognitive stimulation in activities the person enjoys and maintaining a regular schedule of restful sleep might also be helpful,” he added. “None of these are ‘magic bullets’ guaranteed to slow disease progression but are very likely to increase quality of life and overall health, and this has obvious benefits even if the disease itself is not impacted.”
“We were very excited to see a consistent pattern in our analyses. Genetic risk and lifestyle factors were independently associated with risk of dementia, indicating that healthy lifestyle is associated with reduced dementia risk regardless of genetic risk,” Kuźma said. “So it’s not only about those with high genetic risk, but it does suggest that even though we can’t change our genes, we can change our lifestyle to try to reduce the risk of dementia.”