Dementia Risk Could Be Predicted in 10-Year Window, Study Suggests

The risk of older people developing dementia in a 10-year window has been calculated in a study.

Danish researchers investigated data on 104,537 people in Copenhagen, Denmark to uncover how factors including a person's age and sex determined their 10-year risk of developing dementia. They also noted whether the participants carried the E (APOE) protein, believed to be a genetic risk factor of Alzheimer's disease. The protein helps the brain to sweep up amyloid-beta, the plaque which has been linked to Alzheimer's disease.

The white, Danish, participants included in the research took part in two studies carried out in the Danish capital. In the Copenhagen General Population Study, respondents were enrolled between 2003 and 2015, with follow-up examinations ongoing. In the Copenhagen City Heart Study, meanwhile, individuals were first examined between 1976 to 1978, and three more times in the early 1980s, 1990s and 2000s.

Researchers asked volunteers about their lifestyles, performed physical examinations on them, and took blood samples. The participants were divided into three age groups.

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An estimated 5.7 million people in the U.S. have Alzheimer's disease. Getty Images

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Dementia, the neurodegenerative disease of which Alzheimer's disease is the most common form, affects as many as 50 million people worldwide according to the World Health Organization.

Dr. Ruth Frikke-Schmidt, professor at the University of Copenhagen department of clinical biochemistry, said in a statement: "Recently, it was estimated that one third of dementia [cases] most likely can be prevented.

"According to the Lancet Commission, early intervention for hypertension, smoking, diabetes, obesity, depression and hearing loss may slow or prevent disease development. If those individuals at highest risk can be identified, a targeted prevention with risk-factor reduction can be initiated early before disease has developed, thus delaying onset of dementia or preventing it."

A combination of a person's age, sex and whether or not they had a common form of the APOE gene could paint a picture of whether they might develop dementia, the authors found. They published their findings in the Canadian Medical Association Journal.

For women in their 60s, there was a 7 percent risk, compared with 6 percent for men. In the decade following their 70th birthday, their risk climbed to 16 percent and 12 percent respectively, rising to 24 and 19 percent for those aged 80 and above.

But as the study was focused solely on white European participants from a relatively small geographic area, more research is needed to relate the results to a wider population.

"The present absolute 10-year risk estimates of dementia by age, sex and common variation in the APOE gene have the potential to identify high-risk individuals for early targeted preventive interventions," the authors concluded.

Dr. James Pickett, head of research at the U.K.-based charity Alzheimer's Society, told Newsweek prevention is paramount in the organization's priorities.

"Some genes can make us slightly more likely to develop dementia—APOE is one such gene. This study tells us how it has a greater effect on dementia risk in later life."

He continued: "No matter what genes you have, our advice remains the same—the best way to keep your brain healthy in later life is to eat a balanced diet, avoid smoking and excessive drinking, and take regular exercise."

Dr. Rosa Sancho, head of research at the charity Alzheimer's Research UK, told Newsweek: "We know that dementia risk is influenced by a range of factors including age, sex, lifestyle and genetics. APOE is the gene that has the greatest effect on most people's risk of dementia, but researchers have identified variations in around 30 other genes that are also linked to an altered risk.

"Identifying people who are most at risk is a vital part of large-scale risk reduction programs for conditions like heart disease. As researchers work to develop strategies that can help people to maintain a healthy brain, it will become increasingly important to recognize those at the highest risk of dementia, for whom such strategies are likely to be particularly valuable."