Dementia has a silent beginning, according to most scientists. The changes in the brain that lead to diseases like Alzheimer’s begin decades before symptoms like debilitating memory loss begin. The problem is, most people will never know they have the signs of Alzheimer’s in their brain until they’re already in the midst of the disease. And while right now there is no treatment that can stop the progression of Alzheimer’s, researchers have concluded that an Alzheimer’s treatment would need to be started decades before symptoms begin in order to be effective.
But what if we could predict who would get Alzheimer’s years in advance? And what if patients didn’t even have to undergo expensive PET scans or invasive cerebrospinal taps in order to get that information? That’s what a group of Danish scientists has been asking in a study on over 100,000 people that spanned four decades.
Scientists from The University of Copenhagen have put together a test that determines risk of developing Alzheimer’s ten years in advance. The formula considered factors like gender, genetics, age and sex. The test combines a simple blood test with those factors in order to determine risk at different ages.
For example, women between the ages of 60 and 69 with two copies of the ApoE4 gene, the factor most associated with Alzheimer’s besides age itself, had a seven percent risk. In the next decade, that risk jumped to 12 percent. In the 80 to 89-year-old group, the risk rises to 24 percent for women with two copies of ApoE4 and 19 percent for men.
Having a test for Alzheimer’s to determine who is at the highest risk for developing Alzheimer’s could help researchers get treatment into the hands of those who need it most before things like daily functioning and memory are compromised. And while there is no such treatment yet, other studies have shown that interventions like diet can actually make a difference. The FINGER trial, for example, found that a combination of a diet rich in fish and fruits and vegetables, regular exercise and brain training could lower the risk of dementia by up to 30 percent, even amongst those with the ApoE4 gene.
For those who fall into the high-risk category, interventions like those in the FINGER trial could make a big difference. “One interesting finding from the trial is that, if you have ApoE4, which is the main genetic risk factor, it seems that the effect of modifying lifestyle factors may be even stronger,” said Dr. Miia Kivipelto, M.D., one of the key researchers on the study. “That’s a really positive finding—you can’t change your genes but you can pay extra attention to lifestyle factors,” said Kivipelto in an interview with Being Patient.
More and more researchers are turning to prevention as the key to eliminating Alzheimer’s.
“Recently, it was estimated that one-third of dementia most likely can be prevented,” said Ruth Frikke-Schmidt, professor at the University of Copenhagen. “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,” said Frikke-Schmidt.
There are limitations to the study, though—all the people involved were white and of European descent. It could be that people with different backgrounds and the ApoE4 gene don’t have the same risk as the people in the study. And similar to other measures of disease risk, like the Framingham risk score for cardiac disease, it doesn’t take into account several other factors that could be triggering dementia.
This study was published in the Canadian Medical Association Journal.