New Blood Test Finds Alzheimer’s 20 Years Before Symptoms Appear

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As we grow older, many of us worry about developing dementia. Now, a new blood test may detect if you are at risk for the disease 20 years before symptoms appear.

On July 28, researchers at the Alzheimer’s Association International Conference unveiled the results of a study, published in the medical journal JAMA, that found a blood test can identify Alzheimer’s disease — the most common form of dementia — in people with a rare genetic mutation, and do so two decades before cognitive issues develop.

Currently, memory and thinking tests often are used to diagnose Alzheimer’s. But blood testing offers more accuracy and is less expensive than other methods, such as spinal taps and brain scans, USA Today notes.

The blood test looks for an abnormal version of the tau protein found in brain cells — p-tau217 — which “seems to be the most specific to Alzheimer’s and the earliest to show measurable changes,” says the Alzheimer’s Association. It adds:

“Changes in brain proteins amyloid and tau, and their formation into clumps known as plaques and tangles, respectively, are defining physical features of Alzheimer’s disease in the brain. Buildup of tau tangles is thought to correlate closely with cognitive decline. In these newly reported results, blood/plasma levels of p-tau 217, one of the forms of tau found in tangles, also seem to correlate closely with buildup of amyloid.”

The association notes that the new testing technologies can help experts better identify the right people for clinical trials, which could spur the development of drugs to treat dementia.

Maria C. Carrillo, the Alzheimer’s Association chief science officer, says the possibility of being able to detect and treat Alzheimer’s early in the disease progression could be “game-changing for individuals, families and our health care system.”

However, Carrillo also cautions that the findings are “early results,” and it is not known how long it will be before the blood tests are available for clinical use. The next step is to test the new findings in long-term, large-scale studies, she says.

How to fight dementia

Dementia is a devastating disease. While there is no surefire way to prevent it — and no way to cure it — there are steps you can take to lower your risk of being diagnosed with dementia.

For example, research has shown that following the Mediterranean diet can cut your risk of cognitive impairment by more than one-third. For more tips, read “7 Lifestyle Changes That May Help Prevent Dementia.”

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