Researchers are working to develop better methods for detecting Alzheimer's disease at an earlier stage.
However, they emphasize that further studies are needed before the blood test can be used widely.
The findings were published in a study in the Journal of the American Medical Association, as reported by HealthDay.
Although the blood test has already been approved by U.S. authorities, it is not yet recommended for healthy individuals without symptoms.
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The reason is that there are still no treatments capable of slowing the disease in people at high risk.
The same health advice
Researchers point out that the current recommendations remain unchanged.
According to HealthDay, regular exercise, a healthy diet, good sleep, and an overall healthy lifestyle remain the best advice.
The study was based on data from more than 2,600 older adults with no signs of cognitive impairment.
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Participants underwent blood tests, brain scans, and annual follow-up examinations.
The blood test provided the answer
The blood test measures the protein p-tau217, which is associated with Alzheimer's disease.
People with very high levels of p-tau217 had an estimated 38 percent risk of developing cognitive impairment within five years. After ten years, the estimated risk increased to 78 percent.
The findings therefore suggest that a blood test may be able to identify the risk of Alzheimer's disease up to ten years before symptoms appear.
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