Nowadays, tests to detect Alzheimer's disease almost always have memory as an object of analysis. The problem is that this disease may give the first symptoms up to 20 years before memory loss begins, but early diagnosis was still difficult to make.

Scientists at McGill University in Canada are studying ways to detect Alzheimer's as early as possible and thereby initiate therapies that try to delay the development of the disease as much as possible. Interestingly, the lack of sensitivity of smell can be one of the first indications that the person will be affected by this disease.

The study was based on 300 volunteers with Alzheimer's cases in the family, mainly parents. Their average age was 63, and they needed to identify a range of smells, such as gasoline or gum. These volunteers were also periodically tested with lumbar punctures for analysis of spinal fluid, which may show disease-related proteins.

Alzheimer's is currently detected mainly through memory tests.

Those with the greatest difficulty in identifying smells had the most protein present in the body, indicating that both scenarios may be related. The decreased olfactory sensitivity of Alzheimer's patients has been known for at least 30 years, but is usually seen in patients who have already developed the disease.

While not a cure for Alzheimer's, developing methods that can make diagnoses even earlier is one of the goals of modern medicine. Thus, symptoms can be delayed by at least 5 years, and detection is made less and less invasive.