Scientists believe Alzheimer’s begins decades before it was found and now they say simples tests can predict the incidence of the disease in 18 years before it gets detected with current methodology. Instead of physical tests, it is possible to detect it with simple tests on errors on memory and thinking tests, they say.
Kumar B Rajan, an Indian-origin scientist with Rush University Medical Center in Chicago, said: “The changes in thinking and memory that precede obvious symptoms of Alzheimer’s disease begin decades before. While we cannot currently detect such changes in individuals at risk, we were able to observe them among a group of individuals who eventually developed dementia due to Alzheimer’s.”
The study conducted on 2,125 European-American and African-American people from Chicago aged about 73 on average without Alzheimer’s disease, showed that some of them who took tests did give away signs of the disease that may impact them 18 years from now.
The findings showed that 23% of African-Americans and 17% of European-Americans developed Alzheimer’s disease during the study and those who scored lower overall on the memory and thinking tests had an increased risk of developing the disease.
During the first year of the study, it showed that people with lower test scores were about 10 times more likely to develop Alzheimer’s disease than people with higher scores, with the odds up by 10 for every standard deviation that the score was lower than the average.
Based on tests conducted over 13 to 18 years before the final assessments took place, one unit lower in performance of the standardised cognitive test score was associated with an 85 per cent greater risk (relative risk of 1.85) of future dementia.
“A general current concept is that in development of Alzheimer’s disease, certain physical and biologic changes precede memory and thinking impairment. If this is so, then these underlying processes may have a very long duration,” Kumar said.
“Efforts to successfully prevent the disease may well require a better understanding of these processes near middle age,” Kumar said.