The battle against Alzheimer's is picking up pace with new treatments using light therapy and new imaging techniques to provide earlier detection. Recently a latest study has suggested that symptoms of Alzheimer's disease can be detected by memory and cognitive tests 18 years before the disease is clinically confirmed.

Researchers in the study conducted in Chicago, administered nearly 2,125 people with an average age of 73. These people do not have Alzheimer's disease and they went through tests of memory and cognitive skills every three years for 18 years.

Analyzing the numbers of people in the study group who eventually developed Alzheimer's showed that those who scored lower overall on the tests had an increased risk of developing the disease, researchers reported in the journal Neurology.

Study lead author Kumar B. Rajan in the Department of Internal Medicine at Chicago's Rush University, said, “The changes in thinking and memory that precede obvious symptoms of Alzheimer's disease begin decades before”.

They study included both African-American and European-American participants, and almost 61% of the participants were women.

It was found that during the 18 years of the study nearly 23% of the African-American participants and 17% of the European-American participants developed Alzheimer's disease.

Researchers found that in the first years of the study participants who scored lower on the tests were about 10 times more likely to be later diagnosed with Alzheimer's disease than people with higher scores.

Rajan said the study suggests that even slight decline in cognitive function affects future risk of getting Alzheimer's disease.