Onset Of Alzheimer's Can Be Ascertain Two Decades Before Symptoms: Study

Biological and cognitive disruptions in the brain may precede an Alzheimer's disease diagnosis by nearly two decades, and detecting them could improve intervention, a new study claims.

According to Business Standard, the study found an association between low scores on memory and cognitive tests and onset of Alzheimer's disease 18 years later. Every unit of lower performance was associated with an 85 percent increase in future risk of dementia.

For the study, researchers studied 2,125 participants aged 65 years and older from four Chicago neighborhoods. Among the participants, 442 people were diagnosed with dementia due to Alzheimer's during the 18-year study period.

"These associations were consistently larger among European Americans than among African Americans. Performance on individual cognitive tests of episodic memory, executive function, and global cognition also significantly predicted the development of AD dementia, with associations exhibiting a similar trend over 18 years," the researchers wrote in the journal Neurology.

"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. Efforts to successfully prevent the disease may well require a better understanding of these processes near middle age," said Kumar Bharat Rajan, assistant professor at Rush University Medical Center who led the study, told Business Standard.