Alzheimer's treatments may be most effective in middle-aged people

By Sheilah Downey

Memory lapses for people disposed to Alzheimer's disease can start in their mid-50's, much sooner than previously thought, say researchers at the Mayo Clinic in Scottsdale.

Findings of the 14-year study suggest starting treatment for the memory-debilitating disease "not only before people develop symptoms but even before they reach older ages," said researchers.

Scientists studied 815 healthy people, ages 21 to 97, with two copies, one copy and no copies of the APOE e4 gene, the major genetic risk factor for Alzheimer's disease.

Each additional copy of the gene is associated with developing Alzheimer's at a slightly younger age, according to researchers. Approximately one out of four people have one copy of the gene and two percent have two copies, which were inherited from both parents.

"We found that memory declines begin to differentiate groups of people at these three levels of genetic risk starting between ages 55 and 60, years earlier than previously suspected," said lead author Dr. Richard Caselli, Chair of the Mayo Clinic's Neurology Department, "and well before the anticipated onset of clinically significant symptoms."

Caselli said that while other age-sensitive skills change, "memory appears to decline more quickly in APOE e4 gene carriers."

"This suggests that seemingly normal age-related memory loss may actually represent very early, preclinical-stage Alzheimer's disease," said Caselli.

Researchers said that the APOE e4 gene alone is not sufficient to give one the disease, that lifestyle and other genetic factors play a role.

The study's findings were published in the July 16 issue of the New England Journal of Medicine and were done in collaboration with researchers from other institutions in the Arizona Alzheimer's Consortium, including Arizona State University and the Banner Alzheimer's Institute.