People At Genetic Risk For Alzheimer's Age Are Mentally Just Like Noncarriers, Study Finds

... Australian researchers say that a genotype that heightens the risk for Alzheimer's disease does not contribute to cognitive change during most of adulthood. The largest study of its kind has found that carriers and noncarriers show the same type and extent of normal age-related cognitive declines, decades before carriers start to more often develop symptoms of dementia. The findings suggest that the higher-risk genotype acts only in later years to layer disease on top of normal aging. ...