People who have parents diagnosed with Alzheimer's disease or dementia may be more likely to have memory loss themselves in middle age, according to a study that will be presented at the American Academy of Neurology's 61st Annual Meeting in Seattle, April 25 to May 2, 2009.

For the study, researchers used the Framingham Heart Study to follow three generations of participants to study risk factors of Alzheimer's and other diseases. A total of 715 people belonging to the second generation of the Framingham Heart Study with an average age of 59 were included in the research. One group of 282 people had one or both parents with diagnosed dementia. The other group of 433 people had parents without dementia. Scientists tested for a gene thought to be a strong risk factor for dementia, called the ApoEe4 gene.

Among people who were carriers of the ApoEe4 gene, those who had parents with Alzheimer's disease or other dementia had two to three times the risk of having low verbal and visual memory performances than people who did not have parents with Alzheimer's disease.

"This result in people with parents who have Alzheimer's disease is equivalent to about 15 years of brain aging," said study author Stephanie Debette, MD, PhD, of Boston University and a member of the American Academy of Neurology. "The effect was largely limited to those who have the ApoEe4 gene, which supports the idea that the gene is probably at least partially responsible for the transmission of Alzheimer's disease risk between generations. However, all of these individuals were functioning normally, and only further testing can determine whether the poorer performance on memory testing in middle age would lead to an increased risk of developing Alzheimer's disease or other dementia later in life."

The study was supported by the National Institutes of Health.