July 5, 2011
Having a parent with Alzheimer’s disease increases your risk of developing the disease yourself. But people whose mothers had Alzheimer’s are more likely to get the disease than those whose fathers had it.
Those are the results of a new study that looked at the brains of healthy people, some of whose parents had Alzheimer’s. The findings are consistent with earlier research showing that the chances of inheriting the disease from your mother are greater than from your father.
“It is estimated that people who have first-degree relatives with Alzheimer’s disease are four to 10 times more likely to develop the disease themselves compared to people with no family history,” said study author Robyn Honea of the University of Kansas School of Medicine in Kansas City. The findings were published in Neurology, the medical journal of the American Academy of Neurology.
For the study, researchers enlisted the help of 53 mentally alert men and women over age 60. Eleven had a mother with Alzheimer’s, 10 had a father with the disease, and the remainder said they had no family history of the illness.
Each study volunteer underwent a brain M.R.I. scan at the start of the study, then another scan two years later. Although all remained free of serious memory loss and other symptoms of Alzheimer’s, those whose mother had Alzheimer’s had more brain changes typical of Alzheimer’s disease.
Those with a mother with Alzheimer’s had less brain gray matter, a measure of brain vitality, than those without a family history. In addition, those who had a mother with Alzheimer’s disease had about one and a half times more whole brain shrinkage per year compared to those who had a father with the disease. Shrinking of the brain, or what doctors call brain atrophy, is a typical feature of Alzheimer’s disease and also occurs during normal aging.
“Using 3-D mapping methods, we were able to look at the different regions of the brain affected in people with maternal or paternal ties to Alzheimer’s disease,” said Dr. Honea. “In people with a maternal family history of the disease, we found differences in the break-down processes in specific areas of the brain that are also affected by Alzheimer’s disease, leading to shrinkage. Understanding how the disease may be inherited could lead to better prevention and treatment strategies.”
The authors call for more research into the inherited aspects of Alzheimer’s disease.
Having a parent with Alzheimer’s does not mean that you will get the disease yourself. There are many risk factors that come into play. But knowing you may be at increased risk can help to spur lifestyle changes that may help to lower your risk. Experts note that a heart-healthy diet, as well as an active life with lots of physical activity and mental stimulation, may all be good for the brain.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by William J. Netzer, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: R. A. Hones, R.H. Swedlow, E.D. Vidoni, et al: Reduced gray matter volume in normal adults with a maternal family history of Alzheimer disease. Neurology, Vol. 74, March 1, 2010, pages 113-120.