2 Studies Hint at Role of Genetics in Staving Off Dementia

Dorian Martin Health Guide
  • Sometimes it pays to be born in the right family. Two new studies seem to hint at genetic reasons why elders may avoid having dementia.

    Genetic Protection

    A new study out of Mount Sinai School of Medicine in New York has found a family link to the ability to avoid dementia. This study was published in the August 15, 2012 issue of Neurology, the medical journal of the American Academy of Neurology.

    The study involved 277 male veterans who were 75 years old and above who were also free of dementia symptoms. These study participants were administered a test that gauged the levels of C-reactive protein, which is related to inflammation. Interviews with participants about their parents and siblings found that 40 relatives from 37 families did, indeed, have dementia. The researchers then interviewed a secondary, independent group of 51 men who were 85 years old and above about their relatives. They found that nine of 202 relatives had dementia.

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    The analysis found that study participants who had higher amounts of C-reactive protein were more than 30 percent less likely to have relatives who had dementia. Researchers also found similar results in the secondary group. The researchers noted that the protein levels were not associated with education level, marital status, occupation and physical activity.

    “This protein is related to worse cognition in younger elderly people,” said Dr. Jerry Silverman, the study’s lead author. “Thus, for every old people who remain cognitively healthy, those with a high protein level may be more resistant to dementia. Our study shows that this protection may be passed on to immediate relatives.”

    Characteristics of Brain Regions in Some Elderly

    Brain characteristics also play a part in another recent study. Researchers from Northwestern University’s Cognitive Neurology and Alzheimer’s Disease Center selected 12 people who were 80 years old and above who also did as well or better on memory tests than people who 20-30 years younger. The study was published in the Journal of the International Neuropsychological Society.

    The researchers performed MRI scans on the study participants. They found that these people’s cortex, which is the outer layer of the brain that is partially responsible with memory, attention and other thinking abilities, was thicker than a comparison group of people who were of similar age. In fact, the researchers found that the elders’ brain cortex more closely matched the middle-age people who were in the control group.

    The MedlinePlus story notes that this study is unique because it looks at elders who have exceptionally good memories and then tries to determine what makes their brains special. While there is a correlation between memory level in later life and a thick cortex and large brain volume, the study did not show cause and effect. “It could be that those whose brains are better ‘built to last’ structurally are probably those brains that are better built to last from a functional perspective, or that those who are exercising their brains may have less atrophy,” Dr. Russell Swerdlow, director of the University of Kansas’ Alzheimer’s Disease Center told MedlinePlus.

  • The researchers also found that elders who had a superb memory had a larger cingulate cortex than the middle-age study participants. The researchers are not sure whether elderly participants who had this brain region, which also is involved in attention and memory, resisted atrophy as the participants aged or whether these elderly were born with a stronger cingulate cortex.

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    Experts believe that the brains of these elders are helped by genetics supported by a healthy lifestyle. However, the researchers noted that some of these elders in this study smoked regularly, didn’t exercise and/or didn’t work. Therefore, it sounds to me like genetics may be the biggest factor here but it doesn't hurt to embrace a healthy lifestyle.

    Primary Source for this Sharepost:

    American Academy of Neurology. (2012). Resistance to dementia may run in families.

    MedlinePlus. (2012). Sharp as a tack at 90: Here’s why.

Published On: August 17, 2012