Genes May Be Key to Long, Dementia-Free Life
(NEW YORK) -- A study published online Wednesday in the journal Neurology shows some evidence that protection from dementia clusters in families.
Lead investigator Jeremy M. Silverman, a professor in the department of psychiatry at the Mount Sinai School of Medicine, and his colleagues examined 277 male veterans, aged 75 and older, who were free of dementia symptoms. They conducted blood tests to measure levels of a substance called C-reactive protein in the men's blood. Since high levels of C-reactive protein tend to correspond to high levels of dementia in younger elderly patients, some assume those elderly patients with high levels of C-reactive protein who do not develop dementia are somehow resistant to cognitive decline.
The researchers then interviewed 1,329 of the test subjects' relatives to assess their rates of dementia. What they found was that the rates of dementia in the families of patients who exhibited resistance was lower than the rate seen in families of patients who did not show resistance.
To validate these findings further, investigators repeated the study with an older group of 51 patients and surveyed 202 of their relatives. This group returned the same results. In both study populations, patients with resistance to dementia were over 30 percent less likely to have relatives with dementia.
Since C-reactive protein is not always linked to dementia, the conclusions drawn should be met with a critical eye.
"[Dementia] is a very complicated disorder, and the findings in a study like this need to be reproduced in other studies before they are going to be transformative," says Dr. Eric Larson, vice president for research at the Group Health Research Institute based in Seattle.
Still, while the study does not show exactly what is protective in these men, it offers some tantalizing possibilities for future investigation. Silverman's group is already examining the genes of other patients who seem to be protected from dementia and taking note of similarities.
"This study provides one more piece of evidence that 'the cure' may be staring at us from the faces of these survivors, if we could only make out specifically what it was," says Richard Coselli, professor of neurology at the Mayo Clinic in Scottsdale, Ariz. "It also gives us further reason to be optimistic that a cure is not impossible... nature seems to have already found a way."
Copyright 2012 ABC News Radio