Who Gets Alzheimer's? Genes Hold Key
But Genes Aren't Destiny, Study of Identical Twins Shows
When 1 Twin Has Alzheimer's continued...
If Alzheimer's disease was strictly genetic, one identical twin should get the disease about the same time as the other. But when both identical twins had Alzheimer's, there was as much as a 16-year difference in age of onset.
That, Gatz says, clearly shows that there must be a strong interplay between a person's genes and a person's environment.
"For instance, if twins share a gene that is a more risk-promoting gene with regard to how they process fats, then eating more fats would be more dangerous for them," she says. "If one twin ate very few fats, her risk would be much lower. We are sure that kind of thing is going on. That is why it is hard to talk about genetic risks independently of environmental risks."
How to Avoid Alzheimer's
William H. Thies, PhD, vice president for medical and scientific affairs at the Alzheimer's Association, says researchers have a good idea about what some of the environmental risks may be.
"We've long recognized that education has an impact on reducing the likelihood of Alzheimer's disease," Thies tells WebMD. "The other more lately evolving ideas fit mostly around heart disease risk factors. Alzheimer's risk is linked to high blood pressure, high cholesterol, high blood sugar, a high-fat diet, a sedentary lifestyle, and the lack of social connectivity."
We can't pick our parents, so there's not much we can do about genetic risks. But Thies points out that there are several things one can do to cut your risk of Alzheimer's disease -- especially if the disease runs in your family:
- Stay mentally active.
- Be socially involved.
- Get physical exercise.
- Eat a brain-healthy diet.
Genes aren't destiny, Gatz says. If you think you or a loved one may be getting Alzheimer's disease, it's time to act.
"The strong message to people is if there is any kind of concern about dementia, it is important to get a good professional evaluation," she says. "There can be reversible causes of cognitive change. Or doctors may be able to offer either psychological or medical interventions that can slow processes of cognitive change."