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Professor David J. Demko, PhD AgeVenture News Service www.demko.com 
Alzheimer's disease is the most common form of senile dementia affecting approximately 8 percent of the older population. Furthermore, two-thirds of dementia cases in adults aged 65 years and older are Alzheimer-related. As a result, seniors and boomers are anxious to learn which risk factors condemn some adults while sparing others from this horrible degenerative disease?
Four major factors influence your risk to Alzheimer's Disease (AD). Genetic makeup is a major risk factor. Inherited risks to other chronic disease can affect the age at which memory loss can occur, and when symptoms of disorientation and confusion might first appear. Personal lifestyle habits can also raise vulnerability to AD. Finally, brain injury due to alcoholism or prior head trauma are also risk factors. Although genetic risk factors for Alzheimer's have been identified, only a fraction of disease cases can be explained by specific gene mutations. Studies of twins have been helpful in investigating the relative importance of genetic and environmental influences in disease development. For example, if identical twins do not both have a disease, then AD risk factors might be explained by lifestyle factors: what you eat or drink, how much you exercise, level of formal education, and frequency of smoking. Margaret Gatz, Ph.D., and colleagues at the University of Southern California, examined the association between genetic and lifestyle risk factors to Alzheimer's disease. The study included patients who were diagnosed with dementia and their twins, plus a sample of twins without dementia. The researchers confirmed that while genetic inheritance plays a major role in AD risk, other "non-genetic risk factors also play an important role and might be the focus for interventions to reduce disease risk or delay disease onset.” The researchers caution however, that the research findings may be generalizable to the Swedish population from which the study sample was selected. Other scientific studies have identified several genes that contribute to the onset of Alzheimer's. Among these are the presenilin genes, which result in Alzheimer's at an early age—in some cases as early as a person's thirties or forties. These genes are rare, however, and old age remains a primary risk factor for the development of Alzheimer's. The far more common form of Alzheimer's strikes seniors who are in their late 60s, 70s, and beyond. It has been linked to a gene called ApoE4. But just because you carry that gene doesn't mean you will develop dementia for sure. About 60 percent of those who inherit the ApoE4 gene are likely to develop Alzheimer's by age 70. Many elders who have the ApoE4 gene carry on for decades sharp and mentally alert. The findings of the Alzheimer's Twin Study appear in the Archives of General Psychiatry. Volume 63: February 2006, pages 168-174, published by the American Medical Association. See related articles in AgeVenture archives. AgeVenture Topics and Trends AgeVenture Lifestyle Features AgeVenture News Service, www.demko.com BACK TO TOP |