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Risk Factors

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Cartoon showing young man speaking with young woman, near a naked an old man.  Man is telling woman 'Don't mind Gramps.  He's thinks he's at Woodstock.

Risk Factors: contributing factors

The Greatest Risk Factor: Advancing Age

An estimated 5.2 million people in the U.S. are living with Alzheimer’s disease and of that figure, 5 million are age 65 and older. Alzheimer’s is now the sixth-leading cause of death in the U.S., according to the Centers for Disease Control and Prevention. Every 71 seconds, someone develops Alzheimer’s and 10 million baby boomers will develop Alzheimer’s in their lifetime. That’s a frightening figure when you consider that Americans are living much longer than before. Unless a way to prevent Alzheimer’s is discovered, an estimated 11 to 16 million people could develop Alzheimer’s by 2050.

Delaying Onset

Advancing age may be the biggest risk factor for Alzheimer's, but it might also be the best loophole for finding a successful treatment. Alzheimer's usually develops in the last decade of a person's life. A drug or vaccine that could delay its onset by even a few years might mean that the potential victim won't live long enough to experience symptoms. The trick is keeping the disease at bay until the very end of a person's natural life span.

In 2007, the economic value of caregiving provided by a family member or other unpaid caregiving was estimated at $89 billion. If nothing is done to curb the impact of Alzheimer's, the number of individuals age 65 and over
with Alzheimer’s could range from 11 million to 16 million.  By that date, more than  60 percent of people with Alzheimer’s disease will be age 85 or older. 


More women than men have Alzheimer’s and other forms of dementias, mainly because women, on average, live longer than men. Most studies show that female gender is not a risk factor for developing Alzheimer’s once age is considered. In general, women are more likely to develop the disease simply because they live long enough to do so.


In general, the prevalence of Alzheimer’s is higher in people with fewer years of education. Some researchers believe that having more years of education helps build the cognitive function. Others point out that other risk factors, such as other underlying medical conditions that are more prevalent in people with fewer years of education, may be associated with the higher level of Alzheimer’s.


When age, gender, years of education and other factors are taken into consideration, there is not a statistically significant increased risk of developing Alzheimer’s between African-Americans and Caucasians. However, African-Americans are less likely to seek early diagnosis or treatment for Alzheimer’s or other dementia. For people of all ethnic backgrounds, early diagnosis is the key to better management of the disease, possible participation in clinical trials and research, and the ability to evaluate all options for medications that may slow the cognitive decline associated with Alzheimer’s.

Alzheimer's & Genetics

For most people, genetic testing cannot accurately predict Alzheimer's disease. Scientists know of a gene that can increase or decrease a person's chances of getting the most common form of the disease, but determining factors still seem to have as much to do with environment and lifestyle as they do with genetics. Most experts believe that genetic screening for Alzheimer’s is medically and commercially irresponsible at this time.

In contrast, testing for "familial" Alzheimer's is quite accurate. However, there are many factors to consider before undergoing any genetic testing. The inherited form of the disease is very rare, accounting for an estimated two to five percent of all Alzheimer's cases. It usually spreads more quickly and strikes earlier in life than late-onset Alzheimer's. For the small number of people at risk for Familial Alzheimer's, genetic testing can predict early onset familial Alzheimer’s. A genetic counselor can help with the personal decisions that should be carefully weighed before considering genetic testing.