What is Alzheimer’s Disease?

Alzheimer’s disease is the most common form of dementia among older adults. Alzheimer’s disease involves parts of the brain that control thought, memory, and language and can seriously affect a person’s ability to carry out daily activities. Although scientists are learning more every day, right now, they still do not know what causes Alzheimer’s disease.

Who has Alzheimer’s Disease?

As many as 5 million Americans suffer from Alzheimer’s disease. While younger people may get Alzheimer’s disease, it is much less common. The disease usually begins after age 60, and risk goes up with age. About 5 percent of men and women ages 65 to 74 have Alzheimer’s disease, and nearly half of those age 85 and older may have the disease. It is important to note, however, that Alzheimer’s disease is not a normal part of aging.

 What causes Alzheimer’s Disease?

Scientists do not yet fully understand what causes Alzheimer’s disease. There probably is not one single cause, but several factors that affect each person differently. Age is the most important known risk factor for Alzheimer’s disease. The number of people with the disease doubles every 5 years beyond age 65.
Family history is another risk factor. Researchers believe that genetics may play a role in developing Alzheimer’s disease.

Scientists still need to learn a lot more about what causes Alzheimer’s disease. In addition to genetics, they are studying education, diet, and environment to learn what role they might play in developing this disease. Scientists are finding more and more evidence that some of the risk factors for heart disease and stroke, such as high blood pressure, high cholesterol, and low levels of the vitamin folate may also increase the risk of Alzheimer’s disease. Evidence for physical, mental and social activities as protective factors against Alzheimer’s disease is also growing.

References

1. Miniño, A; Xu, J; Kochanek, KD. “Deaths: Preliminary Data for 2008.” National Vital Statistics Reports. Hyattsville, Md.; National Center for Health Statistics; 2010.  
2. Hebert, LE; Scherr, PA; Bienias, JL; Bennett, DA; Evans, DA. “Alzheimer’s disease in the U.S. population: Prevalence estimates using the 2000 Census.” Archives of Neurology 2003;60(8):1119–1122 and Alzheimer’s Association. Early-Onset Dementia: A National Challenge, A Future Crisis. Washington, D.C.: Alzheimer’s Association; 2006; as published by the Alzheimer’s Association, Alzheimer’s Disease Facts and Figures, 2011.  
3. Hebert, LE; Scherr, PA; Bienias, JL; Bennett, DA; Evans, DA. “Alzheimer’s disease in the U.S. population: Prevalence estimates using the 2000 Census.” Archives of Neurology 2003;60(8):1119–1122; as published by the Alzheimer’s Association, Alzheimer’s Disease Facts and Figures, 2011.
4. Alzheimer’s Association. Characteristics, Costs and Health Service Use for Medicare Beneficiaries with a Dementia Diagnosis: Report 1: Medicare Current Beneficiary Survey. Prepared under contract by Julie Bynum, M.D., M.P.H., Dartmouth Institute for Health Policy and Clinical Care, Center for Health Policy Research, January 2009; as published by the Alzheimer’s Association, Alzheimer’s Disease Facts and Figures, 2011.
5. Alzheimer’s Association. Characteristics, Costs and Health Service Use for Medicare Beneficiaries with a Dementia Diagnosis: Report 1: Medicare Current Beneficiary Survey. Prepared under contract by Julie Bynum, M.D., M.P.H., Dartmouth Institute for Health Policy and Clinical Care, Center for Health Policy Research, January 2009; as published by the Alzheimer’s Association, Alzheimer’s Disease Facts and Figures, 2011.