THURSDAY, Dec. 15, 2005 (HealthDay News) -- Experts are now predicting that the global incidence of Alzheimer's disease and other forms of dementia will soar in the next few decades, especially in developing countries.
That prediction is made by an international group of 12 experts, two of them American, who were provided with "a systematic review of published studies on dementia" by Alzheimer's Disease International, a London-based organization.
"We estimate that 24.3 million people have dementia today, with 4.6 million new cases of dementia every year," the experts report in the Dec. 17 issue of The Lancet. "The number of people [with dementia] will double every 20 years, to 81.1 million by 2040," they added.
The number of cases will double by 2040 in developed countries such as the United States, but will more than triple in India, China and other countries in south Asia and the western Pacific, the experts wrote.
"We believe that the detailed estimates in this paper constitute the best currently available basis for policymaking, planning and the allocation of health and welfare resources," they said.
The prediction is very much in line with the forecast made two years ago for the United States by the Alzheimer's Association, said Maria Carrillo, the organization's director of medical and scientific affairs.
"We have 4.5 million cases now," Carrillo said. "We predict a huge increase, to 6.5 million in 2025. That will overwhelm our economy and health-care system, and needs to be addressed in the next five to 10 years by research."
The Alzheimer's Association is currently seeking a $300 million increase in its funding for dementia research, she said.
The exact causes of Alzheimer's disease remain unknown, although it is thought to be related to a gradual build-up of amyloid beta protein plaques within the brain. Cerebrovascular changes have also been linked to increased risk for Alzheimer's, and stroke is a major contributor to other forms of dementia.
The Alzheimer's Disease International experts are recommending public health measures that focus on reducing risk factors for cerebral blood vessel damage, such as high blood pressure, smoking, diabetes and cholesterol. The U.S. Alzheimer's Association agrees with that approach, Carrillo said.
"A lot of research has shown that leading a healthy lifestyle can help preserve mental function," she said. "You should be physically active, mentally active and socially active."
Mental activity is an important element, but physical activity counts as well, said Colin Milner, chief executive officer of the International Council on Active Aging, based in Canada. "Learning a foreign language, juggling, playing ping-pong, you need to engage your mind and your body," he said.
The numbers in the Lancet paper "aren't really a great surprise, because people aren't living healthy lives," Milner said. "Look at diabetes. They're predicting a 165 percent increase over the next five to 10 years. You need to be aware of the impact that not doing something can have on your mind and body."
For more on dementia and how to help prevent it, head to the Alzheimer's Association.