Global prevalence of Alzheimer's disease will grow to 106 million by 2050

More than 26 million people worldwide were estimated to be living with Alzheimer's disease in 2006, according to a study led by researchers at the Johns Hopkins Bloomberg School of Public Health.

The researchers also concluded the global prevalence of Alzheimer's disease will grow to more than 106 million by 2050. By that time, 43 percent of those with Alzheimer's disease will need high-level care, equivalent to that of a nursing home. The findings were presented June 10 at the Second Alzheimer's Association International Conference on Prevention of Dementia held in Washington, D.C. and are published in the Association's journal, Alzheimer's & Dementia.

"We face a looming global epidemic of Alzheimer's disease as the world's population ages," said the study's lead author, Ron Brookmeyer, PhD, professor in Biostatistics and chair of the Master of Public Health Program at the Bloomberg School of Public Health. "By 2050, 1 in 85 persons worldwide will have Alzheimer's disease. However, if we can make even modest advances in preventing Alzheimer's disease or delay its progression, we could have a huge global public health impact."

According to Brookmeyer and his co-authors, interventions that could delay the onset of Alzheimer's disease by as little as one year would reduce prevalence of the disease by 12 million fewer cases in 2050. A similar delay in both the onset and progression of Alzheimer's disease would result in a smaller overall reduction of 9.2 million cases by 2050, because slower disease progression would mean more people surviving with early-stage disease symptoms. However, nearly all of that decline would be attributable to decreases in those needing costly late-stage disease treatment in 2050.

The largest increase in the prevalence of Alzheimer's will occur in Asia, where 48 percent of the world's Alzheimer's cases currently reside. The number of Alzheimer's cases is expected to grow in Asia from 12.65 million in 2006 to 62.85 million in 2050; at that time, 59 percent of the world's Alzheimer's cases will live in Asia.

To forecast the worldwide prevalence of Alzheimer's disease, the researcher created a multi-state mathematical computer model using United Nations population projections and other data on the incidence and mortality of Alzheimer's.