It's time to recognize dementia as the public health challenge it is. It's a devastating syndrome that will affect increasing numbers of Americans living longer lives. But dementia is not a normal part of aging. More and more research shows that dementia can be delayed by wise choices involving personal and public health.
The numbers are staggering. With the World Health Organization predicting a dramatic explosion in global incidence of dementia, the time to act is now. "The number of people living with dementia worldwide is currently estimated at 35.6 million. This number will double by 2030 and more than triple by 2050," says the WHO's report, Dementia: A Public Health Priority.
The most common cause of dementia among older people is Alzheimer's disease, according to the National Institute on Aging, which defines dementia as "the loss of cognitive functioning -- thinking, remembering, and reasoning -- and behavioral abilities, to such an extent that it interferes with a person's daily life and activities." In the United States, more than 5 million people suffer from Alzheimer's, a number expected to grow to 16 million by 2050.
Of those more than 5 million people, two-thirds are women, according to the Alzheimer's Association, which reports that the current cost of care for Americans with Alzheimer's and other dementias is $226 billion a year. Medicare and Medicaid pick up about 68 percent of that cost, which will also grow dramatically by 2050.
Two characteristics of dementia make it a public health challenge. First, there is increasing evidence that even if dementia cannot be prevented, onset can be delayed through the prevention of other chronic conditions. According to the National Institute on Aging, research suggests "that a host of factors beyond basic genetics may play a role in the development and course of Alzheimer's disease. There is a great deal of interest, for example, in associations between cognitive decline and vascular and metabolic conditions such as heart disease, stroke, high blood pressure, diabetes, and obesity." Because many of these conditions are themselves preventable, much more research is needed to bring to the public effective prevention.
As that World Health Organization report states, "Research identifying modifiable risk factors of dementia is in its infancy. In the meantime, primary prevention should focus on targets suggested by current evidence. These include countering risk factors for vascular disease, including diabetes, hypertension, midlife obesity, smoking, and physical inactivity."
Prevention must start early in life to avoid these conditions, and even treatments may be most effective early. As Lawrence K. Altman, MD wrote recently in the New York Times, "many experts now believe that yet-to-be-developed treatments are likely to be effective at preventing or slowing progression of dementia only if it is found before it significantly damages the brain." But before medicines, there is clear evidence that physical activity and social engagement improve brain function and decrease mental decline preceding Alzheimer's, and that relying on medicines alone limits our ability to prevent dementia.
Further research is needed to understand dementia, its causes, influences, and treatments. According to the Alzheimer's Association,"although Alzheimer's is not a normal part of growing older, the greatest risk factor for the disease is increasing age. After age 65, the risk of Alzheimer's doubles every five years... Another Alzheimer's risk factor is family history. Research has shown that those who have a parent, brother, sister or child with Alzheimer's are more likely to develop the disease. The risk increases if more than one family member has the illness. When diseases tend to run in families, either heredity (genetics) or environmental factors or both may play a role." A study by Elissa Wilker, ScD in the May issue of Stroke, for instance, suggests that "air pollution is associated with insidious effects on structural brain aging."
Whatever the cost of the needed research, however, the return on investment is potentially vast. According to the New York Academy of Sciences, "The cost of care for dementia patients worldwide consumed an estimated 1% of the global GDP ($604 billion) in 2010 and is expected to exceed $1 trillion annually in the US alone by 2050."
The second characteristic of dementia that renders it a public health challenge may be even more surprising: the enormous impact increased incidence has on family care-givers, particularly in the low-income and lower-middle-income countries. According to the World Health Organization, "in low-income and lower-middle-income countries direct social care costs are small, and informal care costs (i.e. unpaid care provided by the family) predominate." That means sweeping psychological and physical burdens on millions and millions of people who in turn will have fewer resources to address their own health needs.
The federal government spends less than $600 million annually on research into dementia, according to the Alzheimer's Association's Robert Egge, far less than it spends researching HIV/AIDS and cancer, which have lower costs. The Alzheimer's Association has called for an increase in research funding to at least $2 billion.
Unless we tackle dementia as a public health challenge, and develop effective prevention, it is on a trajectory to become a dramatically more devastating global crisis. The time to address it -- and invest in the research needed to develop strategies of prevention as well as treatment -- is now.