Experts agree that there will be increases in the number of people who develop some form of dementia in the future, but these increases may not be as great as previously estimated, and improved individual health awareness and habits can even delay the onset of dementia for many people.
“The message is more complicated than it used to be,” said Dr. Dallas Anderson, an epidemiologist and an expert on dementia prevalence rates at the National Institute on Aging. “This idea that rates could be going down is really good news and it is probably related to lifestyle factors.”
Conversely, he added about incidences of dementia: “If you think we have a lot of cases now, we will really have a lot of cases as numbers go up in a big way.”
The discrepancy is due to a number of factors, Dr. Anderson explained. A New England Journal of Medicine article (authors Eric B. Larons, M.D., M.P.H., Kristine Yaffe, M.D., and Kenneth M. Langa, M.D., Ph.D) in Nov. 2013 stated: “Although demographics will drive an increase in the number of dementia cases, recent reports—generally based on population-based community studies or survey data—point to declining age-specific prevalence or incidence rates among people born later in the first half of the 20th century. “ This view is based on several studies and surveys, primarily those from England and Sweden.
The article goes on to state that studies conducted over longer periods of time will presumably show more definitive findings on dementia rates. “But for now, the evidence supports the theory that better education and greater economic well-being enhance life expectancy and reduce the risk of late-life dementias in people who survive to old age,” the authors of the New England Journal of Medicine article wrote. “The results also suggest that controlling vascular and other risk factors during midlife and early old age has unexpected benefits. That is, individual risk-factor control may provide substantial public health benefits if it leads to lower rates of late-life dementias.”
Dr. Anderson said that even delaying the onset of dementia has a public health and individual benefit. “We’re talking about a much-reduced impact on public health in our society,” he said. “For the individual, it might give them a greater number of years of independence.”
At this time there is no cure for Alzheimer’s disease or other dementias, and there are no drugs to treat the symptoms. “It’s a good thing to think about lifestyle issues, particularly taking care of medical problems such as high blood pressure and diabetes before you reach older age,” Dr. Anderson said. “Probably the happy message here is that there are some things people can do as opposed to just worrying about dementia.”
In his own family, Dr. Anderson had a father who smoked and suffered poor health in mid-life with heart attacks, but at 65 years of age, Dr. Anderson said he is on a healthier trajectory because of the lifestyle choices he has made and continues to make. “In general, as you approach older age, the better your physical health the better you might be able to stave off dementia,” he said. “There is a mind body connection. What’s good for the body is good for the mind.”
That said, when looking at estimated projections for what some experts call a global dementia “epidemic” not all countries have the same methodologies tracking dementia. “Given the size of the Chinese population, that could affect overall counts,” he said of statistics on dementia from China.
In addition, rates of obesity and diabetes in middle-aged and younger people continue to increase and if those do not reverse, it could lead to higher rates of dementia. Even improved life expectancy could lead to higher rates of dementia for people late in their lives as more people live longer.
“We are still going to have a big increase in dementia,” said Dr. Anderson.