Dementia rates significant decline among older Americans in 21st century

As the baby boomer generation ages, many expect the age-specific risk of dementia to grow in the United States. But researchers have found a significant decline in dementia in recent years, with some 24 percent fewer individuals over the age of 65 suffering the symptoms in 2012 when compared to 2000.

With the average age in 2000 being 75 and 74.8 in 2012, the study found that dementia in those patients actually declined from 11.6 percent to 8.8 percent. A lower risk of dementia was also associated with higher education. Led by Kenneth M. Langa, MD, PhD, of the University of Michigan, the study was published in the JAMA Internal Medicine.

“Our study, along with prior studies, supports the notion that “cognitive reserve” resulting from early-life and lifelong education and cognitive stimulation may be a potent strategy for the primary prevention of dementia in both high- and low-income countries around the world,” wrote the authors. “However, it should be noted that the relationships among education, brain biology, and cognitive function are complex and likely multidirectional; for instance, a number of recent population-based studies have shown genetic links with level of educational attainment, and with the risk for cognitive decline in later life. Higher levels of educational attainment are also associated with health behaviors (for example, physical activity, diet and smoking), more cognitively-complex occupations, and better access to health care, all of which may play a role in decreasing lifetime dementia risk.”

The team admitted social, behavioral, and medical factors contributing to the decline are still uncertain. They encouraged for further work examining dementia to improve gauging the full future social impact as the number of older adults continues to increase.