The prevalence of dementia in the United States significantly declined from 11.6% in 2000 to 8.8% in 2012. A new study by JAMA Internal Medicine attributes this, in part, to an increase in educational attainment.
Dementia has multiple causes and types. It reflects damage to the nerve cells of the brain which can appear in varying locales. Symptoms of memory loss and cognitive changes manifest differently depending on the individual, medical history and etiology.
Alzheimer’s is the most common culprit in those 65 and older. Right behind is vascular damage of the vessels that transport blood to the brain—albeit by stroke or other conditions. Lewy body dementia is another progressive form. There are mixed versions that are also irreversible.
The list continues as it can be linked with other disorders like Parkinson’s disease, traumatic brain injury and external triggers, to name a few. Though the risk of dementia rises with age, this is no guarantee disease will ever develop. A positive family history can also play a role, but is certainly not your destiny.
The National Institute on Aging (NIA)—an arm of the National Institutes of Health (NIH)— commissioned “An Aging World: 2015” from the U.S. Census Bureau to elucidate further the public health challenges of our aging population. It highlights that America’s 65-and-over population should nearly double in the next three decades, from 48 million to 88 million by 2050. The consequence of this impacts retirement, families, the health care system, life expectancy, morbidity and mortality, pensions, housing, transportation and countless societal realms.
So, though this recent investigation shows a promising trend, cases will still accrue.
The latest work — observational, cohort in nature—acquired data from a population-based longitudinal nation-wide survey making up the Health and Retirement study (HRS) of more than 21,000 U.S. adults 65 years and older from 2000 and 2012. As NPR persuasively points out, “Put in more human terms, ‘that’s well over a million people who don’t have dementia, who would have had it if the rates had stayed the same as 2000 rates,’ says John Haaga, who directs the Division of Behavioral and Social Research at the National Institute on Aging, which funded the study.”
The decrease in dementia prevalence was accompanied by a substantial increase in educational attainment. To deconstruct this will require further assessment and is likely multifactorial.
The study was limited by rising over-the-phone interviews in the later years as opposed to more face-to-face in the first round of information collection. Self-reporting has its flaws along with changing criteria for cardiovascular and cognitive measures.
Ultimately, it suggests: “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. However, it should be noted that the relationships among education, brain biology, and cognitive function are complex and likely multidirectional… Higher levels of educational attainment are also associated with health behaviors (eg. 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.”
It underscores that comprehensive understanding for this decline is still uncertain and posits the results are likely from a combination of social, behavioral and medical factors —such as improved treatment and more aggressive control of elevated blood pressure, cholesterol, diabetes and weight. As studies usually do, the authors recommend more research in the field and continued monitoring of trends in our ever-increasing aging population with hopeful discovery of potential protective features.
This bit of good news hits especially close to the heart given I had a grandfather who battled Alzheimer’s, worked many years ago to support the Fisher Center for Alzheimer’s Research Foundation and, subsequently, cared for afflicted patients throughout my medical training.
Dementia is a cruel reality for many and is traditionally heartbreaking for a family. Though all is not known with this latest development and being that this ailment is not an absolute eventuality for many, there is really no harm in continued learning while taking charge of the modifiable risk factors that not only influence this condition, but serve to prevent other ones as well.
