A tier of U.S. Southern states is commonly referred to as the "stroke belt" because of its high prevalence of this condition (see: Drop Me Off at the ER as Soon as I Finish My Fried Fish Dinner). Now comes evidence that people in the this same area also have a higher risk of cognitive decline as a component of this neurologic spectrum (see: U.S. South Has Higher Risk of Cognitive Decline). Below is an excerpt from the article
U.S. South Has Higher Risk of Cognitive Decline For decades public health researchers have known that individuals living in the American South displayed an increased risk of stroke and other forms of cardiovascular disease. A new study finds that individuals living in this region also have a greater incidence of cognitive decline compared to other regions of the country. The region is generally considered to be an 11-state cluster including Alabama, Arkansas, Georgia, Indiana, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia. Researchers believe shared risk factors are to blame for the increased chance of cardiovascular events and cognitive decline. Risk factors have been hypothesized to include increased rates of hypertension, low socioeconomic status, high fat diet, cultural lifestyle, quality of health care facilities, smoking, and infections. In 1965, the “Stroke Belt” first appeared in medical literature to describe the southeastern region of the U.S. where stroke mortality rates were 50 percent higher than the remaining U.S. regions. In the new study, called The Reasons for Geographic and Racial Differences in Stroke (REGARDS), [the lead investigator] recruited over 30,000 U.S. adults aged 45 or older from 2003 through 2007 and is following them for stroke and cognitive decline....Risk of cognitive impairment was 18 percent higher in residents of the Stroke Belt than in those living in non-Belt states after adjusting for the influences of age, sex, race, and education level. The research team suggests that future studies should examine the impact of migration patterns, urban versus rural residence, socioeconomic factors, and educational quality on cognitive decline.
For me, the key sentence in this article addresses the etiologic factors underlying strokes in particular and cognitive decline in general in the South: hypertension, low socioeconomic status, high fat diet, cultural lifestyle, quality of health care facilities, smoking, and infections. To this list I would also add lower educational levels which, of course, is a facet of lower socioeconomic status. Education correlates strongly with health status (see: Low Health Literacy and the Chance of Death; Correlation of Sociodemographic Status with Personal Engagement in Cancer Screening Programs) Obviously, this is a very long list and many of these problems are not amenable to quick fixes. I had never personally associated cognitive decline with a later predisposition to stroke but the correlation definitely makes sense. The brain is dependent on its arterial blood supply for nutrition and oxygen. If that supply is slowly diminished by athero- and arteriosclerosis, brain function will certainly decline over time . Obviously, such a decline may be subtle but the article quoted above describes the test methods used to assess it.