Ideal CV Health at Age 50 Foretells Lower Risk of Later Dementia

Middle-aged adults who maintain ideal CV health by meeting the American Heart Association’s Life’s Simple 7 model—which accounts for smoking, diet, physical activity, body mass index (BMI), glucose, cholesterol, and blood pressure—are at a lower risk of developing dementia when older, according to an analysis of data from Whitehall II.

Whitehall II is an ongoing cohort study of British civil servants, with initial intake from 1985 to 1988. It tracks approximately 10,000 people (66% men) who ranged from 35 to 55 years of age at the time they joined the cohort.

“One of the things we forget is that the brain uses glucose and oxygen. And how do these things get to the brain? It’s through the vascular pathways,” senior author Archana Singh-Manoux, PhD (Université de Paris, France), noted to TCTMD.

“A lot of work on Alzheimer’s disease and dementia is based on finding a cure, or trying to get rid of amyloid and seeing if it works,” she continued. “Our approach has been to look at this slightly differently, from a prevention perspective, . . . trying to figure out what happens to cognition as we get older.”

CV Health Helpful, Even When It’s Not Perfect

For the study, published online recently in BMJ, the researchers assessed whether 7,899 individuals without preexisting CV disease who adhered to Life’s Simple 7 at age 50 might have less risk of dementia as they aged. Scores can range from 0 to 2 points on each dimension. Achieving 12-14 cumulative points equates to optimal CV health, 7-11 points amounts to intermediate CV health, and anything less means poor CV health.

For every eligible participant, lead author Séverine Sabia, PhD (Université de Paris), and colleagues compiled CV health information from medical records (for BMI, glucose, cholesterol, and blood pressure) or via a patient questionnaire (for smoking, diet, and physical activity). These details were collected during the first four clinical examinations for Whitehall II, which occurred in 1985, 1991, 1997, and 2002.

There were 347 cases of dementia recorded over a mean follow-up period of 24.7 years. Women, nonwhite participants, and people with less education were more likely to experience dementia. Mean age at the time of diagnosis was 75.3 years.

For individuals with poor CV health, the dementia incidence rate was 3.2 cases per 1,000 person-years. In absolute terms, there were 1.5 fewer cases of dementia for those with intermediate CV health and 1.9 fewer cases for those with optimal CV health (both per 1,000 person-years).

Overall, having a higher CV health score was associated with an 11% lower risk of dementia (HR 0.89 per 1-point increment; 95% CI 0.85-0.95). This link also was evident in people who did not develop cardiovascular disease during follow-up (HR 0.89 per 1-point increment; 95% CI 0.84-0.95).

“Our results showed reductions in the risk of dementia across the continuum of the 14-point cardiovascular health score, highlighting the importance of clustering of cardiovascular risk factors in midlife for risk of dementia at older ages,” the researchers observe.

When to Start Prevention?

“Prevention is an important element in tackling the challenge posed by the expected tripling of dementia cases by 2050. . . . Cardiovascular risk factors are modifiable, making them strategically important prevention targets. This study supports public health policies to improve cardiovascular health as early as age 50 to promote cognitive health,” Sabia and colleagues conclude.

This work adds to the body of evidence about the connection between heart and brain health. In 2018, Hannah Gardener, ScD (University of Miami, FL), and colleagues published findings from the Northern Manhattan Study showing that higher scores on Life’s Simple 7 were associated with less white matter hyperintensity volume, fewer silent brain infarcts, and greater cerebral volumes. They go so far as to say that the metric might be a “useful measure to quantify optimal brain health.”

Commenting on the Whitehall II results for TCTMD, Gardener said, “We still have a lot to learn about whether midlife is really where we need to start focusing. . . . Midlife certainly matters, but it may be that we want to start focusing [on promoting CV health] earlier than age 50.”