There is a strong belief among both the general population and medical practitioners that physical inactivity and poor diet are associated with cognitive decline as we age. Physical conditioning and diet are closely associated with cardiovascular health that, in turn, is associated with heart disease and stroke. Indeed, better physical condition as we age reduces some of the wear and tear of aging on the brain as evidenced by less atrophy and white matter disease with aging.
Another recent study adds to the evidence that what’s good for the heart is good for the brain. The study (“Cardiovascular health through young adulthood and cognitive function in midlife, Annals of Neurology, 2013, 73: 170-179) followed cardiovascular health of participants over the course of 25 years starting age 18-30. The assumption was that those who maintained greater levels of cardiovascular heath would display better cognition in midlife.
Cardiovascular heath was determined by measuring seven factors that are influenced by life style choices we all make throughout our life. The factors include maintaining healthy weight, eating a healthy diet, not smoking, maintaining physical fitness, keeping cholesterol below 200, controlling blood pressure, and keeping blood sugar below 100. The hypothesis was that the greater the number of these factors kept close to optimal after 25 years the better the cognitive test scores (memory, speed of thinking, and executive function).
Indeed, the greater the number of cardiovascular health factors that remained optimal the better the scores for speed of thinking, memory, and executive function. However, as might be expected scores on all of these variables were generally lower in middle age than when 25 years younger. The factors most predictive of maintaining better memory into middle age were not smoking, keeping total cholesterol low, and maintaining healthy blood pressure. Interestingly, diet had little effect in this study.
Life style choices modestly impact our long-term health. However, cardiovascular health is determined by both our choices and our biology – many will have suboptimal scores on many of these variables even when they make good choices as they age. We need better data for the impact of treatments of these long-range health outcomes, as this study did not separate those who naturally benefitted from healthy choices versus those who were optimal because of treatments (e.g., taking blood pressure medications, statins) as well as choice. In short, we need to control what we can such as exercising regularly and not smoking.
The lesson is that we need to be strategic and proactive throughout our life toward the goal of having better cognitive functions as we age. Efforts at maintaining cardiovascular health as we age pay dividends in the long run. What’s good for the heart is good for the brain.