A new scientific statement from the American Heart Association, published today in the journal Stroke, underscores that brain health is not solely determined by genetics or late-life events but is shaped by a complex interplay of mental, physical, environmental, and lifestyle factors throughout a person's lifetime. The statement, titled "Brain Health Across the Life Span: A Framework for Future Studies," emphasizes that experiences starting in early life can have lasting effects on brain function and the risk of stroke, cognitive decline, and dementia in later years.
According to the U.S. Census Bureau, the number of U.S. adults aged 65 and older is projected to increase from 58 million in 2022 to 82 million by 2050, a 42% rise, with this age group's share of the total population growing from 17% to 23%. This demographic shift is expected to increase the prevalence of brain conditions affecting memory, thinking, and mental health. "As medical and scientific advancements have extended life expectancies, brain health has become increasingly important," said Dr. Elisabeth Marsh, chair of the writing group and a professor of neurology at Johns Hopkins University School of Medicine.
Stroke is now the #4 leading cause of death in the U.S., according to the American Heart Association’s 2026 Heart Disease and Stroke Statistics. A 2023 scientific statement on cognitive impairment after stroke highlighted that more than half of stroke survivors develop cognitive impairment within the first year, and as many as 1 in 3 may develop dementia within five years.
The statement identifies multiple factors that influence brain health. Mental health conditions such as chronic stress, depression, and anxiety can lead to inflammation, stress-related damage, and loss of brain cells. Adverse childhood experiences, including abuse or neglect, may increase the risk of learning difficulties and later cognitive decline. Chronic inflammation, triggered by infection during pregnancy or ongoing stress, can damage brain cells and blood vessels. The gut microbiome, which communicates with the brain via nerves and immune signals, plays a role; healthy gut bacteria protect the brain, while disruptions are linked to conditions like Alzheimer's and Parkinson's disease. Obesity increases inflammation and damages blood vessels, harming brain structure. Sleep is essential for brain function at all ages, and inadequate sleep or sleep disorders like sleep apnea can increase inflammation and memory loss. Social drivers of health, including lower socioeconomic status and limited access to healthy foods and healthcare, are linked to higher risks of type 2 diabetes and high blood pressure, contributing to cognitive decline. Environmental exposures, such as air pollution and heavy metals, can trigger inflammation and harm brain blood vessels.
To improve brain health, the statement highlights lifestyle habits such as those in the American Heart Association’s Life’s Essential 8, including regular physical activity, controlling blood pressure and cholesterol, healthy sleep, avoiding smoking, and managing stress. Healthy eating patterns, such as the Mediterranean diet and fiber-rich foods, support gut health. The statement urges healthcare professionals and policymakers to prioritize mental health screening, expand access to care, and address social conditions. The American Heart Association and the Paul G. Allen Frontiers Group have committed more than $43 million through the AHA-Allen Initiative in Brain Health and Cognitive Impairment to advance research. "Brain health is a lifelong journey, influenced by our mental well-being, environment and lifestyle choices from childhood through late adulthood," said Dr. Mitchell Elkind, the Association's Chief Science Officer for Brain Health.
