Numbers don't lie -- dementia is a global health crisis. According to , dementia impacts more than 55 million individuals worldwide, and there are over 10 million new cases each year. In the U.S. alone, people are living with Alzheimer's.
Because dementia impacts not only the person with the disease but also their family and care team, opportunities to introduce prevention strategies across the entire disease continuum have significant potential to improve outcomes for all.
Research suggests dementia cases worldwide may be preventable by addressing modifiable risk factors. Proven lifestyle- and medicine-based risk reduction strategies that enable us to intervene across the dementia continuum -- as we do with other conditions such as heart disease -- are desperately needed.
What We Know Now
Years of observational studies have identified a number of potentially modifiable factors that may contribute to a person's risk for cognitive decline and dementia, including physical activity, nutrition balance, cardiovascular health, social engagement, head injury, and sleep habits. In the past decade, researchers have begun testing these factors in gold-standard intervention trials. I'll highlight a few.
The study offers some of the strongest evidence to date about reducing risk of mild cognitive impairment (MCI) and dementia through effective treatment of high blood pressure, one of the leading causes of cardiovascular disease worldwide. Reported at the 2017 Alzheimer's Association International Conference (AAIC) and published in JAMA in early 2019, SPRINT MIND found intensive blood pressure control in older adults resulted in a 19% reduction in risk of MCI (a secondary study outcome), although it did not significantly reduce dementia risk.
MCI is a known risk factor for dementia, and everyone who experiences dementia passes through MCI. When you prevent new cases of MCI, you are preventing new cases of dementia.
The SPRINT MIND results strengthen the evidence that what is good for the heart is good for the brain. The researchers continue to follow participants to better understand the long-term impact of the intervention on cognition.
The trial, funded by the National Institute on Aging at the NIH, is the longest phase III study to evaluate the impact of exercise (aerobic compared to strength training interventions) in older adults with all cause MCI, including MCI due to Alzheimer's. Reported at AAIC in 2022, the EXERT trial found that after 12 months, study participants with MCI in both the aerobic exercise intervention arm and stretching arm showed no cognitive decline. A comparison group of other older adults with MCI from the Alzheimer's Disease Neuroimaging Initiative who experienced neither of the EXERT interventions showed significant cognitive decline over 12 months. This suggests that regular physical activity, even modest or low exertion activity such as stretching, may protect brain cells against damage even once cognitive and functional changes are apparent.
Combination approaches with various behavioral interventions have emerged in the landscape in recent years. Perhaps most well-known is the (FINGER), which evaluated multiple strategies -- nutritional guidance, exercise, cognitive training, and vascular risk monitoring -- to reduce the risk of cognitive decline in a population of over 1,200 individuals that had no objective cognitive complaint. Individuals engaged in the intervention had less cognitive decline during the 2-year intervention period compared to those receiving standard care. Replicative and culturally appropriate studies are underway in countries around the world, including the (U.S. POINTER).
What We Are Still Learning
Because the FINGER trial was conducted in a largely homogenous white population in Europe, the results, while illuminating, are not necessarily translatable to all countries, cultures, and ethnicities. Knowing dementia disproportionately impacts in the U.S., it's imperative we uncover strategies to reduce risk, slow progression, and ultimately prevent cognitive decline in all populations and communities.
Led by the Alzheimer's Association and researchers at sites in five communities across the country, U.S. POINTER is a 2-year clinical trial to evaluate whether behavioral interventions that simultaneously target multiple risk factors protect cognitive function in older adults, in particular those of diverse backgrounds and under-represented populations who are at increased risk for cognitive decline. This study is expected to complete recruitment in the first quarter of 2023 and results are expected in 2025.
How Doctors Can Talk to Their Patients
Clinicians regularly receive questions from their patients about a variety of dementia prevention "solutions" that they heard about from friends and colleagues, and on the news and social media. While we wish there was a single strategy, ingredient, or that could prevent dementia altogether, the answer is not that simple.
While we wait for continued results from SPRINT-MIND, U.S. POINTER, and other studies to cement recommendations for a specific risk reduction "recipe" to provide individuals, clinicians can stress the importance of protecting brain health. Good general healthful lifestyle advice like getting regular exercise, eating a balanced diet, not smoking, and managing both heart and overall health can be framed to include that these habits may benefit cognition as well. Your patients and their family members can be referred to credible resources including:
- Alzheimer's Association resources on
- National Institute on Aging on brain health
- CDC
The work being done to identify brain health recommendations and develop therapeutics that target the underlying biology of Alzheimer's and other dementias provides a lot of hope. We're hopeful that treating dementia may soon look like treating heart disease -- combining both drug treatment and brain-healthy lifestyle guidelines with the goal of reducing the risk of dementia.
is the Alzheimer's Association vice president of medical and scientific relations.
Disclosures
The Alzheimer's Association provides funding for the U.S. POINTER study. The Alzheimer's Association forges partnerships with all those with the shared commitment to end Alzheimer's and other dementia, including Alzheimer's organizations around the globe, the National Institutes of Health, National Institute on Aging, universities, corporations, and the pharmaceutical, biotech, and device industries. The Alzheimer's Association received 1.06% of its total 2022 contributed revenue from the biotechnology, pharmaceutical, diagnostics, and clinical research industries. This and additional information can be found at .