Alzheimer's Delayed by Lifestyle Changes, Walking Shown to Help

Understanding the Genetic Risk and Lifestyle Interventions for Alzheimer’s

Kristin Richardson, a business owner in Richmond, Virginia, had never really worried about her brain health until she learned she carried the APOE4 gene. This genetic variant is associated with a higher risk of developing Alzheimer’s disease. The discovery came seven and a half years ago, and it left her terrified. “It’s a horrible, horrible disease with no cure,” she said.

Determined to reduce her risk, Richardson made several lifestyle changes. She focused on getting enough sleep, staying physically active, eating well, maintaining a healthy weight, and engaging in mentally stimulating activities. These efforts reflect a growing understanding that while genetics play a role in cognitive decline, lifestyle choices can significantly influence outcomes.

Two recent studies presented at the Alzheimer’s Association meeting in Toronto offer hope for individuals like Richardson who carry the APOE4 gene. Both studies highlight how diet, brain training exercises, and physical activity can delay memory loss and slow cognitive decline.

The Role of Walking in Cognitive Health

One study examined the impact of walking on 2,985 Black and white older adults, tracking their cognitive status over a decade. Participants were questioned annually about their walking habits and underwent standardized cognitive evaluations. The results showed that those with the APOE4 gene experienced steeper declines in cognition compared to those without the mutation. However, walking appeared to have a protective effect, especially for APOE4 carriers.

Cindy Barha, the study’s senior author and an assistant professor of neuroscience at the University of Calgary, noted that the risk of Alzheimer’s is 12 times higher for individuals with two copies of the APOE4 gene compared to those without. But walking significantly reduced this risk. Women benefited more from increased walking, with a 10% increase in self-reported walking linked to a 4.7% improvement in complex thinking performance. For men, the improvement was 2.6%. Among APOE4 carriers, men saw a greater benefit, with a 12% increase in global cognitive performance.

Barha explained that walking may help maintain brain health by increasing levels of brain-derived neurotrophic factor (BDNF), a protein that supports brain cell health. BDNF acts like fertilizer for the brain, promoting the survival, growth, and connection of neurons. This is particularly important for the hippocampus, the brain’s memory center.

However, the study had limitations, including not tracking the speed or frequency of walking, which could affect the results.

Lifestyle Modifications and Dementia Risk

The second study, led by researchers in Finland, explored the effects of multi-focus lifestyle interventions on dementia risk. The study included 2,469 participants from France, Japan, and Finland, with 709 being APOE4 carriers. Participants were randomly assigned to receive lifestyle modifications or not. The interventions included cognitive training, physical activity, and dietary counseling.

A preliminary analysis revealed that APOE4 carriers benefited more from these interventions than those without the gene variant. Jenni Lehtisalo, a research fellow at the Finnish Institute for Health and Welfare, emphasized that even with a genetic predisposition, lifestyle changes can significantly modify dementia risk. The benefits were about four times greater for APOE4 carriers.

Lehtisalo hopes future research will identify the most effective time window for implementing these lifestyle changes. Dr. Cynthia Boyd, a professor at Johns Hopkins Medicine, praised the studies for showing that concrete steps, such as walking and other lifestyle adjustments, can protect the brain from cognitive decline.

Recommendations for Cognitive Health

Adam Brickman, a professor of neuropsychology at Columbia University, advised that everyone, regardless of genetic risk, should engage in physical activity, maintain a healthy diet, and monitor other dementia risk factors. He noted that knowing one has an increased risk due to the APOE4 allele could motivate healthier behaviors.

For individuals like Kristin Richardson, these studies offer a message of empowerment. While genetics may play a role in Alzheimer’s risk, proactive lifestyle changes can make a meaningful difference in preserving cognitive health.