New research links walking to reduced cognitive decline
A recent observational study suggests that increasing the number of steps taken daily may slow cognitive decline in older adults exhibiting biological signs of early Alzheimer’s disease, reports BritPanorama.
The study highlights the presence of beta amyloid and tau proteins as hallmark signs of Alzheimer’s. Amyloid can start accumulating in the spaces between neurons as early as one’s 30s, potentially disrupting communication between brain cells. As these deposits grow, they can trigger a rapid proliferation of abnormal tau proteins, which form tangles within brain cells, ultimately leading to cell death.
Lead study author Dr. Wai-Ying Wendy Yau, a neurologist at Massachusetts General Hospital, emphasized that “physical activity may help slow the buildup of tau — the protein most closely linked to memory loss — and delay cognitive decline in people with early Alzheimer’s.” The findings indicated that cognitive decline was delayed by an average of three years for individuals who walked between 3,000 to 5,000 steps per day, and by seven years for those achieving 5,000 to 7,500 steps daily.
Despite the promising results, some experts caution against oversimplifying the relationship between steps and Alzheimer’s prevention. Dr. Richard Isaacson, a neurologist not involved in the study, noted, “While the research is informative, relying on a specific number of steps per day to prevent Alzheimer’s is too simplistic.”
Isaacson expressed concern over catchy metrics, stating, “I get really cautious about catchy numbers like walking 5,000 or 7,000 steps.” He emphasized the importance of individualized health plans, especially for those with other health risks such as excess body fat, prediabetes, or high blood pressure. “Just walking a certain number of steps won’t be enough,” he stressed.
Study details and findings
Conducted over 14 years, the study involved 296 participants aged 50 to 90. Researchers employed objective measures to enhance reliability, with the research published in the journal Nature Medicine. Professor Masud Husain from the University of Oxford noted that “the strength of this research is the combination of serial highly specialized scans that measure amyloid and tau deposition in the brain, with cognitive assessments and baseline step count.”
Steps were measured using pedometers, and participants underwent yearly cognitive assessments for an average of nine years. Each participant received an initial PET scan to measure levels of amyloid and tau, with some receiving a follow-up scan at the study’s conclusion.
The findings revealed that higher step counts were correlated with slower accumulation of tau proteins, distinguishing it from the lack of observed decline in beta amyloid associated with increased physical activity. Dr. Yau explained that “instead, for a given amount of elevated amyloid burden, higher step counts were associated with slower accumulation of tau, which largely explained the relationship with slower cognitive decline.”
Although the study cannot establish a direct cause-and-effect relationship due to its observational nature, it highlights the broader trend that activities beneficial to cardiovascular health are similarly beneficial for cognitive function. Dr. Isaacson remarked, “We’ve known for years that mice which exercise on their little wheels have about 50% less amyloid in their brains. While we need more research in people, I’m convinced exercise on a regular basis reduces amyloid buildup and improves cognition.”
With such studies reinforcing the connection between physical activity and cognitive health, the implications for public health strategies, particularly in aging populations, are potentially significant.
