How Many Steps Do You Take a Day? "5,000 Steps" Can Slow Cognitive Decline

Delaying Early Alzheimer's Cognitive Decline by Seven Years with 5,000 Steps a Day

According to recent research, even light walking of about 5,000 steps a day can delay the progression of cognitive decline due to Alzheimer's disease by up to seven years.

The study found that Alzheimer's disease begins when two proteins, amyloid-beta and tau, accumulate in the brain. Amyloid-beta starts to build up between brain cells as early as one's 30s, interfering with signal transmission, and later, tau proteins clump together and damage brain cells.

On the morning of the 19th, tourists visiting Iho Beach in Jeju City are taking a stroll in light clothing. Photo by Yonhap News Agency

A joint research team including Harvard Medical School in the United States tracked nearly 300 middle-aged and older adults for up to 14 years and published their findings in the December issue of the international journal Nature Medicine.

The study subjects were 296 individuals aged 50 to 90 with normal cognitive function at the start of the observation, with a median follow-up period of 9.2 years. The researchers used wearable pedometers to measure each participant's average daily step count and conducted regular brain imaging and cognitive assessments.

Analysis showed that compared to the group walking fewer than 3,000 steps per day, those walking 3,000 to 5,000 steps had approximately 20% less tau protein accumulation and about 40% slower cognitive decline. For those walking 5,000 to 7,000 steps, these effects increased to roughly 30% and 50%, respectively. However, a "plateau" was observed, with no further benefit beyond 7,500 steps per day.

The "high activity" group, walking more than 7,500 steps per day, did not show higher cognitive scores or delayed cognitive impairment compared to the group walking 5,000 to 7,500 steps. In terms of cognitive function, there was no additional benefit to walking more than 7,500 steps.

The research team concluded that higher physical activity helps prevent tau accumulation, thereby supporting cognitive function. Tau is a protein that stabilizes "microtubules," which transport substances within nerve cells. If tau detaches from the microtubules and forms neurofibrillary tangles, it negatively affects nerve cell function. The researchers explained that 84% of the association between physical activity and reduced cognitive decline was related to decreased tau accumulation.

Meanwhile, walking is not just a simple leg exercise. It increases blood flow to the brain, aiding the delivery of oxygen and nutrients and promoting the removal of waste products. This process activates neural networks within the brain and slows the atrophy of the hippocampus, which is responsible for memory.

In particular, walking is also effective for relieving stress and improving sleep quality, making it one of the easiest ways to reduce "brain fatigue."