1日いちにち3000さんぜん～7500ななせんごひゃく歩ほの歩行ほこうがアルツハイマー病びょうの進行しんこう抑制よくせいに寄与きよする可能性かのうせい――米国べいこくにおける長期ちょうき観察かんさつ研究けんきゅうの成果せいか

According to research results published by an American research team, increasing the number of steps per day may help slow the progression of Alzheimers disease in elderly people who show early symptoms.

The accumulation of beta-amyloid and tau proteins in the brain is known to be closely associated with the onset and progression of Alzheimers disease.

In particular, amyloid is believed to begin accumulating between nerve cells around the age of 30, adversely affecting information transmission functions in the brain. As this accumulation progresses, extensive deposits of abnormal tau protein occur, ultimately leading to the death of nerve cells.

This research paper was published in the medical journal Nature Medicine on June 3, 2024.

Dr. Wai Yin Wendy Yau, a neurologist and lead author at Massachusetts General Hospital USA, stated, Physical activity may slow the accumulation of tau protein, which is most closely associated with memory impairment, and thereby help prevent cognitive decline in patients with early-stage Alzheimers disease.

According to a study by Mr. Yau and his collaborators, when elderly people walk 3,000 to 5,000 steps a day, the average decline in cognitive function is delayed by about three years. If they walk 5,000 to 7,500 steps, this delay extends to about seven years.

In relation to this study, Dr. Richard Isaacson of the Florida Institute for Neurodegenerative Diseases stated, Increasing your step count can be a helpful reference, but using step count alone as an indicator for Alzheimers disease prevention is too simplistic, and warned, We need to be cautious about relying too much on specific numbers like 5,000 or 7,000 steps.

He is also conducting research on improving cognitive function in people with genetic risk factors.

Mr. Isaacson further stated, For people with excessive body fat, those who are prediabetic, or patients with high blood pressure, simply walking a certain number of steps is not enough, and measures tailored to each specific case are necessary.

This study was conducted over 14 years with 296 participants aged between 50 and 90.

Although the number of research subjects is limited, the research group made efforts to enhance reliability by using objective evaluation criteria.

Professor Masood Hussain of Oxford University commented as follows: What stands out in this research is the combination of quantitative analysis of amyloid and tau protein accumulation in the brain using PET scans, cognitive function assessment, and step count data. The professor was not involved in this study.

The number of steps was recorded by a pedometer, and the study participants underwent cognitive function tests every year for an average of nine years.

Additionally, the amounts of amyloid and tau protein accumulation were measured by PET scans at the beginning of the study, and some participants also underwent additional PET scans at the end of the study.

According to the results, in people who walk up to 7,500 steps a day, the accumulation of tau protein is delayed by 3 to 7 years, while in those who sit for long periods, the accumulation of tau protein increases significantly faster, and their cognitive function and ability to perform daily activities also decline rapidly.

On the other hand, there is no clear association between physical activity and the reduction of beta-amyloid, which is the precursor to tau protein.

Mr. Yau said, When the amount of amyloid accumulation reaches a certain threshold, increasing the number of steps is associated with suppressing the accumulation of tau protein.

This primary delay in cognitive decline can be explained by this relationship.

Furthermore, this is an observational study and does not provide direct evidence of causality.

However, experts once again point out that heart-healthy lifestyle habits—such as walking, stress management, high-quality sleep, and a primarily plant-based diet—are also effective in maintaining brain health.