medicine
3,000 steps a day may slow Alzheimer's in the brain
Not 10,000 steps. A third of that may be enough.
Researchers who followed almost 300 older adults for nine to 11 years have found that walking just 3,000 steps a day may slow one of the brain changes behind Alzheimer's disease. The pedometer study, written up by Eef Hogervorst of Loughborough University, found that activity did not clear the toxic amyloid plaques most treatments target. Instead, among people who already had those plaques, movement roughly halved the buildup of misfolded tau proteins, which appear later and track more closely with memory decline. Benefits showed up at around half an hour of moderate walking. The sweet spot was 5,000 to 7,500 steps, after which the effect flattened out. More steps did not mean more protection, which quietly undercuts the famous 10,000-step target nobody actually hits. The study was small and limited, the researchers caution, but it joins larger work pointing the same way. A realistic goal, then, is a stroll, not a marathon.
