Brain aging is like the wear and tear on a bridge: cracks appear unnoticed, but if you reinforce the supports in time, the structure lasts longer. Three ordinary things turned out to be such supports — handgrip strength, the ability to move for a long time without breathlessness, and lung capacity. Doctors monitored 51,517 Britons for 12 years and saw that people with the highest levels of each of these abilities developed dementia half as often as those with the weakest levels.
Blood told the story of why this happens. With strong muscles and a resilient heart, plasma contains less neurofilament protein: it appears when nerve cells break down. And with good lung function, levels of the inflammatory molecule GDF15, which damages brain blood vessels, are lower. In total, between 22 and 40 precursor proteins were found for each ability, and they all converge on two pathways: inflammation and blood supply.
Brain scans added the final piece of the puzzle. In fitter participants, the hippocampus, the fold responsible for memory, was larger, and this explained up to 10% of the protective effect. This means physical activity not only quells inflammation but also preserves brain tissue itself, just as regular maintenance preserves the wooden beams of a bridge. The three supports work independently, but they hold up one bridge.
Grip strength in middle-aged people predicts dementia risk more accurately than cholesterol levels or blood pressure.
In the series 'Altered Carbon,' the wealthy transfer their consciousness into new bodies, but even there, the physical shell affects mental clarity, just as in this article.