《柳叶刀》研究：握力是健康的信号

The force of that handshake is actually used by researchers to predict a person's life or death over the coming years.

A study covering 17 countries and nearly 140,000 people, with an average follow-up of four years, put grip strength and death risk on the same table.

For every 5 kg decrease in grip strength, the risk of all-cause death is 16% higher, and the risk of cardiovascular death is 17% higher.

What surprised the researchers even more was that grip strength's ability to predict these two outcomes exceeded that of systolic blood pressure.

In other words, besides measuring blood pressure, giving a dynamometer a squeeze might reveal something blood pressure cannot.

Repeatedly squeezing a grip trainer alone is probably not enough to extend your lifespan.

But it may be an extremely low-cost window for health monitoring.

The reason hand strength can reveal so much information is that it was never just about muscles.

Brian Clark, a physiologist at Ohio University, has a saying: muscles are the puppets at the very end of the neurological chain of command.

The brain gives orders, nerves transmit them, and muscles execute them; if any link loosens, the final grip force will change.

Clenching a hand requires the brain to coordinate and control the 39 muscles of the palm and wrist.

The combined force of the fingers is not a simple sum of their individual strengths; when they tighten together, the total force is actually less than the sum of each finger's strength alone.

This is also why grip strength is often seen as a readout of the state of the nervous system.

A small 2024 experiment with older adults found that participants with lower cognitive test scores had a larger strength gap when exerting force.

In other words, if the hand cannot exert force, the problem may not be in the hand.

Ivan Bautmans, who studies aging at the Free University of Brussels, believes that weakened grip strength may be a precursor to cognitive decline.

He points out that a simple and inexpensive grip strength test can provide valuable early warning.

He also warns that when one hand's strength drops to half that of the other, decline may be accelerating.

Some asymmetry between left and right hands is common; the dominant hand being about 10% stronger than the other is within the normal range.

If the gap is larger, it is worth paying attention.

The reason is that each hand is mainly controlled by the opposite hemisphere of the brain, and degeneration of the nervous system is often uneven.

A meta-analysis published in April this year pooled nine cohort studies involving about 900,000 people.

The results showed that people with a clear difference in strength between hands had a 29% higher risk of dying from cardiovascular disease.

Another meta-analysis published in June, co-authored by Bautmans, included 60 observational studies and about 380,000 people.

The group with stronger grip strength had a 19% lower likelihood of cognitive decline.

However, weak grip strength or left-right imbalance is not itself a diagnosis.

It suggests a more comprehensive examination, not a verdict.

Existing research shows that whole-body resistance training helps maintain mental sharpness.

This is exactly where the grip dynamometer is useful: it is cheap, can be done anywhere, and can prompt a person to seek a more comprehensive check before symptoms appear.