The evidence-led answer
NST verdict
Yes. Grip strength is one of the best simple predictors of future health and lifespan we have. In a study of about 140,000 people across 17 countries, every 5 kg drop in grip strength was linked to roughly a 16% higher risk of dying from any cause over the next few years, and it predicted death better than blood pressure did. It also tracks with bone density, physical function, cognition, mood and how people fare in hospital. Two things matter for how you use this. First, it is a marker, not a magic lever: grip strength stands in for your overall muscle, strength and general robustness, and no study has shown that training your grip specifically lowers your risk of dying. Second, the useful takeaway is not "buy a hand gripper", it is "be a stronger person overall". Whole body strength training is independently linked to lower mortality. So a weak or falling grip is a warning sign worth taking seriously, and the response is general strength training, enough protein and staying active.
Does grip strength really predict health?
Strongly. The PURE study followed 139,691 people in 17 countries for a median of about four years. After adjusting for other factors, every 5 kg lower grip strength was associated with a 16% higher risk of all cause death, a 17% higher risk of cardiovascular death, and higher risks of stroke and heart attack. Grip strength predicted all cause and cardiovascular mortality more accurately than systolic blood pressure.
It is not just mortality. A review of the wider evidence found grip strength consistently associated with overall strength and function, bone density, fractures, falls, malnutrition, cognition, depression, having multiple health conditions, and quality of life, and predictive of future function and how people cope with a hospital stay. That breadth is why grip strength is used as a quick, cheap screening measure in older adults.
So should I train my grip?
Not in isolation, and not as a longevity strategy. First, grip strength is a marker, not a proven lever. In PURE itself, grip strength was not linked to some outcomes, new onset diabetes, falls, fractures in that dataset, and the authors were explicit: it is not known whether improving strength reduces mortality. Grip strength is standing in for your overall muscle mass, strength and robustness. Squeezing a gripper trains your forearms; it does not turn the dial on the thing the number is actually reflecting.
Second, the actionable version already exists. Muscle strengthening activity, resistance training that builds whole body strength, is independently associated with roughly 10 to 17% lower all cause and cardiovascular mortality. So the sensible response to a weak grip is to get stronger overall, and your grip improves as a by product.
What this means in practice
Treat grip as a signal, not a target. You can measure it with a hand dynamometer, but the more useful check is whether everyday tasks are getting harder, opening jars, carrying shopping, getting up off the floor. A falling grip is worth a doctor's attention, especially if it is unexplained or rapid, since it can flag under nutrition, illness or general deconditioning. The fix, for most people, is whole body resistance training two to three times a week, enough protein, and less sitting; grip strength improves along with everything else. Skip the standalone hand gripper as a health purchase. It is fine as training for climbers or grip sport athletes, but it is not a longevity tool.
Practical meaning
Treat grip as a signal, not a target: a hand dynamometer can measure it, but noticing everyday tasks getting harder (jars, shopping, getting off the floor) is more useful. A falling grip is worth raising with a doctor, especially if unexplained or rapid, since it can flag under nutrition, illness or deconditioning. For most people the fix is whole body resistance training two to three times a week, enough protein and less sitting; grip improves as a by product. A standalone hand gripper is fine for climbers, not a longevity purchase.
Limitations and uncertainty
The grip strength and muscle strengthening studies are observational, so grip strength predicts and is associated with risk, it is not shown to cause it, and the PURE follow up was short (about four years). The biomarker review is single author and weighted to older adults; its long list of associations is 'tracks with', not 'causes'. Using the muscle strengthening activity evidence as the actionable answer is a reasoned bridge, since grip is a proxy for overall strength and building overall strength is what the mortality data support.