Researchers said the strength of someone's grip may reveal how fast they're aging, their education level -- and even their future health, the Newsmax Health reported.

The International Institute for Applied Systems Analysis researchers reviewed more than 50 published studies from around the world for their article in the journal PLOS ONE.

They found that people with more education at age 69 tended to grip just as strongly as less educated people at age 65, suggesting the latter were aging about four years faster.

Another study the authors reviewed was done on more than a million Swedish adolescent males, whose handgrip strength was measured as part of an exam for military service.

Those with lower handgrip strength were significantly more likely to die earlier, have heart disease, be at higher risk of suicide and experience psychological problems.