A limp handshake is a surefire way to make a bad impression at a job interview.

But a lack of firmness might have more serious implications — it could be a sign someone is at risk of an early death, a study suggests.

Researchers at the University of Michigan have linked poor grip strength to a higher risk of diseases like cancer or heart disease.

They found elderly people with low grip strength had biologically older DNA and more harmful biomarkers than their peers. 

Doctors have long known there is a link between a declining grip as you age and a shorter lifespan, but they are still unsure why these two things are linked. The Michigan researchers have tied it to the process of DNA methylation.

Researchers found that a weak grip strength was linked to higher levels of DNA methylation, which can lead to cancer, heart disease, nervous system issues and increase a person's overall risk of death (file photo) Researchers found that a weak grip strength was linked to higher levels of DNA methylation, which can lead to cancer, heart disease, nervous system issues and increase a person's overall risk of death (file photo)

Researchers found that a weak grip strength was linked to higher levels of DNA methylation, which can lead to cancer, heart disease, nervous system issues and increase a person’s overall risk of death (file photo)

‘There is a large body of evidence linking muscular weakness, as determined by low grip strength, to a host of negative aging-related health outcomes,’ researchers wrote in the study.

‘Given these links, grip strength has been labelled a “biomarker of aging”; and yet, the pathways connecting grip strength to negative health consequences are unclear.’

Many diseases become more common as a person gets older. But, doctors believe there is a difference between a person’s ‘real’ age and their ‘health’ age.

Some people age better than others, and lifespans can vary wildly based on genetics and lifestyle choices such as diet and exercise.

While boiling down a person’s overall health to an exact number is impossible, scientists have developed tools over the years that can determine how near or far death may be.

One of those tools is measuring grip strength. While something that can often be overlooked, the amount of power a person can draw from their hands and forearms can be a strong indicator of overall health.

In a 2019 report, a Campbell University expert wrote that grip strength is linked to bone density, risk of fractures, cognitive impairment, diabetes and overall quality of life. 

Michigan researchers hoped to find the link between grip strength and overall health.

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In the latest research published in the Journal of Cachexia, Sarcopenia and Muscle, researchers gathered data from 1,300 men and women around 70 years old over ten years.

Each participant used a Smedley spring dynamometer – a gripping tool – to test the power in their hand every two years.

They would grab the device and squeeze as hard as they could two times with each hand, and the highest result recorded would be included in the study.

Using blood samples, the research team also gathered data on DNA methylation levels in each participant.

The National Cancer Institute describes DNA methylation as the process of methyl, a chemical derived from methane, getting added to DNA.

‘The addition of methyl groups can affect how some molecules act in the body,’ the NCI writes.

‘For example, methylation of the DNA sequence of a gene may turn the gene off so it does not make a protein.’

Increases in DNA methylation are linked to cancer, heart disease, and nervous system issues.

The Michigan research team found a strong correlation between a person’s grip strength and their biological age.

As time when on, people whose grip strength degraded were also more likely to develop a severe chronic condition or to die during the study period.

Researchers are not sure why DNA methylation is linked to early mortality but believe that muscle strength could help protect against it.

‘Future research is needed to understand the extent to which [DNA methylation] age mediates the association between grip strength and chronic disease, disability and early mortality,’ they wrote.