Do smartphones threaten our physical health? Here’s what we know about their impact


A sports doctor writes in his book that smartphones are a problem for our physical health and recommends that people try to reduce their screen time.


Two years ago, a doctor in Brest, France launched a campaign to attempt to get people to put down their smartphones.

The challenge was carried out among a self-selected group already ready to reduce the time they spent on their phones.

Yet Yannick Guillodo, a sports doctor with Brest’s University Hospital Centre (CHU), says around three-quarters of the nearly 500 participants they surveyed were unable to reduce their phone time by an hour a day.

But nine in 10 of those that did succeed were more physically active, according to their analysis which is in pre-print.

Now, he’s written a book published in French with a provocative title that translates to “Smartphones Kill” (Le smartphone tue), warning that not only are the phones hard to put down, but they also make people more sedentary.

“I was initially interested in the relationship between the number of smartphones and induced sedentary lifestyle. Because when we look at the smartphone, we are sitting on a sofa, or in a chair,” he told Euronews Health.

“If I spend one more hour on a smartphone sitting in a chair, I spend one more hour [sitting]. And on that, we have studies which clearly show that a sedentary lifestyle is a clear risk factor for chronic diseases, so-called non-communicable diseases such as diabetes, stroke, heart disease, certain cancers and so on,” he added.

Phones linked to a sedentary lifestyle

Andrew Lepp, a professor at Kent State University in the US, has also studied the topic of phone use and physical activity.

“We have conducted numerous surveys assessing sedentary behaviour, physical activity, and cell phone use,” he said in an e-mail.

“Without a doubt, people who use the cell phone more also spend significantly more time sitting,” he added.

He also found that people who use the phone more tend to use it for exercise.

“If you are scrolling, texting, even talking with your phone during exercise then it decreases exercise intensity,” he said.

In a study published in the journal Digital Health in 2019, Lepp and co-authors wrote that high cell phone use could be “a significant predictor” of what they call an “active couch potato”.

Those are people who meet the requirements for physical activity but also lead very sedentary lifestyles.

“The active couch potato is also an at-risk group because generally speaking, the negative health impacts of too much sitting are independent of the benefits of physical activity,” he said.

Are there other physical health impacts from smartphones?

Paul Elliott, a professor at Imperial College London, is looking into the impact of smartphones on whether they lead to long-term health problems.

In a recent study published this month, he and other researchers found using a mobile phone, thankfully, does not increase your risk of developing brain cancer.

The study, which began in 2007, was based on 250,000 mobile phone users and is the largest multinational follow-up study investigating the topic.


“Because of the prospective nature of the study where we ask about mobile phone use and follow people up before they develop disease (as well as obtaining objective data on mobile phone use, with participant consent, from the mobile phone operators), we can look at a wide range of diseases, not just brain cancers,” Elliott said.

“These include other cancers, cardiovascular disease, neurological diseases and studies of fertility and reproductive effects. We have also been looking at the development of symptoms such as headache,” he added.

Elliott was also a co-author of a study published in 2021 that looked at the use of digital technology on body mass index (BMI) in adolescents, which found an association between the two.

It was “partly mediated by insufficient sleep,” the researchers said in conclusion, suggesting that there may be multiple factors involved.

Guillodo in Brest, meanwhile, is also interested in these multiple factors that contribute to our health due to smartphone use, including how they influence our eating habits and our sleep.


He thinks that smartphone use should be considered when policymakers think about preventing physical inactivity.

Solutions must come from all aspects of society including individuals, companies, governments and Big Tech, he said.

Guillodo recommended small changes such as turning off phones during dinner and 45 minutes before bed as well as turning them off in work meetings.


Leave a Reply

Your email address will not be published. Required fields are marked *