Your life span could be shortened by too much screen time, suggests new study

Using our phones too much can directly impact on how long we live, a new study has suggested.

21st-century humans are, more often than not, likely to spend a fair bit of the day (and night) looking at screens; this amount can often get out of balance.

It is thought on average adults spend 34 years of their lives with their faces in a screen, and a new study has looked into how our eyes’ light exposure can impact life expectancy.

Using fruit flies, the Buck Institute for Research on Aging studied the relationship between exposure and how long they live. Fruit flies were chosen because they have similar biological processes to humans.

The research’s lead author Dr Brian Hodge said they were surprised to discover that the eye can “directly regulate” lifespan.

Circadian rhythms, the body’s 24-hour body clock that regulates our bodies’ functions throughout the day, are behind this.

Circadian rhythms adapt to various light levels and temperatures as we move through the day, pulling the strings with the hormones that make us hungry or tired.

Working night shifts, watching TV or being exposed to light at night can throw these carefully balanced bodily processes off-kilter, which can be bad news for our health.

Senior author Professor Pankaj Kapahi said: “Staring at computer and phone screens, and being exposed to light pollution well into the night, are conditions very disturbing for circadian clocks.

“It messes up protection for the eye and that could have consequences beyond just the vision, damaging the rest of the body and the brain.”

In the past, the same group of researchers discovered that by restricting the diets of fruit flies they could increase their lifespans – this also affected their circadian rhythms.

They wanted to uncover which genes worked like a clock, finding that not only did dietary restriction have the biggest impact, but also that most came from a part of the eye called photoreceptors, which respond to light.

Their research led them to find out if genes in the eye are connected to lifespan, assessing whether light in the eye can cause photoreceptor degeneration and inflammation.

“Dysfunction of the eye can actually drive problems in other tissues,” said Professor Kapahi.

An experiment found that flies kept in constant darkness lived for longer.

“We always think of the eye as something that serves us, to provide vision,” Professor Kapahi said. “We don’t think of it as something that must be protected to protect the whole organism.”