Hours plunked down in front of the TV or staring at a phone screen in childhood could bring poor heart health decades later, a new study shows.

Finnish researchers say kids who were largely sedentary tended to turn into young adults who battled high cholesterol and other health troubles.

“Our study shows increased sedentary time in childhood may contribute to two-thirds of the total increase in a person’s cholesterol levels before their mid-twenties,” study lead author Dr. Andrew Agbaje said in a news release from the Endocrine Society.

“This suggests childhood sedentariness may be a major risk factor for elevated cholesterol and subsequent premature heart attack or stroke when individuals reach their mid-forties,” said Agbaje, who is at the University of Eastern Finland in Kuopio.

His team published its findings Dec. 14 in The Journal of Clinical Endocrinology & Metabolism, an Endocrine Society journal.

In the study, 11-year-olds were fitted with activity trackers and were also regularly checked for cholesterol levels. Their health was then followed for 13 years.

One main finding: ‘Couch potato’ kids became even more rooted to their sofas as they aged. Average sedentary time rose from 6 hours per day in childhood to 9 hours per day as they became young adults.

Agbaje’s group calculate that this lack of physical activity contributed to 70% of the rise in cholesterol over the same time period.

‘Light’ physical activity decreased from about 6 hours per day in childhood to half that by young adulthood.

Moderate-to-vigorous physical activity stayed relatively stable, at 50 minutes per day, on average. This type of activity did seemed linked with a lowering of total cholesterol, but only if the person also managed to keep obesity at bay, the team found.

So, “engaging in light physical activity for 3-4 hours/day may be an effective way to reduce high cholesterol and avoid heart health issues later in life,” Agbaje said.

More information

Find out more about childhood activity and heart health at the University of Rochester Medical Center.

SOURCE: Endocrine Society, news release, Dec. 14, 2023

Source: HealthDay