Friday, 04/17/2026
Health
Kids who watch lots of TV have lower bone mass as adults
Update: 05/09/2016
Children and teens followed until age 20 - when bone mass is\r\npeaking - had lower bone mass at that age the more hours they had spent\r\nwatching TV in childhood, researchers reported online July 4th in the Journal\r\nof Bone and Mineral Research.
\r\n\r\n\r\n\r\n“What we need to make clear is that it’s not necessarily the\r\nact of watching TV that is driving the link between TV and health outcomes, but\r\nthe act of sitting for long periods,†said Natalie Pearson of the School of\r\nSport, Exercise and Health Sciences at Loughborough University in the U.K., who\r\nwas not part of the new study.
\r\n\r\n\r\n\r\n“The first set of data collected on TV viewing in the\r\ncurrent study was collected 15 years ago,†and since then more and more young\r\npeople have started watching TV on demand, using iPads, smart phones and apps,\r\nshe told Reuters Health by email.
\r\n\r\n\r\n\r\nFor the study, led by Joanne A. McVeigh at Curtin University\r\nin Perth, Australia, the parents of more than 1,000 Australian kids reported\r\nhow much TV each child watched per week at ages 5, 8, 10, 14, 17 and 20 years -\r\nthough at older ages the kids started to self-report their own TV watching\r\nhabits.
\r\n\r\n\r\n\r\nResearchers sorted the kids into three groups based on their\r\nTV watching patterns over time: about 20 percent watched less than 14 hours of\r\nTV per week as children and teens and were considered consistent low-level\r\nwatchers, more than 40 percent watched 14 or more hours per week as children\r\nand teens and were consistent high-level watchers, and 35 percent increased\r\nfrom low to high levels of TV watching per week over the years.
\r\n\r\n\r\n\r\nAt age 20 the participants had X-ray scans to assess bone\r\nmineral content.
\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\nThe researchers accounted for height, body mass, physical\r\nactivity, calcium intake, vitamin D levels, alcohol, and smoking at age 20, and\r\nstill found that kids who were consistently high-level TV watchers at younger\r\nages had lower bone mineral content than others as adults.
\r\n\r\n\r\n\r\nImmobilization for prolonged period of time is detrimental\r\nto bone health, said Dr. Sebastien Chastin of Glasgow Caledonian University in\r\nthe U.K., who was not part of the new study.
\r\n\r\n\r\n\r\n\r\n\r\n“Sitting watching television does two things, it takes away\r\nfrom being active, therefore we do not get the benefit of physical activity and\r\nsecond it immobilizes us for prolonged period of time which we know from bed\r\nrest studies triggers physiological response that change the balance in our\r\nbody chemistry that keeps our bone strong,†Chastin told Reuters Health by\r\nemail.
\r\n\r\n\r\n\r\n“Several studies have shown over the years that there is a\r\nrelationship between the time we spend sitting and bone health,†he added.
\r\n\r\n\r\n\r\n"Poor bone health ultimately can lead to osteoporosis\r\n(brittle bone disease) which affects over 200 million women worldwide," he\r\nsaid.
\r\n\r\nOur bodies reach peak bone density around age 22, after\r\nwhich time bone density decreases over time, though we can slow the decrease by\r\nmaintaining an active and healthy lifestyle, Chastin said.
\r\n\r\n\r\n\r\n“Impact sports are the most beneficial for bone health,†he said,\r\nciting parkour or “free running†in particular for muscle strength, balance and\r\ncoordination.
\r\n\r\n\r\n\r\n“It is often very difficult to make parents and doctors\r\naware of the very long term health implications of sitting (at a screen or\r\nother sitting occasions such as school time, work time, travel etc.) for long\r\nperiods, as in today’s society we are very interested in the immediate\r\nresponses to our actions and not what will happen 20 years down the line,â€\r\nPearson said.
\r\n\r\n\r\n\r\nThere are practical ways to break up periods of seated\r\nscreen time, like getting up during ads or while working on a computer getting\r\nup to answer the phone instead of emailing a colleague or friend, she said.
\r\n\r\n\r\n\r\nSOURCE: bit.ly/29uRk1N
\r\n\r\n\r\n\r\nJ Bone Miner Res 2016.
KATHRYN\r\nDOYLE - Reuters