A new report analysing 35 different scientific studies of the effect of television on the viewer has identified 15 negative physical and psychological effects associated with watching television. While television has long been blamed for the rise in childhood obesity and diminished reading among children, this study, authored by Dr. Aric Sigman, suggests even more serious consequences for children who watch TV regularly.
The study, published in the respected Biologist magazine, and reported widely throughout Great Britain, found links between habitual TV viewing and obesity, cancer, autism, diabetes, Alzheimer's, attention disorders, and even the breakdown of cells capable of healing wounds. Equally alarmingly, Dr. Sigman claims a significant body of research now points to television as a key factor in reducing levels of the hormone melatonin, the substance that regulates the body's internal clock and also governs the speed at which puberty develops.
Melatonin is a hormone produced by the pineal gland in the brain which plays a key role in regulating the body's internal clock. Dr. Sigman's report suggests that the light emitted by television screens may play a part in suppressing melatonin levels in the blood, which may disrupt the sleep patterns of children and teens as well as the age at which they enter puberty. The ever-earlier onset of puberty has puzzled researchers since it began in the 1950s, precisely when televisions became widely owned.
Dr Sigman also linked TV watching to attention issues, saying that rapid "jump cuts" fracture attention spans while at the same time the brain is programmed to reward itself with the neurotransmitter dopamine for being able to cope with an onslaught of novelty on the screen.
Dr Sigman told writer Fergus Shepherd of Scotsman.com that young children should be banned from watching TV at all, and introduced to it "judiciously" after that. "To allow children to continue to watch this much screen media is an abdication of parental responsibility -- truly hands-off parenting," said Sigman.
A summary of the negative effects reported by Dr. Sigman, as associated with regular TV viewing in 35 studies:
OBESITY
TV viewing is directly related to and now considered an independent cause of obesity. Sitting in front of a screen commands an increasingly large part of children's lives and, Dr Sigman believes, has replaced physical activity for many. Inactivity can also overlap with poor diet.
HEALING
TV seems to be involved in alterations in the activity, size and consistency of skin immune cells. It may lead to an increase in the migration of "cutaneous immune system mast cells", parts of body tissue that play a key role in healing wounds and offering defence against disease.
HEART TROUBLE
TV can set the conditions for long-term cardiovascular illness, some research claims. The adult risk of raised cholesterol and the potential for heart disease is strongly linked to TV viewing habits formed in childhood and teenage years, setting up a store of problems for later life.
METABOLISM
The metabolic rate decreases as average weekly hours of television viewing increases. Lowered metabolism leads to a reduced ability to burn fat. Combined with high-calorie food and drinks, it sets the stage for obesity and other health issues.
EYESIGHT
Permanent eyesight damage previously attributed to genetics is now being strongly linked to television-screen exposure. TV and computer screens are blamed for a rising incidence of myopia as they demand long periods of fixed attention from the viewer.
ALZHEIMER'S
TV really does rot your brain, apparently. Viewing between ages 20 to 60 is associated with the development of Alzheimer's disease: for each additional daily hour of television viewing, the associated risk of Alzheimer's disease development increases. Attention, memory and reaction time may also be affected.
ATTENTION SPAN
Long periods of TV viewing seems to affect what are called the "neuronal mechanisms" behind attention and impulse control, which damages brain-cell development and the person's ability to concentrate on non-TV subjects. For children this brain damage would be associated with mean learning difficulties and attention disorders.
HORMONES
Watching television suppresses production of melatonin, a key hormone and powerful antioxidant that has important roles in the immune system, sleep/wake cycle and the onset of puberty. Melatonin regulates the body's internal clock but bright screens may interrupt production.
CANCER
Reduced levels of melatonin may also result, Dr Sigman suggests, in a greater chance that cell DNA will produce cancer-causing mutations. Some doctors have speculated on a link between sleeplessness and cancer, which one expert suggested formed a "pathway from stress to disease".
EARLY PUBERTY
Exposure to TV screens affects the melatonin levels of younger children, in particular at the onset of puberty. Animal studies link low melatonin levels to early puberty.
AUTISM
Cornell University last year published research suggesting that television may be a trigger in young children with a tendency to autism, which affects 1 in 166 children and has increased in recent decades.
SLEEP
A significant relationship was found between exposure to television and sleeping difficulties in different age groups ranging from infants to adults. Television viewing among infants and young children is independently associated with irregular sleep schedules.
HUNGER
Watching TV may directly increase appetite and body-fat production, through alterations in the hormones leptin and ghrelin, which regulate feelings of being full and of hunger respectively.
BRAIN GROWTH
Even interactive media such as computer games have been associated with limited neurological activity as monitored by brain scans. Unlike reading, watching television has been found by neuroscientists to be a "non-intellectually stimulating activity" for brain development.
DIABETES
TV viewing is associated with abnormal glucose metabolism and Type-two diabetes, most likely linked to side-effects of a sedentary lifestyle.
(This study was reported in the Biologist Magazine, but only Members of the Institute of Biology (IOB.org) can view the past year's worth of Biologist Magazines online. For other detailed coverage of this study, see InformationLiberation.com, or my website,
YourParentingSolutions.com, )
About the Author
Dr. Laura Markham, the Dear Abby of Parenting, is a clinical psychologist who hosts the popular advice column "Ask Dr. Laura" at the parenting web site
YourParentingSolutions.com, The Good Dr. answers questions from parents of infants through teens, offering parent-tested solutions you can use every day to connect with your kids and create a richer family life. Her work appears regularly on a dozen parenting sites and in print, and she frequently speaks with groups of parents, both online and in person, about transforming their parenting. Dr. Laura lives in New York with her husband, son and daughter.