As much of a national pastime as baseball, television has woven itself into the fabric of American life. Yet, 10 ways watching TV can be downright dangerous have emerged from scientific research. Below we break down each alarming effect, backed by solid studies.
10 Gives You High Cholesterol
A 1990 investigation at the University of California, Irvine examined cholesterol levels in youngsters to see whether screen time or video‑game play made a difference. The shocking finding? Kids who clocked more TV hours showed markedly higher cholesterol, and those who perched in front of the set for four hours daily were almost four times as likely to develop heart disease later on.
The elevated cholesterol stemmed largely from poorer diet choices and a sedentary lifestyle among these television‑obsessed children. (The sample mainly consisted of white, middle‑class youth.)
9 Makes You Violent
Back in 1960, Professor Rowel Huesmann launched a long‑term study to capture the influence of media violence on youngsters. Ten years later his team uncovered a clear link: children exposed to violent programming were significantly more prone to act aggressively than peers who weren’t.
While some still debate whether media violence constitutes a public threat, researchers liken the correlation to that between smoking and lung cancer—most exposed won’t develop the disease, but the risk is unmistakably higher.
8 Makes You Dumber
A Johns Hopkins study led by Dina Borzekowski discovered that children who logged more than two hours of TV a day, especially those with a personal set in their bedroom, scored noticeably lower on standardized exams than their peers. By contrast, having a computer with internet access was linked to higher scores.
Further evidence from New Zealand tracked roughly 1,000 babies into adulthood and found that heavy TV viewers achieved far fewer educational milestones, with lower rates of high‑school and college graduation.
7 Lowers Your Sperm Count
Published in the British Journal of Sports Medicine, Harvard School of Public Health researchers reported that men leading a sedentary lifestyle—particularly those who spent long stretches glued to the TV—had sperm counts 44 percent lower than more active counterparts. The critical threshold was roughly 20 hours of TV per week (just under three hours per day).
Conversely, men who logged at least 14 hours of exercise weekly boasted the highest sperm counts. The study’s senior author, Jorge Chavarro, noted that TV ads for food likely spur extra eating, driving the observed drop.
6 Turns You Into A Criminal
British researchers examined over 11,000 children born between 2000 and 2002 and found that those who watched three or more hours of TV daily were more inclined to engage in antisocial acts such as bullying or stealing. Interestingly, the same link did not appear for kids who logged three or more hours of video‑game play each week.
One explanation points to the sheer volume of violence in televised content. A New Zealand study of 1,000 participants reported an average of eight violent incidents per hour of programming, with children’s cartoons sometimes exceeding that rate.
5 Lowers Your Odds Of Surviving Colon Cancer
A cohort of more than 1,500 colorectal‑cancer patients revealed that those who logged extensive TV time before diagnosis faced a markedly higher five‑year mortality rate than peers who watched little or none. Post‑diagnosis viewing, however, showed no clear impact on survival.
A larger U.S. National Cancer Institute study of 566,000 participants echoed a similar trend, noting a modest association between high TV exposure, reduced exercise, and poorer survivability—though the link didn’t reach statistical significance. The takeaway? Any amount of movement beats none.
4 Inhibits Sleep
A joint investigation by MassGeneral Hospital for Children and Harvard’s School of Public Health explored how TV exposure during pregnancy and early childhood influences sleep. Researchers measured infants’ time in rooms with a running TV, older children’s viewing habits, and whether bedrooms housed a set.
Findings showed each hour of TV cut sleep by seven minutes, while a bedroom TV shaved off a full 30 minutes—an effect especially pronounced in boys. A parallel Spanish study reported that nine‑year‑olds who watched five hours daily slept an hour less than peers limited to 1.5 hours.
3 Decreases Language Development
Two separate investigations highlight TV’s toll on early speech. The Seattle Children’s Research Institute tracked over 300 infants wearing audio recorders for up to 16 hours a day. Each hour of TV exposure corresponded with a loss of roughly 770 spoken words heard, which in turn curtailed the babies’ own vocalizations.
A complementary study demonstrated that live, interactive conversation beats screen time for language acquisition. Nine‑month‑old American infants exposed to a Mandarin speaker in person learned to differentiate speech sounds after just 12 sessions, whereas those who watched the same speaker on TV showed no improvement.
2 Makes You Drink More
A collaborative team from the Netherlands and Canada recruited 80 young men (ages 18‑29) and exposed them to television content featuring varying levels of alcohol portrayal. Participants who watched programs saturated with drinking cues consumed, on average, 1.5 more bottles of beer or wine than those viewing alcohol‑free content.
Although the researchers cautioned that long‑term drinking habits weren’t proven to shift, they emphasized the immediate cue‑driven craving effect, noting that “it might work as a cue that affects craving and subsequent drinking in people who are drinkers.”
1 Kills You Early
An Australian study linked excessive television time to a dramatic reduction in lifespan. Watching six hours per day shaved nearly 4.8 years off life expectancy, while each additional hour after age 25 trimmed roughly 22 minutes.
Supporting evidence from Harvard’s School of Public Health found that exceeding three hours of daily TV—or any comparable sedentary activity—boosted the risk of premature death by 13 percent, chiefly through heightened chances of diabetes and cardiovascular disease.