TV May Speed Onset of Puberty

Jul 02, 2004 04:05 AM EDT

A recent Italian study has found that watching too much television may distort the hormonal balance of adolescents and push many of them into early puberty.

The study found children denied access to television for just one week experienced a 30% jump in their melatonin levels. The hormone is thought to prevent the early onset of puberty. If confirmed, this would be the first sign of a direct physiological impact of television upon the young.

Radiation may be to blame

Research focused on 75 junior-school children in an Italian village, whose parents agreed to deny them access to television, computers and video games for a week. Ball games, public reading and other activities were organized to involve parents and children.

The scientists hypothesize that the light and radiation coming from television and computer screens disturbs the production of melatonin.

Some animals use melatonin to time their reproduction, changing it to suit their environments. In humans, the hormone regulates the body's internal clock. Levels are at their lowest in the daylight hours, but peak in the evening around eight o'clock as the body prepares for sleep.

Phenomenon is increasing

The phenomenon of precocious puberty—when children develop the first signs of puberty earlier than the normal ages of ten for girls and eleven-and-a-half for boys—is increasing throughout the western world.

In 1990, the first signs of precocious puberty were around the age of eight for girls—the whole process taking two years to complete. Now, according to the study, some children enter puberty as young as seven.

While researchers believe there are multiple causes for this effect, they feel television viewing may be one of them.