Controlling the onset of adolesence

ADOLESCENCE, quite rightly, has a bad reputation. It is tough for youngsters when their sex hormones surge and for parents to watch their little angels turn into raging beasts. It is especially hard if puberty begins when children are very young.

Today, drugs that can be injected to delay puberty are reserved for extreme cases. But that could change. Better drugs are expected to emerge in the next decade thanks to the discovery of the gene that kick-starts puberty (see "The teen gene"). That raises an intriguing question: should we leave the timing of puberty to the whim of nature or take control?

There is plenty of evidence that the timing of puberty matters. One study compared women whose periods started before age 11 with those who matured later. It found lasting differences: the early maturers' educational achievements were lower and they tended to be shorter and have weight problems. Other studies suggest that early puberty is linked to increased risks of breast and prostate cancers.

As yet, however, it is not clear if delaying puberty will reverse these harmful effects. We do not know, for example, if puberty itself increases the risk of cancer or if some other factor causes both early puberty and a higher cancer risk. Until that evidence is in, doctors and parents should dismiss the notion of a pharmaceutical fix for borderline cases.

In the meantime, we do know that the recent decline in the average age of onset of puberty has been caused at least in part by increasing obesity. So, for parents worried about the early emergence of raging beasts, throw out the computer games and buy them some tennis shoes.