MP-turned-pundit Matthew Parris is fretting about a very big subject – his ears. In his column in the Times this week, he said that as he has got older his ears have got larger. "They started quite big and now it's becoming embarrassing," he complained. "Are there any pills you can take to shrink them? Never mind penis enlargement. I'm looking for ear reduction."

Parris may not realise it, but he was writing on the 20th anniversary of one of the first scientific studies of ear size. Anecdotally, it had always been felt that old blokes tended to have bigger ears than everyone else. In July 1993, James Heathcote, a GP in Bromley, and a group of his colleagues set out to test the observation. They measured the ears of a randomly selected group of 206 of their patients over the age of 30, and calculated that ears increased by an average of 0.22mm per year – a centimetre (or just under half an inch) over 50 years.

Heathcote's findings were backed up by Japanese data published in 1996 and by an Italian study in 1999. The latter concluded that men's ears were significantly larger than women's, that ears did tend to get bigger as people got older, and that the growth occurred in both men and women. Whatever Parris thinks, this is not just an old man issue. It may be that women wear their hair longer, so we are less aware of their ears.

Several reasons have been adduced for the growth. Ears (and indeed noses) sag with age, thanks both to a loss of elasticity in the skin and to the effects of gravity. Earlobes droop, a phenomenon that can be accentuated by heavy earrings. More controversially, it has been suggested that because, unlike bone, cartilage continues to grow and ears are made of cartilage, that may also account for the phenomenon. But the evidence is sketchy, and some researchers argue that cartilage is only being replaced and does not account for the growth in ear size.

The good news for Parris is that plastic surgery can halt much of the drooping, and "lobe jobs" are increasingly common – a snip at a couple of grand. At the moment, it is mainly women who are having it done, to reverse the effects of a lifetime of dangly earrings, but men are sure to follow. Over to you, Matthew. Ear today, gone tomorrow.