研究：耳朵會隨着年齡增長而變大
前英國國會議員現評論家馬修•帕里斯在最近的一篇專欄中提到，隨着年齡的增長，他本來就大的耳朵變得更大了，他覺得有些尷尬，正在尋找使耳朵縮小的方法。
帕里斯可能不知道，他寫這篇文章之時正是有關耳朵大小的最早一項科學研究的二十週年的日子。1993年7 月，倫敦布羅姆利區的一名非專科醫生詹姆斯•希思科特和他的同事們開始觀察耳朵大小。他們從自己的病人裏隨機挑選了206名30歲以上的病人，測量他們的耳朵，計算髮現耳朵每年平均增長0.22毫米，50年就能長1釐米。後來，1996年日本發表的研究數據和1999年意大利的一項研究證實這一發現。
研究中已列出的耳朵隨年齡增長而變大原因有以下幾種：由於皮膚失去彈性以及重力的影響，耳朵（鼻子也是）會隨着年齡的增加而下垂；耳垂下垂，如果戴着重重的耳環，這一現象可能加重；更有爭議的一個原因是，有人提出，軟骨不像骨頭，會繼續增長，而耳朵是由軟骨構成的，這可能也算作耳朵不斷增大的原因之一。
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.
