Age

It should come as no surprise that the most common introductory sentences in doctors' commentary are about the age. These opening remarks appear every now and then in the morning round: "This is a 75-year-old man who came in with a fever."

That's the way medical students have been taught to describe a patient, I know.

The at-a-glance knowledge of a patient's age is so important (universal, I might add) that nobody dares to skip it. Well, yes and no. Yes, that number on the top right corner of patient's case note might give you an inkling how fit the patient is, but never emphasize too much on the chronological age. I'm more interested in my patient's biological age, and I've taught my students so.

Biological age, as it happens, is imprecise and less scientific. To many, this kind of guesswork seems like counting the grey hair. In the hands of experts, like yourself, it is a window into your real age. Instead of magical formula, it refers to "how old do you feel you are?"

Time for a quick quiz: How old do you feel you are?

A simple question, but a meaningful one. That's what I just learned from a research publication of the English Longitudinal Study of Ageing. Researchers studied some 6500 adults aged 52 years and older, asking the exact question I just mentioned. Some of them perceived their age close to their actual age; some felt more than one year older than their chronological age. More than half (me included if I were recruited), in fact, rated their age at least 3 years younger than their actual age.

Take one more close look at the mortality rate after 8 years of follow-up, and you'll see the pattern. Alas, after adjusting for the baseline health, physical disability, and health behavior such as smoking and alcohol use, those who felt younger live longer than those who felt their actual age or older. It's not hard to explain the finding if the terminal ill patients rated themselves older. But the same conclusion was shown after excluding death within 12 months of baseline question. In short, feeling young gives you a phenomenal edge over longevity. The upshot is that we now better understand the merit of feeling young - a sense of mastery.

Although trite, the old saying still is true. "It's not how old you are. It's how you are old."