Do tall people die younger?
I was making fun of a colleague at work who has recently returned to smoking cancer sticks. His retort was, "Yeah, well, tall people die younger." Since I'm about 6-7, this hit me right in the heart--which I suspect is the organ at fault. Is his claim true?
You actually acknowledge the possibility this shrimp may be right? Some might call that a very untall attitude. The classic short-guy's-nightmare response would be more like: Look, little man (that's how 6-2 George H. W. Bush once referred to 5-10 Nicaraguan president Daniel Ortega), everybody knows tall people, particularly tall men, are not only healthier, they're more successful, smarter, sexier, and more widely looked up to (duh, but you see how heightist bias is embedded in the language). Setting aside issues of success, getting lucky, etc, experts--even short ones--have long recognized that as a society's physical well-being improves due to improved nutrition and so on, its members get taller. Over the past 150 years, the average height of Europeans has increased by around eight inches; more recently the average height of the Chinese has been increasing about an inch per decade. Conversely, research on refugees has found that 14-year-old North Korean males are six inches shorter than their South Korean counterparts, presumably due to malnutrition. At minimum this seems to mean: tall = healthy society. Many researchers have gone farther and claimed: tall = healthy you. However, this being an era of diminishing resources, a few iconoclasts argue (possibly in earshot of your coworker) that not only is small beautiful, it's better for you and the planet too.
One of the most vocal short-is-good advocates is Thomas Samaras, director and senior researcher at San Diego-based Reventropy Associates. Samaras advocates what he calls "entropy theory," which holds that increased body mass and energy expenditure means faster aging. Over the past 30 years Samaras and his colleagues have published a stack of papers challenging heightist wisdom. For example, they say, studies allegedly showing that tall people live longer than short ones don't account for confounding variables such as socioeconomic status and smoking (poor people and smokers tend to be smaller). Factor stuff like that out, they contend, and the differences largely disappear. In fact, maybe the numbers head in the opposite direction--Samaras and company interpret other studies as indicating that you die six months sooner for every extra centimeter of height. Throw in the fact that big people suck up more resources than diminutive ones and you've got a good argument that what we really need to do, as Steve Martin once encouraged, is get small.
To emphasize, this is the minority opinion. In a 2002 commentary on one of Samaras's papers, British epidemiologist George Davey Smith, who's done his own investigations into the relation between height and mortality, presents what I take to be the majority view: (1) In developed countries, taller people live longer than shorter ones and have lower death rates when all causes are considered. (2) Taller people exhibit higher death rates from a few specific causes, notably cancer unrelated to smoking and aortic aneurysm. Possibly that's because bigger people eat more as children and so are at greater risk for eating-related cancers, and, having longer aortas, have more to rupture. (3) This is more than made up for by taller people's decreased tendency to die of coronary heart disease, stroke, and respiratory disease. Davey Smith thinks that's because tall people have better lung function and because "being taller than average is an indicator of favorable childhood social circumstances."
Short folks will likely reply: This guy's missing the point. Nobody denies that, when you compare two societies, or one society at two points in time, the better-fed crowd will be taller and live longer. The issue is whether, with environmental considerations out of the mix, taller means healthier. You have to be skeptical--lots of short middle-class people aren't that way because of deprived childhoods but because they had short ancestors. One suspects Samaras may be right when he says all the variables aren't being controlled for. On the other hand, Samaras's contention that short is not just as good as but better than tall is also dubious. Rodent studies suggest that sharply cutting back on food intake will prolong life, and few dispute that pigging out in typical American fashion is a sure way to shorten it. However, the key factor here is surely not height (Samaras at times seems to be saying that we ought to starve kids in order to stunt their growth, although he tells me that's not his intent), but weight in relation to height. Since there's not much adults can do about their height anyway, why worry about it? Pending further and one hopes more illuminating research, the best bet for prolonging life seems to be: watch what you eat, and eat a lot less.