Last week, a team of researchers led by Geoffrey Kabat of Albert Einstein College of Medicine published a study showing that each additional 4 inches of height increases the risk of all types of cancer by 13 percent among post-menopausal women.
That statistic should shock you. If we could hold all other risk factors equal—which, of course, we cannot—the average woman in China, simply due to her height, would be 13 percent more likely to get cancer than an average Guatemalan woman. Dutch women, with an average height above 5-foot-6, would be more than 25 percent more likely to get cancer than Guatemalans. And female models and WNBA players—well, the numbers look even worse for them.
Most people I know would love to be taller. Parents with slow-growing children often ask pediatricians for growth hormone to save their kids the indignity of being short. I get it. Tall people—particularly tall men—earn more money and are held in higher esteem than their shorter colleagues. Tall people also have higher IQs and a wider selection of mates. The association between height and success is perpetuated, in part, because tall, successful people marry tall and successful.
Most of the benefits of height come down to our inability to separate correlation from causation. Height doesn’t make people smart; the two traits are simply outgrowths of the same underlying cause. Parents who can afford to feed and raise their children well have kids that are both taller and smarter. There’s plenty of evidence that height is easily separable from intelligence. Here’s just one compelling point: The tallest sibling in a family is no more likely than the others to have the highest IQ.
I don’t blame short people for wishing on a star for height, or parents for seeking out growth hormones for their children. The sociological data is compelling at a surface level, and there are some concrete advantages to height—being able to reach the top cupboard is convenient. But the evidence linking height to life-threatening disorders should give us all pause.
Physicians and epidemiologists began studying the link between height and longevity more than a century ago. Early researchers believed that tall people lived longer, falling prey to the correlation–causation confusion described above. In fact, in the early 20th century height was indeed a reflection of better nutrition and hygiene, which increased longevity. Once the studies were limited to otherwise homogeneous populations, a consensus emerged that short people are longer-lived.
Among Sardinian soldiers who reach the age of 70, for example, those below approximately 5-foot-4 live two years longer than their taller brothers-in-arms. A study of more than 2,600 elite Finnish athletes showed that cross-country skiers were 6 inches shorter and lived nearly seven years longer than basketball players. Average height in European countries closely correlates to the rate of death from heart disease. Swedes and Norwegians, who average about 5-foot-10, have more than twice as many cardiac deaths per 100,000 as the Spaniards and Portuguese, who have an average height just north of 5-foot-5. Tall people rarely live exceptionally long lives. Japanese people who reach 100 are 4 inches shorter, on average, than those who are 75. The countries in the taller half of Europe have 48 centenarians per million, compared to 77 per million in the shorter half of the continent.
Setting aside simple mortality, individual diseases are also more common among tall people. American women above 5-foot-6 suffer recurrent blood clots at a higher rate. Among civil servants in London, taller people have been shown to suffer from more respiratory and cardiovascular illness. And then there’s cancer. Height is associated with greater risk for most kinds of cancer, except for smoking-induced malignancies.
Unlike intelligence, which has a merely coincidental relationship with height, there are plausible biological explanations for why short people live longer. Researchers have found that the lungs of taller people don’t function as efficiently, relative to their bodies’ demands, as those of short people. Explanations for the link between height and other disorders are slightly more speculative, but largely credible. Tall people have more cells, which may increase the chances that some of them will mutate and lead to cancer. The hormones involved in rapid growth may also play a role in cancer development. It’s even possible that the foods that lead to fast growth during childhood may increase the likelihood that a person will eventually develop cancer. The link between height and clots probably has to do with the length and weight of the columns of blood that travel between the heart and the body’s extremities.
The recent study linking cancer to height in post-menopausal women also helps disprove a popular theory—that height is inversely related to longevity because men are taller and die younger than women. Tall people, we now know, suffer more illness even when gender is eliminated as a variable.
The fact that tall people die younger appears to be an immutable physical reality. A short person is like a Honda Civic: compact and efficient. Tall people are Cadillac Escalades. With all that extra weight and machinery, something’s just bound to go wrong. Against that backdrop, those who wish for more height for themselves or their children face a Sophie’s choice. Even if a couple of extra inches of height will increase your standing in the community, your IQ, and even your lifetime income, does that justify trading in years of your life?
At 6 feet tall, I’m no giant, but I’d gladly shrink down a few inches to fit better into airplane seats. And as I get older, and begin to worry about what percentage of my life is behind me, I’d practically miniaturize myself if it would get me five or 10 more years.