We could be on the verge of advances that extend the human life span by decades. In 2010, for example, a Stanford team increased the life span of worms by up to 30 percent by blocking the expression of certain proteins. That same year, researchers at Boston University identified 150 places on the human genome that are responsible for long life, and Harvard researchers rejuvenated mice by manipulating the animals’ telomeres, the portion of DNA that caps chromosomes.
It might seem as if a magic pill isn’t so far off. But before we get too cheery about the prospects for these discoveries, it’s useful to be reminded of the many longevity “breakthroughs” that have come and gone in the past. One such potential advance was hailed in the November 1929 issue of Technology Review, in an essay called “Forestalling Death: The Cow’s Contribution to Human Longevity,” by James A. Tobey.
None of the explorers in the realm of eternal life, none of the necromancers or alchemists of old, none of the gazers at crystals or the readers of the stars, have been successful in their quest for the fountain of youth. Modern science has done better.
In the previous 125 years, Tobey observed, average life span had risen from the low 30s to the upper 50s. This was primarily due to reductions in infectious disease and in the infant death rate—in 1929, he noted, there were a mere 64 deaths per 1,000 infants (today’s rate in the United States is six deaths per 1,000). The primary causes of death were changing as well.
Tuberculosis, long the captain of the men of death, and frequently the despoiler of young manhood, has dropped to fifth place. Ahead of it are heart disease, cancer, nephritis, and cerebral hemorrhage, in that order … Typhoid fever, for instance, now causes a mortality only one-fifth as great as a quarter of a century ago.
This was good, but Tobey—author of more than a dozen books on public health, including Cancer: What Everyone Should Know About It (1932) and Your Diet for Longer Life (1948)—felt we could do better. It wasn’t enough to simply reduce a threat such as infectious disease—it was imperative that we find something we could add to our lives, or maybe simply increase our intake of something we were already consuming. He felt recent research might have uncovered just such a substance.
It is a well recognized fact … that those races which have been nourished on foods containing a preponderance of dairy products have always been the most vigorous and long-lived, as well as the most important historically. The conquerors have been users of cows.
He pointed to recent experiments at Columbia University, wherein one set of rats had been given an “adequate diet” of one-sixth dried whole milk and five-sixths whole wheat. An “optimal diet” group, meanwhile, received double the milk and less wheat.
The average duration of life was almost exactly ten percent greater in those subjects receiving the optimal diet … Is it possible that we have had the fountain of youth within our grasp throughout the ages that man has been seeking this liquid phantasm? Milk has always been recognized as the one most nearly perfect food … but apparently it possesses hitherto undreamed of virtues.
Those virtues appear to have dimmed 25 years later, when Tobey revisited the subject in a May 1954 TR piece called “Is There a Limit to Human Life?” He didn’t mention dairy once in that lengthy article, and his tone in general was less upbeat, even though the average U.S. life expectancy had risen to 68 years (it is now 78).
Centenarians are, of course, always asked as to what they attribute their great ages, but invariably their answers are a bit weird, often absurd, and completely lacking in uniformity. In the olden days the few favored persons who attained to great old age undoubtedly did so through the operation of the law of the survival of the fit, but in our modern sanitary civilization the achievement of unusual old age is probably largely a matter of heredity and—luck.
Timothy Maher is TR ’s assistant managing editor.