To Live Long, Don't Prosper

Sometimes research results apparently point to conclusions that scientists don't recognize. Since I'm not a scientist, I'm willing to translate (with tongue in cheek, please note) the hidden news embedded in the February Natural History magazine. This issue of the American Museum of Natural History's monthly publication concentrates on the topic of aging.

Human aging is an undercurrent in the articles, but is rarely the main theme. The scientist-authors roam all over the biological map to establish the evolutionary purpose of aging how the process is manifested in organisms from paramecia to elephants. At least in passing, they also note some ways in which creatures delay the physical failings that come with the passage of time.

Collectively, these ways make up a prescription for a long, strait life. First, forget sex. The longest-lived organisms do without---at least for several generations. Very simple organisms, say single-celled animals, don't age. When they reproduce, they do so by splitting or sprouting, and the two resulting cells are identical to, and just as old as, the founding cell. They do need to exchange genetic material eventually to overcome the bad effects of inevitable mutations, but only after these minuscule Methuselahs have lived a long time.

Some more complex organisms that reproduce without sex also seem to be able to stave off aging. A clump of creosote bushes in the southwestern U.S. is the oldest known plant. Its founder. sprouted thousands of years ago, and the present bush is actually a clone, genetically indistinguishable from the original.

So sex can be hazardous to your health. That shouldn't surprise Alaskans. Look what spawning does to our salmon.

Then there's food. Medical researchers insist that things like fats, salt, and sugar---that is, items we instinctively find tasty---are hazardous to our health. Strong evidence lies in the worldwide epidemic of diabetes; it may afflict as many as 100 million people worldwide. In the U.S., it is the leading cause of adult blindness and leads to a third of kidney failures. Studies of some of the most diabetes-susceptible populations, Pima Indians of Arizona and Nauru islanders of the South Pacific, have pointed to rich and regular meals as the culprit. Both peoples had no diabetes when they lived on high-fiber plant foods and occasional wild meat or fish.

Worse yet, research with mice and rats has shown that if young rodents are put on severe diets, given enough essential nutrients with 30 to 40 percent less food than normal, they will live half again as long as rats fed standard amounts. Apparently not only what we think of as poor quality but also poor quantity of foodstuffs is good for longevity.

Stress, of course, is unhealthy. The mellow tortoise outlives the nervous rabbit by decades, even without help from predators. Opossums on Sapelo Island off Georgia have lived without much threat from predators for generations. They have become a laid-back lot, napping in the open in broad daylight, and can live a year longer than their more pressed mainland cousins.

Studies with houseflies carry that idea further. Crowded together, 200 to a cubic-foot cage, male houseflies die after about 16 days. With 100 flies in the same cage, they are less agitated by their cagemates, fly about less and live 20 days. Put into a vial by themselves, the solitary (and probably bored) flies last 50 days.

Temperature also can affect longevity. Take that housefly and chill its vial down to 55 degrees Fahrenheit, and the fly will live more than six months. Cold bees also slow down, living months instead of weeks. Many aquatic creatures seem to live longer in cold water. Atlantic shad have spawning migrations like salmon, but the fish living south of Georgia spawn once and die while northern ones return again. In southern Canada, the shad may visit their chilly spawning streams seven times.

A scientist would say I'm jumping to conclusions here, yet it seems pretty clear. For a long life, you should be lonely, hungry, cold, and bored. At least, it certainly would feel long.