Slimmer Life-Span Gains
Starving mice, drugs in the water and sighing.
EATING LESS may prolong the lives of mice by 67%, but cutting calories may not similarly hyperextend human life, as some have theorized, say scientists from the University of California at Los Angeles and Irvine. After comparing the longevity of Japanese sumo wrestlers (who average 5,500 calories per day) with that of typical Japanese males (2,300 calories), the researchers hypothesized that restricting one’s daily diet to even as few as 1,500 calories may prolong human life a mere 7%. In both mice and men, restricted caloric intake decreases fertility—a more pronounced effect in mice because they invest 10 times as much energy in reproduction.
TRACE AMOUNTS OF psychiatric, anti-epileptic and veterinary drugs, among other sorts, have turned up in drinking water from the most advanced water-treatment plants in the United States, the United Kingdom and Italy, British scientists say. These drugs enter the drinking-water supply via sewage-treatment plants that discharge “cleaned” water with traces of unmetabolized drugs into rivers and streams. Researchers say that the long-term effects of consuming a cocktail of prescription drugs (however low the dose) are unknown. But it could take a lifetime of drinking two liters of tainted water a day to ingest a single dose of a single drug.
THE CLEANER SEX? It’s women, according to a Harris Interactive survey of hand-washing habits. When asked if they always wash after using a public restroom, 94% of women polled said yes, compared with 88% of men. But when unknowingly observed in public restrooms across the country, only 90% of women washed, compared with 75% of men. Both sexes admit they are less likely to wash after using the facilities at home, where no one’s watching.
SIGHING is a respiratory function meant to prevent the lung from collapsing, but according to Polish researchers, in social mammals (including humans) it may have evolved to communicate relief in addition to its respiratory role. To test this theory, they caged lab rats in individual chambers, gave them a series of shocks and conditioned them to expect a respite after a safety signal. Sighs were 7.5 times more frequent during the relief period; variations in how they sighed proved that the sighs were intentional, not reflexive, perhaps meant as an all-clear signal, the scientists say.
MICROGRAVITY TECHNOLOGY developed for NASA is being used to produce larger quantities of cord-blood-derived embryonic-like stem cells, or CBEs. Using spinning devices, researchers at the University of Newcastle suspend the cells in a liquid, which allows them to grow faster than if they were on the flat surface of a laboratory dish and also minimizes damage to the cells. In large amounts, CBEs could help reverse liver, brain and vascular tissue damage.