Elixirs of youth sound fanciful, but the first crude antiaging drugs may not be so far away. To date, two compounds have sparked scientists' interest: resveratrol, a substance found in grapes, red wine and peanuts; and rapamycin, first isolated in the soil of Easter Island. Both compounds seem to work in animals to mimic the biological response to calorie restriction, an imperfectly understood technique that extends life span in lab specimens, including yeast, mice and, most recently, rhesus monkeys.
Resveratrol is currently available as a dietary supplement. A drug formulation of resveratrol is now being put to a more rigorous test, in clinical trials as a treatment for Type 2 diabetes and cancers. The company behind the drug, Sirtris Pharmaceuticals (bought by pharma giant GlaxoSmithKline in 2008), is touting that compound and two others chemically unrelated to resveratrol but targeting the same pathway as drugs that battle aging-related diseases.
Rapamycin, the other big candidate, has one clear advantage over resveratrol: it's already FDA approved as a drug but as an immunosuppressant. Don't expect it to be rolled out to the masses as a miracle drug just yet though. Rapamycin leaves users susceptible to infection at least in the doses typically used today and has other harmful side effects too.