Smell Less, Live Longer?

The effects of a low-calorie diet on the longevity of most animals is widely known in scientific circles: Caloric restriction extends animal lifespans by activating cellular protection mechanisms. But, according to a study into the lifespans of roundworms, just restricting the smell of those calorie-filled foodstuffs may turn the trick!

Three years ago, researchers at Washington University School of Medicine in St. Louis discovered that a class of anticonvulsant medications increased the lifespan of a roundworm, but prior to concluding their new study, they had no idea why. “We’ve learned that the drugs inhibit neurons in the worm’s head that sense chemicals in their surroundings–the neurons are like the worm’s nose,” says Dr. Kerry Kornfeld, who led the research team. “Like roundworms that are grown in a food-scarce environment, the worms exposed to the anticonvulsant ethosuximide lived longer. But these worms ate plenty of food. That suggests that the worms’ sensation of food is critical to controlling their metabolism and life span.”

In short, if the worms sensed that food was abundant, their metabolism adjusted accordingly by promoting rapid ingestion and rapid growth and, therefore, rapid aging. By contrast, when the worms sensed a shortage of food, their bodies made “metabolic decisions” to delay growth, conserving energy and thus extending their lifespans–even if the food shortage was only an olfactory illusion.

Does this mean that olfactory impairment in humans translates into added years? It’s probably a little more complex, says Kornfeld, but it certainly hints at a connection. “Emerging evidence suggests that core metabolic pathways that modulate lifespan in worms also modulate lifespan in vertebrates such as mice and perhaps humans. In an ancient common ancestor, these pathways might have caused metabolic adjustments that affect lifespan. That could be reflected in our own biology.”

No word yet on further studies to confirm the phenomenon in humans, but if Dr. Kornfeld decides to recruit volunteers willing to clothespin their noses while subsisting on a steady diet of eclairs, I’ll be first in line!