I stumbled across an interesting article a couple of years ago in NY Magazine about a group who had chosen to willfully live on the brink of starvation because they believe it will help them live longer than virtually anyone in history. (Jeanne Calmart currently holds the record, having died at 122)

NOVA ran a segment on one of their shows about caloric restriction and the science of longevity as well.

The basic idea is that if you cut the amount of calories you eat each day to the absolute bare minimum, your lifespan will go up. Researchers have discovered that it works in mice and worms, so why not humans?

A group calling themself the CRONies (Calorie Restriction with Optimal Nutrition) decided to try it out on themselves. The closest thing to human research had been an ad hoc experiment done when scientists in the Biosphere discovered that they didn’t have nearly as much food as they expected. Deciding to just gut it out, they were discovered healthier after they came out than before they’d gone in.

Figuring out if human lifespans can be extended 50% or more through eating (a lot) less has become a significant area of scientific study. Figuring out if it works, how it works, and whether there is a way to boil it down into a pill could make some company very, very wealthy.

For the first time, a study found a difference between the effects of calorie restrictions in rats and humans. In rats and other animals, low calorie diets cause a reduction in a growth factor called IGF-1. In humans that following similar very-low calorie diets, IGF-1 levels were similar to sedentary individuals.

IGF-1 levels are proportionate to the amount of protein eaten and low levels are thought to be one of the main reasons for the longer lives of calorie deprived animals.

When scientists asked CRONies to lower their protein intake, they discovered that IGF-1 levels dropped. They also found that strict vegans had similarly low IGF-1 levels. Does that mean that vegans have already found the secret to longer lives? Not really - vegans may or may not live longer than your average meat-eating human (or, maybe not) but there’s no evidence that vegan living extends the maximum lifespan.

There’s plenty of evidence that eating less (while maintaining good nutrition) will improve your health, which undoubtedly which increases your chances at a long, healthy life. But, the jury is still out on whether that alone will help people set new longevity records.