Ever since the 1930s, researchers have known that calorie restriction could dramatically extend life in some organisms. Radically reduce the calories an organism gets–say by 40 percent or more–and the organism will often live longer than you would have thought possible. This effect was seen in worms, mice, and some other species, with the attendant hope that it might work in humans as well. While the precise mechanism hasn't been understood completely, essentially it seemed that when it's getting less nutrition, the body goes into some kind of survival mode that allows it to forestall the ravages of age.
The joke about calorie restriction is this: If you eat nothing but lettuce and millet for the rest of your days, you may not live forever, but it'll sure seem like forever. Nevertheless, there are some hardy souls who are trying (see here, for example), subsisting on meager meals and poking new holes in their belts while they contemplate what things will be like when 100 is the new 50. But according to a new study, they may be wasting their time:
To those who enjoy the pleasures of the dining table, the news may come as a relief: drastically cutting back on calories does not seem to lengthen lifespan in primates.
The verdict, from a 25-year study in rhesus monkeys fed 30% less than control animals, represents another setback for the notion that a simple, diet-triggered switch can slow ageing. Instead, the findings, published this week in Nature, suggest that genetics and dietary composition matter more for longevity than a simple calorie count.
That would certainly seem to explain the people who actually live to an unusually old age, none of whom seem to do anything to extend their lives that millions of other people do with far less success. But calorie restriction always seemed like a bad bargain to me anyway. If someone offered you an extra 20 years, but you had to be miserable and hungry from this day forward, would you take the deal? Evolution has wired us to have an intense desire for food (smart move, evolution!), and human ingenuity has devised a near-infinite variety of foods that are wonderful to eat. Every once in a while some supplement or substance comes along that is hailed as the thing that will stop you from being hungry, but I've never been interested in those—give me a pill that will allow me to eat a pint of Ben&Jerry's every night without ever gaining any weight, and now we're talking.
So what we really need from science is a way to extend our lives that requires no effort, commitment, or compromise of our existing lifestyles. Now that would be something.