Starvation Mode is a Myth: The Science

Scientists have identified the first gene essential to extending the lives of animals on low-calorie diets, raising the prospects of a longevity pill.

In earlier research, "caloric restriction" extended the life, sometimes 40% longer than average, of creatures ranging from mice to worms. Some studies in people and monkeys are exploring whether near-starvation diets, which consist of perhaps 70% of the calories consumed in a normal diet, will help them live longer, too.

But "those diets are pretty tough to stick with," says Andrew Dillin of the Salk Institute for Biological Studies in La Jolla, Calif., whose international team's gene research is reported in today's issue of the journal Nature. Discovery of the gene, called PHA-4, raises hopes that uncovering the genetic machinery behind caloric restrictions may enable people to skip starvation and still live longer.

Other genes have been linked to low-calorie diets and life extension in the past, but in the new study, the team found that the presence or absence of PHA-4 in worms was the make-or-break factor in whether a starvation diet extended their lives, regardless of whether they had any of those other genes.

Dillin calls PHA-4 the "primordial" gene underlying a process that likely arose in feast-or-famine conditions in the past, where creatures that evolved metabolisms that worked more efficiently under starvation conditions survived. Versions of the gene, which the team has patented in worms, are found in mammals, too, and the team is conducting experiments on mice to see its effect.

"We are on the threshold of some pretty big discoveries in caloric restriction," says MIT biologist Leonard Guarente, who was not part of the PHA-4 study. A number of recent discoveries, such as last year's report by Harvard Medical School researchers that resveratrol, which is found in red wine, has life-extending properties in mice, also have boosted hopes for life-extension treatments.

"My suspicion is that (treatment) won't be a substitute for a healthy lifestyle. You'll still need to go to the gym," Guarente says. "But if you are fit, we'll find something to make you fitter and if you aren't, we'll likely find something to help."

In the study, Dillin's team turned their gene on and off by adding gene-silencing compounds to the worm's food. If similar experiments work in mice, a final step would be to try boosting the activity of the mammalian version of the gene, called Foxa1, in people.

Starvation is nothing new in human history, Dillin notes, but in previous centuries people lacked antibiotics, sanitation and hospitals, likely disguising any longevity benefits hidden in famine.

(c) USA TODAY, 2007

Yes DO encourage people to eat healthy and watch their macro nutrients AND their micronutrients. Those are ridiculously important. No one is suggesting otherwise. The problem is, we're putting too much emphasis on this..... unit of measurement called a calorie and not enough emphasis on nutritional standards.

I would caution everyone to be careful of how you accept advice from any source. Not to say that anything said here is just out and out wrong, but we must always remember the our bodies goal is homeostasis. How do we gain size in muscle? By placing a load on them (resistance training). Our muscles grow to handle the "new" load placed on them. From what I've studied, the starvation mode is not a myth, but may be misunderstood. My understanding of the it is when the body does not have adequate amounts of necessary macronutrients and has to look to other sources.

Carbs are our main source of energy, so we need them. Once the carbs are depleted, the body targets fat stores. That's the basic premise behind low carb diets. You get to the fat sooner, but your energy levels are very low. This is where problems usually show. If the your carbs and calories are too low, your body may bypass the fat and begin to use protein (muscle) for energy. I'm sure we will all agree tha that would be counter productive. Could that be why you're not losing fat even though you've dropped your calories? Probably. Starvation mode does not shut the body down, but it will alter the way it rids itself of fat weight.

So the point is you don't have to make 1200 cals per day??

Is that an acccurate summary?