Wednesday September 5, 2012

Everyone is familiar with the overwhelming evidence which proves that eating too many calories causes weight gain. Actually, we don’t even need researchers to tell us that. We can see the results for ourselves when we step on the scale after a big holiday feast.

Too much of that overindulgence can lead to obesity, an epidemic in this country that has been linked to a whole slew of health problems which can shorten one’s life expectancy.

Some theorize that if eating too many calories is bad for you, then eating less than the recommended daily amount must be good for you. Since 1934, research has shown that lab rats, mice, yeast, fruit flies and round worms fed 10 to 40 percent fewer calories than their free-eating peers lived some 30 percent longer. In some studies, they lived twice as long. Such findings have spawned a growing community of believers who seek better health and longer life in calorie-restricted diets.

However, new research published last week turns that conventional wisdom on its head. The Christian Science Monitor reports that a study from the National Institute on Aging suggests a surprising disconnect between health and lifespan. The study, which began in 1987, shows the extreme, emaciating diet doesn’t increase lifespan in rhesus monkeys, whose physiology, genetics and median lifespan (27 years) are closer to humans than are the rodents in earlier calorie-restriction research.

The

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NIA study found that most of the 57 calorie-restricted monkeys had healthier hearts and immune systems and lower rates of diabetes, cancer or other ills than the 64 control monkeys. But there was no longevity pay-off.

"The calorie-restricted monkeys lived no longer than the other monkeys," NIA’s Julie Mattison, who helped lead the study, told Reuters.

The NIA study showed that even monkeys starting calorie restriction early in life, from 1 to 14 years of age, had no lifespan edge over their gourmand peers. With 19 of the 40 monkeys whose eating was restricted starting in youth still alive, the NIA scientists calculated, the chance that they will outlive free-eating monkeys is less than one-tenth of 1 percent.

Perhaps more surprising, Christian Science Monitor reports, is that health markers were often worse in monkeys that began calorie restriction as young adults than older ones, the opposite of what scientists expected. And more of the animals that started calorie restriction when young died of causes unrelated to aging than did their free-eating peers.

So the moral of the story here is, if something is bad for you that doesn’t necessarily mean you should take the opposite extreme and assume you’re making the healthier choice. As with most things in life, moderation is usually the best course to follow.

And one more thing -- don’t assume that conventional wisdom based on decades-old research is the hard-fast truth. There inevitably will be a new study to disprove an established theory, and another one after that to disprove the last one, and so on and so on.