There were monkeys placed on calorie restriction at different times of their lives – and while some had laboratory changes that looked great – they still lived the same amount as monkeys who were not skinny.

This was in contrast to a study that reported monkeys who were calorie restricted lived longer (that study published in 2009). But that study had an uncomfortable caveat that no one wanted to talk about: some of the deaths of the calorie restricted monkeys were disregarded. Had they included all of the monkeys, there would have been no extension of life for them either.

It is hard for scientists to let go of an assertion- one that we have held dear for a number of years. In fact, it was in the 1930’s that the first studies done on rats showed that those who fed less lived longer. No one repeated that study, but there were signs that it might not be so.

Leonard Hayflick, Ph.D. – the first scientist of aging

At the cellular level Leonard Hayflick did studies in the 1960’s showing that human cells were programed to divide about 50 times and then go into a senescent period. Elephants who lived longer had more cell divisions, and mice had less. This Hayflick limit was seen as the maximum of lifespan – and what it means in human years is a matter of debate. The cells didn’t live longer if they were starved for nutrients.

Still others did calorie restriction studies on fruit flies, worms, yeast, and while there lifespans appeared to increase, it was difficult to draw that conclusion to human beings. There then came some evidence based on mice studies that showed lab mice who were calorie restricted lived longer than lab mice that were fed normally. But even those studies came into question because when this theory was tested on wild mice, those mice didn’t live any longer if their diet was restricted.

Confused – so were most. So the decision was made to test this with the closest relatives of humans, the monkeys. This meant years of study. The first to conclude was The University of Wisconsin, who cherry picked their data and when all monkeys were included there was no increase in lifespan. Sadly, most of us got the headline version – eating less means living longer.

You may have seen the Sixty Minute report of the group of people, who based on that study, began in earnest to eat less, much less than other people. All with the belief that if they ate less they would live longer, live better, and avoid the diseases of aging like cancer and heart disease.

The advantage of science is we keep testing the hypothesis – and now it appears that the data from human cells by Dr. Hayflick was correct.

Hayflick was the first to note decrease in telomere length as cells divide. However, as Hayflick is quick to point out, telomere length is more correlation than causation. And yet many people use telomere length as a marker for their aging therapy.

What we know now- don’t over eat, because that does lead to decreased life span. So when someone says they have the answer to aging- chances are they don’t.