The NYT has a nice article on the battle between two US labs trying to see if a calorie restricted diet will make monkeys live longer. They are finding different results, and it’s getting testy:
Two rival research groups set out in 1987 to answer a tantalizing question: Could a diet kept meager in calories pay off in longevity?
Both teams, one at a National Institute on Aging laboratory in Baltimore and the other at the University of Wisconsin, studied colonies of rhesus monkeys, which can live past age 40, and it was 22 years before the first results were released. The restricted diet, the Wisconsin team reported in 2009, seemed to be working.
But three years later, the Baltimore team said that its monkeys on reduced-calorie diets were living no longer than those given a normal diet. The differing results puzzled the researchers.
Now, the Wisconsin team has struck back, asserting on Tuesday in the journal Nature Communications that the Baltimore study was effectively in error because its control monkeys were also fed a leaner than normal diet.
I get why they’re upset. Studying the same monkeys for more than 35 years has got to be massively expensive. Moreover, you’re dedicating your whole life to one study. You want to get results, and you want to be right.
The crux of the problem comes down to the control. One group, the one which is seeing results, let their control monkeys eat a terrible diet. The other one is keeping their control monkeys relatively healthy. Both agree that the diet monkeys are eating a calorie-restricted diet, like 30% fewer calories than normal.
The lab that let the control monkeys eat like crap is seeing longevity increased by 40%. The lab which keeps the controls relatively healthy is not seeing those results.
I think their arguments are somewhat beside the point. I think they’re both right.
I have no trouble – none at all – believing that a calorie restricted diet is better than a diet full of crap. Does anyone really doubt that avoiding obesity, fats, cholesterol, etc. will not lead to a decrease in heart disease, diabetes, and death? When you compare a calorie-restricted diet to a terrible diet, you’re going to see great results.
But what most companies, and lots of Americans, want to see is increased longevity in healthy people. They want to try and find magic ways to make already long-living people even more long-lived.
I see this all the time in how we approach medicine in the US. Statins work really well for people with really high cholesterol, so we start giving it to people with cholesterol that’s barely high. Then we wonder why it didn’t make a difference in the latter group. We see Barrett’s espohagitis in people with really bad gastroesophageal reflux, and next thing you know everyone I know with even the slightest amount of heartburn is on an antacid. Now, all my friends who are thin, in shape, and eat no meat are concerned about wheat destroying their lives.
Most of us are healthy. We need to start acting that way.
It may be that eating a massively caloric-reduced diet may incrementally increase the length of our lives. But it’s unlikely. Further, almost none of us are going to stick to that diet for the forty years the monkeys will. There’s only so much you can improve upon health.