The key might be in one experimental method. All 76 Rhesus Monkeys in the UW study entered as adults. Researchers found out how many calories each monkey craved and ate on it’s own, then reduced that by 30 percent in the experimental group. In the NIA study, the number of calories each of the monkey was allotted came from a standardized food intake chart.
UW reasearchers tried to reconcile the older study to their own, and found that all the monkeys in the NIA study weighed less than those in their own study and often less than monkeys in an online database of weights for research monkeys. Five of the monkeys in the NIA study lived 40 or more years. That, as far as the UW researchers know, is unusual. Their conclusion? The monkeys in the earlier NIA study may have all been subjected to calorie restriction to differing degrees.
It will be interesting to watch the continuing interpretation and review of these two studies. Even if the NIA study was administering calorie restriction to both control and experimental groups, the results could help us understand how different levels of caloric restriction work. Both of these studies could help us confirm that eating fewer calories changes the way we age, and bring us closer to unlocking that mechanism so we could use it too, without the exreme diets.
University of Wisconsin-Madison. “Monkey caloric restriction study shows big benefit; contradicts earlier study.” ScienceDaily. ScienceDaily, 1 April 2014. http://www.sciencedaily.com/releases/2014/04/140401111957.html