One for the Ages???

After reading this lay article I found several points that left a bad taste in my mouth. One of the key problems I found was the author's lack of significant proof. When he finally mentioned some numbers to back up the suggestions they were scarce and prove nothing. Out of the original 76 rhesus monkeys only 50 are still alive. There is no mention here about how many were from the experimental group and how many are from the control group. The difference in cancer of 5 to 3 (control vs. esperimental groups respectively) is not a significant difference. In addition the causes of cancer are still not fully understood so this is quite possibly due to the randomness of the disease.
The author also wrote about the "lower insulin levels". If we think back to PSIO 202 we can recall insulin is released by the pancreas in response to sugar levels. Now, if you are taking in less calories you are most likely taking in less sugar.
Another point that is not mentioned here is the quality of the diet. If someone were to reduce their caloric intake it would be necessary for them to maximize the amount of nutrients in their diet. To put it another way if you are going to eat less than a normal diet, that limited amount must be of a higher quality. With that in mind how much of the longevity observed is due to less calories and how much is due to a better quality diet.
Sorry to sound like a skeptic here but there just seemed to be too many gaps in the information to convince me.