Controversy of Protein Requirements, Especially In Those Over Age 65
Controversy of Protein Requirements, Especially In Those Over Age 65.
Dr. Ron Rosedale
Protein requirement is a function of lean mass and activity, pregnancy, growth etc. However there is apparently a controversy as we “age”. Studies have shown quite definitively that lowering protein extends lifespan in many species, however one study has shown that in humans this held true prior to age 65 after which an increase in protein may be more beneficial. Other studies have also shown increased protein requirements in the elderly.
- I believe that the controversy and discrepancy arises, as so often in nutritional studies, from the study subjects having typically eaten a high carbohydrate diet during the study and certainly prior to. As such, any conclusion should have the amendment, “in those eating a high carbohydrate diet”.
As has been shown in numerous studies, insulin and leptin resistance and hyperinsulinemia and hyperleptinemia (high fasting insulin and leptin) becomes more and more severe and common as we age. This leads to the inability to properly burn fat thus requiring the burning of glucose as one’s primary fuel. Glucose is stored in our bodies to a minimal extent, and the body wishes to save the little that is stored (as glycogen in liver and muscles) for anaerobic emergencies such as fight or flight.
As such, those who are addicted to burning glucose, including most people over age 65, will get much of their glucose “fix” especially when they are sleeping and not eating, from the breakdown, rapamycin, of protein. Thus, and as is well known, we break down more protein than we make as we get into the “golden years”.
I believe that it is the unnecessary breakdown of protein especially into glucose to be used as fuel rather than to build components as far more desirable, that would lead to an increase in dietary protein requirements.
- However, on my diet as one is much more insulin sensitive with lower levels of insulin and leptin such that burning fat is one's primary fuel rather than glucose, protein requirements go down.
There are other reasons. The protein that you put into your mouth is not necessarily breaking the cells will eat. If one is taking the common acid blocking drugs known as proton pump inhibitors, such as Nexium and Protonix
Then, there is another very critical reason that is not discussed. One of the primary objectives and effects of the Rosedale plan is to reduce stimulation of the target of rapamycin (mTOR) pathway. This is critical and one of the major beneficial effects is to increase the process of autophagy that allows one to "eat" damaged parts, especially proteins within cells.
These damaged and damaging proteins are broken down and recycled to make fresh, far better functioning, proteins and other parts without having to put this extra protein in your mouth. In other words, your cells are then able to eat protein without you having to eat extra protein. what’s interesting and perhaps paradoxical is that dietary amino acids from protein stimulated mTOR more than any other nutrient and when mTOR is stimulated and raised it reduces this beneficial and critical process of autophagy, that by the way has been shown to be critical in the life extension from calorie restriction. In other words, by eating less protein your cells can actually eat more.
Dr. Ron Rosedale