Too Much Protein?April 07, 2014
Too Much Protein?
One of the more expedient ways to lose weight is to embark on a low-carb diet. The so-called Atkins diet that is currently used at Duke to create the most effective method of weight loss in America is very popular. It effectively satisfies appetite and allows people to lower their insulin levels. With lower insulin, you have a lower impetus to store calories. With satisfied appetite, folks can then tap into their fat stores. That’s called weight loss.
Along comes a fly in the ointment. Levine, et al, in this study followed the observation that both mice and humans with defects in their IGF-1 receptors (insulin growth factor – surrogate for growth hormone) live longer and have reduced age-related illnesses. Protein restriction lowers IGF-1 activity in humans. With that, a natural question arises: what happens to humans with low and high protein intake diets?
Levine and his team embarked on a statistical analysis of 6381 adults from NHANES (our national nutrition study population that represents America). They were over age 50. They parsed out those folks who ate less than 10% of their calories from protein, 11-19% and over 20% for comparison study. After 18 years of follow-up, they found some remarkable differences between the groups. Under age 65, a high protein diet resulted in mucher high rates of death (three times the rate) from cancer and heart disease. And then, at age 65 it switches. Low protein becomes dangerous and high protein became protective. And uniquely, the protein effect was erased if the source was plant protein. (Vegetarians can breathe a sigh of relief here.) Humans eat what they want. Mice eat what you feed them.
In the same journal, a follow-up study using mice with variable amounts of protein found that you could dictate the risk of premature mortality by protein restriction more accurately than with calorie restriction. Mice with low-protein and high carbohydrate fared the best. When the researchers lowered calories but not the protein, no benefit was obtained in life extension.
The key is probably a specific protein called mTOR. The low protein, high carb mice had low levels of mTOR in their blood, and it rose in proportion to the quantity of specific amino acids that are more abundant in animal, but not plant proteins. And interestingly enough, low protein but high fat erased the benefit. This is a very controversial topic! It raises many questions, and one study may not be enough to swing any major opinions. But a new light has been turned on. What do we do the for long haul if we are to take this research into our own “data base”
WWW. What Will Work for Me? This sounds to me like the results of the China Study. mTOR gives us something specific to study and examine. As I put it together, weight loss is clearly a huge priority for reduction in diabetes risk. The Atkins approach may have a role. Clearly, there are societies that have eaten nothing but animal protein for millennia without adverse effect that we have been able to parse out. (If you die by age 35-40, no effect on longevity is determined). My suspicion is that this study is flawed, not by design but by the changes in meat. Our modern animal protein is all feedlot based, with little omega fats and no Vitamin K2. Little wonder eating more of it may cause trouble. But long term, perhaps we are back to more plant-sourced material. Esselstyn has proven you can reverse heart disease with a plant-based, no oil diet. The China Study showed the same. Colin Campbell’s first observation in his Philippine studies was that high protein diets resulted in cancer. I suspect the carbohydrates we should be having should be low glycemic, whole foods and not anything in a bag, a box, a carton, or from a fast food lane. That corroborates “alkaline diets” based on green vegetables. Fascinating. Don’t you love the twists and turns of this nutrition tale?
1. A great way to lose weight is by the Atkins approach? T or F Answer: True
2. This study shows that folks who eat more animal protein will have at least three times the mortality than those who eat less than 10 % of their calories from animal sources. T or F Answer: True, if under age 65.
3. Then, after age 65, increased protein becomes protective? T or F Answer: That's exactly what this study showed.
4. In mice, the exact same effect was shown - and the protein mTOR was found to be the controlling feature. T or F Answer: True
5. Vegetable protein did not seem to cause the same harmful effect. T or F Asnwer: True
6. Studies like this might not be complete, because they don't control for such variables as omega fats, which are missing from modern western animal protein, or Vitamin K2 - also missing. Answer: Hmmm. Good point.
7. But the basic physiology of this study seems sound, and corroborates other modern observations like Esselstyn's work reversing vascular disease and Colin Campbell's work in the China Study (despite flaws and criticisms of both). T or F Answer: True
8. I'm eager to hear more on this topic. It appears the mTOR line of investigation might bear future insights. Answer: You bet!
This Column was written by Dr John Whitcomb at Brookfield Longevity, Brookfield, Wisconsin