Will Brink Talks About Protein and Nutrition: Protein Myths That Won't Die

by Will Brink

I wrote the first version of this protein myths article in 1995 for MuscleMedia. At that time, there was little data supporting some of my conclusions, and even less data supporting the other sides conclusions!

Years later, we now have plenty of data to support my contention that most of what people are told about the “dangers” of high protein diets is wrong. It was wrong in 1995, and it’s wrong today. In this article we will explore some of that newer research.

When it comes to the topic of nutrition there are many myths and fallacies that float around like some specter in the shadows. They pop up when you least expect them and throw a monkey wrench into the best laid plans of the hard training athlete trying to make some headway.

Of all the myths that surface from time to time, the protein myth seems to be the most deep rooted and pervasive. It just won't go away. The problem is, exactly who, or which group, is perpetuating the "myth" cant be easily identified.

You see, the conservative nutritional/medical community thinks it is the bodybuilders who perpetuate the myth that athletes need more protein and we of the bodybuilding community think it is them (the mainstream nutritional community) that is perpetuating the myth that athletes don't need additional protein! Who is right?

If you tell the average nutritionist you are on a high protein diet because you are an athlete they will often reply, "oh you don't want to do that, you don't need it and it will lead to kidney disease" without a single decent study to back up their claim!

You see they too are susceptible to the skulking myth specter that spreads lies and confusion. In this article I want to address once and for all (hopefully) the protein myth as it applies to what the average person is told when they tell their doctor or some anemic "all you need are the RDAs" spouting nutritionist that he or she is following a high protein diet.

Protein Myth #1 "High protein diets are bad for your kidneys”

For starters, the negative health claims of the high protein diet on kidney function is based on information gathered from people who have preexisting kidney problems, which has little to no relevance to healthy athletes. You see one of the jobs of the kidneys is the excretion of urea (generally a non toxic compound) that is formed from ammonia (a very toxic compound) which comes from the protein in our diets.

People with serious kidney problems have trouble excreting the urea placing more stress on the kidneys and so the logic goes that a high protein diet must be hard on the kidneys for healthy athletes also. Now for the medical and scientific facts.

There is not a single scientific study published in a reputable peer - reviewed journal using healthy adults with normal kidney function that has shown any kidney dysfunction what so ever from a high protein diet. Not one of the studies done with healthy athletes that examined this issue, or other research I have read, has shown any kidney abnormalities at all. For example, a recent study that examined the renal (kidney) function of athletes who follow a high protein diet–that is protein intake well above the US RDA– found no negative effects of a higher protein intake on the kidney function of these athletes.

The study called “Do Regular High Protein Diets Have Potential Health Risks on Kidney Function in Athletes? (International Journal of Sport Nutrition, 10 {1}) examined the kidney function of bodybuilders and other well-trained athletes following a high and medium protein diet.

The athletes underwent a 7-day nutrition record analysis as well as blood sample and urine collection to determine if their high-medium protein intakes affected their kidney function. The study found the athletes had renal clearances of creatinine, urea, albumin, and glomular filtration rates that were within the normal range.

The authors concluded “there were no correlations between protein intake and creatinine clearance, albumin excretion rate, and calcium excretion rate.” Furthermore, animals studies done using high protein diets also fail to show any kidney dysfunction in healthy animals.

One study that looked at the effects of a high protein diet on older dogs (“Effects of aging and dietary protein intake on uninephrectomized geriatric dogs.” Am J Vet Res 1994 Sep;55(9):1282-90) found not only did a high protein diet have no ill effects on the dogs kidneys, the dogs getting the higher protein intakes lived longer! Now don't forget, in the real world, where millions of athletes have been following high protein diets for decades, there has never been a case of kidney failure in a healthy athlete that was determined to have been caused solely by a high protein diet.

If the high protein diet was indeed putting undo stress on our kidneys, we would have seen many cases of kidney abnormalities, but we don't nor will we. From a personal perspective as a trainer for many top athletes from various sports, I have known bodybuilders eating considerably more than the RDA recommends (above 600 grams a day) who showed no kidney dysfunction or kidney problems and I personally read the blood tests! Bottom line? Higher than RDA intakes of protein will have absolutely no ill effects on the kidney function of a healthy athlete, period.

So far, the data continues to support what we in the sports nutrition/bodybuilding field have been saying for decades, higher than RDA intakes of protein are perfectly healthy for athletes and their kidneys. Now of course too much of anything can be harmful and I suppose it's possible a healthy person could eat enough protein over a long enough period of time to effect kidney function, but it is very unlikely and has yet to be shown in the scientific literature in healthy athletes or “regular” people for that matter.