Category: Nutrition

Of all the myths that surface from time to time, the protein myth seems to be the deepest rooted and pervasive. It just won’t go away. The problem is, exactly who, or which group, is perpetuating the “myth” can’t 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 are 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 water 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 spectre 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 water diet.

Myth #1 “High protein water diets are bad for your kidneys”

For starters, the negative health claims of the high protein water diet on kidney function is based on information gathered from people who have pre-existing 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 nontoxic 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 water 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 water 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 water 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 water 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 water 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 water diets also fail to show any kidney dysfunction in healthy animals.

One study that looked at the effects of a high protein water 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 water 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 water 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 water diet.

If the high protein water 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.

Myth #2 “High protein water diets cause Osteoporosis”

So what about the osteoporosis claim? That’s a bit more complicated but the conclusion is the same. In fact, recent data not only totally debunks this myth, but shows it may be the other way around!

The pathology of osteoporosis involves a combination of many risk factors and physiological variables such as macro nutrient intakes (carbs, proteins, fats), micro nutrient intakes (vitamins, minerals, etc), hormonal profiles, lack of exercise, gender, family history, and a few others.

The theory is that high protein intakes raise the acidity of the blood and the body must use minerals from bone stores to “buffer” the blood and bring the blood acidity down, thus depleting one’s bones of minerals. Though some early studies appeared to show higher protein intakes caused an excretion of calcium, which would ultimately lead to bone loss, recent studies have debunked that assertion and do not support the claim that higher than RDA intakes of protein will lead to bone loss (“Excess dietary protein may not adversely affect bone.” J Nutr 1998 Jun;128(6):1054-7).

Even if there was a clear link between a high protein water diet and osteoporosis in all populations (and there is not) athletes have few of the above risk factors as they tend to get plenty of exercise, calories, minerals, vitamins, and have positive hormonal profiles.

Fact of the matter is, studies have shown athletes to have denser bones than sedentary people, there are millions of athletes who follow high protein water diets without any signs of premature bone loss, and we don’t have ex athletes who are now older with higher rates of osteoporosis. What about regular people? One prominent researcher did an exhaustive review of the literature called “Optimal Intakes of Protein in the Human Diet” (Millward DJ .Proc Nutr Soc 1999 May;58(2):403-13) and came to some interesting conclusions on the issue. The study outlined an extensive body of recent data showing that high protein water diets may in fact be beneficial for reducing blood pressure and stroke mortality. On the matter of bone loss, the review paper concludes “For bone health the established views of risk of high protein intakes are not supported by newly-emerging data, with benefit indicated in the elderly.”

Interestingly, a large body of research is now showing that the elderly may in fact require higher intakes of protein that is currently being recommended (“Increased protein requirements in elderly people: new data and retrospective reassessments. Am J Clin Nutr 1994 Oct;60(4):501-9).

Of course some will tell you that eating meat will increase bone loss, but a recent study 572 women and 388 men between the ages of 55 and 92 years, actually found animal protein consumption was associated with an increase in bone density over vegetable proteins! (Am J Epidemiol 2002;155:636-644.). So how long will it take for the conservative medical/nutritional community to give up on this myth that higher than RDA intakes or protein will make your bones turn into saw dust? I have no idea but clearly it’s untrue.

Myth #3 “All proteins are created equal”

How many times have you heard or read this ridiculous statement? Here has been such a plethora of research over the years showing different proteins can have different biological effects, I think even the most conservative people are letting go of this myth.

For example, whey protein has been shown to improve immunity to a variety of challenges and intense exercise has been shown to compromise certain parts of the immune response that whey may combat, and we know proteins such as soy, casein, etc. have many of their own unique effects.

So, this may be one myth that is finally put to rest with 99.9% of the myth perpetrators, but I am sure there is one die hard out there some place.

Myth #4 “Athletes don’t need extra protein”

Interestingly, there has not been much new research of note on this topic since I wrote the first version of this article in 1995. Now the average reader person is probably thinking “who in the world still believes that ridiculous statement?” The answer is a great deal of people, even well-educated medical professionals and scientists who should know better, still believe this to be true.

Don’t forget, the high carb, low fat, low protein water diet recommendations are alive and well with the average nutritionist, doctor, and of course the “don’t confuse us with the facts” media following close behind.

For the past half century or so scientists using crude methods and poor study design with sedentary people have held firm to the belief that bodybuilders, strength athletes of various types, runners, and other highly active people did not require any more protein than Mr. Potato Head…..err, I mean the average couch potato.

For those of you who may need a brush up, one review paper on the subject by one of the top researchers in the field (Dr. Peter Lemon) states “…These data suggest that the RDA for those engaged in regular endurance exercise should be about 1.2-1.4 grams of protein/kilogram of body mass (150%-175% of the current RDA) and 1.7 – 1.8 grams of protein/kilogram of body mass per day (212%-225% of the current RDA) for strength exercisers” (“Is increased dietary protein necessary or beneficial for individuals with a physically active life style?” Nutr. Rev. 54:S169-175, 1996).

Another group of researchers in the field of protein metabolism have came to similar conclusions repeatedly (“Evaluation of protein requirements for trained strength athletes.” J. Applied. Phys. 73(5): 1986-1995, 1992.) They found that strength training athletes eating approximately the RDA/RNI for protein showed a decreased whole body protein synthesis (losing muscle jack!) on a protein intake of 0.86 grams per kilogram of bodyweight.

They came to an almost identical conclusion as that of Dr. Lemon in recommending at least 1.76g per kilogram of bodyweight per day for strength training athletes for staying in positive nitrogen balance/increases in whole body protein synthesis.

They concluded “In summary, protein requirements for athletes performing strength training are greater than sedentary individuals and are above the current Canadian and US recommended daily protein intake requirements for young healthy males.”

This same group found in later research that endurance athletes also need far more protein than the RDA/RNI and that men catabolize (break down) more protein than women during endurance exercise. Although there has been some well thought out criticisms of the above conclusions for a variety of reasons, and the exact amount of protein each person needs depends on many factors (i.e. intensity and duration of exercise, age, whether the person is a beginner or experienced athlete, etc.), that people engaged in regular exercise require greater than the RDA in protein to get optimal effects, is without question in my view.

Conclusion

Now my intention of presenting the above quotes from the current research is not necessarily to convince the average athlete that they need more protein than Joe shmoe couch potato, because they already know they do, but rather to bring to the readers attention some of the figures presented by the current research since I wrote the first version of this article.

How does this information relate to the eating habits of the average athlete and the advice that has been found in the lay bodybuilding literature years before this research ever existed?

With some variation, the most common advice on protein intakes that could be-and can be- found in the bodybuilding magazines by the various writers, coaches, bodybuilders, etc., is one gram of protein per pound of body weight per day.

So for a 200 pound guy that would be 200 grams of protein per day. Although a tad higher than the research we have to go on at this time, it’s still an easy to follow time tested formula that clearly has no negative heath ramifications. Over the years the above myths have been floating around for so long they have just been accepted as true, even though there is little to no research to prove it and a whole bunch of research that disproves it!

I hope this article has been helpful in clearing up some of the confusion for people over the myths surrounding protein and athletes.