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PROTEIN DEBATE: Which Protein Is Best?

 

By William Misner, Ph.D.

William Misner, Ph.D.
William Misner, Ph.D.
From 1996 until his retirement in 2006, Dr. Bill worked full-time as Director of Research & Development at Hammer Nutrition. Among his many accomplishments, both academically and athletically, he is an AAMA Board Certified Alternative Medicine Practitioner and the author of "What Should I Eat? A Food-Endowed Prescription For Well Being".

A protein food strength or weakness is based on the quality and quantity of its essential amino acid profile for healthful growth effects. For example, Soy protein generates known cardiovascular benefits, while Whey protein reproduces significant muscle growth effects. Protein quality may therefore be judged by its essential amino acid yield per serving. The body cannot make essential amino acids for itself and is therefore dependent upon dietary sources.

ESSENTIAL AMINO ACIDS MILLIGRAMS PER 26 GRAMS
AMINO ACID SOY WHEY
LEUCINE 1546 2609
ISOLEUCINE BCAA 921 1333
VALINE BCAA 940 942
METHIONINE 245 443
ARGININE 1428 480
HISTIDINE 489 425
LYSINE 1184 2222
PHENYLALANINE 977 831
TRYPTOPHAN 595 244
TOTALS 9039 10491

Non-essential amino acids are also beneficial for replacing exercise-cannibalized amino acids from muscle mass. Therefore, the amino acid profile for Soy and Whey may also be compared in terms of their non-essential amino acids donor potency:

AMINO ACIDS MILLIGRAMS PER 26 GRAMS
AMINO ACID SOY WHEY
CYSTEINE 244 869
ASPARTIC ACID 2180 2039
ALANINE 808 230
GLUTAMIC ACID 3589 2683
GLYCINE 789 78
PROLINE 940 179
SERINE 977 180
TYROSINE 714 172
TOTALS 10241 6430

These values represent individual amino acid content in SOY and WHEY. Next, compare Soy and Whey to other protein sources: human milk, eggs, and cow milk, beef:

COMPARISON OF AMINO ACID PROFILES IN COMMON PROTEINS [2] AMINO ACID (mg AA/g protein)
Amino Acid Human Milk Cow Milk Egg Beef Soy Whey
Histidine 26 27 22 34 19 16
Isoleucine BCAA 46 47 54 48 49 54
Leucine BCAA 93 95 86 83 82 89
Valine BCAA 55 64 66 50 48 82
Lysine 66 78 70 89 64 88
Methionine 42 33 57 40 26 32
Tyrosine 72 102 93 80 92 65
Threonine 4 44 47 46 38 65
Tryptophan 17 14 17 12 14 22
TOTALS 421 504 512 482 432 513

Blue notes highest amino acid value. Red notes lowest amino acid value. PROTEIN DIGESTIBILITY CORRECTED AMINO ACID SCORE (PDCAAS)Protein growth potency is judged by its weakest essential amino acid. The PDCAAS classifies protein quality for humans based on the amino acid requirements the most demanding age group (2-to-5-years) and is adjusted for digestibility. Only three proteins are considered "Complete" based on their PDCAAS score:

PROTEIN PDCAAS
WHEY 1.0
SOY 1.0
EGG 1.0
Grains & Legumes 1.0
Grains & Vegetables 1.0
Grains, Nuts, & Seeds 1.0
Rice & Peas 1.0
Legumes, Nuts, & Seeds 1.0
Beef 0.92
Rice + Milk 0.92
Peas 0.73
Oats 0.57
Peanuts 0.52
Rice 0.47
Corn 0.42
Wheat Gluten 0.25

PROTEIN EFFECTS SERUM CHOLESTEROL LEVELS When rabbits were fed various foods then were examined for blood serum cholesterol after 28 days on each protein, the following results in serum cholesterol were reported:

PROTEIN SOURCE POSTPRANDIAL SERUM CHOLESTEROL (mmol/l)
Soy Protein Isolates 0.4
Soy Protein Concentrates 0.6
Peanut Protein 2.1
Wheat Gluten 2.1
EGG White (raw) 2.7
Pork Protein Concentrate 2.8
Beef Protein Concentrate 4.1
Casein (MILK) 5.2
Skim MILK 5.9
Whole EGG 6.1

AMINO ACIDS ACCESS THE BRAIN, ENERGY LEVELS, MOOD, EMOTION, APPETITE, AND MUSCLE GROWTH HORMONE RELEASE There are 4 main classes of amino acids. When amino acids from the same class are present simultaneously with others, they compete for entry through the blood-brain barrier. A single free-form amino acid will cross blood-brain barrier with greater potency effect. When, for example, Glutamine, Arginine, Tryptophan, Glycine, and the BCAA's (Leucine, Valine, and Isoleucine) are taken as free form amino acids without having to compete against other amino acids in their class have been reported to stimulate maximal hGH release with muscle growth rate increased effects. Each of the 4 classes are listed with their corresponding amino acids: LARGE NEUTRAL CLASS

Tryptophan Phenylalanine Tyrosine Methionine LeucineBCAA ValineBCAA IsoleucineBCAA
SMALL NEUTRAL CLASS

AsparagineGlutamineProlineSerine
ACIDIC CLASS

GlutamicAspartic
BASIC CLASS

Arginine Ornithine Lysine

The protein food's amino acid profile of affects its biological value. Protein food sources can be consumed together regenerating a complete protein rating PDCAAS 1.0-score.  One protein may have a better effect if it is mixed with another based on the strength and weaknesses of its amino acid profile. Only 3 protein amino acid profiles have been rated as "Complete" or with a perfect PDCAAS score of 1.0. "Complete Proteins" are SOY, WHEY, & EGG WHITES. PDCAAS means "Protein Digestibility Corrected Amino Acid Score."  An argument can be made for consuming whey protein during strength or speed training cycles, and soy during endurance cardio training cycles keeping the carbohydrates to protein ratio of 3-4 to 1 as total dietary protein of 1.7 grams during speed/strength training but no more than 1.4 grams/kilogram bodyweight during endurance training cycles. Only small portions of protein should be consumed during exercise, which operate to blunt protein deficits created by exercise. During the first 30 minutes after exercise it is important that the athlete consume a large protein meal of 40 grams with 120-160 grams carbohydrates to refill the lean muscle mass stores for recovery and "muscle growth" after exercise. Too much dietary protein above 1.7 grams per kilogram body weight is not necessary, increasing the risk of elevating nitrogen, ammonia, urea, dehydration, and increasing feelings of malaise from nitrogen toxicity impacting stress on the liver and kidneys. More is not always better, but balance is always key. [3]

[1] Director Research and Product Development EMG, Whitefish, Montana 1-800-336-1977.

[2] National Research Council. Recommended Dietary Allowances, 10th ed. National Academy Press, 1989; Values for whey hydrosylate are from Boza, JJ et. al. (12) and may vary slightly depending on how the whey is produced; Values for soy isolate (Supro-620) are from Young VR. (13).

[3] Misner, W.D., The Great Hammer Protein Debate: Which Protein Is The Best, How Much And When? THE JOURNAL OF ENDURANCE:2001:#8.


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