American Fitness Professionals & Associates

Bill Misner, Ph.D.1

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 BCAA 1546 2609

ISOLEUCINE BCAA 921 1333VALINE

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:

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

2

COMPARISON OF AMINO ACID PROFILES IN COMMON PROTEINS2

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

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

protein isolate (Supro-620) are from Young VR. (13).

3

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 acids3:

LARGE NEUTRAL CLASS

Tryptophan

LeucineBCAA

Methionine

Phenylalanine

ValineBCAA

Tyrosine

Iso-lecucineBCAA

SMALL NEUTRAL CLASS

Asparagine

Proline

Glutamine

Serine

3 Alanine, Glycine, Cystine, & Taurine are unassigned amino acids with no classification as far as the blood brain barrier is

concerned.

4

ACIDIC CLASS

Glutamic

Aspartic

BASIC CLASS

Arginine

Lysine

Ornithine

UNASSIGNED

Alanine, Glycine, Cystine, & Taurine are unassigned amino acids with no classification

related to competing for blood-brain barrier entry.

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 key. 4

4 Misner, W.D., The Great Hammer Protein Debate: Which Protein Is The Best, How Much And When? THE JOURNAL OF

ENDURANCE: 2001:#8.