Is There a Battle Brewing between the American Heart Association’s Nutrition Committee and McDougall?

The story begins with the publication of an article on the hazards of high protein diets (Atkins, the Zone, Sugar Busters, etc.) by the Nutrition Committee of the American Heart Association (AHA).  Unfortunately, the Committee made a serious error when writing about plant-food based diets.  As you will read below, I have attempted to correct this mistake; so far without success.  And it appears the battle for the truth may have just begun.

This letter from me (John McDougall) appeared in the June 25, 2002 issue of the American Heart Association Journal, Circulation (105:197):

Plant Foods Have a Complete Amino Acid Composition

The Statement for Health Professionals from the Nutrition Committee of the Council on Nutrition, Physical Activity, and Metabolism of the American Heart Association on Dietary Protein and Weight Reduction contains often quoted, but incorrect, information of the adequacy of amino acids found in plant foods.¹  This report states, “Although plant proteins form a large part of the human diet, most are deficient in 1 or more essential amino acids and are therefore regarded as incomplete proteins.” 

William Rose and his colleagues completed research by the spring of 1952 that determined the human requirements for the eight essential amino acids.²  They set as the “minimum amino acid requirement” the largest amount required by any single subject, and then doubled these values to make the “recommended amino acid requirement,” which was also considered a “definitely safe intake.”  By calculating the amount of each essential amino acid provided by unprocessed complex carbohydrates (starches and vegetables),³  and comparing these values with those determined by Rose,¹ the results show that any single one, or combination, of these plant foods provide amino acid intakes in excess of the recommended requirements.  Therefore, a careful look at the founding scientific research and some simple math proves it is impossible to design an amino acid deficient diet based upon amounts of unprocessed starches and vegetables sufficient to meet the calorie needs of humans.  Furthermore, mixing foods to make a complementary amino acid composition is unnecessary.⁴

The reason it is important to correct this misinformation is because many people are afraid to follow healthful pure vegetarian diets – they worry about  “incomplete proteins” from plant sources.  A vegetarian diet based around any single one, or combination, of these unprocessed starches (rice, corn, potatoes, beans, etc.) with the addition of vegetables and fruits supplies all the protein, amino acids, essential fats, minerals, and vitamins (with the exception of vitamin B12) necessary for excellent health.  To wrongly suggest people need to eat animal protein for nutrients will encourage them to add foods that are known to contribute to the cause of heart disease, diabetes, obesity, and many forms of cancer, to name just a few common problems.⁵

1. St. Jeor S, Howard B, Prewitt E.  Dietary protein and weight reduction.   A statement for health professionals from the Nutrition Committee of the Council on Nutrition, Physical Activity, and Metabolism of the American Heart Association.  Circulation 2001;104:1869-74.
    

2. Rose W.   The amino acid requirement of adult man.  Nutr Abst Rev 1957;27:63l-47.
    

3. J Pennington.  Bowes & Church’s Food Values of Portions Commonly Used.  17^th Ed. Lippincott. Philadelphia- New York. 1998.
    

4. M. Irwin, Hegsted D.  A conspectus of research on protein requirements of man.  J Nutr 1971;101:385-428.
    

5. Weisburger J.  Eat to live, not live to eat.  Nutrition 2000; 16:767-73.

 John McDougall, MD

On the same page as my letter there is a rebuttal from a representative of the Nutrition Committee of the American Heart Association.  I do not have permission to reprint it for you, but I can tell you my opinion is: It is a poorly written paragraph, which would leave most readers confused.  However, in the rebuttal the Committee clearly has refused to admit the error, and make appropriate corrections. 

I have sent the following letter to the Nutrition Committee of the American Heart Association, all of the authors of the original article, and the editors of the journal.  I will let you know their response.

Thursday, July 11, 2002 

To the Nutrition Committee of the Council on Nutrition, Physical Activity, and Metabolism of the American Heart Association

Dear Sirs:

The June 25, 2002 issue of the journal Circulation (105:197) printed a letter of mine in which I corrected a statement made by the Nutrition Committee of the Council on Nutrition, Physical Activity, and Metabolism of the American Heart Association (Circulation 104:1869-74, 2001).   This report states, “Although plant proteins form a large part of the human diet, most are deficient in 1 or more essential amino acids and are therefore regarded as incomplete proteins.”  This statement is not correct, as I have clearly shown in my letter.

Accompanying my letter was a response from Barbara Howard, PhD, who I assume represents the Nutrition Committee.  Her letter was confusing and undocumented by a single scientific citation.  However, rather than admit the Committee’s report was in error, she reaffirmed their previous position by writing “…we did carefully state that ‘most’ are deficient in one or more essential amino acids…”

Failure to resolve the truth about the adequacy of plant proteins threatens the health of millions of people seeking better guidance for proper nutrition; therefore, my efforts will not be dismissed with a careless response from the Nutrition Committee of the American Heart Association.  Please grant me the courtesy of a professional and honest answer by either:

1)  Showing me that I am incorrect by citing scientific research that contradicts my position and the studies I have provided.  These scientific papers accompanying my letter represent the original experiments performed to determine human protein needs.  I will not accept someone else’s professional opinion on this issue – because, as you know, even the “best experts” can be wrong.  Show me the basic research -- as I have done for you.

2) Admitting the article by the Nutrition Committee of the Council on Nutrition, Physical Activity, and Metabolism of the American Heart Association contains incorrect information concerning the adequacy of plant proteins (Circulation 104:1869-74, 2001).  And giving this matter the serious, open attention it deserves.

I expect this to be handled in a timely, professional, and public manner.  You owe it to society and to your readers.  I will not let this matter rest – and if I get another response that suggests disinterest and confusion about the subject, or worse yet, possibly an attempt to avoid admitting an important error in basic science, I will take this matter elsewhere for a public hearing.

Sincerely,

John McDougall, MD

©2002 John McDougall All Rights Reserved