When Your Friends Ask: Where Do You Get Your Protein?
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If you don't know where you get your protein while following a plant-food-based diet, you're in good company. The Nutrition Committee of the American Heart Association, scientists from the Human Nutrition Research Center and Medical School at Tufts University, and registered dietitians, research nutritionists and physicians of Northwestern University, and the Harvard School of Public Health are just a few examples of "experts" you look to for advice who have the protein story wrong.1-4 Consequences of their shortfall are as grave as a lifetime of sickness and obesity, and premature death, for innocent people. These professionals must be held accountable.
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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.
(American Heart Association)
Plant
protein sources, although good for
certain essential amino acids, do not
always offer all nine essential amino
acids in a single given food. For
example, legumes lack methionine, while
grains lack lysine. (Tufts Human
Nutrition Research Center)
Single
plant protein foods usually are lower in
protein quality than most animal
proteins because they lack significant
amounts of various essential amino
acids. (Tufts University Medical School)
Other
protein sources lack one or more amino
acids that the body can't make from
scratch or create by modifying another
amino acid. Called incomplete proteins,
these usually come from fruits,
vegetables, grains, and nuts. (Harvard
School of Public Health)
Plant
sources of protein (grains, legumes,
nuts, and seeds) generally do not
contain sufficient amounts of one or
more of the essential amino acids. Thus
protein synthesis can occur only to the
extent that the limiting amino acids are
available. (Feinberg
School of Medicine, Northwestern
University) |
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Ignorance Sickens and Kills People
Don't think it matters little if our public policy makers and educators remain ignorant about our nutritional needs. Misinformation leads to disastrous outcomes. People have serious health problems like heart disease, type-2 diabetes, multiple sclerosis, and inflammatory arthritis that can be easily resolved by a diet based solely on plant foods. However, advice to make this dietary change may be withheld from you or a family member because of the erroneous fear that such a diet will result in a greater catastrophe, like a nutritional collapse from protein deficiency.
Consider this scenario: Your loving husband of 35 years has a massive heart attack. He recovers and both of you pledge you will do anything—even eat cardboard—in order to avoid a repeat experience. On your first follow-up visit you tell your doctor that your family is going to follow a low-fat, vegan diet (all plant foods) from here on out. Your doctor says, "You can't do that; you will become protein deficient—plant foods are missing essential amino acids—you must eat meat and other high quality animal foods." Even though you vigorously explain meat, dairy, and eggs are the reasons you almost lost your husband, your doctor insists that you would be foolish to embark on such a course and defends that position with the writings of the Nutrition Committee of the American Heart Association.
The Nutrition Committee of the American Heart Association Has It Wrong
In an October 2001 research paper published in the Heart Association's journal, Circulation, the Healthcare Professionals from the Nutrition Committee of the Council on Nutrition, Physical Activity, and Metabolism wrote, "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."1 My letter to the editor correcting this often quoted, but incorrect information, about the adequacy of amino acids found in plants was published in the June 2002 issue of Circulation.5 Another letter from me in the November 2002 issue of Circulation demanded a correction.6 But, the head of the nutrition committee, Barbara Howard, PhD, would not admit she was wrong and used research from the world's leading expert on protein, Professor Joe Millward, to defend her position.6
Joe Millward, PhD, Professor of Human Nutrition, University of Surrey (England), reviewed the published letters of disagreement between the American Heart Association (AHA) and myself, and wrote the following to me on July 10, 2003, "I thought I had made my position quite clear in my published papers. In an article I wrote for Encyclopedia of Nutrition (Millward DJ. 1998 Protein requirements. Encyclopedia of Nutrition. Academic Press pp 1661-1668) I said 'Contrary to general opinion, the distinction between dietary protein sources in terms of the nutritional superiority of animal over plant proteins is much more difficult to demonstrate and less relevant in human nutrition.' This is quite distinct from the AHA position which in my view is wrong."7
I informed the American Heart Association about Dr. Millward's position, but so far they have chosen to remain silent—and annually, 1.25 million people in the USA alone suffer with heart attacks—an often fatal condition entirely preventable by following a low-fat diet based solely on plant foods—all of which contain all of the essential amino acids in ideal amounts for humans.
Plants--the Original Sources of Protein and Amino Acids
Proteins are made from chains of 20 different amino acids that connect together in varying sequences—similar to how all the words in a dictionary are made from the same 26 letters. Plants (and microorganisms) can synthesize all of the individual amino acids that are used to build proteins, but animals cannot. There are 8 amino acids that people cannot make and thus, these must be obtained from our diets—they are referred to as "essential."
After we eat our foods, stomach acids and intestinal enzymes digest the proteins into individual amino acids. These components are then absorbed through the intestinal walls into the bloodstream. After entering the body's cells, these amino acids are reassembled into proteins. Proteins function as structural materials which build the scaffoldings that maintain cell shapes, enzymes which catalyze biochemical reactions, and hormones which signal messages between cells—to name only a few of their vital roles.
Since plants are made up of structurally sound cells with enzymes and hormones, they are by nature rich sources of proteins. In fact, so rich are plants that they can meet the protein needs of the earth's largest animals: elephants, hippopotamuses, giraffes, and cows. You would be correct to deduce that the protein needs of relatively small humans can easily be met by plants.
People Require Very Little Protein
The World Health Organization (WHO) recommends that men and women obtain 5% of their calories as protein. This would mean 38 grams of protein for a man burning 3000 calories a day and 29 grams for a woman using 2300 calories a day. This quantity of protein is impossible to avoid when daily calorie needs are met by unrefined starches and vegetables. For example, rice alone would provide 71 grams of highly useable protein and white potatoes would provide 64 grams of protein.8
Our greatest time of growth—thus, the time of our greatest need for protein—is during our first 2 years of life—we double in size. At this vigorous developmental stage our ideal food is human milk, which is 5% protein. Compare this need to food choices that should be made as adults—when we are not growing. Rice is 8% protein, corn 11%, oatmeal 15%, and beans 27%.8 Thus protein deficiency is impossible when calorie needs are met by eating unprocessed starches and vegetables.
The healthy active lives of hundreds of millions of people laboring in Asia, Africa, and Central and South America on diets with less than half the amount of protein eaten by Americans and Europeans prove that the popular understanding of our protein needs is seriously flawed.
WHO Recommendations:
(With a wide safety margin) |
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Men: |
5% |
Women: |
5% |
Pregnant: |
6% |
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Percent of Calories of Proteins16
(Selected Foods) |
Food |
% Protein |
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Grains & Flours: |
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Cornmeal |
9 |
Brown Rice |
9 |
Oatmeal |
15 |
White Rice |
7 |
Whole
Wheat Flour |
16 |
White
Flour |
11 |
|
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Starchy
Vegetables |
|
Black
Beans |
27 |
Cassava |
10 |
Corn |
11 |
Kidney
Beans |
27 |
Peas |
28 |
Potato |
8 |
Sweet
Potato |
7 |
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Green
Vegetables |
Asparagus |
42 |
Broccoli |
42 |
Carrots |
10 |
Lettuce |
40 |
Onions |
32 |
Mushrooms |
12 |
Spinach |
51 |
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Animal
Foods |
Beef |
53 |
Chicken |
46 |
Pork |
29 |
Salmon |
43 |
Whole Milk |
21 |
Skim Milk |
39 |
Human Milk |
5 |
Cheddar
Cheese |
25 |
Cottage
Cheese |
68 |
Egg |
32 |
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Faulty
Observations Lead to High Protein
Recommendations
People commonly
believe: the more protein consumed the better.
This faulty thinking dates back to the late
1800s, and was established without any real
scientific research. An assumption was made
that people who could afford to do so would
instinctively select a diet containing the right
amount of protein. After observing the diets of
laborers, soldiers, and workers in Western
Europe and the USA, recommendations of 100 and
189 grams of protein a day were established.9 People’s innate ability to select a proper diet
is disproved by the present day popularity of
burger joints, donut shops, and pizza parlors.
Further confusion
about our protein needs came from studies of the
nutritional needs of animals. For example,
Mendel and Osborne in 1913 reported rats grew
better on animal, than on vegetable, sources of
protein. A direct consequence of their studies
resulted in meat, eggs, and dairy foods being
classified as superior, or "Class A"
protein sources and vegetable proteins
designated as inferior, or "Class B"
proteins.9 Seems no one considered
that rats are not people. One obvious
difference in their nutritional needs is rat
milk is 11 times more concentrated in protein
than is human breast milk. The extra protein
supports this animal’s rapid growth to adult
size in 5 months; while humans take 17 years to
fully mature.
The recent
popularity of high protein diets has further
popularized the fallacy that “more protein is
good for you.” True, high protein diets, like
Atkins, will make you sick enough to lose your
appetite and temporarily lose weight, but this
fact should not be extrapolated to mean high
protein is healthy—in fact, the opposite is
true.
The Truth Has
Been Known for More than a Century
In 1903, the head
of Yale’s department of biochemistry, Professor
Russell Henry Chittenden, reported profound
health benefits gained by cutting popular
recommendations for protein held at his time by
half to two-thirds (from 150 grams to 50 grams
daily). His research included detailed dietary
histories and laboratory studies of his
subjects.9
In the 1940s,
William Rose performed experiments on people
which found daily minimum protein needs to be
about 20 grams a day. Further research on men
found single plant foods consumed in an amount
sufficient to meet daily needs easily met these
human requirements for all 8 essential amino
acids.9 (A more detailed discussion
of the history of protein recommendations is
found in my December 2003 newsletter article: A
Brief History of Protein: Passion, Social
Bigotry, and Enlightenment.)
The results of Dr.
Rose's studies are summarized in the following
chart, under "minimum requirements". From the
chart, it is clear that vegetable foods contain
more than enough of all the amino acids
essential for humans.10
(grams per day)
Amino Acids |
Rose’s Minimum Requirement |
Rose’s Recommend Requirement |
Corn |
Brown
Rice |
Oatmeal
Flakes |
Wheat
Flour |
White
Beans |
Potatoes |
Sweet
Potatoes |
Tryptophan |
.25 |
.50 |
.66 |
.71 |
1.4 |
1.4 |
1.8 |
.8 |
.8 |
Phenylalaline |
.28 |
.56 |
6.13 |
3.1 |
5.8 |
5.9 |
10.9 |
3.6 |
2.5 |
Leucine |
1.10 |
2.20 |
12.0 |
5.5 |
8.1 |
8.0 |
17.0 |
4.1 |
2.6 |
Isoleucine |
.7 |
1.4 |
4.1 |
3.0 |
5.6 |
5.2 |
11.3 |
3.6 |
2.2 |
Lysine |
.8 |
1.6 |
4.1 |
2.5 |
4.0 |
3.2 |
14.7 |
4.4 |
2.1 |
Vailine |
.8 |
1.6 |
6.8 |
4.5 |
6.4 |
5.5 |
12.1 |
4.4 |
3.4 |
Methionine |
.11 |
.22 |
2.1 |
1.1 |
1.6 |
1.8 |
2.0 |
1.0 |
.8 |
Threonine |
.5 |
1.0 |
4.5 |
2.5 |
3.6 |
3.5 |
8.5 |
3.4 |
2.1 |
Total Protein |
20 |
37 (WHO) |
109 |
64 |
108 |
120 |
198 |
82 |
45 |
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(grams per day)
Amino Acids |
Taro |
Asparagus |
Broccoli |
Tomatoes |
Pumpkin |
Beef Club Steak |
Egg |
Milk |
|
Tryptophan |
1.0 |
3.9 |
3.8 |
1.4 |
1.5 |
3.1 |
3.8 |
2.3 |
|
Phenylalaline |
3.0 |
10.2 |
12.2 |
4.3 |
3.0 |
11.2 |
13.9 |
7.7 |
|
Leucine |
5.2 |
14.6 |
16.5 |
6.1 |
6.0 |
22.4 |
21. |
15.9 |
|
Isoleucine |
3.0 |
11.9 |
12.8 |
4.4 |
4.3 |
14.3 |
15.7 |
10.3 |
|
Lysine |
3.4 |
15.5 |
14.8 |
6.3 |
5.5 |
23.9 |
15.3 |
12.5 |
|
Vailine |
3.5 |
16.0 |
17.3 |
4.2 |
4.3 |
15.1 |
17.7 |
11.7 |
|
Methionine |
.6 |
5.0 |
5.1 |
1.1 |
1.0 |
6.8 |
7.4 |
3.9 |
|
Threonine |
2.7 |
9.9 |
12.5 |
4.9 |
2.7 |
12.1 |
12. |
7.4 |
|
Total Protein |
58 |
330 |
338 |
150 |
115 |
276 |
238 |
160 |
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You Don’t Need
Beans or to “Combine” Your Foods
Many investigators
have measured the capacity of plant foods to
satisfy protein needs. Their findings show that
children and adults thrive on diets based on
single or combined starches, and grow healthy
and strong.10 Furthermore, no
improvement has been found from mixing plant
foods or supplementing them with amino acid
mixtures to make the combined amino acid pattern
look more like that of flesh, milk, or eggs. In
fact, supplementing a food with an amino acid in
order to conform to a contrived reference
standard can create amino acid imbalances. For
example, young children fed diets based on wheat
or corn and supplemented with the amino acids
tryptophan and methionine in order to conform to
the standard requirements set by the Food and
Agriculture Organization of the United Nations (FAO)
developed negative responses in terms of
nitrogen balance (the body's utilization of
protein).10
People who are
worried about getting sufficient protein will
sometimes ask me if they can still follow the
McDougall Diet if they do not like beans. From
the chart above, you will notice that any single
starch or vegetable will provide in excess of
our needs for total protein and essential amino
acids—thus there is no reason to rely on beans
or make any efforts to food combine different
plant foods to improve on Nature’s own marvelous
creations.
Potatoes Alone
Suffice
Many populations,
for example people in rural Poland and Russia at
the turn of the 19th century, have
lived in very good health doing extremely hard
work with the white potato serving as their
primary source of nutrition. One landmark
experiment carried out in 1925 on two healthy
adults, a man 25 years old and a woman 28 years
old had them live on a diet primarily of white
potatoes for 6 months. (A few additional items
of little nutritional value except for empty
calories—pure fats, a few fruits, coffee, and
tea—were added to their diet.)11 The
report stated, “They did not tire of the uniform
potato diet and there was no craving for
change.” Even though they were both physically
active (especially the man) they were described
as, “…in good health on a diet in which the
nitrogen (protein) was practically solely
derived from the potato.”
The potato is such
a great source of nutrition that it can supply
all of the essential protein and amino acids for
young children in times of food shortage.
Eleven Peruvian children, ages 8 months to 35
months, recovering from malnutrition, were fed
diets where all of the protein and 75% of the
calories came from potatoes.
(Soybean-cottonseed oils and pure simple sugars,
neither of which contains protein, vitamins, or
minerals, provided some of the extra calories.)12 Researchers found that this simple potato diet
provided all the protein and essential amino
acids to meet the needs of growing and small
children.
Excess Protein
Causes Diseases of Over-nutrition
Unlike fat,
protein cannot be stored. When it is consumed
in excess of our needs, protein is broken down
mostly by the liver, and partly by the kidneys
and muscles. Consumption in excess of our needs
overworks the liver and kidneys, and can cause
accumulation of toxic protein byproducts.
Proteins are made
of amino acids, and are, therefore, acidic by
nature. Animal proteins are abundant in
sulfur-containing amino acids which break down
into very powerful sulfuric acid. These kinds of
amino acids are abundant in hard cheese, red
meat, poultry, seafood, and eggs, and their
acids must be neutralized by buffers found in
the bones. The bones dissolve to release the
buffering materials; eventually resulting in a
condition of weakened bones, known as
osteoporosis. Released bone materials often
settle and coalesce in the kidney system,
causing kidney stones. Fruits and vegetables
are largely alkaline, preserving bone health and
preventing kidney stones.13 (A more
detailed discussion of the health consequences
from excess protein is found in my January 2004
newsletter article: Protein Overload.)
Diseases of
over-nutrition are directly connected to planet
health, too. Recommendations to eat animal
foods for protein have resulted in an
environmental catastrophe. Livestock produces
18% of the greenhouse gases; these food-animals
occupy 26 percent of the ice-free surface of the
Earth and 33 percent of the total arable land is
used to produce their food. One telling tragedy
is they account for the deforestation of 70
percent of Amazon rainforests, which act as the
“lungs of the Earth.”14 (A more
detailed discussion of the environmental damage
from livestock is found in my December 2006
newsletter article: An Inconvenient Truth: We
Are Eating Our Planet To Death.)
Protein
Deficiency Is Really Food Deficiency
How many cases of
the so-called “protein deficiency state,”
kwashiorkor, have you seen? I have never seen a
case, even though I have known thousands of
people on a plant-food based diet. How about
those starving children in Africa? The picture
one often sees of stick-thin children with
swollen bellies in famine areas of Asia or
Africa is actually one of starvation and is more
accurately described as “calorie deficiency.”10
When these children come under medical
supervision, they are nourished back to health
with their local diets of corn, wheat, rice,
and/or beans. Children recovering from
starvation grow up to l8 times faster than usual
and require a higher protein content to provide
for their catch-up in development—and plant
foods easily provide this extra amount of
protein.10 Even very-low protein
starchy root crops, such as cassava root, are
sufficient enough in nutrients, including
protein, to keep people healthy.15
Starving People
Die of Fat, Not Protein, Deficiency
In 1981, 10 Irish
prisoners from the Republican Army (IRA) went on
a hunger strike. Nine out of 10 of these men
died between 57 and 73 days (mean of 61.6 days)
of starvation after losing about 40% of their
body weights (the remaining striker died of
complications of a gunshot wound).16,17
This experience gave doctors a chance to observe
first hand the metabolic changes that occur
during starvation. Protein stores were generally
protected during starvation, with most of the
energy to stay alive being derived from the
men’s fat stores. It was estimated that the
hunger strikers had lost up to 94% of their
body-fat levels, but only 19% of their
body-protein levels at the time of death.16 They died when they ran out of fat. Since fat
is more critical than protein, people should be
asking, “Where do you get your fat (on any
diet)?
Since Nature
designed her plant foods complete, with abundant
amounts of fat, protein, carbohydrates, vitamins
and minerals, “Where you get a specific
nutrient?” is almost never a relevant question,
as long as there is enough to eat. So, why have
scientists, dietitians, medical doctors,
diet-book authors, and the lay public become
fixated on a non-existent problem? Protein is
synonymous with eating meat, poultry, fish,
dairy, and eggs—the foods traditionally consumed
by the wealthier people in a society—thus,
protein-eating means higher social status.
High-protein foods are also high-profit foods.
Therefore, propagating the protein myth is
motivated by egos and money—and the usual
consequences of pain and suffering follow
closely behind these two human frailties.
References:
1) St Jeor S, Howard B,
Prewitt E. Dietary protein and weight reduction:
a statement for healthcare professionals from
the Nutrition Committee of the Council on
Nutrition, Physical Activity, and Metabolism of
the American Heart Association. Circulation.
2001; 104: 1869–1874.
2) Tufts
University: http://www.thedoctorwillseeyounow.com/articles/nutrition/protein_2/
http://www.quackwatch.org/03HealthPromotion/vegetarian.html
3) Harvard School
of Public Health: http://www.hsph.harvard.edu/nutritionsource/protein.html
4) Northwestern
University: http://www.feinberg.northwestern.edu/nutrition/factsheets/protein.html
5) McDougall J. Plant foods
have a complete amino acid composition.
Circulation. 2002 Jun 25;105(25):e197; author
reply e197.
6) McDougall J.
Misinformation on plant proteins. Circulation.
2002 Nov 12;106(20):e148; author reply e148.
7) Personal
Communication with John McDougall, MD on July
10, 2003.
8) J Pennington.
Bowes & Church’s Food Values of Portions
Commonly Used. 17th Ed. Lippincott.
Philadelphia- New York. 1998.
9) The December 2003
McDougall Newsletter: A Brief History of
Protein: Passion, Social Bigotry, and
Enlightenment.
10) McDougall J.
The McDougall Plan. New Win Publ. 1983; pages
95-109.
11) Kon S.
XXXV. The value of whole potato in human
nutrition. Biochemical J. 1928; 22:258-260
12) Lopez de
Romana G. Fasting and postprandial plasma free
amino acids of infants and children consuming
exclusively potato protein. J Nutr. 1981
Oct;111(10):1766-71.
13) The January 2004 McDougall
Newsletter: Protein Overload.
14) The December 2006
McDougall Newsletter: An Inconvenient Truth: We
Are Eating Our Planet To Death.
15) Millward DJ.
The nutritional value of plant-based diets in
relation to human amino acid and protein
requirements. Proc Nutr Soc. 1999
May;58(2):249-60.
16) Leiter LA,
Marliss EB. Survival during fasting may depend
on fat as well as protein stores. JAMA
1982;248:2306
17) ZSurvival. Ann Intern
Med. 1997 Sep 1;127(5):405-9.
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