Healthy Lifestyle

Animal vs. Plant Protein

Some writers claim that protein is protein, be it animal or plant, except for the way that animals are treated. How do you respond to this?

We have information that the primary difference between animal and plant proteins is their amino acid profiles and it is those profiles that direct the rates at which the absorbed amino acids are put to use within the body. Animal based proteins, of course, are much more similar to our proteins, thus are used more readily and rapidly than plant proteins. That is, ‘substrate’ amino acids derived from animal based proteins are more readily available for our own protein synthesizing reactions which allows them to operate at full tilt. Plant proteins are somewhat compromised by their limitation of one or more amino acids. When we restore the relatively deficient amino acid in a plant protein, we get a response rate equivalent to animal proteins. My own lab produced experimental data to support this view–and of course, similar observations of years past in other laboratories can also be interpreted in this way.

Some of the profile differences between animal and plant proteins have been previously noted by the ratios of arginine to lysine which are predictive, in turn, of tissue responses.

Animal proteins also have a higher concentration of sulphur containing amino acids that get metabolized to acid-generating metabolites. As a result, a slightly lower physiological pH must be corrected and buffers like calcium are used to attenuate these adverse acid effects–to the disadvantage of the host.

But my main thesis, insofar as my own work is concerned, is that our observations on protein and cancer, although studied in considerable detail, were signals of hypotheses that were more important and more global. [...]

Muscling Out the Meat Myth

It’s my guess that there’s hardly another myth in nutrition so insidious yet so intractable as that which encourages us to believe that consuming lots of high-quality protein

– basically the stuff of animal-based foods – makes for fitness, bigness, and strength of body. Rooted in antiquity, this myth began to sprout in the minds of men (especially men, it seems) long before protein was identified and named.

The myth took root in the belief that we could get our strength, our agility, and our ability to soar to unimaginable heights if only we consumed the flesh and bodies of animals. Much later, in the early nineteenth century, when scientists identified protein as being more or less equivalent to the flesh of the animals they worshipped, it was heralded as the treasured nutrient. In the words of the famous chemist Justis von Liebig, it was none other than the very “stuff of life itself.”

Quality Protein by Whose Standards?

Around the beginning of this century, scientists came to believe – erroneously – that animal proteins led to improvements in sport competitiveness. This was combined with their stand that animal flesh, milk and eggs spurred body growth more “efficiently” than plant protein. Efficiency, in this sense, meant that by eating animal protein one could gain more body weight per pound of protein consumed. High “efficiency of utilization” occurs with animal protein because the proportion of amino acids (the building blocks of protein) in animal muscle most closely match the proportion of amino acids needed to synthesize protein in our own bodies. We know now that this may be a drawback, but at the time the scientists equated -efficiency of utilization” with “quality,” a bias that persists today.

Efficiency, or [...]

Eating More Calories, Staying Thinner

Although the average caloric intake of the Chinese is higher than that of Americans (2640 vs. 2360 for adult males), and despite their smaller stature, the Chinese are much thinner than Americans. This may be attributed partially to the greater level of physical activity in rural China, but the evidence also suggests that it is explained partly by the composition of the diet.

The mainstay of the Chinese diet is cereal grain. Carbohydrate intake accounts for 70% of the caloric intake in rural China compared to about 40% in the U.S. More importantly, only 15% of the calories consumed by rural Chinese men comes from fat, compared to almost 40% in the U.S. Although the total amount of protein is more or less comparable in these two populations, the source of the protein is very different: in the U.S. over 70% of the protein is derived from non-fish animal foods compared to only 7% in rural China.

The Cornell-Oxford-China Nutririon project, conducted in mainland China and Taiwan, is a massive survey of over 10,000 families designed to study diet, lifestyle, and disease across the far reaches of rural China. By investigating simultaneously more diseases and more dietary characteristics than any other study to date, the project has generated the most comprehensive database in the world on the multiple causes of disease.

Grass-Fed Animal Agriculture

(In response to a reader’s question concerning Dr. Mercola’s views on The China Study)

I’ve seen the views of Dr. Mercola several times, and this is my response:

For background, it should be noted that Dr. Mercola’s views, when he says that The China Study is “seriously flawed”, parallel very closely those of the Weston A Price Foundation (WAPF), a Washington-based agricultural lobbying group, who asserts, among other claims, that high cholesterol diets are healthy even beneficial and who not surprisingly support the consumption of raw un-pasteurized, un-homogenized grass-fed beef and other animal-based food products.

They also, perhaps to be politically correct, recommend the consumption of fruits and vegetables but in a way that is virtually meaningless. They rely heavily on a personal survey that a dentist, Weston Price, did during the 1920s and 1930s when he visited a total of 14 indigenous peoples in various parts of the world to examine and photograph their dental health (dental caries and dental arch formation). However, by principally relying on Price’s findings, WAPF goes far beyond what Price actually did. They would have us believe that he published extensive data to support the health value of cow’s milk and high cholesterol animal based foods and, further, that he ‘discovered’ a fat soluble factor in milk that is likely responsible for these healthy effects of cow’s milk. I read his book and there are no data that Price accumulated, tabulated and interpreted to support that view. Indeed, the so-called fat soluble factor was noted at a time during the early days of vitamin discoveries when little was known about their metabolism and biochemically functional effects, except that they divided into water and fat soluble substances.

Although I find it difficult at [...]

What’s For Lunch?

The latest version of the Dietary Guidelines for Americans was recently published by the United States Department of Agriculture (USDA) and, except for some minor adjustments in format and design, and the addition of two new guidelines to show that the panel was doing some work, little if anything was accomplished. The guidelines are supposed to bring us up to date on what we ought to be eating. The new guidelines encourage regular physical activity and practicing food safety.

Revised every five years to reflect the latest in scientific evidence, the report sounds reasonable enough. Mainly, it infers better health if we eat more vegetables, fruits and whole grain foods, achieve and maintain a healthy weight, do regular physical activity, avoid consuming excesses of sugar, sodium and alcohol while reducing our average fat intake from its present 35% of energy consumption to 30% or less.

Although this report may be increasing public awareness of the diet and health connection, these guidelines also have another very significant, but troubling, purpose. In effect, the report establishes a reference standard of implied good health for widely used government subsidized food assistance programs. One such program is the National School Lunch Program (NSLP), now providing meals for about 26 million American elementary school children. That’s about one in five families who have one or more children participating in the program, in the hope in many cases that their children are getting a dose of good health not otherwise available to them.

In my view, this government food subsidy program, also run by the USDA, is a disaster and has been so for many years. An extensive evaluation of the program published in the American Journal of Clinical Nutrition in 1995 [...]

Casein Consumption


I have been a eating “mostly-vegan” diet for several years now. I do not consume milk, cheese, meat, or whole eggs. I am not strict vegan because occasionally I eat egg whites, fat-free yogurt, or soy based “meat products” and cheese containing casein. I recently read The China Study and was completely astounded with how detrimental casein is to the human body. Is the amount of casein in these products considered relatively “safe” for moderate consumption (a few times per week)?

The main story line of the book relates the sequence of experimental research studies with which my current ideas about nutrition emerged. I began by doing very traditional research, by focusing on a relatively specific objective, or hypothesis. Namely, does casein–when fed to rats–encourage the growth of experimental tumors and, if so, how does it work? This is traditional research strategy.

First, we confirmed that casein does have this property (thus supporting the preliminary research of others) and, second, we learned how it does it (involving multiple ‘mechanisms’). In the traditional sense, the evidence was overwhelming. Using traditional science practice, we should be concluding that casein is a chemical carcinogen, perhaps the most relevant carcinogen that we consume.

But importantly, we also had evidence that this effect was reserved for a dietary level of casein that is above a threshold required to meet the rat’s needs for protein, i.e., 10-12% of total calories. We also obtained evidence that this is true for casein but not for wheat protein or for soy protein, even when these latter proteins are fed at 20% of total calories. However, the fact that this casein effect exists above 10-12% on up to 20% or so makes these findings [...]