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 [...]

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

Question

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 [...]

Dietary Fat is Only Partly Where It’s At

The breast cancer/dietary fat relationship, once a key point in getting American women to switch their eating habits, has now been seriously challenged.

A prominent Harvard study of nearly 90,000 American nurses, backed up by somewhat similar studies from other laboratories, has shown no relationship between the risk of breast cancer and the amount of fat we eat.

While it may be tempting for many women to ease off their diet regimes, the relationship between dietary fat and cancer should not be idly dismissed. The problem is that the Harvard study, although well executed, is very narrowly focused, leaving many women understandably confused. A clue to alleviating this confusion may be found when the Harvard data are compared with our findings from rural China. Contrary to Harvard’s conclusions, we found a significant association between dietary fat and breast cancer.

Harvard Study vs. China Project

The Harvard study compared nurses who ate “low-fat” diets with nurses who consumed higher fat diets. Total fat intake ranged from a modest level of 25% to as much as 45% of calories. According to evidence available in other reports, however, the women who consumed the lower amounts of fat, ate so-called “low-fat” foods such as leaner meats, low-fat milk, and low-fat dressings and spreads. Needless to say, they still indulged in eating large amounts of animal-based foods, rather than adding more fruits and vegetables to their diets.

Considerable evidence indicates this may be a formula for failure. The data from rural China, for example, depart from the Harvard data in several important ways. First, we compared people who ate diets containing fat ranging from 6% to 25% of calories (instead of 25-45%). Unlike participants in the Harvard research, we discovered that people in [...]

Protein

Answer to a Reader’s Question:

Many people are rightfully confused about the various ways that protein recommendations are established, and fail to know the main factors that have caused the confusion. Understanding the protein recommendations requires an understanding of the history of protein research and the serious bias that crept into the science over the years. From the beginning, there was a very strong bias that has emphasized the health importance of protein and this almost always meant animal-based protein. This bias arose even though the research results clearly showed in many cases that it SHOULD NOT be emphasized. Nonetheless nutrition researchers still emphasized higher consumption of protein because it was the “sign of civilization itself” as was said in the early 1900s and, further, that those who did not consume these generous amounts of protein (i.e., meat) were “of an effeminate nature”!

Researchers continually pushed the protein idea and continually found ways to develop methodologies and algorithms to ‘show’ that higher levels of protein were advisable. The whole concept of protein “quality” was devised so that it could be said that animal protein was high quality and plant proteins were low quality when, in fact, the concept of quality only indicated a biological efficiency of utilization per unit protein consumed. Naturally, animal-based proteins more nearly mimic our needs because they are composed of the right ratio of amino acids, thus are used more efficiently. But these studies were mostly based on animal production research that served the farm community (also served for my PhD thesis!) far more than it served the interests of human health. More efficiently used “high quality” proteins also efficiently grow cancer cells as well!

However, it’s important not to miss [...]