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 [...]

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 [...]

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 [...]