Did our primitive ancestors have superior diets of raw food that gave them immunity to many diseases of modern civilization? Did the adoption of modern diets and lifestyle introduce disease and tooth decay to tribal people? According to followers of various raw foods diet plans, the answer is an emphatic and proven “yes.” However, this school of dietary philosophy is in contrast to the teachings of modern nutrition, public health, and also Traditional Chinese Medicine. In this article, I will look at the history and questionable research behind the raw foods philosophy.

I have personally gone through many phases with philosophy and diet since high school—I was vegetarian for 8 years (on and off vegan) and searched endlessly for the ideal foods, whether sprouts, seaweeds, or whole grains. I was resistant to the recommendations of my Chinese teachers, who suggested that I wouldn’t be so cold and tired if I ate some meat. However, after years of resistance, I went to China with the intention of accepting whatever food I was offered. That ended my vegetarianism and vastly expanded my menu. While some people definitely benefit from a vegetarian diet (even if only for a few months), examining the claims and research backing the fringe elements of health foods philosophy has been an important step for me in being comfortable and relaxed in my more “normal” diet.

The raw foods movement is very curious in that it’s not a specifically vegetarian movement and it sounds on the surface to be based upon scientific findings. Two key figures in the raw foods movement are Dr. Weston Price and Dr. Francis Pottenger. Dr. Price was a dentist who traveled the world around 1930 looking at the teeth of “primitive” people who didn’t have a Westernized diet and lifestyle. According to the Price-Pottenger Nutrition Foundation, “Wherever he went, Dr. Price found that beautiful straight teeth, freedom from decay, stalwart bodies, resistance to disease and fine characters were typical of primitives on their traditional diets, rich in essential food factors.” (http://price-pottenger.org/price.htm). Dr. Pottenger was a researcher who was raising stray cats so he could harvest their adrenal glands to make adrenal extracts. He fed them various scraps of food from a butcher shop, and noticed that his cats eating cooked food got sick and had problems with reproduction. He set up a group of cats to eat raw meat and found that they didn’t have the same diseases and reproductive problems. Are you ready to give up cooked food and start eating raw beef and broccoli so you, too, can live a long, happy life free of dental problems and the “diseases of modern civilization?” Don’t throw out that wok yet! Let’s examine these claims in more detail first.

The Price-Pottenger Foundation puts forth 10 conclusions of Price’s research. They can all be found at the link above. Here are a few which are more useful for our discussion:

1. Dental decay is caused primarily by nutritional deficiencies.

2. Contact with civilization, followed by adoption of the "displacing foods of modern commerce" was disastrous for all groups studied. Although radically different, 14 tribal diets provided almost complete immunity to tooth decay and resistance to disease. The diets contained no refined or devitalized foods.
3. Rampant dental caries [cavities] were followed by progressive facial deformities in children born to parents consuming refined and devitalized foods. These changes consisted of narrowed facial structure and dental arches, along with crowded teeth, birth defects and increased susceptibility to infectious and chronic disease.

4. If civilized man is to survive, he must incorporate the fundamentals of primitive nutritional wisdom into his modern life-style.

OK, now we can have some fun! Here are the conclusions again, followed by my commentary.

1. Dental decay is caused primarily by nutritional deficiencies.

Dental decay is primarily caused by bacteria that produce acids that eat away the tooth enamel. A lack of tooth-strengthening calcium and fluoride (a naturally occurring mineral in some foods and water sources) allow these bacteria to eat away the teeth faster. While nutritional deficiencies are certainly the cause of many various health problems, it is well established that it is bacteria that cause tooth decay and infections. It has also been shown that eating more sticky carbohydrates increases the ability of bacteria to multiply on the surface of the teeth, speeding decay. However, someone with no nutritional deficiencies who eats a lot of sweet, sticky foods will still get plenty of tooth decay.

2. Contact with civilization, followed by adoption of the "displacing foods of modern commerce" was disastrous for all groups studied. Although radically different, 14 tribal diets provided almost complete immunity to tooth decay and resistance to disease. The diets contained no refined or devitalized foods.

It’s time for a strong dose of reality. “From the Paleolithic to the late Mediaeval period the mean life expectancy of humans increased from between 20 and 30 years to 30 to 40 years.” That is from a wonderful article by W. J. MacLennan and W. I. Sellers at http://mac-huwis.lut.ac.uk/~wis/papers/ProcRCollPhysEdinb1999.html. Over the past 150 years, the general life expectancy on earth has nearly doubled. In 1840, the life expectancy for a male was about 43 years. Now it is about 76 years. The increase is most apparent in wealthy industrialized nations. Finding an ancient burial site with skeletons over 40 years old is very rare. Most people on diets of “no refined or devitalized foods” died before they were 35, and they still do. This is largely due to communicable diseases, with trauma and malnourishment close behind. It is a true statement that modern people have more degenerative diseases than primitive people, but there is a big difference between dying of cancer at 76 and dying of smallpox at 25. I’ll take the degenerative disease, thank you very much. To suggest that since people who died in their 30s didn’t have cancer, we should follow their dietary traditions is obviously a logical fallacy. While the modern diet does contain sticky, sweet foods which can accelerate tooth decay, instead of modern commerce being disastrous to tribal peoples, it has generally doubled their lifespan within 1-2 generations, if only through controlling communicable diseases. Frankly, part of me wishes that this weren’t so, as I have always cheered for the tribal lifestyle that treads more lightly on the earth. But a dose of reality is powerful medicine! Even defenders of Price’s conclusions have admitted that he did find many unhealthy tribes, but passed them over looking for the healthy ones. If that is the case and 14 tribes with healthy teeth had radically different diets, then it is unlikely that raw food was what gave them better teeth—as with the discovery of natural fluoride in Colorado well water, it could be that these tribes simply had natural sources of fluoride in their water or special foods/herbs.

3. Rampant dental caries were followed by progressive facial deformities in children born to parents consuming refined and devitalized foods. These changes consisted of narrowed facial structure and dental arches, along with crowded teeth, birth defects and increased susceptibility to infectious and chronic disease.

If this were true, we should have almost nothing but deformed infants being born now. Something not considered in this conclusion is the high rate of infant mortality among tribal people. Somewhere between 25% and 35% of babies died before they were 5, usually of infectious disease and malnutrition, though sometimes due to outright infanticide. Infanticide was common with deformed babies. To visit a primitive tribe and see mostly strong-looking 10 year olds, none of whom are deformed or disabled, may simply mean that all of the weak, deformed, and disabled children are dead.

4. If civilized man is to survive, he must incorporate the fundamentals of primitive nutritional wisdom into his modern life-style.

Primitive nutritional wisdom was to try as hard as possible to not die of starvation. Without refrigeration or modern kitchens, food was eaten quickly and raw. Parasites and other food and waterborne illnesses were common, as were diseases of malnutrition. While modern diets do contain more tooth-decay promoting sugars than many traditional diets, we also have a greater ability to practice dental hygiene. Cutting down sugary foods and brushing the teeth regularly after eating such foods is a sensible thing to do. However, the real evidence does not support mimicking a tribal diet by eating raw meats and avoiding cooked vegetables. Civilized man does indeed have some survival challenges, but eating grubs and raw foods does not solve them. While returning to a primitive level of infant mortality would slow down our overpopulation crisis it’s not a suitable solution either.

Dr. Price may have come across some useful information in his travels and documentation of primitive diets, but his conclusions are clearly wrong in many cases. Any findings he made should have been confirmed by repeated research over the past 70 years. Since his conclusions were sloppy (he had already determined his conclusions before doing his research, so he was viewing things through a strong filter) it is unlikely that modern scientists would choose to fund thorough research to confirm his claims. This isn’t an AMA conspiracy, but common sense.

Let’s look more at Dr. Pottenger and his cats. Here is an excerpt from The Price-Pottenger Foundation (http://www.price-pottenger.org/Articles/PottsCats.html):
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Pottenger's Cats - A Study in Nutrition

Francis M. Pottenger, Jr., MD

Between the years of 1932 and 1942, Dr. Francis Marion Pottenger, Jr. conducted a feeding experiment to determine the effects of heat-processed food on cats. His ten-year cat study was prompted by the high rate of mortality he was experiencing among his laboratory cats undergoing adrenalectomies […snip...].

In his effort to maximize the preoperative health of his laboratory animals, Francis fed them a diet of market grade raw milk, cod liver oil and cooked meat scraps from the sanitarium… Therefore, Francis was perplexed as to why his cats were poor operative risks. In seeking an explanation, he began noticing that the cats showed signs of deficiency. All showed a decrease in their reproductive capacity and many of the kittens born in the laboratory had skeletal deformities and organ malfunctions.

As his neighbors in Monrovia kept donating an increasing number of cats to his laboratory, the demand for cooked meat scraps exceeded supply and he placed an order at the local meat packing plant for raw meat scraps, again including the viscera, muscle and bone. These raw meat scraps were fed to a segregated group of cats each day and within a few months this group appeared in better health than the animals being fed cooked meat scraps. Their kittens appeared more vigorous, and most interestingly, their operative mortality decreased markedly.

The contrast in the apparent health of the cats fed raw meat and those fed cooked meat was so startling, it prompted Francis to undertake a controlled experiment... He wanted to find answers to such questions as: Why did the cats eating raw meat survive their operations more readily than those eating cooked meat? Why did the kittens of the raw meat fed cats appear more vigorous? Why did a diet based on cooked meat scraps apparently fail to provide the necessary nutritional elements for good health? He felt the findings of a controlled feeding experiment might illumine new facts about optimal human nutrition.

Many people in the raw foods movment take Pottenger’s study as proof that cooked foods are “toxic” and raw foods are “vital” for both cats and humans. There are people who eat raw beef, chicken, and other meats due to their interpretations of Pottenger’s study over 60 years ago.

Nutritional science has not stood still since Pottenger did his experiments. In my research for this article, I came across a wonderful site with an article about Pottenger’s cats (and enzymes, fruitarianism, etc.), which goes into much more detail than I will here. If you’re interested in learning more about these topics, browse over to http://www.beyondveg.com/tu-j-l/raw-cooked/raw-cooked-1h.shtml.

Among the obvious points to make regarding Pottenger’s experiment are that cats are not humans, domestic cats have been breeding just fine on diets of cooked cat food without deformities or reduce lifespan (as our wonderfully cute 13 year old cat napping on the chair next to me shows), and that animal experimentation can lead to poor conclusions about human health. For example, rats make their own Vitamin C, and cats were later discovered to not be able to make their own Taurine. The inability of cats to synthesize the amino acid Taurine out of other amino acids makes them very different than humans. Thus Taurine is an essential amino acid for cats and a non-essential amino acid for humans.

Studies in the 70s went a step further than Pottenger’s as the Taurine issue was being discovered. Two groups of cats were fed completely synthetic diets, one with Taurine and one without Taurine. The Taurine-deficient cats developed the same diseases and birth defects as Pottenger’s cooked food group, but the group on the completely synthetic diet with Taurine did just fine for several generations. It was also shown that cooking meat changes Taurine enough as to make it unavailable for cats to absorb. So it appears there is not a magical “life force” in raw foods necessary for healthy cats, but simply an amino acid that cats need but humans don’t.

Mentioning “life force” in raw foods brings up the last issue and person in this article—food enzymes and Edward Howell. Dr. Howell wrote a book on enzymes in 1946 and then revised it in 1985 with Enzyme Nutrition, which is still available. His main theory is that we have limited “enzyme potential” in our bodies which is a main determinant of health and longevity. Raw foods, according to Howell, maintain their “enzyme potential” which is analogous to a “life force” and when consumed prevent us from using up our own enzymes. Thus, eating raw foods contributes to health, whereas eating cooked foods (with destroyed enzymes) requires us to use up some of our supposedly limited supply of enzymes.

To start with, I’d like to be very clear that it is impossible to “kill the enzymes” as they are NOT alive. Enzymes are special proteins, which are no more alive than any other molecule—they don’t reproduce, move around on their own, or exhibit any other characteristics of life. It is completely ridiculous to talk in terms of foods with enzymes as “living” and foods without active enzymes as “dead.” In case you haven’t heard this type of statement before, here’s a prime example from a proponent of “living foods”:

“The Standard American Diet is nearly the exact opposite of the diet found among the people of the planet who live the longest, healthiest lives. The SAD diet is composed primarily of dead food; i.e., processed, refined, cooked. It has literally been cooked to death. There is no life left in it…Living food is any food in which the life force (enzymes) have not been destroyed by heat, chemicals, radiation, decay, freezing, refinement, etc. Enzymes are the life force in living food.” http://www.selfgrowth.com/articles/Spencer1.html

If you’ve read this far, you hopefully recognized the completely unsupported “fact” that the people who “live the longest, healthiest” lives eat raw food and are not average Americans. While I am not trying to make the point that the Standard American Diet is the healthiest diet in the world, Americans, Japanese, and Europeans are the ones who live the longest, healthiest lives—largely to the “dead” nature of the food and water in modern civilization. While the author of the above quote is simply mistaken in assigning life to enzymes, the idea that having living things in your food is good is backwards. I prefer my meat, water, and even most vegetables to be as dead as possible when I eat them. If there is any “life” on such foods, it is more likely to be from bacterial contamination than a mystical life force that will increase longevity.

Dismissing the notion that enzymes are alive does not address the other claims of enzyme benefits. Enzymes are necessary for digestion—our body makes many enzymes such as amylase, protease, lipase, etc. Raw plants do contain enzymes that were being used by the plant for growth and cellular processes when they were alive. Enzymes are relatively fragile, and cooking does deactivate most of the enzymes found in plants and meats. However, so does stomach acid! Most of digestion and absorption of nutrients takes place in the small intestine. Digestion starts in the mouth, but it is the acid in the stomach which has the strongest affect on bacteria and enzymes which may be in the foods we eat. Ideally any bacteria or parasites on raw foods will be killed by out stomach acid. This process also deactivates most enzymes in raw foods. If the enzymes in raw foods are to help us digest those foods, they must do it quickly, before the stomach acid deactivates them. It is highly unlikely that they make a significant difference—the idea that they do is not supported by any research I’m aware of. In general, raw foods don’t contain a high amount of enzymes. Taking enzyme pills (such as the ones developed and sold by Edward Howell!) provides a much higher dose of enzymes than found in any raw food. Those pills have to be coated with a special substance to prevent the stomach acid from deactivating them. They may be useful to some people with specific diseases that limit natural enzyme production, but I was unable to find any evidence of health benefits to normal people.

Readers of Howell’s books may disagree, and point to Howell’s 1985 book that he claims is an abridged version of a 700 page book he wrote earlier. Apparently, he repeatedly points to research documented in this 700 page book, and that is the basis for the “proof” of his theory of enzyme potential. However, there is no record of this book existing other than Howell’s claims—even searching library catalogs and rare/antiquarian book services shows no record of it existing.

An ironic note in the enzyme/raw foods debate is what happens when cats eat raw fish. There is an enzyme in raw fish, thiaminase, which breaks down the B-vitamin thiamine. Raw fish are not a part of the natural feline diet. This is good, because a cat can become ill and die if they consume enough of this enzyme—it’s a clear case of a nutritional deficiency being created by an enzyme in raw food!

I am not promoting an opposite extreme to the raw foods philosophy, such as only eating foods that have been boiled for 30 minutes or more. I like many raw foods, especially fresh organic salads of mixed baby greens. I also like sushi upon occasion. However, I generally prefer cooked foods—steamed vegetables, sautéed mushrooms and onions, grilled steaks, roasted turkey, simmered soups.

Nutrition has long been a passion of mine. However, I readily admit that the evidence shows that sanitation and public health have done more to extend the human lifespan than any particular type of diet. There are certainly nutrients that have been shown in valid, modern studies to reduce the chance of getting certain diseases (such as antioxidants for preventing Alzheimer’s and heart disease). It is likely that continued nutritional research will help us find ways to reduce the chance of getting other degenerative diseases. Raw foods (including raw meats) are unlikely to be the key—the proponents of this philosophy rely upon outdated, manipulated research that is selectively interpreted to reach the conclusion they set out to prove. Ancient humans were certainly not healthier and longer-lived than the average modern American, and there is not a mystical vital force in raw foods or enzymes which has been shown to exist and be important to longevity. In this article, I didn’t even go into the numerous cases where cooking will destroy toxins (such as in kidney beans) or increase the availability of nutrients (such as in carrots).

So it’s time to celebrate one less dietary notion to feel guilty about! Break out the steamer, fire up the grill, pour a glass of something pasteurized! Eat cooked food, drink dead water, and be very merry, for one day, at a far older age than our prehistoric ancestors, we will certainly die!