Raw Food - Raw Deal?
Some claim that cooking your food ruins its nutrients or makes it poisonous, in a misguided effort to promote raw food.
by Brian Dunning
March 1, 2007
Also available in Russian
Turn your stove off, put those pots and pans away, and prepare to be dazzled
by a delicious meal made from fresh, raw fruits and vegetables. But wait! They're
not just healthy and delicious: Raw foodists are claiming a lot more
Raw foods are delicious, they're easy to prepare, you'll probably spend less
money on food, you'll spend less time washing dishes, and you're a lot less
likely to burn yourself in the kitchen. Nobody denies any of these benefits;
I certainly don't. What I do deny are some of the other, less honest claims
that some of the more militant raw foodists make. I don't know why they make
these claims, since most of them are so obviously untrue. Raw food is already
a great thing; it doesn't need to be defended or supported by lies.
I should point out that I am a huge raw food fan. Nobody likes raw
food more than I, or eats it in larger quantities. However, my raw food diet
consists mostly of fish in Japanese restaurants, and it only supplements my
regular diet of normal food. But by making this disclosure, I do claim full
protection from the appearance of bias in this episode.
Let us now listen to some of the disingenuous claims made by some raw foodists:
Animals in the wild don't get sick because they eat a natural, raw diet.
Apparently, a lot of raw foodists honestly believe — or at least say that
they believe — that wild animals don't get sick, and therefore we wouldn't
either if we only ate raw food like animals, as if that's the significant
difference between people and wild animals. In fact, disease is the major cause
of mortality in wild animals. Check with any of the various wildlife groups
who send veterinarians and biologists out into the jungles of the world to
care for wild animals. This claim is especially hard to support given the numerous
high profile cases of disease in wild animal populations: avian flu, chimpanzee
ebola, widespread hoof and mouth disease, bubonic plague in rats.
The correlary claim is that raw foodists will not get sick. Unfortunately
there is not a single example in the whole human race of someone who doesn't
get sick, so this claim is just as untrue. Of all the original raw food gurus
who have since passed away, please note that they have all passed away.
Eating raw foods will increase your lifespan.
Humans are living longer than ever before, and that's shown through overwhelming
evidence. This is due to modern health care. You can try to debate this point
and say that cooked food makes us live shorter than we naturally should, but
you're on thin ice. All the evidence is completely against you. The argument
is purely faith-based.
By far the greatest driver in longevity is heredity. Diet is not a significant
factor, statistically. Actually there is some recent research showing that
80% of centenarians have abnormally large HDL particles, compared to 8% of
the general population.
On a related note, I am intrigued by the low-calorie longevity. As you probably
know, lab mice live 50% longer when fed an extremely low-calorie diet. There
is a group of people who call themselves "life extensionists" who
eat low-calorie diets. It should be noted that the significant factor in this
diet is low-calorie: not vegan, not raw, not organic, not free of corporate
hate energy; simple low-calorie is all it takes. But since there are not yet
any long term clinical studies on humans, we can't yet assess whether what's
good for mice is good for people, but it is still interesting.
Because of the same mathematical curiosity that we discussed in the Natural
Hygiene episode, people who adopt a raw food diet can genuinely claim to have
average lifespans that are longer than the general population. This is because
most raw foodists choose to adopt the lifestyle during healthy adulthood, when
they're already past infancy and early childhood where many deaths occur in
the general population, thus bringing down the general population's average
life expectancy. When any group composed largely of adults claims a longer
life expectancy than the general population, be skeptical of the reasons they
give. It's true of all adults.
Humans are the only primates who eat meat.
You'll hear this a lot from raw foodists, but it's simply not true, as a read
of any reference material, or a trip to any zoo, will reveal. Almost all apes
are omnivorous. At one extreme you have baboons, who have been known to hunt
goats and sheep in packs. At the other extreme you have gorillas, who eat insects
as a small part of their diet. Most other apes, such as chimps, eat eggs, birds,
and small mammals. Anyone who tells you this is trying to support an unsupportable
claim: they're simply telling a far-out lie to convince you that eating meat
Cooked food is toxic.
I'm not even sure how to answer this one. Obviously, if cooked food was toxic,
everyone on earth would have died long ago. Generations ago. Tens of thousands
of years ago. Every speck of evidence shows quite conclusively that everyone
talking about this is, well, alive. Cooked food is not toxic, or else we'd
Cooking makes organic compounds non-organic.
Let's review what an organic compound is. Ever take o-chem in college? Organic
chemistry is the study of carbon compounds, and organic compounds are those
formed by living organisms, with molecules containing two or more carbon atoms,
linked by carbon-carbon bonds. These can be double bonds, where the carbon
atoms share 4 electrons, or in the case of saturated fatty acids, they can
be single bonds, where the carbon atoms share two electrons, and the other
electrons are shared with bonded hydrogen atoms. Breaking these bonds would,
in effect, make an organic compound non-organic.
So really, the claim being made by the raw food people is that cooking breaks
those carbon-carbon bonds. You would have to really, really cook your
food to break these bonds. Carbon-carbon bonds will begin to break at temperatures
above 750 Fahrenheit, or about 400 Celsius. So if you cook your food in a ceramics
kiln, then yes, it is possible to chemically change it into a non-organic compound.
But if you're looking for it to happen at regular cooking temperatures, well
then, you need to retake your o-chem.
Cooking kills needed enzymes in the food. Without these enzymes, the body
cannot properly digest the food.
This is one of the more common claims that you'll hear, and it's based on
a gross misunderstanding of digestion basics. Our digestive enzymes are produced
by our body, and secreted into our mouth and stomach through glands. Humans
do not need to eat digestive enzymes in order to digest. We are not Jeff Goldblum
in The Fly.
Moreover, the claim that cooking "kills needed enzymes" is silly
on two fronts. First, pretty much anything that you digest gets "killed" in
the process — that's kind of the whole point of digestion. Enzymes contained
in the food that you eat are broken down into their constituent amino acids
by your digestive process, and it's these amino acids that are absorbed through
"Killing needed enzymes" is pretty much what you want your digestive
system to do: break them up into amino acids that you can use. Trumpeting this
fact with alarmism as if it's a bad thing, should really give you pause to
consider how well these people know what they're talking about.
White blood cells flood the stomach after eating cooked food, because
they're trying to fight the poison that just entered the body.
Neither I nor a doctor friend had ever heard of a mechanism by which white
blood cells could enter the stomach, except in certain acute conditions involving
gastric ulcers, where the stomach is open to the vascular system. The claimed
phenomenon of pus in the stomach as a consequence of consuming cooked food
does not ever appear to have been observed in medical literature, so this has
all the appearances of being just another made-up lie.
Cooking food renders it unrecognizable to the body as food.
Well, again, we have a misunderstanding of the digestive system. The word
"food" is just a label that people put on certain things that they
eat. I could also eat dirt, and I wouldn't call it food. My stomach doesn't
care what I call it: The digestive enzymes in my saliva and my stomach are
going to treat it just the same. A raw food guy might eat a banana and a steak,
but he's only going to label one of them food. I label both of them food. Doesn't
matter to the digestive enzymes, which make no such query and apply no such
labels. Regardless of what you call it, the digestive enzymes are going to
break down whatever parts of it they can, and the resulting molecules are still
going to be absorbed through the epithelial cells in the ileum. The dirt's
going to pass right through me, but that cooked steak is going to end up in
the raw food guy's bloodstream, nourishing his body, whether he likes it or
not. He doesn't have to call it food.
Animals live to a much greater multiplier of their maturity age.
For some reason, this is often put forth as support for raw foodism. Presumably,
raw foodists blame human consumption of cooked food for this. Why they draw
this particular causal relationship is not clear.
And again, it's another claim that's simply not true, and you don't have to
dig very far to discover this. Say that humans reach sexual maturity around
age 13, and our average lifespan is around 75. That's about a 6:1 ratio of
lifespan to maturity age. By the raw foodists' claim, animals should all be "much
higher" than this. While it is true that most smaller animals are higher,
most larger animals are right in the ballpark with us, and in many cases their
ratios are lower. A lot of animal species achieve sexual maturity when they
reach a particular size, not a particular age, so you can't always draw a direct
comparison. Bottlenose dolphins, for example, range from 2:1 to 4:1, meaning
that they live to be only two to four times their maturity age. Elephants are
the same as humans, about 6:1. Gorillas are a little less than humans, ranging
5:1 to 6:1. Siberian tigers range from 4:1 to 5:1. Grizzly bears range from
3:1 to 6:1. In short, the claim is patently untrue, in addition to being irrelevant
to raw foodism. The ratio of lifespan to maturity age has evolved in each species
by the normal process of natural selection, adapted for each species' needs
and environment. Evolution is not driven by recent diet choices.
If you want to eat raw food, by all means, go right ahead. It's healthy and
it's delicious. But you can enjoy it without making absurd claims, and you
can enjoy it without pointlessly attacking the alternatives. Please be careful
that you don't catch E. Coli or salmonella, unless you're one of the people
that tries to spread any of the above lies; in which case, don't worry about
E. Coli and salmonella. If it's raw it can't hurt you. Eat up.
By Brian Dunning
Cite this article:
Dunning, B. "Raw Food - Raw Deal?" Skeptoid Podcast. Skeptoid Media,
1 Mar 2007. Web.
24 Apr 2018. <http://skeptoid.com/episodes/4030>
References & Further Reading
Bugianesi, R., Salucci, M., Leonardi, C., Ferracane, R., Catasta, G., Azzini, E., Maiani, G. "Effect of domestic cooking on human bioavailability of naringenin, chlorogenic acid, lycopene and ß-carotene in cherry tomatoes." European Journal of Nutrition. 1 Dec. 2004, Volume 43, Number 6: 360-366.
Koebnick, C., Strassner, C., Hoffman, I., Leitzmann, C. "Consequences of a Long-Term Raw Food Diet on Body Weight and Menstruation: Results of a Questionnaire Survey." Annals of Nutritional & Metabolism. 1 Mar. 1999, Volume 43, Number 2: 69-79.
Russo, Ruthann. The Raw Food Diet Myth. Bethlehem: DJ Iber Publishing, Inc., 2008.
Schneider, J., Mohle-Boetani, J., Vugia, D., Menon, M. "Escherichia coli 0157:H7 Infections in Children Associated with Raw Milk and Raw Colostrum From Cows --- California, 2006." Morbidity and Mortality Weekly Report. 13 Jun. 2008, Volume 57, Number 23: 625-628.
Subramanian, S. "Fact or Fiction: Raw veggies are healthier than cooked ones." The Science of our Food. Scientific American, 31 Mar. 2009. Web. 25 Sep. 2015. <http://www.scientificamerican.com/article/raw-veggies-are-healthier/>
Wrangham, Richard. Catching Fire, How cooking made us human. New York: Basic Books, 2009.
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