Raw food is rich in bacteria, not nutrients

The raw food crazies are making themselves sick.

There's a thing called the Raw Food Movement that has been growing in popularity in recent years. Proponents argue that it's far healthier than our usual (human) diet of cooked foods, claiming that cooking removes many of the natural enzymes that make food nutritious. They also believe that cooking creates harmful toxins.

What's really happening, though, is that raw foodies are putting themselves at risk of serious bacterial infections. Just last week, we learned that a salmonella outbreak tied to raw food has sickened people in 15 states so far. The CDC reports that the outbreak is linked to Garden of Life's RAW Meal Organic Shakes, which come in chocolate, vanilla, and vanilla chai flavors. The FDA issued a recall and warned that "persons infected with Salmonella often experience fever, diarrhea (which may be bloody), nausea, vomiting and abdominal pain."

According to the CDC, no one has died from any of these Salmonella infections, although 4 people have been hospitalized.

It's not clear why raw food is so trendy, other than the obsession of some people with everything "natural."

Natural or not, cooking is one of mankind's greatest inventions. It allows us to spend far less time eating, because cooked food is much easier to chew and digest. We extract more nutrients from cooked food–not fewer, despite what the raw foodies claim. Chimpanzees, our closest relative, spend up to 50% of their waking hours eating, because they subsist entirely on raw food. A 2011 study by Chris Organ and colleagues at Harvard University pointed out that

"The ancestors of modern humans who invented food processing (including cooking) gained critical advantages in survival and fitness through increased caloric intake."

Cooking our food has another huge advantage as well: it kills harmful bacteria and viruses. The current Salmonella outbreak could easily have been avoided if people had simply cooked their food instead of consuming raw shakes.

Raw foodies, though, seem to live in Opposite Land, where food science gets turned on its head. The website RawFoodLife.com claims that

"Science now proves that cooking not only destroys nutrition and enzymes but chemically changes foods from the substances needed for health into acid-forming toxins, free-radicals and poisons that destroy our health!"

Er, no. Science proves nothing of the sort (nor does that website provide any citations to scientific articles to back up its claim). As Christopher Wanjek explained ten years ago at LiveScience,

"plant enzymes, which raw dieters wish to preserve, are largely mashed up with other proteins and rendered useless by acids in the stomach. Not cooking them doesn't save them from this fate. Anyway, the plant enzymes were for the plants ... they are not needed for human digestion. Human digestive enzymes are used for human digestion."

Raw foodies also love raw milk, another dangerous trend, which has sickened thousands of people in the U.S. over the past decade. That topic deserves another column all to itself, but for now, suffice it to say that one of the greatest scientists of the 19th century, Louis Pasteur, discovered that heating milk briefly can kill a host of dangerous pathogens. Pasteurization, which is named for him, has been rightly credited with saving millions of lives. A few years ago, the Royal Society named pasteurized milk the 2nd greatest invention in the history of food (after refrigeration).

Obviously some foods, fruits in particular, are generally eaten raw, and fruits are indeed very healthy. But don't be fooled into thinking that cooking somehow makes food bad for you: it doesn't. Cooked food is easier to digest, more nutritious, and to most of us, pretty darned tasty.

The perfect hamburger, spoiled

20 years ago, we cooked hamburgers the way we liked them.  If you wanted your burger medium rare, well, good for you.  A thick, juicy burger, seared on the outside and just a bit pink on the inside, was the centerpiece of any good summer cookout. That was a more innocent time.

In 1993, a deadly outbreak of E. coli infections hit the northwestern U.S., sickening hundreds of people and killing four children.  The outbreak was traced to undercooked ground beef from a hamburger chain called Jack in the Box.

Fortunately, we live in a highly educated, advanced society, where the citizenry understands that its health depends on having bacteria-free food.  The unsanitary conditions that allowed E. coli to enter the food supply, including assembly-line slaughterhouse practices, were quickly halted.  New government regulations assured that any factory that shipped contaminated beef would be shut down.  Inexpensive, accurate DNA testing now detects almost all bacteria at a neglible cost.  Food-borne outbreaks of bacterial infections have been rare ever since.

Ha ha ha ha ha!  Just kidding!  Of course we can't have government regulators getting in the way of efficient food manufacturing!  Consumers ought to know that it's their fault if they get sick.  We must cook our burgers until they're as sterile as a Martian landscape.  That's simply the trade-off we must make to have such cheap food these days.

It's not that we don't check for any bacteria at all.  In fact, the U.S. Department of Agriculture recently announced that it would begin testing beef for six different deadly strains of E. coli.  Until now, it has only tested for the O157:H7 strain, which was behind the 1993 outbreak.  I guess this is progress.  However, the USDA will not be testing for salmonella bacteria or for any other nasty microbes.

The beef industry is opposed to any efforts by the government to test its products for bacteria.  For many years now, it has been remarkably successful, through lobbying efforts in Congress and through lawsuits, at rendering the USDA powerless.  As one example: twelve years ago the USDA tried to shut down a beef plant in Texas that failed its salmonella tests.  The beef industry challenged the USDA in court and won, and the USDA still doesn't have the power to shut down a plant for salmonella contamination.

We have the technology to detect all the bacteria that keep turning up in beef and chicken.  DNA testing technology has gotten much faster, cheaper, and more accurate in the 20 years since the Jack-in-the-Box outbreak, but we still don't use it on our food.  The meat industry won't say why it opposes DNA tests for contamination, but no one knows how consumers might react if they knew how much bacteria was really in their meat.

The USDA does test for E. coli O157:H7.  In the first half of this year, it tested 6,427 beef samples.  Out of those, 470 (7%) tested positive, which is pretty startling, considering that this is just one strain out of six known to be deadly to humans, and considering that we've known about this one since 1993.

(Chicken, by the way, has similar problems, with most raw chicken (organic or not) being contaminated by salmonella or campylobacter bacteria.  It helps that no one likes chicken cooked rare.)

Where does all this bacteria comes from, anyway? You may already know the answer: poo.  Beef and chicken production facilities aren't very good at keeping the (ahem) waste material separated from the meat.  Changing the way our beef is produced would cost more, undoubtedly. But is it unreasonable to ask a food producer to deliver safe food?

Luckily, if you cook meat long enough, it can't hurt you.  It might not taste as good, but hey, we all make compromises.  So broil those burgers through and through, and if they're a bit dry, well, that's what ketchup is for.