Field of Science

Allergy sufferers beware! These eyedrops are a scam.

Spring allergy season is upon us, and plants are bursting into leaf and bloom, spreading pollen everywhere. For some of us, this otherwise beautiful season is a time to stock up on antihistamines and tissues, and we try our best to stay indoors.

When pollen causes red, itchy eyes, we look for eyedrops to provide some relief. The American Academy of Allergy, Asthma, and Immunology and has a list of eyedrops here that includes products such as Zaditor®, Alaway®, and others. These eyedrops contain real medicine that can soothe itchy eyes and reduce your allergy symptoms.

So I was in the pharmacy section of my local grocery store, Giant, looking for eye relief, but they were sold out of Zaditor. Right next to the empty slot, though, I saw a row of other eyedrops from a company called Similisan®, and I took the picture shown here.
Homeopathic eye drops at Giant Foods in Baltimore.
Looks legitimate, right? Each box has a cross on it (apparently intended to resemble the logo of the Red Cross), and they are in the pharmacy section. I picked up the box labeled "Allergy Eye Relief" to take a closer look, though, and saw the word "homeopathic" near the bottom of the box.

Uh oh. It turns out that these products are little more than very, very expensive bottles of sterile water. For $9.99 you get 10 ml of water that contains several extracts–in vanishingly small amounts–for which there is no evidence whatsoever that they have any effect on allergies. Similisan's allergy relief bottle contains:

  • Honeybee
  • Eyebright (a plant)
  • Sabadilla lily (another plant)

Yes, that's right: they grind up honeybees and put them in the eyedrops. The (wacky) idea is that because bee stings cause allergic reactions, a tiny bit of ground-up bee in solution will prevent those reactions. This flawed principle is the basis for all of homeopathy, which has stuck around for 200 years despite the complete absence of evidence that it works.

As I've written before, homeopathic drugs get a free pass on regulation, thanks to Congress. Homeopaths will tell you that their drugs are regulated by the FDA (they often make this claim in the comments on my articles - just watch), but they're not. All the FDA can do is check to see if the products contain the ingredients listed on the label. Unlike real drugs, though, the FDA does not and cannot require that these "drugs" have any effect whatsoever.

I don't think I need to say more about ground-up bees, but what about those other two ingredients? Eyebright is a plant that has "little or no evidence of efficacy" for eye infections. Its use dates back to the ancient Greeks, and has an interesting history:
"Eyebright was used as early as Theophrastus and Dioscorides, who prescribed infusions for topical application in the treatment of eye infections. This in large part was due to the similarity of the “bloodshot” petals to irritated eyes."
That's right: the flower petals look like irritated eyes, and this was enough to get the early Greeks to try them out as a treatment. Needless to say, the physical appearance of a plant has nothing to do with its efficacy as a medicine. (But try telling that to a homeopath.)

Sabadilla, the third ingredient, is a plant extract used as an insecticide, with an active ingredient called veratrine. As Laura Pottorff from Colorado State University explains, "its dust can be highly irritating to the eyes." Therein lies the homeopath's motivation for using sabadilla in eyedrops: homeopaths believe that a substance that irritates the eyes will somehow soothe the eyes if it is sufficiently diluted.

Similisan claims that their 3 homeopathic eyedrops will relieve itching, burning, watering, and redness in your eyes. The box just says it's "manufactured according to homeopathic principles," but doesn't explain that it hasn't been shown to be effective. You have to go to their website to discover that
"The uses of our products are in compliance with official Homeopathic Compendia. They were not the subject of approved applications reviewed by the Food and Drug Administration prior to marketing." 
In other words, they've never presented any evidence that these things actually work.

One can only hope that the sabadilla in Similisan's eye drops is sufficiently diluted; if not, you're putting insecticide in your eyes. The package says that all three ingredients are at 6X dilution, which in homeopathic jargon means 1 part in 1 million. The problem is that homeopathic substances have no real standards, so we don't know how much of the active ingredients were in the original mixture before dilution.

I was curious to see if Whole Foods Market sold the same stuff, and not surprisingly they do, in their special section devoted to homeopathy. (I've written about WFM and their love affair with homeopathy before.) The only difference is that Similisan costs more at Whole Foods, $11.99 to $14.99 depending on which flavor you buy (check out the photo below).

Homeopathic eye drops at Whole Foods Market. How much
money do you want to waste on a tiny water bottle?
Homeopathic eye drops are nothing more than really, really expensive water. At $10 for 10 ml, that works out to $1000 per liter. Similisan proudly states that it's sold at a wide variety of U.S. retailers and pharmacies, including CVS, Kroger, Publix, RiteAid, Safeway, Target, Walgreens, Walmart, and Wegmans. Seems like they're doing quite a good business selling their $1000/liter water.

Consumers beware: the eyedrops you're looking at, even in the Pharmacy section of the store, might be expensive, ineffective make-believe medicine. Make sure to read the package closely; the fake medicine is sometimes right next to the real stuff, and the packaging is designed to fool you.

Washington Post's Science section descends into pseudoscience

The Washington Post has some bad news about migraines.
Every Tuesday, the Washington Post has a special section devoted to Health and Science. It’s usually my favorite section, with features such as “medical mysteries” and highlights of the latest news from the world of science.

Not this week. Instead, the front page of the section featured a lengthy article that was a long anecdote by a woman who firmly believes that acupuncture cured her migraines. The title gave me a feeling of dread: “Acupuncture needles stung, but they cured my migraines” (the online version linked here has a different title). As I feared, there wasn't a whit of science in it.

Let’s get one thing out of the way first: acupuncture is rank pseudoscience. It’s based on a primitive, pre-scientific notion of a “vital force” (for which no evidence exists), usually called qi, that runs through the body along meridians (no evidence for these either). Plunging needles into the meridians is supposed to manipulate this vital force and cure all sorts of things, ranging from pain to infections to cancer. All of this is nonsense. If you want to know more, I recommend Acupuncture Watch; or see Ben Kavoussi’s article explaining how postmodernism, with its notion that all truth is relative, has allowed acupuncture and other mystical, archaic beliefs to gain traction in medical practice; or check out Jann Bellamy’s discussion of acupuncture as “legalized quackery”.

I’ve written about the nonsense that is called acupuncture before (in 2013, and in 2012, and in 2010), so I won’t rehash that here. But it’s really disheartening to see a great (or once-great?) newspaper devote a large chunk of its weekly science section to pseudoscience.

Back to this week’s nonsense article. In this lengthy piece, author Margarita Gokun Silver describes how she began to experience debilitating migraines after the age of 40, which grew worse over time. She tried pain relievers, which worked at first but then stopped working. One expensive pill worked for the migrations but gave her severe nausea. Eventually, she writes, “exhausted by these side effects, I turned again to the Internet.”

Great. Now, there’s nothing wrong with looking for solutions in the Internet–we all do it. But this is an article in the Washington Post Science section! Nowhere does the author describe anything resembling actual science. Instead, she describes how she discovered a “breakthrough” in her yoga class, when another yoga student suggested acupuncture. She decided to give it a try.

(You might be wondering, who is Margarita Gokun Silver? She describes herself as a writer, novelist, and painter–not a scientist or a doctor.)

After several acupuncture sessions, the author tells us, her migraines seemed less frequent, and eventually she decided she was cured. She still gets migraines, but when they get bad she uses acupuncture again. This, she tells us, is her cure.

The entire story is a classic example of how we can fool ourselves into thinking that whatever we tried last is what worked. Migraines come and go, and this woman’s story is not unusual. She had a long series of bad migraines that eventually subsided, and she still gets them. When they were at their worst, she tried everything she could find, and when the episodes became less frequent, she gave full credit to acupuncture. She might just as well have tried chocolate milk, and then written an article claiming “chocolate milk cured my migraines!”

I don’t blame the author (well, not much) for wrongly believing that correlation equals causation. But we have scientific methods that are really, really good at figuring out if a treatment works. Scientists have already looked at this particularly claim, and the bottom line is that acupuncture doesn’t cure migraines. If you don’t believe me, then read the article about treating migraines by Dr. Steven Novella, a Yale neurologist who specializes in headaches, and look at his summary of how not to treat migraines, which points out that
“acupuncture proponents have been able to change the rules of clinical research so that essentially negative or worthless studies of acupuncture are presented as positive.”
Last week's Washington Post Science section was a major fail. I can't imagine why they gave a lengthy forum to a non-scientist to write about pseudoscience. If they wanted to feature a story about migraines, there's plenty of good science out there, even if there's no magical cure. What's next, Washington Post? Will you invite Jenny McCarthy to write about vaccines and autism, or Gwyneth Paltrow to discuss detox treatments? I sure hope not.

Why are we growing corn to fuel our cars? Three reasons why ethanol is a bad idea.

Most of us are driving around right now in cars powered by a combination of gasoline and ethanol. Ethanol is a fuel alternative produced from corn (mostly), and it has been touted for years as cleaner, carbon-neutral alternative to gas.

The problem is that ethanol’s benefits have been greatly exaggerated, leading to Congressional regulations that required ever-increasing amounts of ethanol in our gasoline supply. The government requirement goes back to 2005, when gas prices were much higher and the U.S. was in the midst of the Iraq war. Ethanol was supposed to be a clean way to reduce our dependence on foreign oil. The growing mandate for ethanol has instead created an enormous, artificial demand that has had unintended consequences, many of them bad.

Some background: Congress requires automakers to meet fuel economy (“CAFE”) standards for all their cars and light trucks. To encourage ever-greater use of ethanol, Congress modified the CAFE standards in 2005. As a result of that law, this year the EPA will require refiners to use 18.1 billion gallons of ethanol to fuel our cars.

Politicians still love ethanol. In the 2016 presidential campaign, several candidates came out in support of continuing the corn-based fuel program, hoping this position would win them votes in the Iowa caucuses. Iowa is a big corn state.

Unfortunately for the rest of us, mandating the use of ethanol is a terrible policy. Here are three reasons why.

1. Ethanol lowers your gas mileage–a lot. Ethanol only has about 2/3 the energy content of gasoline, meaning it simply cannot provide the same amount of power per gallon (or liter) as gas. E85 fuel, which uses 85% ethanol and 15% gasoline, is widely available, and some gas stations now offer no alternative. Consumer Reports put E85 to the test, and found that highway mileage decreased by 29% and city mileage by 22%. Car and Driver ran their own tests and found a 30% drop in mileage on E85. According to the Union of Concerned Scientists, nearly all gas sold in the US today has 10% ethanol–much less than in E85, but still providing lower fuel efficiency than straight gasoline.

Making things worse, ethanol attracts water and is more corrosive to some metals and rubber than gasoline. So it's bad for your car.

2. Using ethanol doesn’t reduce carbon emissions. The main argument for using ethanol is that because the carbon contained within it was recently put in the ground, burning ethanol (and releasing that carbon) is carbon neutral. Compared to extracting oil, which has lain in the ground for millions of years, growing corn and extracting ethanol puts far less carbon back in the atmosphere.

This argument makes sense, but only in a very narrow context. In an article published in Science in 2008, Timothy Searchinger and colleagues pointed out that previous analyses
“failed to count the carbon emissions that occur as farmers worldwide respond to higher prices and convert forest and grassland to new cropland to replace the grain (or cropland) diverted to biofuels.” 
When the scientists accounted for these land-use changes, they found that using corn to produce ethanol will double greenhouse emissions over a 30-year period. Switchgrass is only slightly better, increasing emissions by 50%. As the Union of Concern Scientists explains that “sustainable production is possible” only if we stop making ethanol from corn.

Admittedly this is a complex topic, but it seems that ethanol-from-corn simply doesn't reduce carbon emissions. Thus the entire justification for using ethanol to fuel our cars is unsound.

3. Increasing fuel efficiency means we’ll never be able to meet Congress’s mandated levels of ethanol usage, not unless we sacrifice even more gas mileage. Automakers have made great progress in producing more fuel-efficient cars, and the growing electric car market (Tesla!) mean that we’re using less and less fuel each year. This is terrific for reducing carbon emissions, but it means that Congress’s original mandate to use more ethanol becomes far harder to satisfy.

What happened was that back in 2005, Congress told us how to solve a problem (carbon emissions from our cars), instead of just encouraging us to solve it using innovative new ideas. Corn producers and their government representatives—governors, Senators, Representatives—all got behind the ethanol “solution” because they saw increased profits in it. Now we are stuck with a non-solution that, as the NY Times recently put it, is “a boon for Iowa and a boondoggle to the rest of the country.” It’s long past time to end the ethanol mandate.

Long term antibiotic use for Lyme disease doesn't work, according to new study

Fifteen years. That's how long scientists have been trying to prove a negative: that "chronic Lyme disease" does not exist, and that long-term antibiotic usage does not help with symptoms that include joint pain and fatigue. This past week, a study in the New England Journal of Medicine showed that long-term antibiotic usage–the favorite treatment prescribed by doctors who call themselves "Lyme literate"–is a failure. Will it convince any of those doctors to change their practice? I doubt it.

Lyme disease is a serious illness, caused by bacteria that are transmitted through tick bites. Although the disease has been infecting humans for centuries, it got its name relatively recently, in 1975, when two Yale doctors, Stephen Malawista and Allen Steere, investigated a cluster of illnesses near the town of Lyme, Connecticut. The symptoms included joint pain that resembles arthritis, so much so that Malawista initially called it "Lyme arthritis." A few years later, biologist Willy Burgdorfer discovered the true cause, and the bacterium Borrelia burgdorferi was named after him. As deer have spread through the suburbs of modern society, ticks traveling with them have spread Lyme disease far and wide; the NIH reported over 36,000 cases in the U.S. in 2013. (Note that the CDC estimates the true number of cases may be closer to 300,000, ten times the number actually reported to health authorities.) Lyme is also common in Europe.

Luckily for most of us, a brief course of antibiotics usually cures people completely of Lyme disease. For some people, though, symptoms including fatigue and joint pain can linger for up to six months. The cause of these longer-term symptoms remains a mystery, and is an active area of current research. One possible explanation from the CDC is that
"the lingering symptoms are the result of residual damage to tissues and the immune system that occurred during the infection."
Unfortunately, the lack of a scientific explanation has opened the door to wildly speculative treatments, based on little or no evidence, by doctors who think they know the answer. These doctors, some of whom have adopted the label "Lyme literate," insist that their patients suffer from what they call Chronic Lyme Disease. Among other things, they've formed an association called ILADS that claims that:
"Most cases of chronic Lyme disease require an extended course of antibiotic therapy to achieve symptomatic relief" and "many patients with chronic Lyme disease require prolonged treatment until the patient is symptom-free."
Not only do these treatments cost far more than the 2-week course of treatment recommended by the Infectious Disease Society of America, but they also have the potential to cause harm: it's just not good for you to be on antibiotics for months or years. Indeed, one of the first studies (in 2001, by Mark Klempner and colleagues) to look at the efficacy of long-term antibiotic use explained its motivation as follows:
"Case reports and uncontrolled trials describe success with prolonged antibiotic therapy, often with a recurrence of the symptoms after the discontinuation of therapy. In view of the substantial morbidity and even death associated with prolonged parenteral antibiotic treatment of Lyme disease, it is important to determine the efficacy of such therapy."
"Substantial morbitity and even death": clearly, long-term antibiotic treatment is not something to be prescribed lightly. The 2001 study found no benefit from long-term versus short-term antibiotic usage for the treatment of Lyme disease.

Despite the science, some doctors persist in prescribing–against the advice of professional societies–long-term courses of antibiotics. Because the practice continues, a European group conducted a new study of long-term antibiotic use in patients who claim to have persistent symptoms from Lyme disease. Anneleen Berende and colleagues reported the results of this well-designed double-blind, placebo-controlled study in the New England Journal of Medicine just last week. Their findings matched those of the 2001 study: long term antibiotic use has no benefits for patients.

The study had three arms: a placebo group and two different treatment groups, who were given two different antibiotics. Everyone got a two-week treatment with real antibiotics, followed by 12 more weeks of either antibiotics or placebo. The pills were created just for this study to look identical, so that neither the doctors nor the patients knew who was getting the placebo.

In an editorial accompanying the article, my Hopkins colleagues Michael Melia and Paul Auwaerter explain that the take-home message is that
"Patients with subjective, vexing symptoms attributed to Lyme disease should not anticipate that even longer courses of antibiotics will produce relief, a finding that is in concert with results from previous trials."
I doubt that "Lyme literate" doctors will accept the latest results and stop prescribing long-term antibiotic use; their websites indicate that they already know that they are right. I hope, though, that patients will start to question doctors who put them on long-term, possibly harmful antibiotic regimens that don't provide any benefit.

(For more information, see this excellent video by Dr. Auwaerter about Lyme disease and its treatment.)

This could be the end of youth football

The end of a lawsuit this month might also signal the end of youth football. The plaintiff in the suit, Debra Pyke, claimed that her son suffered brain damage from repeated head injuries in his youth football league, which caused chronic traumatic encephelopathy, or CTE. Just a couple of weeks ago, the youth football league Pop Warner settled the $5 million case, reportedly for under $2 million.

Debra Pyke’s son, Joseph Chernach, committed suicide in 2012 at the age of 25. He had played youth football for four years, from the ages of 11 to 14, and her lawsuit claims that he suffered from CTE as a result. CTE has been in the news a great deal of late, after it was discovered by Dr. Bennet Omalu to be the cause of early dementia in an alarming number of NFL football players. (Actor Will Smith plays Omalu in the recently released movie, Concussion.)

Pyke’s lawsuit holds nothing back in its claims about the damage of football. She argues that tackle football is a "war game,” and provides copious examples to back it up, including these:
“Football is not a contact sport. It’s a *collision* sport. Dancing is a good example of a contact sport.” (from former Michigan State coach Duffy Daugherty)
“Pro football is like nuclear warfare. There are no winners, only survivors.” (from Frank Gifford, former NFL player and long-time football broadcaster)
The lawsuit includes multiple arguments about why children are more vulnerable to head injuries. Their brains are still developing, and have less myelin to protect their brain cells from damage. Until the age of 14, children's are disproportionately large, and their necks are weaker than adults’ necks, making them prone to greater rotational forces when hit in the head.

Just looking at pictures of young boys wearing football helmets makes many of these points obvious. The idea that young boys are intentionally crashing into one another, often involving their heads, should give any parent cause for concern. Slate writer John Culhane described this as a “bobblehead effect” in which “their brains crash back and forth in their skulls.”

When Pyke’s lawsuit was filed last year, Culhane called it “The Lawsuit That Could Threaten Kids’ Football.” Despite the title of his article, he concluded that
“even in the unlikely event that she [Pyke] wins her case, youth football isn’t going anywhere. But a finding that Pop Warner is carrying on an abnormally dangerous activity would surely drive up the cost of insurance, and therefore make the sport more expensive for participants. It might also make more parents question whether they want to risk their children’s safety.” 
The “unlikely event” didn’t happen, but only because the league settled the suit.

Pop Warner football has a dedicated safety section on its website. It includes pages devoted to their concussion policy, and articles that argue that “rewards outweigh risks” and that “the relationship between developing CTE and playing football remains unclear. The link between the number of concussions a person sustains and the risk of developing CTE is also uncertain.”

Using words such as “unclear” and “uncertain” seems to me to be a classic example of sow confusion rather than admitting the obvious: youth football can be dangerous. Consider the “pee wee” league game in 2012 where five boys got concussions in a single game. The coaches were suspended afterwards, but the damage had already been done. At the time, the NY Times pointed out that “Pop Warner has done more than perhaps any other organization to try to protect young players from head injuries,” but the fact is that football is a violent contact sport.

(Pop Warner did not respond to my request for comment.)

As the New York Post reported when the settlement was announced, Pop Warner had $2 million in liability coverage for players in Wisconsin at the time of the lawsuit, in 2012. They now carry $1 million per player and allow individual chapters to add another $1 million.

Think about that for a second. Why would you want your son to play in a youth sports league where the league feels the need to carry a $2 million insurance policy on every player?

Parents: you and your kids have other options besides football. Youth sports are a great way for kids to exercise, have fun, make new friends, and learn the value of teamwork. Your kids can choose soccer, tennis, baseball, or basketball, all of which have large networks of youth leagues. Many regions of the country have other sports as well. There’s no reason to suit up a child with a helmet on his still-growing head and send him out on a field to be knocked around and possibly concussed.

Joseph Chernach suffered a tragedy, and his family’s suffering will never go away. We’re now learning that even powerfully built grown men suffer permanent injuries on the football field. There’s no reason to expose children or teenagers to similar risks.

Bad news flash: scientists did not cure autism, cancer, or Alzheimer's

This week I'm calling out some recent headlines about medical "breakthroughs" that were wildly misleading. Even when the science itself is good, bad reporting raises false hopes and eventually undermines the public's confidence. At some point, people will just no longer believe the headlines claiming that someone has once again cured cancer.

My first example of bad news is from a couple of weeks ago. I was struck by a headline that showed up in one of my news feeds that read
"Neuroscientists reverse autism symptoms"
Wow, I thought. This would be a real breakthrough if it were true. I traced the headline back to the MIT press office, where I then saw the subheading: "turning on a gene later in life can restore typical behavior in mice." Uh oh: extrapolating any treatment from mice to humans is fraught with problems, and studying a complex behavioral disorder like autism is even more difficult.

The HuffPo fell for it, though. Their headline read "Some Autism Symptoms May Be Reversed By Gene Editing, Scientists Suggest". So did the Daily Mail, which went with this headline:
"Reversing autism 'at the flick of a switch': 'Turning on' a single gene in mice has been found to reduce autistic behaviours"
At least they mentioned mice in the headline. But then they wrote that “scientists have announced a major breakthrough in treating the genetic cause of the spectral condition." Sorry, but there's no new treatment available. (Never mind the poor writing that used "spectral condition" to describe autism spectrum disorder.)

What did the researchers actually do? They studied a gene (see the paper here) that is already known to be associated with autism in humans–though only about 1% of cases–and that has already been shown to affect the behavior of mice as well. They created a means of "fixing" this gene in mice, and showed that it can restore some of the mouse behaviors to normal. My assessment: this is nice incremental work on a gene that seems to affect behavior in both mice and humans. I don't see it leading to any advances in the treatment of human autism for at least a decade, if ever.

So where are we on reversing autism? Probably no closer than we were before this report appeared. I give the science a B, but the science news gets an F.

A second, more recent bit of "bad news" appeared just a few days ago, when CNN reported that
"Breakthrough in cancer research could spawn new treatments"
Sigh. I can't count the number of times I've read that cancer is about to be cured, only to learn that no new treatment exists, and nothing is even close. So what is this new breakthrough?

CNN reported that
"Researchers discovered that even though cancer cells mutate wildly within a person's body, the cancer cells within each patient also have common mutations–ones that could be isolated and fought off by certain immune cells."
This didn't sound like news to me. Genome scientists have sequenced the DNA of cancer cells in exquisite detail in recent years, and we already know that cancer cells share common mutations. The paper itself, which appeared in Science on March 3, revealed a far less dramatic story.

First of all, the new research applies only to lung cancer. It's a highly technical result that showed that certain immune cells in the body could–just maybe–fight off a particular type of lung cancer. There's no new treatment here, and there won't be for many years, if ever. The science here is pretty good, so I'm giving it an A-, but the reporting over-hyped its impact. Because they included the cautionary "could spawn new treatments", I'll give CNN a C.

The third bit of news is older, but it's still making the rounds on social media. The headline is a real attention grabber:
"New Alzheimer’s treatment fully restores memory function"
If this is true, we're talking Nobel Prize material. Alzheimer's is a devastating condition that affects a large percentage of elderly people, and there's no known treatment. But when I looked up the paper itself, from March 2015, I discovered that it's a study in mice, not humans. The scientists here used a mouse that's been genetically modified to have brain defects that resemble some signs of Alzheimer's. They showed that they could use ultrasound–actually this part is pretty cool and quite exciting–to reduce some of the brain defects in the mice.

Will this lead to any human treatments? Maybe, but there are numerous problems and caveats, as neuroscientist Matthew Zabel pointed out soon after the study appeared. And the effect, even in mice, was rather small: it's wildly inaccurate to claim that it "fully restores memory function." I give the science an A, but gets an F for that headline.

In all of these cases, the scientists involved are at least a little bit (if not a lot) complicit in the over-exuberant headlines. I understand their eagerness to call attention to their work, but by promising too much, they risk disappointing the public when no cures emerge one, two, five, or even ten years later. Journalists and scientists need to work harder to come up with headlines that excite people about the potential of science without making it seem that we've already cured humankind's most devastating diseases.

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 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.