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Epigenetics: It doesn’t mean what quacks think it means

Epigenetics. You keep using that word. I do not think it means what you think it means.

I realize I overuse that little joke, but I can’t help but think that virtually every time I see advocates of so-called “complementary and alternative medicine” (CAM) or, as it’s known more commonly now, “integrative medicine” discussing epigenetics. All you have to do to view mass quantities of misinterpretation of the science of epigenetics is to type the word into the “search” box of a website like Mercola.com or NaturalNews.com, and you’ll be treated to large numbers of articles touting the latest discoveries in epigenetics and using them as “evidence” of “mind over matter” and that you can “reprogram your genes.” It all sounds very “science-y” and impressive, but is it true?

Would that it were that easy!

You might recall that last year I discussed a particularly silly article by Joe Mercola entitled How your thoughts can cause or cure cancer, in which Mercola proclaims that “your mind can create or cure disease.” If you’ve been following the hot fashions and trends in quackery, you’ll know that quacks are very good at leaping on the latest bandwagons of science and twisting them to their own ends. The worst part of this whole process is that sometimes there’s a grain of truth at the heart of what they say, but it’s so completely dressed up in exaggerations and pseudoscience that it’s really, really hard for anyone without a solid grounding in the relevant science to recognize it. Such is the case with how purveyors of “alternative health” like Joe Mercola and Mike Adams have latched on to the concept of epigenetics.
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Posted in: Basic Science, Cancer, Evolution, Neuroscience/Mental Health

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Worms, Germs, and Dirt: What Can They Teach Us About Allergies and Autoimmune Diseases?

Whipworms in the intestine

Whipworms in the intestine. Click to enlarge.

Humans evolved in an environment where they were exposed to animals, dirt, and a variety of pathogens and parasites. Our immune systems evolved to cope with that environment. Now most of us live in a different environment, with safe drinking water, flush toilets, food inspection, immunizations, and public sanitation. This means that we are far less likely than our ancestors to die of infectious diseases or to harbor intestinal worms. But it seems that the cleaner we get, the more likely we are to suffer from allergies and autoimmune diseases. One hypothesis is that our immune systems evolved to require early challenges by parasites and pathogens in order to develop properly. A hygienic environment fails to give our immune system the exercise it needs, resulting in imbalances and malfunctions.

The hygiene hypothesis was first proposed to explain observations like these:

  • Hay fever and allergies were less common in large families where children were presumably exposed to more infections through their siblings.
  • Polio attack rates were higher in high socioeconomic groups than in lower ones.
  • Allergies and many other diseases were less common in the developing world.

Investigation of these and other phenomena is contributing to a better understanding of the immune system, which is a good thing. At the same time, it has led some people to deliberately infect themselves with intestinal worms in an attempt to cure their allergies and autoimmune diseases, which may not be such a good thing. These treatments are far from ready for prime time, are risky, and they have a high yuck factor. The very idea of deliberately infecting yourself with worms is unpalatable, and finding wiggly live creatures in your stool or passing a 20 foot tapeworm are not generally considered to be pleasant experiences.  (more…)

Posted in: Book & movie reviews, Epidemiology, Evolution

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780.6

You can tell what a doctor does for a living by the ICD-9 codes they have memorized. There is an ICD-9 code for nearly every medical condition. Weightlessness is 994.9. Must be there for NASA, I have yet to see a weightless patient. Decapitation by guillotine is E978. There, I suppose, in case Marat returns from the dead. There is an ICD-9 code for the initial visit after being sucked into jet engine (V9733XA) and one for subsequent visits (V9733XD). Why do I suspect V9733XD has yet to be used?

780.6 is my personal favorite. Fever. All my patients have fever and 780.6 was certainly the first ICD-9 code I committed to memory. I have an endless interest in fever and after last Fridays post I thought I would toss in my two cents worth. I will remind my readers that I am an adult ID doctor (who I treat, not necessarily how I behave) and unless specifically mentioned, all that follows applies to those who can legally drink, vote and serve in the military.

98.6 F. It is not normal body temperature. Well it is. But it is not. 98.6 F as average body temperature is an enduring medical myth. (more…)

Posted in: Basic Science, Evolution, History, Science and Medicine

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CAM and Creationism: Separated at Birth?

Over the past weekend, I had the opportunity to attend CSICon in Nashville, Tennessee. The Committee for Skeptical Inquiry (“CSI”) combats all sorts of pseudoscience, including creationism/creation science/intelligent design and alternative/complementary/integrative medicine. Our own Team SBM was ably represented by Harriet Hall, David Gorski and Kimball Atwood, whose presentation highlighted the credulous acceptance of CAM in some medical schools, and by Steve Novella, who gave a talk on the placebo effect and its exploitation by CAM proponents. Among many other presentations were those on the Mayan calendar and the end of the world, unmasking of (supposedly) paranormal events, and the neurobiology of memory. Pseudoscience was given a well-deserved thrashing by rational minds.

On Saturday, I once again had the pleasure of hearing Eugenie Scott ,Ph.D., the virtually one-woman anti-creationism campaign who founded and heads the National Center for Science Education (NCSE). As I listened to her talk I couldn’t help but being struck by a number of similarities in the weaknesses apparent in arguments for creationism/ creation science/intelligent design (or “ID”)and those for alternative/complementary/integrative medicine (or “CAM”). I doubt the two groups like to think of themselves as ideological twins, but gosh, they sure do look alike.

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Posted in: Evolution, History, Religion, Science and Medicine

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Thumbthing Worth Reading

I intended to read Sam Kean’s new book The Violinist’s Thumb: And Other Lost Tales of Love, War, and Genius as Written by our Genetic Code  just for fun. I was expecting a miscellany of trivia loosely gathered around the theme of DNA. But I found something much more worthwhile that I thought merited a book review to bring it to the attention of our readers. Kean interweaves entertaining stories into a somewhat disjointed but nonetheless valuable history and primer of genetics. The title refers to Paganini, whose DNA created the unusual joint flexibility that facilitated his unprecedented feats of virtuosity on the violin.

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Posted in: Basic Science, Book & movie reviews, Evolution, History

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Learning from Animals: Evolutionary Medicine with a Twist

In 2005, cardiologist Barbara Natterson-Horowitz was called to the zoo to examine a non-human patient, an emperor tamarin with heart failure.  She was surprised when the veterinarian told her not to look her patient in the eyes because eye contact could cause capture myopathy. In this condition, when an animal is captured, restrained, and feels threatened, there is a catastrophic surge of adrenaline that damages muscle tissues and can kill. It was described decades ago, but medical doctors don’t read the veterinary literature. It wasn’t until the early 2000s that American doctors began to recognize a similar phenomenon in human patients, takotsubo or stress-induced cardiomyopathy.

She began to wonder whether animals got other human diseases. She quickly learned that they did. Jaguars get breast cancer and may carry the same BRCA1 gene that plagues Ashkenazi Jewish women, rhinos get leukemia, penguins get melanoma, gorillas die from ruptured aortas, and koalas are in the midst of an epidemic of sexually transmitted chlamydia.  Wild dragonflies infected with parasites become obese and develop a form of metabolic syndrome. Pretty much every human disorder occurs in animals too.

With the help of writer Kathryn Bowers, she distilled her findings into a book: Zoobiquity: What Animals Can Teach Us About Health and the Science of Healing.  It’s a good read: informative, well argued, spiced with intriguing trivia, and more entertaining than a trip to the zoo. (more…)

Posted in: Book & movie reviews, Evolution, Veterinary medicine

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Do We Need “Evolutionary Medicine”?

3 years ago I wrote an article critical of “evolutionary medicine” as it was presented in a new book.   Recently a correspondent asked me if I thought another book, Why We Get Sick: The New Science of Darwinian Medicine, by Randolph M. Nesse, MD and George C. Williams, PhD, was a more reasonable approach to the subject. It was published in 1994 and got good reviews from respected scientists like Richard Dawkins (“Buy two copies and give one to your doctor.”) and E.O. Wilson (“bringing the evolutionary vision systematically into one of the last unconquered provinces…”).  I was able to obtain a copy through interlibrary loan.

The book was interesting and gave me some things to think about, but it didn’t convince me that “Darwinian medicine” is a new science, that its existence as a separate discipline is justified, or that its unique approach offers any real practical benefits for improving medical care.

Why do we get sick? A simplistic view of evolution holds that it systematically eliminates any factors that decrease fitness for survival. So why does disease persist? Why didn’t we evolve to be “fit” enough to never get sick? Because evolution is not a straightforward process.

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Posted in: Book & movie reviews, Evolution

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Why haven’t we cured cancer yet? (Revisited): Personalized medicine versus evolution

About a year ago, I addressed what might seem to the average reader to be a very simple question: Why haven’t we cured cancer yet? As I pointed out at the time, it’s a question that I sometimes even ask myself, particularly given that cancer has touched my life. Three years ago, my mother-in-law died of a particularly nasty form of breast cancer. Even though I am a breast cancer surgeon, I still wonder why there was nothing that could save her (and there still is nothing that could have saved her, if it existed then) from a decline over several months followed by an unpleasant death. Yet, as a cancer researcher, I do understand somewhat. A couple of years ago, I wrote in depth about the complexity of cancer from a science-based viewpoint, as compared, of course, to the incredibly simplistic view that many purveyors of alternative medicine quackery promote as being The One True Cause of Cancer. As I put it at the time, shamelessly stealing from Douglas Adams: Cancer is complicated. You just won’t believe how vastly, hugely, mind-bogglingly complicated it is. I mean, you may think algebra is complicated, but that’s just peanuts to cancer.

I saw more evidence of that at the American Association for Cancer Research meeting last week. In fact, if there’s anything I’ve learned, it’s that developing personalized therapy for cancer is going to be a hell of a lot more difficult than we had ever suspected. Actually, it wasn’t just the AACR meeting that taught me this, but it’s as good a pretext as any to discuss some cool new science. I only wish it was science that pointed an obvious path forward to the development of personalized therapy. On the other hand, if it were easy then anyone could do the “personalized therapy for dummies” approach that, for example, Stanislaw Burzynski takes. Then there’s the even more ridiculously simplistic approach that certain practitioners of “complementary and alternative medicine” (CAM) take.

So why haven’t we cured cancer yet? Again? One reason that I discussed last time I covered this topic concerns a study that used the latest next generation sequencing (NGS) techniques to sequence seven aggressive and advanced prostate cancers. I described the results as these genomes looking like someone threw a miniature grenade into the nucleus of a prostate epithelial cell. In other words, these are some really messed up genomes. (I wanted to use another word to describe it, but this is a family blog—sort of, anyway.) I used this example to explain once again that cancer is not a single disease. It’s hundreds of diseases. Although there are common themes in how cells become cancerous, such as loss of responsiveness to growth signals with a resultant ability to grow unchecked, evasion of programmed cell death (apoptosis), inducing the surrounding tissue to provide a blood supply (angiogenesis), evading the immune system, and invading the blood or lymphatic systems to travel elsewhere in the body and take up shop in other organs, such as liver, lung, or bone, individual cancers acquire these necessary (to the cancer) abilities through many different mechanisms. For this reason, it’s completely ridiculous to speak of a “cure for cancer.”

It’s also the reason I expressed skepticism when Steve Novella discussed a potential universal anti-cancer drug. Ditto when the press breathlessly reports studies suggesting a “universal cancer vaccine.” While these sorts of research findings are promising, they need to be put into perspective. We’ve seen their like many times before, and various cancers are still deadly diseases. In fact, my career intersected with this sort of hype back in the 1990s, when I studied combining angiogenesis inhibitors with radiation therapy in experimental models of cancer in mice. For a period of time in the late 1990s, I lived the hype. Then reality, as it always does, brought us all down to earth. Now, 15 years later, we know that angiogenesis inhibitors, although useful, are not any sort of “magic bullet” cure for all solid tumors. Like many advances before, they have now taken their place in the armamentarium of anticancer drugs, more important than some but not as important as others.

It’s even more complicated than that.

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Posted in: Basic Science, Cancer, Evolution

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“Motivated reasoning,” alternative medicine, and the anti-vaccine movement

One theme that we at Science-Based Medicine keep revisiting again and again is not so much a question of the science behind medical therapies (although we do discuss that issue arguably more than any other) but rather a question of why. Why is it that so many people cling so tenaciously to pseudoscience, quackery, and, frequently, conspiracy theories used by believers to justify why various pseudoscience and quackery are rejected by mainstream science and medicine? Certainly, I’ve touched on this issue before on several occasions, for example, with respect to the anti-vaccine movement, the claim that abortion causes breast cancer, and how we as humans crave certainty.

It turns out that science and science-based medicine are hard for humans to accept because they often conflict with what our senses perceive and brains interpret as irrefutable evidence. The pattern-seeking function of our brain, when evaluating questions of causation in medicine, frequently betrays us. For instance, when a parent sees her child regress into autism sometime not long after being vaccinated, the easiest, most instinctive, and most emotionally compelling conclusion is that the vaccine must have had something to do with it. When scientists tell her that, no, in large studies looking at hundreds of thousands of children, there is no good evidence that vaccination confers an increased risk of autism and a lot of evidence that it does not, it’s a very hard message to believe, because it goes against how the parent interprets what she’s seen with her own eyes. Indeed, how often have we seen believers in the vaccine-autism link pour derision on the concept that when something like autistic regression happens in close temporal proximity to vaccination that the correlation does not necessarily equal causation? Similarly, believers in “alternative medicine” who experience improvement in their symptoms also pour derision on the observation, explained so well by R. Barker Bausell in Snake Oil Science, that people frequently take remedies when their symptoms are at their worst, leading them to attribute natural regression to the mean to whatever nostrum they started taking at the time.

These issues have come to the fore again, thanks to an article by an acquaintance of mine, Chris Mooney, author of The Republican War on Science, Storm World: Hurricanes, Politics, and the Battle Over Global Warming, and Unscientific America: How Scientific Illiteracy Threatens our Future (co-authored with Sheril Kirshenbaum). The article appeared in a recent issue of Mother Jones and was entitled, rather ironically, The Science of Why We Don’t Believe Science. Chris made his name as an author primarily in writing about the science of anthropogenic global warming and the political battles over policies intended to mitigate it and, to a lesser extent, over creationism and evolution denial. Of late he has written about the anti-vaccine movement as an anti-science movement, leading predictably to his being attacked by the likes of J.B. Handley as viciously as I and others have. Also of note, although he was widely praised for The Republican War on Science and Storm World, Mooney has been widely criticized in some circles for being too critical of “new atheists” and for lack of substance. In his current article, he discusses some of the science thus far about why people can cling to beliefs that science doesn’t just cast doubt upon but shows convincingly are totally wrong.
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Posted in: Evolution, Neuroscience/Mental Health, Pharmaceuticals, Politics and Regulation, Science and the Media, Vaccines

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Evolution in Medicine

A recent series of article in the Proceedings of the National Academy of Sciences (PNAS) discusses the role of evolutionary biology in modern medicine. The authors collectively make a forceful point – medicine is an applied science. It is based upon a number of basic sciences, and one of those basic sciences is evolution.

The most obvious example is bacterial antibiotic resistance. Antibiotics place a selective pressure on a bacterial population, often resulting in the emergence of resistant strains. Understanding this “evolutionary arms race” between bacteria and antibiotics allows us to develop strategies for minimizing resistance.

But there are less obvious ways in which evolutionary principles apply to infectious diseases. It has been known for a long time that sickle-cell trait provides resistance to malaria (the blood cells are less hospitable to the P. falciparum protozoan parasite that is one cause of malaria). This explains the persistence of sickle cell disease in populations where malaria is endemic.

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Posted in: Evolution, Science and Medicine

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