A new study published in The American Journal of Clinical Nutrition is reporting an association with eating meat and weight gain. This is a fairly robust epidemiological study, but at the same time is a good example of how such information is poorly reported in the media, leading to public confusion.
The data is taken from the European Prospective Investigation into Cancer and Nutrition–Physical Activity, Nutrition, Alcohol, Cessation of Smoking, Eating Out of Home and Obesity (EPIC-PANACEA) project. This is a long term epidemiological study involving hundreds of thousands of individuals, and is therefore a great source of data. We are likely to see many publications from from it. This one looked at the association of meat eating – poultry, red meat, and processed meat – with total weight. From the methods:
A total of 103,455 men and 270,348 women aged 25–70 y were recruited between 1992 and 2000 in 10 European countries. Diet was assessed at baseline with the use of country-specific validated questionnaires. A dietary calibration study was conducted in a representative subsample of the cohort. Weight and height were measured at baseline and self-reported at follow-up in most centers. Associations between energy from meat (kcal/d) and annual weight change (g/y) were assessed with the use of linear mixed models, controlled for age, sex, total energy intake, physical activity, dietary patterns, and other potential confounders.
Homeopathy is having a bad year. From a scientific point of view, it has had a couple of bad centuries. The progress of our scientific understanding of biology, chemistry, and physics has failed to confirm any of the core beliefs of homeopathy. Like does not cure like (this is a form of superstition known as sympathetic magic, with no basis in science). Diluting substances does not make them stronger – a notion that violates the chemical law of mass action and the laws of thermodynamics. And countless clinical studies have shown that homeopathic preparations are nothing more than placebos. That homeopathy cannot work and does not work is settled science, as much as it is possible for science to be settled.
Despite the science, homeopathy has persevered through a combination of cultural inertia and political support. But in the last year there are signs that this trend may be reversing. In the UK The House of Commons Science and Technology Committee (STC) released a report, Evidence Check 2: Homeopathy, in which they conclude that homeopathy is failed science and should be completely abandoned – no further support in the NHS and no further research.
Following that the British Medical Association has openly called for an NHS ban on homeopathy, calling the practice “witchcraft.”
Now German politicians are starting to echo the same sentiments. (more…)
One of my goals in writing for this blog is to educate the general public about how to evaluate a scientific study, specifically medical studies. New studies are being reported in the press all the time, and the analysis provided by your average journalist leaves much to be desired. Generally, they fail to put the study into context, often get the bottom line incorrect, and then some headline writer puts a sensationalistic bow on top.
In addition to mediocre science journalism we also face dedicated ideological groups who go out of their way to spin, distort, and mutilate the scientific literature all in one direction. The anti-vaccine community is a shining example of this – they can dismiss any study whose conclusions they do not like, while promoting any horrible worthless study as long as it casts suspicion on vaccines.
Yesterday on Age of Autism (the propaganda blog for Generation Rescue) Mark Blaxill gave us another example of this, presenting a terrible pilot study as if we could draw any conclusions from it. The study is yet another publication apparently squeezed out of the same data set that Laura Hewitson has been milking for several years now – a study involving macaque infants and vaccinations. In this study Hewitson claims a significant difference in brain maturation between vaccinated and unvaccinated macaque infants, by MRI and PET analysis. Blaxill presents the study without noting any of its crippling limitations, and the commenters predictably gush.
Last week at TAM8 some SBM colleagues (David Gorski, Kimball Atwood, Harriet Hall, Rachel Dunlop) and I gave two workshops on how to find reliable health information on the web. As part of my research for this talk I came across a recent and interesting study that I would like to expand upon further – Quality and Content of Internet-Based Information for Ten Common Orthopaedic Sports Medicine Diagnoses.
The fact that the article focuses on orthopedic diagnoses is probably not relevant to the point of the article itself, which was to assess the accuracy of health information on the web. They looked at 10 orthopedic diagnoses and searched on them using Google and Yahoo, and then chose the top results. They ultimately evaluated 154 different sites with multiple reviewers for quality of content and also for their HON rating.
For background, the HON rating comes from an independent organization, the Heath on the Net Foundation, that rates health care sites on a number of criteria. These include assessment of how authoritative the sources are, the level of transparency, and if opinions expressed are justified with evidence and references. While generally reasonable, the HON assessment does not necessarily involve a thorough assessment of the quality of the science on a given website, and many sites with what I would consider dubious information have earned the HON seal of approval.
Last year Ben Kavoussi published an interesting article on SBM called Astrology with Needles in which he purported a historical connection between acupuncture and bloodletting. I had previously thought that bloodletting was a uniquely Western cultural invention – part of Galenic medicine involving the balancing of the four humors, one of which being blood. (In the West bloodletting faded away with the advent of science-based medicine in the 19th century.) I was intrigued by this connection and have since been doing my own reading on the topic. It turns out that bloodletting was common throughout ancient cultures and not unique to the west.
In fact acupuncture was originally a form of bloodletting – the “needles” were really lances and the acupuncture points locations over veins to be opened. Chi, or the Chinese concept of the life force, was believed to be partly in the blood, and blood letting could be used to free the flow of chi. This was closely related to the Galenic concept of using bloodletting to free the flow of static blood in the tissue.
For example, in the ancient medical text of Suwen, we find:
When heaven is warm and when the sun is bright,
then the blood in man is rich in liquid
and the protective qi is at the surface
Hence the blood can be drained easily, and the qi can be made to move on easily…
Mark Hyman, a proponent of so-called “functional medicine” promoting himself over at the Huffington Post (an online news source that essentially allows dubious medical infomercials to pass as news) has posted a particularly egregious article on personalized medicine for dementia. In the article Hyman distorts the modern practice of medicine, the current state of genetic science, and the very notion of “disease.” It is, as usual, a fine piece of medical propaganda sure to confuse many a reader.
Hyman starts with some standard epidemiology of dementia – it is a common and growing disorder – but then descends quickly into distortion and pseudoscience.
Conventional Medicine Strawman.
Hyman creates what readers are likely to recognize by now as the standard straw man of conventional or science-based medicine, and then uses that caricature to create a false dichotomy with his “functional” medicine. He writes:
The International Society for Stem Cell Research (ISSCR) is a professional organization of stem cell researchers. I am happy to see that they see it as their responsibility to respond to the growth of dubious stem cell clinics offering unproven treatments to desperate patients.
In a recently published handbook for patients, they write:
The International Society for Stem Cell Research (ISSCR) is very concerned that stem cell therapies are being sold around the world before they have been proven safe and effective.
Stem cell therapies are nearly all new and experimental. In these early stages, they may not work, and there may be downsides. Make sure you understand what to look out for before considering a stem cell therapy.
Remember, most medical discoveries are based on years of research performed at universities and companies. There is a long process that shows first in laboratory studies and then in clinical research that something is safe and will work. Like a new drug, stem cell therapies must be assessed and meet certain standards before receiving approval from national regulatory bodies to be used to treat people.
This is good advice for any new treatment.
One of the recurring themes of Science-based medicine is that we live in the age of misinformation. The internet and social networking have made everyone their own expert – by democratizing information (which I favor, as it has many benefits to society) the field has been leveled for various types and sources of information. But this has the very negative effect of equalizing information in terms of quality as well – so low quality and even outright incorrect or fraudulent information can compete on equal footing with more reliable, vetted, and professionally sourced material. That is exactly why one of the primary goals of SBM is to be a resource for consumers and professionals to help sort through it all.
Recently David Gorski sent around a link to an e-book, Natural Cancer Treatments, that epitomizes the dark underbelly of health misinformation on the internet.
The book opens up with the standard disclaimer that ostensibly is to protect the public but in reality is simply legal cover for the purveyors of misinformation – it says to seek the advice of your physician and that this book is not meant to discourage anyone from seeking standard therapy for cancer. This is boiler plate CYA for quacks. It is also utter hypocrisy as it is placed immediately below two quotations that set the tone for the book:
On June 11, 2009 Dr Margaret Chan, the director general of the World Health Organization (WHO) declared that the H1N1 flu that was then spreading around the world was an official pandemic. This triggered a series of built-in responses in many countries, including stockpiling anti-viral medications and preparing for a mass H1N1 vaccination program. At the time the flu was still in its “first wave” and the fear was that subsequent waves, as the virus swept around the world, would become more virulent and/or contagious – similar to what happened in the 1918 pandemic.
This did not happen. At least our worst fears were not realized. The H1N1 pandemic, while serious, simmered through the winter of 2009-2010, producing a less than average flu season, although with some worrisome difference.
The Centers for Disease Control (CDC) estimates:
- CDC estimates that between 43 million and 89 million cases of 2009 H1N1 occurred between April 2009 and April 10, 2010. The mid-level in this range is about 61 million people infected with 2009 H1N1.
- CDC estimates that between about 195,000 and 403,000 H1N1-related hospitalizations occurred between April 2009 and April 10, 2010. The mid-level in this range is about 274,000 2009 H1N1-related hospitalizations.
- CDC estimates that between about 8,870 and 18,300 2009 H1N1-related deaths occurred between April 2009 and April 10, 2010. The mid-level in this range is about 12,470 2009 H1N1-related deaths.
The development of drugs and other treatments for specific symptoms or conditions relies heavily on either serendipity (the chance finding of a beneficial effect) or on an understanding of underlying mechanisms. In pain, for example, there are limited ways in which we can block pain signals – such as activating opiate receptors or inhibiting prostaglandins. There are only so many ways in which you can interact with these systems. The discovery of a novel mechanism of modulating pain is therefore most welcome, and has the potential of leading to entirely new treatments that may have better side-effect profiles than existing treatments and also have additive clinical effects.
A recent study by Nana Goldman et. al., published in Nature Neuroscience, adds to our understanding of pain relief by identifying the role of adenosine in reducing pain activity in the peripheral nervous system. The researchers, in a nice series of experiments, demonstrated that producing a local painful stimulus in mice causes the local release of ATP (adenosine triphosphate) that peaks at about 30 minutes. This correlates with a decreased pain response in the mice. Further, if drugs are given that prolong the effect of adenosine, the analgesic effect itself is prolonged.
Also, if drugs are given that activate the adenosine A1 receptor, the observed analgesic effect is replicated. When these experiments are replicated in knockout mice that do not have the gene for the adenosine A1 receptor, there is no observed analgesic effect.
Together these experiments are fairly solid evidence that local pain results in the local release of adenosine that in turn binds to the adenosine A1 receptor inhibiting the pain response. This is potentially very exciting – it should lead to further investigation of the adenosine A1 receptor and the effects of activating and inhibiting it. This may lead to the development of drugs or other interventions that activate these receptors and may ultimately be a very useful addition to our ability to treat acute and chronic pain.