A recent Cochrane review of the use of cholesterol-lowering statin drugs in primary prevention has sparked some controversy. The controversy is not so much over what the data says, but in what conclusions to draw from the data.
Statin drugs have been surrounded by controversy for a number of reasons. On the one hand they demonstrably lower cholesterol, and the evidence has shown that they also reduce the incidence of heart attacks and strokes. The data on whether or not they reduce mortality has been less clear, although this latest data actually supports that claim. However, statins have also been blockbuster drugs for pharmaceutical companies and this has spawned concerns (some might say paranoia) that drug companies are pushing billions of dollars worth of marginally effective drugs onto the public.
So are statins a savior or a scam? Life does not always provide nice clean answers to such simple dichotomies. The evidence clearly shows that statins work and are safe. However, pharmaceutical companies do like to present their data in the best light possible, and they need to be watched closely for this. The recent review does call them on some practices that might tend to exaggerate the utility of statins. Finally, the real question comes down to – where should we draw the line in terms of cost-benefit of a preventive measure like statins.
Let’s look as this recent review of the data to see what it actually shows.
At SBM we are highly in favor of physicians and scientists interfacing with the public, using mainstream and new media to promote the public understanding of science and to explain the modern practice of medicine. Now that Dr. Dean Edell has retired (unfortunately) from his radio show, it is probable that Dr. Mehmet Oz has the highest exposure of any media physician. I have never personally been a fan of Oz – a product of Oprah Winfrey, he has always mixed reasonable medical advice with promotion of dubious alternative health care. Harsh critics of Oz have charged him with selling out in order to promote his media career.
Regardless of his motivations, Oz has recently gone beyond coyly flirting with pseudoscience by directly promoting Joseph Mercola – a notorious internet doctor who himself promotes all sorts of pseudoscience and fear-mongering on his website. In an interview on his show, Dr. Oz praises Mercola while refraining from directly mentioning any of the more controversial positions that he takes. I will discuss the interview itself below, but first some background on Mercola.
Mercola is infamous among promoters of SBM for a number of reasons. First his website is highly monetized. While he frequently resorts to the “Big Pharma” conspiracy talk, he himself prints information on his site that supports the sales of supplements and other products. In my opinion this makes him a snake oil salesman, and everything he writes can no longer be considered objective medical advice but rather is advertising copy. I have no problem with monetizing websites to pay for bandwidth, as long as it’s within reason. But at some point you cross a fuzzy line where the website content is there to support sales, rather than the other way around – and Mercola is way past that line.
But far more importantly, the information on Mercola’s website is not science-based. Mercola frequently engages in rank fear-mongering – promoting every preliminary study that may suggest a possible connection as if it were a proven health risk.
The 1023 campaign is a UK based organization whose purpose is to raise awareness of the actual claims of homeopathy. The name is a reference to Avogadro’s number (6.02214179×10^23), which is the number of atoms or molecules of a substance in one unit called a mole. This is an important basic concept in chemistry, for it means that there are a finite number of bits of a substance in any solution, which further means that solutions cannot be infinitely diluted. You cannot have fractions of a molecule of any substance. There is therefore a dilutional limit – a point beyond which if you further dilute a solution you are increasingly likely to have removed all of the original substance.
Homeopathic preparations frequently use serial dilutions that vastly exceed this dilutional limit. This is a central fallacy of homeopathy (what homeopaths call a “law” of homeopathy). Samuel Hahnemann, who invented the fiction of homeopathy, knew about the dilutional limit but believed that substances gave their magical essence to water when diluted. Modern homeopaths believe this too, but in order to make their nonsense more marketable to a 21st century culture a tad more used to science (or at least scientific jargon) than Hahnemann’s, they have desperately tried to wrap “magical essence” in sciencey technobabble.
The 1023 campaign’s main purpose is public awareness. It appears that the best tool defenders of science-based medicine have against homeopathy is simply to make the public aware of what it actually is. I have not found any good surveys that quantify public beliefs on the subject (sounds like a good project) but it is my subjective experience (and that of many of my colleagues) from talking to countless patients and acquaintances that many if not most people are simply not aware of what homeopathy actually is. The term is often conflated with herbal or “natural” remedies. Shock and disbelief is a common reaction to explanations of what homeopaths actually claim.
It seems that for every established science there is an ideological group who is motivated to deny it. Denialism is a thriving pseudoscience and affects any issue with the slightest political or social implications. Sometimes, even easily verifiable facts can be denied, as people seem willing to make up their own facts as needed.
Denialists have an easy job – to spread doubt and confusion. It is far easier to muddy the waters with subtle distortions and logical fallacies than it is to set the record straight. Even when every bit of misinformation is countered, the general public is often left with the sense that the topic is controversial or uncertain. If denial is in line with a group’s ideology, then even the suggestion of doubt may be enough to reject solid science.
We see this when it comes to the effectiveness of vaccines, the evolution of life on earth, and anthropogenic global warming. A recent Pew poll shows that the campaign of global warming denial has been fairly successful – while the science becomes more solid around the consensus that the earth is warming and humans are contributing to this, the public is becoming less convinced.
A recent article in the journal Neurology reports the results of an observational study regarding the use of so-called complementary and alternative medicine (CAM) by patients with an incurable brain glioma. They found that 40% of patients sought some type of CAM treatment. These results are in line with prior surveys, but require closer inspection.
The study defined CAM as:
Complementary therapy was defined as methods or compounds not used in routine clinical practice and not scientifically evaluated.
This is a problematic definition, but reflects the fact that there is no universally accepted and clean definition of CAM. CAM is a hodge-podge of therapies and modalities that have only one thing in common – they have not met the science-based standard of care. It is not accurate to say that they are “not scientifically evaluated.” Some CAM therapies have not been evaluated, but many have, and have already been adequately found to lack efficacy. In the current study homeopathic remedies were the most commonly reported. Homeopathy has certainly been studied – and found to be indistinguishable from placebo.
Echinacea continues to be a popular herbal product, used primarily for treating and preventing colds and flus. Sales were estimated at $132 million in the US alone in 2009, an increase of 7% over the previous year. Reports of major negative clinical trials have had only a modest and temporary effect on the popularity and sale of this herb, contradicting claims that the utility of such research is to inform consumers.
In the current issue of the Annals of Internal Medicine there is a new study of Echinacea for the treatment of cold symptoms: Echinacea for Treating the Common Cold, A Randomized Trial. I won’t hold out the punchline – the study was completely negative. But let’s put the results of this study into the context of the history of Echinacea and the clinical evidence.
History of Echinacea
Modern proponents of Echinacea frequently cite as support the claim that this plant has been used for centuries by many Native American cultures. This much is well-documented, but what is not clear is what Echinacea was used for. For this there is no clear answer, except that Echinacea was used for 15-20 different and unrelated conditions, from fatigue to snake bites. Let us consider the value of the claim for traditional use of any treatment.
A recent study published in the Archives of Opthalmology compare patching of one eye vs acupuncture in the treatment of amblyopia in older children, and finds positive results from acupuncture. The study, and its press, are a good example of the hazards of studying highly implausible modalities.
First let’s dissect the study itself – from the abstract:
In a single-center randomized controlled trial, 88 eligible children with an amblyopic eye who had a best spectacle-corrected visual acuity (BSCVA) of 0.3 to 0.8 logMAR at baseline were randomly assigned to receive 2 hours of patching of the sound eye daily or 5 sessions of acupuncture weekly. All participants in our study received constant optical correction, plus 1 hour of near-vision activities daily, and were followed up at weeks 5, 10, 15, and 25. The main outcome measure was BSCVA in the amblyopic eye at 15 weeks.
For background, amblyopia occurs when the brain tends to ignore visual information from one eye. This results from a variety of causes, but commonly from the two eyes having different refractive errors (anisometropic) – one eye may be more near-sighted or far-sighted than the other. The brain cannot combine information from both eyes, so it ignores one. This can be corrected in younger children, up to age 7, by correcting the vision for the refractive problems. If visual correction alone is not enough, then patching one eye (the strong eye) to force the brain to use the weak eye can be effective. This is usually done for only 2 hours a day, otherwise amblyopia of the patched eye can occur.
Cell phones continue to be a focus of epidemiological studies and public concern, despite the fact that so far there is no compelling evidence of any health risk from cell phones. Concerns are likely to be sparked anew with the report of a study linking cell phone use to behavioral problems in children.
The study, by Divan, Kheifets, Obel, and Olsen, is a follow up of a prior study which showed a correlation between cell phone use in pregnant women and behavior problems in their children. They sought to replicate this study with a larger data set and taking into consideration more possible confounding factors. They found:
Results The highest OR for behavioural problems were for children who had both prenatal and postnatal exposure to cell phones compared with children not exposed during either time period. The adjusted effect estimate was 1.5 (95% CI 1.4 to 1.7).
Conclusions The findings of the previous publication were replicated in this separate group of participants demonstrating that cell phone use was associated with behavioural problems at age 7 years in children, and this association was not limited to early users of the technology. Although weaker in the new dataset, even with further control for an extended set of potential confounders, the associations remained.
I have the pleasure of announcing that this is the 1000th post of Science-Based Medicine. The first post introducing the blog was on January 1st 2008 – almost three years ago. We have published steadily since then, and this post marks number 1000.
I would like to take this time to thank the many regular contributors and editors who have added to the success of SBM, as well as the regular readers and commenters. I would especially like to thank David Gorski, the managing editor, who has done much of the day-to-day management of SBM and is largely responsible for its growth.
We have plans to continue to build SBM into a better and better resource for science in medicine. We are just getting started, so stay tuned.
The controversy over the human consumption of meat and dairy products from cloned cows continues. The UK Advisory Committee on Novel Foods and Processes, after reviewing the evidence, concluded that there was no substantial difference between meat and dairy from cloned cows compared to conventional cows. However, food products from cloned animals and their offspring remain banned in Europe.
Use of offspring of cloned cows, sheep and pigs are legal in the US, South America, and Asia. Australia is likely to follow suit in a year or two. The European Union (EU) has an effective ban at the moment, but the policy is under review. The UK is also negotiating with the EU regarding the use of clones.
There is not much of a theoretical reason to suspect that cloned animals would present a health risk. The primary concern is that something unanticipated might have occurred during the cloning process, causing the animal to be genetically or developmentally abnormal. However, if the cloning process works properly this should not happen. Further, if mutations do occur, but the animal lives, it is likely that any changes do not represent a risk to humans who consume the meat or dairy from such clones.