Archive for January, 2011

Energy Drinks

My stimulant of choice is coffee. I started drinking it in first-year university, and never looked back. A tiny four-cup coffee maker became my reliable companion right through graduate school. But since I stopped needing to drink a pot at a time, an entirely new category of products has appeared — the energy drink. Targeting students, athletes, and others seeking a mental or physical boost, energy drinks are now an enormous industry: from the first U.S. product sale in 1997, the market size was $4.8 billion by 2008, and continues to grow. (1)

My precious coffee effectively has a single therapeutic ingredient, caffeine. Its pharmacology is well documented, and the physiologic effects are understood. The safety data isn’t too shabby either: it’s probably not harmful and possibly is even beneficial. (I’m talking about oral consumption — no coffee enemas. Please.) In comparison, energy drinks are a bewildering category of products with an array of ingredients including caffeine, amino acids, vitamins, and other “natural” substances and assorted “nutraceuticals,” usually in a sugar-laden vehicle (though sugar-free versions exist). Given many products contain chemicals with pharmacologic effects, understanding the risks, signs of adverse events, and potential implications on drug therapy, are important.

So are energy drinks just candied caffeine delivery systems? Or are these syrupy supplements skirting drug regulations?


Posted in: Herbs & Supplements, Nutrition, Politics and Regulation

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Obesity Denial

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.


Posted in: Epidemiology, Public Health

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Followup: More Evidence against the XMRV Virus as a Cause of Chronic Fatigue Syndrome

A mouse leukemia retrovirus, xenotropic murine leukemia virus-related virus (XMRV retrovirus), has been under consideration as a possible cause of chronic fatigue syndrome (CFS, and also prostate cancer). In a study published in Science in October 2009, Lombardi et al. found XMRV in 67% of CFS patients and 3.7% of controls. Several subsequent studies in the UK, the Netherlands, and the US — by lead authors Erlwein, van Kuppleveld, Groom , Switzer and Henrich — failed to find XMRV at all.

Now a new study published in Retrovirology by Hue et al. shows that the original positive findings were likely erroneous and due to contamination in the lab. The complete article is available online.

We provide several independent lines of evidence that XMRV detected by sensitive PCR methods in patient samples is the likely result of PCR contamination with mouse DNA and that the described clones of XMRV arose from the tumour cell line 22Rv1, which was probably infected with XMRV during xenografting in mice. We propose that XMRV might not be a genuine human pathogen.


Posted in: Basic Science

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Deadly Choices about vaccination

appThe year 2011 is starting out rather promisingly, at least from the point of view of science-based medicine. Its beginning coincides with the release of two — count ‘em, two! — books taking a skeptical, science-based look at vaccines and, in particular, the anti-vaccine movement. First off the mark is a new book by a man whom the anti-vaccine movement views as the Dark Lord of Vaccination, sitting up in Barad-dûr (apparently the University of Pennsylvania and Children’s Hospital of Philadelphia), a man utterly reviled by anti-vaccine quacks everywhere, Dr. Paul Offit. He has been subjected to considerable bile and harassment due to his simply standing up for the science behind vaccines. The book is entitled, appropriately enough, Deadly Choices: How the Anti-vaccine Movement Threatens Us All. Also being released is a new book by Seth Mnookin entitled The Panic Virus: A True Story of Medicine, Science, and Fear. Mnookin is a contributing editor at Vanity Fair and whose work has appeared in numerous publications. Because I got a copy of Deadly Choices before my copy of The Panic Virus arrived, I decided to review Deadly Choices first; after I’ve managed to read The Panic Virus, I’ll write a review of it as well. Both books are arrows shot at the heart of the pseudoscience and fear at the heart of the vaccine manufactroversy, and it might well be useful to compare and contrast the two once I’ve finished The Panic Virus.

In the meantime, let’s take a look at Deadly Choices, an excellent, well-researched book with which I have relatively few disagreements. It is a followup to Dr. Offit’s last book, Autism’s False Prophets: Bad Science, Risky Medicine, and the Search for a Cure, which I reviewed back when it first came out. In contrast to Autism’s False Prophets, which concentrated primarily on the manufactroversy that claims that vaccines are responsible for the “autism epidemic,” Deadly Choices steps back to take a broader look at the anti-vaccine movement. Regular readers of SBM hardly need to be reminded how pervasive and dangerous the modern-day anti-vaccine movement has become. Indeed, it is a frequently discussed theme of this blog, given that the anti-vaccine movement is such a major force among the forces that deny the efficacy of scientific medicine and seek either to replace it with unscientific or pseudoscientific “alternatives” or to “integrate” pseudoscience into science-based medicine. Indeed, anti-vaccine sentiment infuses large swaths of what we refer to as “complementary and alternative medicine” (CAM), be it chiropractic, homeopathy, traditional Chinese medicine, or a wide variety of other modalities and systems.

In examining the modern anti-vaccine movement, Dr. Offit structures his book into three major sections. First, beginning in a chapter entitled The Birth of Fear, Dr. Offit begins with a description of the birth of the modern anti-vaccine movement, which in the U.S. Dr. Offit traces, in large part, to the broadcast of an irresponsible and anecdote-driven news documentary about the diptheria-pertussis-tetanus (DPT) vaccine in 1982, and in the U.K. to a scare about the DPT triggered by a presentation by Dr. John Wilson to the Royal Society of Medicine about horrific complications thought to be due to the pertussis vaccine in the DPT. Next, Dr. Offit goes back into history to describe the development of the anti-vaccine movement in the 1800s in England and notes parallels with the modern day anti-vaccine movement. Finally, the story shifts back to today, where he describes the situation now, how demands for vaccines turned into fear of vaccines, and what we might do about it.

Posted in: Book & movie reviews, Vaccines

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