Dr. H. Gilbert Welch has written a new book Over-diagnosed: Making People Sick in the Pursuit of Health, with co-authors Lisa Schwartz and Steven Woloshin. It identifies a serious problem, debunks medical misconceptions and contains words of wisdom.
We are healthier, but we are increasingly being told we are sick. We are labeled with diagnoses that may not mean anything to our health. People used to go to the doctor when they were sick, and diagnoses were based on symptoms. Today diagnoses are increasingly made on the basis of detected abnormalities in people who have no symptoms and might never have developed them. Overdiagnosis constitutes one of the biggest problems in modern medicine. Welch explains why and calls for a new paradigm to correct the problem. (more…)
I wasn’t really surprised to learn that camel milk is being promoted as a medicine. I long ago realized that the human power of belief is inexhaustible. The news did make me laugh, probably because camels are rather funny-looking animals, because I am easily amused, because it reminded me of some of my favorite camel jokes, and because it wouldn’t do any good to cry.
Camel milk has been claimed to cure or benefit patients with diabetes, tuberculosis, stomach ulcers, gastroenteritis, cancer, allergies, infections, parasites, autism, even AIDS. This isn’t really quite as silly as it might sound. PubMed does list several studies showing health benefits from camel milk. A handful of studies have suggested that camel milk improves control of blood sugar in diabetes, but they are preliminary studies that typically compare standard treatment to standard treatment plus camel milk rather than using a blinded control. There are also a few small, poor quality studies suggesting a possible benefit in allergies, in peptic ulcers, in infections such as hepatitis, and in schistosomiasis. All in all, the research doesn’t amount to much. Camel milk can only be classed as experimental treatment. The existing studies justify doing more (and better quality) research, but they don’t justify prescribing it to treat patients.
Journalist Gary Taubes created a stir in 2007 with his impressive but daunting 640-page tome Good Calories, Bad Calories. Now he has written a shorter, more accessible book Why We Get Fat: And What to Do About It to take his message to a wider audience. His basic thesis is that:
- The calories-in/calories-out model is wrong.
- Carbohydrates are the cause of obesity and are also important causes of heart disease, type 2 diabetes, cancer, Alzheimer’s, and most of the so-called diseases of civilization.
- A low-fat diet is not healthy.
- A low-carb diet is essential both for weight loss and for health.
- Dieters can satisfy their hunger pangs and eat as much as they want and still lose weight as long as they restrict carbohydrates.
He supports his thesis with data from the scientific literature and with persuasive theoretical arguments about insulin, blood sugar levels, glycemic index, insulin resistance, fat storage, inflammation, the metabolic syndrome, and other details of metabolism. Many readers will come away convinced that all we need to do to eliminate obesity, heart disease and many other diseases is to get people to limit carbohydrates in their diet. I’m not convinced, because I can see some flaws in his reasoning. (more…)
A November letter to the editor in American Family Physician chastises that publication for misusing the term “secondary prevention,” even using it in the title of an article that was actually about tertiary prevention.
I am guilty of the same sin. I had been influenced by simplistic explanations that distinguished only two kinds of prevention: primary and secondary. I thought primary prevention was for those who didn’t yet have a disease, and secondary prevention was for those who already had the disease, to prevent recurrence or exacerbation. For example, vaccinations would be primary prevention and treatment of risk factors to prevent a second myocardial infarct would be secondary prevention.
No, there are three kinds of prevention: primary, secondary and tertiary. Primary prevention aims to prevent disease from developing in the first place. Secondary prevention aims to detect and treat disease that has not yet become symptomatic. Tertiary prevention is directed at those who already have symptomatic disease, in an attempt to prevent further deterioration, recurrent symptoms and subsequent events. (more…)
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.
One of our readers suggested that I review the book The Great Influenza: The Epic Story of the Deadliest Plague in History, by John M. Barry. It’s not a new book (it was published in 2004) but it is very pertinent to several of the issues that we have been discussing on this blog, especially in regards to the current anti-vaccine movement. It’s well worth reading for its historical insights, for its illumination of the scientific method, and for its accurate reporting of what science has learned about influenza.
In the great flu epidemic of 1918, influenza killed as many people in 24 weeks as AIDS has killed in 24 years. It’s hard to even imagine what that must have been like, but this book helps us imagine it. It tells horror stories: children found alone and starving beside the corpses of their parents in homes where all the adults had died, decomposing bodies piling up because there was no one left who was healthy enough to bury them. Sometimes the disease developed with stunning rapidity: during one 3 mile streetcar trip, the conductor, 3 passengers, and the driver died. In another incident, apparently healthy soldiers were being transferred to a new post by train; during the trip, men started coughing, bleeding, and collapsing; and by the time it arrived at its destination, 25% of the soldiers were so sick they had to be taken directly from train to hospital. 2/3 of them were eventually hospitalized in all, and 10% of them died. The mind boggles. (more…)
Myths and misconceptions about cancer abound. Oncologists are frequently criticized for torturing patients by burning, cutting and poisoning without making any real progress in the war against cancer. Siddhartha Mukherjee, an oncologist and cancer researcher, tries to set the record straight with his new book The Emperor of All Maladies: A Biography of Cancer.
It is a unique combination of insightful history, cutting edge science reporting, and vivid stories about the individuals involved: the scientists, the activists, the doctors, and the patients. It is also the story of science itself: how the scientific method works and how it developed, how we learned to randomize, do controlled trials, get informed consent, use statistics appropriately, and how science can go wrong. It is so beautifully written and so informative that when I finished it I went back to page 1 and read the whole thing again to make sure I hadn’t missed anything. I enjoyed it just as much the second time.
It will be a story of inventiveness, resilience, and perseverance against what one writer called the most “relentless and insidious enemy” among human diseases. But it will also be a story of hubris, arrogance, paternalism, misperception, false hope, and hype, all leveraged against an illness that was just three decades ago widely touted as being “curable” within a few years. (more…)
In 1996, Alan Sokal got a bogus paper published in the journal Social Text. It was a parody full of meaningless statements in the jargon of postmodern philosophy and cultural studies. The editors couldn’t tell the difference between Sokal’s nonsense and the usual articles they publish.
Now a British professor of medical education, Dr. John McLachlan, has perpetrated a similar hoax on supporters of so-called “integrative” medicine. He reports his prank in an article in the British Medical Journal (BMJ).
After receiving an invitation to submit papers to an International Conference on Integrative Medicine, he invented a ridiculous story about a new form of reflexology and acupuncture with points represented by a homunculus map on the buttocks. He claimed to have done studies showing that
responses are stronger and of more therapeutic value than those of auricular or conventional reflexology. In some cases, the map can be used for diagnostic purposes.
A Walmart ad in my local newspaper trumpets “75% of all Americans don’t get enough Vitamin D” and offers to sell me Maximum Strength Vitamin D3, 5000 IU capsules to “promote bone, colon and breast health.” Meanwhile, the Institute of Medicine (IOM) tells me that “the majority of Americans and Canadians are receiving adequate amounts of … vitamin D” and that no one should take more than 4000 IU a day. Apparently Walmart and the IOM aren’t talking to each other.
The media have been giving the impression that vitamin D is a new wonder drug. They have told us that we aren’t getting enough sunlight, that a large percentage of us suffer from vitamin D deficiency, and that low levels of vitamin D are associated with cancer, multiple sclerosis, peripheral vascular disease, diabetes, rheumatoid arthritis, Parkinson’s and Alzheimer’s disease, and other conditions. Low levels of vitamin D have been linked to higher overall mortality (but so have high levels of vitamin D!). The anti-vaccine folks have been telling us (without any controlled studies) that vitamin D supplements are better than vaccines for preventing influenza. There’s no good evidence that raising vitamin D levels with supplements actually prevents any of these conditions, but many people think it should, and doctors have increasingly been measuring blood levels and prescribing high dose supplements. Is this just another passing fad like the enthusiasm for vitamin C, or are we belatedly recognizing a serious deficiency problem?
I’ve had a lot of inquiries about “is this information trustworthy?” and “how much vitamin D should I be taking?” I’ve been telling people that I didn’t know, that recent findings will soon result in new recommendations, and I’ve been eagerly awaiting the new guidelines. Now we have them, thanks to the IOM. They are not what most of us anticipated. Since so many doctors had been advocating higher levels to prevent things like cancer, I thought official recommended intake levels would go up; instead, they went down.
The Accreditation Council for Graduate Medical Education (ACGME) has released proposed new standards to limit working hours for medical residents. Bus drivers are allowed to drive for 10 hours and then are required to have 8 hours off duty. Airline pilots can be scheduled for up to 16 hours on duty — being at work, ready to fly — and up to eight hours of actual flight time in a 24-hour period, with a minimum of eight hours for rest between shifts. Physicians in residency training work 80 hours or more a week (compared to 75 hours a month for airline pilots) and are regularly on duty for more than 24 hours at a time. If adequate rest is an important safety measure for drivers and pilots, isn’t it important for doctors too?
When I was an intern and resident, my hours were a little better than some. Instead of every other night, I was on call every third night. I had to work from about 7 AM one day to 5 PM the following day (34 consecutive hours). I stayed in the hospital: there was a call room with a bed, but if we got to lie down it was never for very long. When I got off duty, my sleep-deprived body demanded that I go home and crash. It was only every third day when I worked “only” a 10 hour shift, that I could devote an evening to all the other activities of my life like laundry, grocery shopping, and trying to read medical journals. One memorable weekend I worked from Saturday morning to Monday evening and only got to lie down for about 20 minutes. I don’t think I made any fatigue-induced mistakes that hurt patients, but by Monday afternoon I was groping my way through brain fog and running on fumes. (more…)