Diets fail. Not just often, but almost always—90% of the time. If diets worked we wouldn’t have a worldwide obesity problem. And obesity is a problem that needs to be solved. The prevalence of obesity has doubled since 1980. As a public health issue, there are few determinants of illness that are more destructive, as obesity contributes to the growing rates of diabetes, heart disease, and even cancer. There’s no “one true cause” of all illness, but obesity comes pretty close. When people ask me for the single most important thing they can do for their health, my advice (after quitting smoking) is to (1) ensure you keep your weight under control and (2) exercise in any way possible.
Despite its tremendous impact on health, I’ve only blogged about obesity in an indirect way—by pointing out what doesn’t work. Dr. Oz is my perpetual source of bad health information with his regular promotion of bogus “weight loss” supplements like the green coffee bean “miracle”. I’ve also criticized eating programs like the fads of “Eating Clean”, gluten “intolerance”, or harmful diet delusions like “detox”. It’s the typical skeptical science blogger approach—spot pseudoscience, debunk it, and hope you did something good. But none of my posts have focused on what one should do—just what you shouldn’t. Weekly SBM contributor Dr. Mark Crislip recently commented that what we (SBM) support manifests in what we oppose. He’s right, because that’s the easy approach. Using the principles of science-based medicine, there’s an awful lot to oppose in the current writing and popular opinion on how to treat obesity. And my professional advice in the role of a pharmacist has been limited to steering people away from supplements, and then giving some basic advice about dietary planning. Anecdotes and platitudes. I admit that I’ve told patients to “eat less and exercise more”.
I am excited to tell you about a wonderful new endeavor that is helping to promote critical thinking about science and medicine. It’s a free online course on “Food for Thought” that offers a scientific framework for understanding food and its impact on health and society from past to present.
The “Food for Thought” course is a product of EdX, which offers online college courses from Harvard, MIT, and other prestigious universities. They provide videos with interactive features and access to online student communities. Students can audit a course and get full access to all the materials including tests, assignments, and discussion forums with no commitment, and can choose what and how much they want to do. (more…)
We (the authors and editors) at SBM get accused of many nefarious things. Because we deliberately engage with the public over controversial medical questions, we expect nothing less. It goes with the territory. In fact, if there were a lack of critical pushback we would worry that we were not doing our job.
Still, it is disconcerting to see the frequently-repeated ideological accusations in response to simply evaluating and reporting the evidence. That is what we do here – follow the science and evidence. When that trail leads to a conclusion that some people do not like (usually for ideological reasons) a common response is to accuse us of ideology, malfeasance, being part of a conspiracy, or having conflicts of interest or ulterior motives. That is easier, I suppose, than engaging with us on the science.
One common accusation is that we are shills for the pharmaceutical industry, and downplay or ignore the benefits of diet and “natural” treatments. A search through the SBM archives demonstrates that this accusation is false – we criticize bad science and poor-quality control, regardless of who is committing it. Sometimes pseudoscience is used to promote a drug, sometimes a nutritional supplement, and sometimes pure magic. (more…)
This will be a departure from my usual posts. Several announcements in the news and medical journals have caught my attention recently, and as I delved into the details, I thought I would share them with our SBM readers. Topics include AIDS cures, the continuing danger of polio, eating nuts for longevity, racial differences in vitamin D, and the use of pharmacogenetic testing to guide the dosage of anticoagulant drugs. They are all examples of science-based medicine in action.
Have patients been cured of AIDS?
I read that the HIV virus had returned in patients thought to have been cured by bone marrow transplants, and I mistakenly thought they were referring to the original claim of cure I had read about. Nope, that one still stands. (more…)
Elsevier has announced that they are retracting the infamous Seralini study which claimed to show that GMO corn causes cancer in laboratory rats. The retraction comes one year after the paper was published, and seems to be a response to the avalanche of criticism the study has faced. This retraction is to the anti-GMO world what the retraction of the infamous Wakefield Lancet paper was to the anti-vaccine world.
The Seralini paper was published in November 2012 in Food and Chemical Toxicology. It was immediately embraced by anti-GMO activists, and continues to be often cited as evidence that GMO foods are unhealthy. It was also immediately skewered by skeptics and more objective scientists as a fatally flawed study.
The study looked at male and female rats of the Sprague-Dawley strain of rat – a strain with a known high baseline incidence of tumors. These rats were fed regular corn mixed with various percentages of GMO corn: zero (the control groups), 11, 22, and 33%. Another group was fed GMO corn plus glyphosate (Round-Up) in their water, and a third was given just glyphosate. The authors concluded: (more…)
It is a triumph of marketing over evidence that millions take supplements every day. There is no question we need vitamins in our diet to live. But do we need vitamin supplements? It’s not so clear. There is evidence that our diets, even in developed countries, can be deficient in some micronutrients. But there’s also a lack of evidence to demonstrate that routine supplementation is beneficial. And there’s no convincing evidence that supplementing vitamins in the absence of deficiency is beneficial. Studies of supplements suggest that most vitamins are useless at best and harmful at worst. Yet the sales of vitamins seem completely immune to negative publicity. One negative clinical trial can kill a drug, but vitamins retain an aura of wellness, even as the evidence accumulates that they may not offer any meaningful health benefits. So why do so many buy supplements? As I’ve said before, vitamins are magic. Or more accurately, we believe this to be the case.
There can be many reasons for taking vitamins but one of the most popular I hear is “insurance” which is effectively primary prevention – taking a supplement in the absence of a confirmed deficiency or medical need with the belief we’re better off for taking it. A survey backs this up – 48% reported “to improve overall health” as the primary reason for taking vitamins. Yes, there is some vitamin and supplement use that is appropriate and science-based: Vitamin D deficiencies can occur, particularly in northern climates. Folic acid supplements during pregnancy can reduce the risk of neural tube defects. Vitamin B12 supplementation is often justified in the elderly. But what about in the absence of any clear medical need? (more…)
I’m sure I’m not the only health professional that bites their tongue whenever a patient starts a question with “I heard on Dr. Oz that…” More often than not, I have expectations to realign, and some assumptions to correct. I could easily devote all my posts to simply correcting information presented on the Dr. Oz show. But given I’m blogging here biweekly, and Dr. Oz has a daily television show, I’ll never be able to catch up. So while my first choice in topics isn’t to add a post to our extensive Dr. Oz archives, I often end up, like many other health professionals, needing to respond to his shows shortly after they air.
Should you happen to be someone that has never seen the Dr. Oz show, Dr. Mehmet Oz is an Oprah protégé who has gone on to build a health media empire that is possibly the biggest vehicle for health pseudoscience and medical quackery on television. Whether it’s promoting homeopathy, recommending unproven supplements, or advocating ridiculous diet plans, there seems to be no health subject too dubious to endorse. Oz has established an impressive track record of providing highly questionable health advice. A few months ago I examined his absurd endorsement of green coffee beans, followed by his dubious “clinical trial” of green coffee beans that likely didn’t meet minimal research ethics standards. Then there was the weight loss “miracle” (his words), red palm oil, which followed the same episodic formula of breathless hyperbole backed by questionable evidence. One of the meta-trends of the Dr. Oz show are weight loss secrets – typically gimmicky interventions, supplements and therapies that he promotes as panaceas for obesity. (more…)
It’s likely you know someone who has bought into the notion that nutrition is everything, the source of all health and the cause of all illness. Nutrition is very important, to be sure, but it is only one of many possible causes of disease, and if you live in a Western industrialized nation you probably have adequate nutrition. The notion, however, that food can heal is powerfully alluring, and it makes great headlines. The result is that people who read the headlines for the latest food to avoid, or the latest ingredient that will make them live longer or stave off disease, seem to have an association for everything. Eating around them is to be constantly told that food X is good for you and will prevent Y, or that some other food should be avoided because it causes Z.
Red peppers will help prevent cancer and help you lose weight. Garlic will help prevent heart disease and aids in iron metabolism. Cayenne pepper prevents strokes. Peaches prevent heart disease and cancer. In fact- think of any food at random and type “random food health benefits” into Google and chances are you will be rewarded with a list of the amazing health benefits of whatever food you wish.
My usual response when offered such advice is – you know, food is healthy for you. I recommend you eat food every day. Food is full of nutrition, essential vitamins and minerals, and will give you energy. If you don’t eat food, your health with dramatically suffer. But don’t eat too much food – that’s not healthful.
A Swedish researcher, Staffan Lindeberg, has been studying the inhabitants of Kitava, one of the Trobriand Islands of Papua New Guinea. He claims that sudden cardiac death, stroke, and exertion-related chest pain never occur in Kitava; and he attributes this to their eating a Paleolithic diet.
2,250 people live on Kitava. They are traditional farmers. Their dietary staples are tubers (yam, sweet potato and taro), fruit, fish, and coconut. They don’t use dairy products, alcohol, coffee, or tea. Their intake of oils, margarine, cereals, and sugar is negligible. Western foods constitute less than 1% of their diet. Their activity level is only slightly higher than in Western populations. 80% of them smoke daily and an unspecified number of them chew betel. The macronutrient composition of the Kitavan diet was estimated as 21% of total calories from fat, 17% from saturated fat, 10% from protein, and 69% from carbohydrates.
Lindeberg’s Kitava study examined a sample of 220 Kitavans aged 14-87 and compared them to healthy Swedish populations. They found substantially lower diastolic blood pressure, body mass index, and triceps skinfold thickness in the Kitavans. Systolic blood pressure was lower in Kitava than in Sweden for men over 20 and women over 60. Total cholesterol, LDL cholesterol, and apolipoprotein B were lower in men over 40 and in women over 60. Triglycerides were higher in Kitavans aged 20-39 than in Swedes of the same age. HDL was not significantly different. (more…)
I never used to write much about genetically modified organisms (GMOs) before. I still don’t do it that often. For whatever reason, it just hasn’t been on my radar very much. That seems to be changing, however. It’s not because I went seeking this issue out (although I must admit that I first became interested in genetic engineering when I was in junior high and read a TIME Magazine cover article about it back in the 1970s), but rather because in my reading I keep seeing it more and more in the context of anti-GMO activists using bad science and bad reasoning to justify a campaign to demonize GMOs. Now, I don’t have a dog in this hunt, (Forgive me, I have no idea why I like that expression, given that I don’t hunt.) I really don’t. I was, not too long ago, fairly agnostic on the issue of GMOs and their safety, although, truth be told, because I have PhD in a biomedical science and because my lab work has involved molecular biology and genetics since I was a graduate student in the early 1990s, I found the claims of horrific harm attributable to GMOs not particularly convincing, but hadn’t bothered to take that deep a look into them. It was not unlike my attitude towards the the claims that cell phones cause cancer a few years ago, before I looked into them and noted the utter lack of a remotely-plausible mechanism and uniformly negative studies except for a group in Sweden with a definite ax to grind on the issue. Back then, I realized that there wasn’t really a plausible mechanism by which radio waves from cell phones could cause cancer in that the classic mechanisms by which ionizing radiation can break DNA molecular bonds and cause mutations don’t apply, but I didn’t rule out a tiny possibility that there might be an as-yet unappreciated mechanism by which long term exposure to radio waves might contribute to cancer. I still don’t, by the way, which has gotten me into the odd kerfuffle with some skeptics and one physicist, but I still view the likelihood that cell phone radiation can cause cancer as being just a bit more plausible than homeopathy.
As was the case for the nonexistent cell phone-cancer link, there has now been a steady drip-drip-drip of bad studies touted by anti-GMO activists as “evidence” that GMOs are the work of Satan that will corrupt or kill us all (and make us fat, to boot). Not too long ago, I came across one such study, a truly execrable excuse for science by Gilles-Eric Séralini at the University of Caen purporting to demonstrate that Roundup-resistant genetically modified maize can cause horrific tumors in rats. I looked at the methods and conclusions and what I found was some of the worst science I had ever seen, every bit as bad as the quack “science” used by the antivaccine movement. It wasn’t for nothing that I made the comparison, because the anti-GMO movement is very much like the antivaccine movement and the cranks who claim that cell phone radiation causes cancer. As if to demonstrate that very point, last week I came across an article by the all-purpose crank to rule all cranks, Mike Adams, at NaturalNews.com entitled GMO feed turns pig stomachs to mush! Shocking photos reveal severe damage caused by GM soy and corn: