Why take a drug, herb or any other supplement? It’s usually because we believe the substance will do something desirable, and that we’re doing more good than harm. To be truly rational we’d carefully evaluate the expected risks and benefits, estimate the overall odds of a good outcome, and then make a decision that would weigh these factors against any costs (if relevant) to make a conclusion about value for money. But having the best available information at the time we make a decision can still mean decisions turn out to be bad ones: It can be that all relevant data isn’t made available, or it can be that new, unexpected information emerges later to change our evaluation. (Donald Rumsfeld might call them “known unknowns.”)
As unknowns become knowns, risk and benefit perspectives change. Clinical trials give a hint, but don’t tell the full safety and efficacy story. Over time, and with wider use, the true risk-benefit perspective becomes more clear, especially when large databases can be used to study effects in large populations. Epidemiology can be a powerful tool for finding unexpected consequences of treatments. But epidemiologic studies can also frustrate because they rarely determine causal relationships. That’s why I’ve been following the evolving evidence about calcium supplements with interest. Calcium supplements are taken by almost 1 in 5 women, second only to multivitamins as the most popular supplement. When you look at all supplements that contain calcium, a remarkable 43% of the (U.S.) population consumes a supplement with calcium as an ingredient. As a single-ingredient supplement, calcium is almost always taken for bone health, based on continued public health messages that our dietary intake is likely insufficient, putting women (rarely men) at risk of osteoporosis and subsequent fractures. This messaging is backed by a number of studies that have concluded that calcium supplements can reduce bone loss and the risk of fractures. Calcium has an impressive health halo, and supplement marketers and pharmaceutical companies have responded. There are pills, liquids, and even tasty chewy caramel squares embedded with calcium. It’s also fortified in foods like orange juice. Supplements are often taken as “insurance” against perceived or real dietary shortfalls, and it’s easy and convenient to take a calcium supplement daily, often driven by the perception that more is better. Few may think that there is any risk to calcium supplements. But there are now multiple safety signals that these products do have risks. And that’s cause for concern. (more…)
It’s one of the most common quackeries out there, used by a wide variety of practitioners for a wide variety of ailments blamed on “heavy metal toxicity.” Chelation therapy, which involves using chemicals that can bind to the metal ions and allow them to be excreted by the kidneys, is actually standard therapy for certain types of acute heavy metal poisoning, such as iron overload due to transfusion, aluminum overload due to hemodialysis, copper toxicity due to Wilson’s disease, acute heavy metal toxicity, and a handful of other indications.
My personal interest in chelation therapy developed out of its use by unscrupulous practitioners who blamed autism on the mercury-containing thimerosal preservative that used to be in many childhood vaccines until 2001 but has since all but disappeared from such vaccines except for one vaccine (the flu vaccine, for which a thimerosal-free alternative is available) and in trace amounts in some other vaccines. Mercury became a convenient bogeyman to add to the list of “toxins” antivaccinationists hype in vaccines. In fact, my very first post after I introduced myself on this very blog discussed the idea that mercury in vaccines was a significant cause of autism and autism spectrum disorders, and I’ve periodically written about such things ever since, in particular the bad science of Mark and David Geier, whose idea that chemical castration of children with Lupron “works” against “mercury-induced” autism is based on a chemically ridiculous idea that somehow testosterone binds mercury and makes it harder to chelate. Unfortunately, this particular autism quackery has real consequences and has been responsible for the death of a child.
Chelation isn’t just for autism, however. Despite many practitioners advertising it for autism, cancer (often with dubious studies that I might have to take a look at), Alzheimer’s disease (which Hugh Fudenberg has blamed on the flu vaccine, a claim parroted by Bill Maher, of course!), and just about every ailment under the sun, it’s easy to forget that the original use for chelation therapy promoted by “alternative medicine” practitioners was for cardiovascular disease. When it is used for coronary artery disease or autism, on a strictly stoichiometric and pharmacological basis, it is extremely implausible. Moreover, it is not without potential complications, including renal damage and cardiac arrhythmias due to sudden drops in calcium levels. Such arrhythmias can and have led to death in children, and in adults complications such as renal failure and death.
Being fat is bad except when it’s good. It’s called “the obesity paradox.” (No, that isn’t a mis-spelling for “two physicians who treat fat people.”) The adverse health effects of obesity are well established, but there are exceptions. Obesity appears to confer an advantage in certain subgroups with conditions like heart disease and diabetes.
In the News
Casual consumers of some recent media reports might interpret them as an excuse to stop trying to lose excess weight, especially if they are diabetic. Others might think we have been lied to about the dangers of the obesity epidemic. The reality is more complicated. (more…)
I recently received an e-mail from a high school science department head who is teaching a unit on nutritional science. He asked for my opinion of a YouTube video of a lecture advocating a high saturated fat diet. The speaker is Donald W. Miller, Jr., M.D., a cardiothoracic surgeon at my alma mater, the University of Washington. My correspondent commented, “I have a feeling that there is room for some skepticism.” I agree: there’s a whole lot of room for skepticism.
An article based on that video lecture is available on Dr. Miller’s website. It’s entitled “Enjoy Saturated Fats, They’re Good for You!” If you want to judge for yourselves, I recommend the article over the video, as he is a poor public speaker.
Dr. Miller’s website contains a lot of disturbing material. He appears to be a contrarian who disagrees with the consensus of scientific experts on a wide variety of topics, for instance:
- Health Benefits of a Low-Carbohydrate, High-Saturated Fat Diet
- Fighting Fluoride [fluoride is poison!]
- Cardiac Surgeon Dr. Donald Miller Tells Dr. Dean Ornish to Take a Hike
- Avoid Flu Shot, Take Vitamin D [flu is a Vitamin D deficiency disease?]
- Questioning HIV/AIDS, Human-Caused Global Warming, and other Orthodoxies in the Biomedical Sciences
- A User-Friendly Vaccination Schedule [no vaccinations before age 2, no live vaccines, etc.]
He refers to questionable sources of information like the Weston Price Foundation and the notorious AIDS denialist Peter Duesberg. (more…)
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…)
Birds of a feather flock together. As they investigated the risk factors for cardiovascular disease and diabetes, medical detectives observed that the usual suspects liked to hang out together. Obesity, high blood pressure, abnormal blood lipids, and elevated blood sugars regularly appeared together in the same patient. It looked like a syndrome that might boil down to one underlying cause. They called it “metabolic syndrome” and started applying the concept to clinical practice.
It seemed like a good idea at the time, but now skeptical scientists are expressing their doubts. (more…)
Red meat consumption has been linked to diabetes, cardiovascular disease, and several types of cancer (breast, colorectal, stomach, bladder, prostate, and lymphoma). There are plausible mechanisms: meat is a source of carcinogens, iron that may increase oxidative damage, and saturated fat. But correlation and plausibility are not enough to establish causation. Is red meat really dangerous? If so, how great is the risk? A couple of recent studies have tried to shed light on these questions, but they have raised more questions than they have answered.
A Systematic Review and Meta-Analysis
A new study in Circulation, “Red and Processed Meat Consumption and Risk of Incident Coronary Heart Disease, Stroke, and Diabetes Mellitus. A Systematic Review and Meta-Analysis,” by Micha, Wallace and Mozaffarian, is a systematic review of the literature. It analyzed 17 prospective cohort studies and 3 case-control studies, with a total of 1.2 million subjects. As far as I can judge, it appears to be a well-done systematic review with excellent methodology and multiple precautions. They even looked for things like publication bias (which they did not find).
They found that the consumption of processed meats, but not red meats, is associated with a higher incidence of coronary heart disease and diabetes. (Processed meats include bacon, sausage, ham, hot dogs, salami, luncheon meat and other cured meats.) The increased risk per 50 gram serving of processed meats per day was 42% for heart disease and 19% for diabetes. Unprocessed red meats were not associated with CHD and were associated with a nonsignificant trend towards higher risk of diabetes. They found no association with stroke, but this was based only on 3 studies.
Over 26 million Americans are taking statin drugs. Some people think they should be available over-the-counter without a prescription, and it has even been facetiously suggested that they should be added to our drinking water. The protective effect of statins in cardiovascular disease and in high-risk patients with high cholesterol levels is well established. But what about people with no heart disease and normal cholesterol levels – can they benefit too?
The New England Journal of Medicine has pre-released an important new study on statins online prior to its planned publication date of November 20, 2008. It is certain to stir up a lot of controversy, and the International Network of Cholesterol Skeptics will not be happy, because it contradicts some of their favorite arguments. They have claimed that statins do more harm than good, that reducing cholesterol levels is harmful to health, that the benefits of statins and/or cholesterol lowering do not extend to women and the elderly, and that studies showing benefits of statins are meaningless because they do not show reduction of overall mortality. This study indicates otherwise. (more…)
I’m really tired of arguing about cholesterol, but I feel obliged to stand up once more to defend science-based medicine from unfair calumny.
Lewis Jones’s article “Cholesterol-shmesterol” in Skeptical Briefs (December 2007) included errors and misconceptions about cholesterol. It was a re-hash of the same kind of misinformation that is being spread by The International Network of Cholesterol Skeptics (THINCS) and that I addressed in an earlier post. THINCS would like us to believe that cholesterol has nothing to do with heart disease; that low cholesterol is harmful and high cholesterol is beneficial; and they demonize statins, even falsely claiming that they cause cancer.
I answered Jones with my own article “Cholesterol Clarifications” in the June 2008 issue of Skeptical Briefs. I said I agreed that cholesterol does not “cause” heart disease, that low-fat and low-cholesterol diets have been promoted way beyond the evidence and that statins are being over-prescribed. The public has a lot of misconceptions, but thoughtful science-based doctors agree that the evidence shows: (more…)
There is an organization that calls itself The International Network of Cholesterol Skeptics (THINCS). Its members “thinc” they are smarter than the average doctor. They “thinc” that cholesterol has nothing to do with cardiovascular disease and that we have been deluded into waging a “cholesterol campaign” for which the scientific evidence is non-existent. They say, “What we all oppose is that animal fat and high cholesterol play a role.” I find even the wording of this statement problematical: one does not usually hear scientists “opposing” matters of fact or non-fact. They go on to say, “The aim with this website is to inform our colleagues and the public that this idea is not supported by scientific evidence; in fact, for many years a huge number of scientific studies have directly contradicted it.”
They tell us about those contradicting studies; but they don’t tell us about the flaws in those studies, they misrepresent some of the results, and they don’t tell us about the many good studies that support the cholesterol/heart link. The issue is a complex one, and it is easy to find studies to support any claim. Good science is about weighing all the evidence pro and con before reaching a conclusion. As far as I can see, these folks have cherry-picked the literature to support an agenda. They seem to have a vendetta against statin drugs in particular.
The website solicits complaints of adverse effects from statin drugs. It features a petition to the WHO that you can sign requesting an investigation of statin side effects. It alleges that lowering cholesterol endangers the elderly. It provides “what the medical journals and newspapers won’t let you hear” – letters and papers that have been rejected for publication. It lists books, published papers and talks by its members. It solicits financial contributions to the cause.
This movement seems to have started with Uffe Ravnskov’s book The Cholesterol Myths, published in Swedish in 1991 and in English in 2000. That book has been severely criticized, for instance in The Skeptic’s Dictionary , where Bob Carroll points out some of the distortions and deceptive techniques found in the cholesterol skeptics’ arguments. A typical claim: “Cholesterol is highly protective against cancer, infection and atherosclerosis” and “high TC [total cholesterol] and LDL levels are beneficial at all ages.” These statements are not only false, they are potentially dangerous to the health of those who believe them. (more…)