Wouldn’t it be great if we could find a way to prolong our lives and to keep us healthy right up to the end? Ponce de León never found that Fountain of Youth, but science is still looking. What are the chances science will succeed? How’s it doing so far?
In his new book The Youth Pill: Scientists at the Brink of an Anti-Aging Revolution, David Stipp tries to answer those questions. From the title of the book, I expected hype about resveratrol or some other miracle pill; but instead it is a nuanced, levelheaded, entertaining, informative account of the history and current state of longevity research. It makes that research come alive by telling stories about the people involved, the failures and setbacks, and the agonizingly slow process of teasing out the truth with a series of experiments that often seem to contradict each other.
Anti-aging can mean several things. Extending the average lifespan is not the same as extending the maximum life span. Extending lifespan is not the same as preventing the degenerative changes characteristic of aging. (more…)
Shingles (herpes zoster) is no fun. It usually begins with a couple of days of pain, then a painful rash breaks out and lasts a couple of weeks. The rash consists of blisters that eventually break open, crust over, and consolidate into an ugly plaque. It is localized to one side of the body and to a stripe of skin corresponding to the dermatomal distribution of a sensory nerve. Very rarely a shingles infection can lead to pneumonia, hearing problems, blindness, brain inflammation (encephalitis) or death. More commonly, patients develop postherpetic neuralgia (PHN) in the area where the rash was. The overall incidence of PHN is 20%; after the age of 60 this rises to 40%, and after age 70 it rises to 50%. It can be excruciatingly painful, resistant to treatment, and can last for years or even a lifetime.
The Medical Letter recently evaluated “bioidentical” hormones and concluded
There is no acceptable evidence that “bioidentical” hormones are safe or effective. Patients should be discouraged from taking them.
“Bioidenticals” include progesterone, estrogens (estriol, estradiol, and estrone), and testosterone. They have mainly been promoted as a safer, more natural alternative to menopausal hormone replacement therapy (HRT), but they are also claimed to increase energy, well-being, and quality of life, and to have an anti-aging effect. Suzanne Somers recommends them for all age groups and both sexes. There is no evidence to support any of those claims.
The whole “bioidentical” thing is a pseudoscientific concept: it is a marketing term rather than a scientifically meaningful one. Bioidenticals are promoted by celebrities like Suzanne Somers, a few maverick medical doctors like Kent Holtorf, proponents of “natural” medicine, patients who were frightened by the Women’s Health Initiative study of hormone replacement therapy, and critics of Big Pharma. The mainstream scientific community is in consensus: a number of medical organizations, from the American Cancer Society to the Mayo Clinic, have issued statements similar to that of The Medical Letter.
The Internet is a wonderful new medium for communicating ideas and information in a rapid and interactive way. Many articles are followed by a “comments” section. Like so many things in this imperfect world, comments are a mixed blessing. They can enhance the article by correcting errors, adding further information, and contributing useful thoughts to a productive discussion. But all too often they consist of emotional outbursts, unwarranted personal attacks on the author, logical fallacies, and misinformation. They provide irrational and ignorant people with a soapbox for promoting prejudices and false information.
To illustrate, let’s look at the responses to something I wrote about a weight loss product called Isagenix that is sold through a multilevel marketing scheme. To quote the website,
The Isagenix cleanse is unique because it not only removes impurities at the cellular level, it builds the body up with incredible nutrition. Besides detoxing the body, Isagenix teaches people a wonderful lesson that they don’t need to eat as much as they are accustom to and eating healthy choices are really important and also a lot of the food we are eating is nutritionally bankrupt. [errors are in the original]
I didn’t set out to write an article about this. It started when I received an e-mail inquiry about Isagenix. I posted my answer on a discussion list and it was picked up and published on the healthfraudoz website. Sandy Szwarc approved of it and kindly reposted it on her Junkfood Science blog.
As I write, the comments on the healthfraudoz website have reached a total of 176. A few commenters approved of what I wrote, but the majority of commenters tried to defend Isagenix. Their arguments were irrational, incompetent, and sometimes amusing. (more…)
It’s boring to try to ferret out reliable health information from dry medical journals. It’s easier and more fun to watch a movie. A new movie promises to change the way you think about your health. To bring you breakthroughs that will transform your understanding of how to get well and stay well. To share the discoveries of leading researchers and health practitioners about miracle cures that traditional medicine can’t explain.
If this makes your baloney detector light up, good for you!
The Living Matrix: A Film on the New Science of Healing is an atrociously bad movie that falls squarely in the tradition of What the Bleep Do We Know? In his book Nonsense on Stilts, Massimo Pigliucci characterized the “Bleep” movie as “one of the most spectacular examples of a horribly tangled mess of science and nonsense,” and this new movie is more of the same. Bleep was just silly, but The Living Matrix is potentially dangerous because it might persuade patients to make poor decisions about their medical care. (more…)
The General Chiropractic Council, a UK-wide statutory body with regulatory powers, has just published a new position statement on the chiropractic subluxation complex:
The chiropractic vertebral subluxation complex is an historical concept but it remains a theoretical model. It is not supported by any clinical research evidence that would allow claims to be made that it is the cause of disease or health concerns.
They remind chiropractors that they must make sure their own beliefs and values do not prejudice the patient’s care, and that they must provide evidence-based care. Unfortunately, they define evidence-based care as
clinical practice that incorporates the best available evidence from research, the preferences of the patient and the expertise of practitioners, including the individual chiropractor her/himself. [emphasis added]
This effectively allows “in my experience” and “the patient likes it” to be considered along with evidence, effectively negating the whole point of evidence-based medicine.
Dr. Andrew Wakefield was almost single-handedly responsible for frightening the public about a possible association between autism and the MMR vaccine. His alarmist recommendations directly led to lower vaccination rates and a resurgence of measles to endemic levels in the UK. The MMR/autism interpretation of his 1998 article in The Lancet was retracted by 10 of his 12 co-authors. The article itself was “fully retracted from the public record” by The Lancet. And now Wakefield has lost his license to practice medicine after the General Medical Council’s exhaustive 2½-year review of his ethical conduct.
His career was in shreds and there was only one way left for him to fight back: to write a book. Callous Disregard: Autism and Vaccines — The Truth Behind a Tragedy has just been published. I tried hard to read it with an open mind and to understand his point of view. He did make some points that I will accept as valid unless they can be refuted by the others involved. Some of what he said and did was apparently misinterpreted and distorted by his critics. But the book did not convince me that he was an ethical, rigorous scientist or that MMR is linked to autism or to bowel disease. In my opinion the book does nothing to scientifically validate his beliefs or to excuse his behavior, but rather boils down to self-serving apologetics and misleading rhetoric. It also undermines his claim that he is a good scientist by showing that he values anecdotal evidence (“listening to the parents”) over experimental evidence. (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.
We know that drinking alcohol during pregnancy can cause birth defects; the government-mandated warnings on alcoholic beverage labels constantly remind us of that fact. But toxicologists remind us that the poison is in the dose: what is the dose of alcohol that causes birth defects? Heavy drinking can cause fetal alcohol syndrome, but there is no evidence that light to moderate drinking can cause it. Alcohol has been implicated in a number of other adverse effects on pregnancy and on the fetus. We simply don’t know if there is a threshold dose below which alcohol intake is safe, so the default position of most medical authorities has been to advise total abstinence during pregnancy. This is not a truly evidence-based recommendation, but rather an invocation of the precautionary principle. Those advising complete abstinence have been accused of paternalism and bias by wine-lovers and other critics, for instance here and here.
The literature on alcohol and pregnancy is extensive and confusing. It addresses many different endpoints, looking at effects on children and on the pregnancy itself. The studies are inconsistent in how they define “moderate” or “light” drinking, and they rely on self-reports that may not be accurate.
It would be impossible to read and accurately summarize such a large body of literature (over 21,000 hits on PubMed!), but here are a few examples that illustrate the scope, diversity, and conflicting results of these studies: (more…)