Humans, like many other animals, crave the taste of salt. Animals frequent salt licks, humans have traded salt for equal weights of gold, and the word “salary” comes from the Roman soldier’s allowance for purchasing salt. Salt appears in our language in idioms like “worth its salt” and “salt of the earth.” Shakespeare’s play King Lear is a variant of a folktale where a daughter tells her father she loves him as much as meat loves salt. In a murder mystery I read years ago, a character listed the four food groups as sweet, salty, sticky, and chocolate.
It’s no fair: everything that tastes good turns out to be bad for us. We love the taste of salt, but dietary guidelines tell us we should all limit our sodium intake to less than 2.3 grams (2300 mg) a day to avoid high blood pressure and death from cardiovascular disease. And those who are over 51, African American, or who have high blood pressure, chronic kidney disease or diabetes should limit their intake even further, to 1500mg a day or less. (Note: the salt molecule consists of an atom of sodium and an atom of chloride; 40% of the weight is sodium, so 1500 mg of sodium equals 3750 mg of salt, roughly ¾ of a teaspoon. Over 75% of our salt is already in the food, not added from the salt shaker.) In 2010, the American Heart Association lowered its recommendations to 1500 mg a day for everyone. We thought that was good advice, but new evidence has muddied the waters. (more…)
Without a doubt the big medical story of the last week or so has been the ongoing outbreak of Ebola virus disease in West Africa, the most deadly in history thus far. Indeed, as of this writing, according to a table of known Ebola outbreaks since 1976 at Wikipedia, in Guinea, Sierra Leone, and Liberia, the three nations affected thus far, there have been 1,440 cases and 826 deaths. Worse, the World Health Organization (WHO) is reporting that it is spreading faster in Africa than efforts to control it. In particular, late last week it was announced that two Americans who had been infected with Ebola were going to be flown back to the US, specifically to Emory University, for treatment, a development that ramped up the fear and misinformation about Ebola virus to even greater heights than it had already attained, which, unfortunately, were already pretty high. Indeed, the ever-reliably-histrionic Mike Adams of NaturalNews.com wrote a typically hysterical article “Infected Ebola patient being flown to Atlanta: Are health authorities risking a U.S. outbreak?” On Saturday, we learned that Dr. Kent Brantly, an aide worker for Samaritan’s Purse, a Christian charity run by Franklin Graham, son of the well-known preacher, Billy Graham, who had been evacuated from Liberia aboard a private air ambulance, had arrived in Georgia.
This latest development inspired medical “experts,” such as Donald Trump, to stoke fear based on the arrival of two infected Americans in the US. For instance, last Friday, after it was first announced that the Ebola-infected Americans would be flown back to the US, Trump tweeted:
The state of New York allows religious and medical (but not philosophical) exemptions from school vaccination mandates. New York City has a policy of excluding unvaccinated schoolchildren from classes when there is an outbreak of vaccine-preventable disease reported in a particular school. Two sets of parents whose children had religious exemptions sued New York City and the state in federal court when their children were temporarily excluded from school under the policy, in some cases for up to a month. In other words, they were demanding that their unvaccinated children be allowed to attend even though there was an outbreak of vaccine-preventable disease at the school.
These cases were consolidated with another filed by parents, the Checks, who claimed their child had been improperly denied a religious exemption. The parents had applied for a medical exemption, which was denied, as well as a religious exemption, which was granted, but then revoked. (The record is somewhat confusing on this sequence of events, but that sequence is not relevant to our discussion.) The unvaccinated child was ultimately sent to a private school, even though she should have been excluded from admission under New York City law there as well.
Last week, a federal judge dismissed all three cases (they had been consolidated and assigned to one judge) in an opinion holding that neither the students’ nor the parents’ constitutional rights were violated, including their First Amendment right to free exercise of religion. The plaintiffs have filed an appeal. (more…)
Introduction: An unexpected e-mail arrives
One of the consequences of the growing traffic and prominence of this blog over the last few years is that people who would otherwise have probably ignored what I or my partners in blogging write now sometimes actually take notice. Nearly a decade ago, long before I joined this blog as a founding blogger, if I wrote a post criticizing something that a prominent academic said, it was highly unlikely that that person would even become aware of it, much less bother to respond to whatever my criticism was. I was, quite simply, beneath their notice, sometimes happily, sometimes unhappily.
It appears that those days might be over. Last week Dr. Daniel Kopans, a prominent Harvard radiologist and well-known long-time defender of screening mammography, sent me a rather unhappy e-mail complaining about my “attack” on him on this blog, a charge that he repeated in a subsequent e-mail. Before I publish his initial e-mail verbatim (with his permission), I would like to point out that, while it’s true that I did criticize some of Dr. Kopans’ statements rather harshly in my post about the Canadian National Breast Screening Study (CNBSS), even characterizing one statement as a “howler,” I would hardly characterize what I wrote as an “attack.” That to me tends to imply a personal attack. Using Dr. Kopans’ apparent definition, what he has said and written about investigators like those running the CNBSS, as documented in my post, about H. Gilbert Welch, who published a large study in 2012 estimating the extent of overdiagnosis due to mammography, and the U.S. Preventive Services Task Force (USPSTF), the group that in 2009 suggested changing guidelines for routine screening mammography in asymptomatic women to begin at age 50 instead of age 40, would appear to also qualify as “attacks.”
Be that as it may, I also wondered why Dr. Kopans hadn’t noticed my CNBSS post until more than three months after it had originally appeared. Then, the day after I received Dr. Kopans’ e-mail, my Google Alert on mammography popped up an article in the Wall Street Journal by Dr. Kopans entitled “Mammograms Save Lives: Criticism of breast-cancer screenings is more about rationing than rationality.” That’s when I guessed that someone probably had either posted or e-mailed Dr. Kopans a link to my previous post in response to that article. Given the confluence of events, I think it’s a perfect time to discuss both Dr. Kopans’ e-mail and his article, because they cover many of the same issues. (more…)
Dug the Dog strikes again.
I was all set to write about a mass of pseudoscience published in a prominent online news/comment site, one that addressed a topic near and not-so-dear to my heart, mainly EMF and cell phone radiation as an alleged cause of cancer and many health problems. Ready to rip into it with gusto, I did have a bit of reservation because I had recently addressed the very same topic when Dr. Oz engaged in a bit of fear mongering about it. It must have been posted to various breast cancer forums or forums dedicated to discussing the purported health issues due to cell phones, because every so often, for the last three months, outraged commenters would show up and lash out at me. But, then, I was made aware of an article that appeared in the New York Times a couple of days ago that brought up memories of something I haven’t written about for a long time.
Besides, I can always blog about the other execrable article on my not-so-super-secret other blog. That’s what it’s there for.
In any case, the NYT article appeared, appropriately enough, in the Fashion & Style section, not the Health section, and is entitled “He Tells the Clintons How to Lose a Little. Dr. Mark Hyman: Advising the Clintons on Their Health.” It’s written by Amy Chozick, a reporter I’ve never heard of, probably because I know the names of most, if not all, of the health reporters for the NYT and national news outlets, but am blissfully unfamiliar with reporters covering the fashion and style beat. Actually, it turns out that Chozick is a political reporter “with a focus on covering Hillary Clinton.” Obviously her focus isn’t on covering health, as her article makes clear.
Does Tamiflu have any meaningful effects on the prevention or treatment of influenza? Considering the drug’s been on the market for almost 15 years, and is widely used, you should expect this question has been answered after 15 flu seasons. Answering this question from a science-based perspective requires three steps: Consider prior probability, be systematic in the approach, and get all the data. It’s the third step that’s been (until now) impossible with Tamiflu: Some data was unpublished. In general, there’s good evidence to show that negative studies are less likely to be published than positive studies. Unless unpublished studies are included, systematic reviews are more likely to miss negative data, which means there’s the risk of bias in favor of an intervention.
The absence of a full data set on Tamiflu (oseltamivir) and the other neuraminidase inhibitor Relenza (zanamivir) became a rallying point for BMJ and the AllTrials campaign, which seeks to enhance the transparency and accessibility of clinical trials data by challenging trial investigators to make all evidence freely available. (Reforming and enhancing access to trial data was one of the most essential changes recommended by Ben Goldacre in his book, Bad Pharma.) In 2009, Tamiflu’s manufacturer, Hoffman-La Roche committed to making the Tamiflu data set available to investigators. Now after four years of back-and-forth between BMJ, investigators, and Roche, the full clinical trials data set has been made freely available. An updated systematic review was published today in BMJ (formerly The British Medical Journal), entitled “Oseltamivir for influenza in adults and children: systematic review of clinical study reports and summary of regulatory comments.” This will be a short post covering the highlights. As the entire study and accompanying data are freely available, I’ll await continued discussion in the comments. (more…)
As I write this, I am attending the 2014 meeting of the American Association for Cancer Research (AACR, Twitter hashtag #AACR14) in San Diego. Basically, it’s one of the largest meetings of basic and translational cancer researchers in the world. I try to go every year, and pretty much have succeeded since around 1998 or 1999. As an “old-timer” who’s attended at least a dozen AACR meetings and presented many abstracts, I can see various trends and observe the attitudes of researchers involved in basic research, contrasting them to that of clinicians. One difference is, as you might expect, that basic and translational researchers tend to embrace new findings and ideas much more rapidly than clinicians do. This is not unexpected because the reason scientists and clinical researchers actually do research is because they want to discover something new. Physicians who are not also researchers become physicians because they want to take care of patients. Because they represent the direct interface between (hopefully) science-based medicine and actual patients, they have a tendency to be more conservative about embracing new findings or rejecting current treatments found not to be effective.
While basic scientists are as human anyone else and therefore just as prone to be suspicious and dismissive of findings that do not jibe with their scientific world view, they can (usually) eventually be convinced by experimental observations and evidence. As I’ve said many times before, the process is messy and frequently combative, but eventually science wins out, although sometimes it takes far longer than in retrospect we think it should have, an observations frequently exploited by advocates of pseudoscience and quackery to claim that their pseudoscience or quackery must be taken seriously because “science was wrong before.” To this, I like to paraphrase Dara O’Briain’s famous adage that just because science doesn’t know everything doesn’t mean you can fill in the gaps with whatever fairy tale that you want. But I digress (although only a little). In accepting the validity of science that indicates either that a medical intervention that was commonly used either doesn’t help, doesn’t help as much as we thought it did, or can even be harmful, they have to contend with the normal human reluctance to admit to oneself that what one was doing before might not have been of value (or might have been of less value than previously believed) or that, worst of all, might have caused harm. Or, to put it differently, physicians understandably become acutely uncomfortable when faced with evidence that the benefit-risk profile of common treatment or test might not be as favorable as previously believed. Add to that the investment that various specialties have in such treatments, which lead to financial conflicts of interest (COI) and desires to protect turf (and therefore income), and negative evidence can have a hard go among clinicians.
One of my favorite shows right now is True Detective, an HBO show in which two cops pursue a serial killer over the course of over 17 years. Starring Woody Harrelson and Matthew McConaughey, it’s an amazingly creepy show, and McConaughey is amazing at playing his character, Rustin Cohle. I’m sad that the show will be ending tomorrow, but I really do want to see how it ends.
Unfortunately, as much as I like Matthew McConaughey as an actor, he is in part responsible for re-inspiring a movement that has the potential to do profound harm to patients and cancer research. That’s because his other big role over the last year has been in an Oscar-nominated movie, Dallas Buyers Club, where he plays Ron Woodroof, an early AIDS patient who in the 1980s smuggled unapproved pharmaceutical drugs into Texas when he thought he found them effective at alleviating his symptoms, distributing them to fellow sufferers by establishing the “Dallas Buyers Club” while battling the FDA. I haven’t seen the movie, and I really don’t want to, given that, from everything I’ve heard about it, it’s basically the story of a “brave maverick” who bucks the FDA, complete with all the tropes about indifferent bureaucrats who don’t care if these brave patients die. That might not be so bad if it weren’t also riddled with inaccuracies and misinterpretations of the AIDS crisis in the 1980s. Worse, the real Woodruff rejected the one truly promising drug at the time, AZT, as hopelessly toxic and instead smuggled drugs like Peptide T, which never panned out. Basically, what Woodruff appears to have smuggled as part of his activities for the “Dallas Buyers Club” was a mixture of useless supplements, experimental drugs that were never approved, and a handful of experimental drugs that showed promise. Meanwhile, the movie portrays the FDA as the implacable enemy of these sorts of activities, jackbooted thugs not unlike the stereotype promoted by “health freedom” quacks who don’t like the FDA preventing them from selling their quackery. As far as I can tell without actually seeing the movie, the overall message is a typical uplifting story of an underdog who fights the power and in doing so finds redemption. (more…)
Affecting public health has a few components. It includes providing a safe environment at home, at work, and in public spaces. It involves protecting the food and water supply from pathogens and toxins. Perhaps the most challenging component, however, is affecting people’s behaviors. Humans are complex psychological animals, and simply providing information to facilitate a rational decision may not always have the intended effect.
Those in power wishing to protect the public from themselves can simply pass laws that coerce people into safer behavior, such as seat belt laws and helmet laws. This approach amounts to outlawing certain unhealthy choices. There is also the “nudge” approach where the unhealthy choice is not outlawed, but the healthier choice is facilitated or made the default choice so that people have to work harder if they still wish to make the unhealthier choice for themselves.
Short of passing laws to force or nudge people in the right direction, the default approach to improving healthy behaviors is to provide information via either public service announcements or warning labels. How effective, however, are such measures? (more…)
You may have noticed that men and women are different. I hope you have noticed. As the French say, vive la différence! It’s not just that one has dangly bits and the other has bumpy chests. Or that one has to shave a beard and doesn’t like to ask for directions while the other has menstrual periods and likes to discuss feelings. There are differences in physiology and in the incidence of various diseases. For instance, normal lab values for hemoglobin are higher for men than for women, and autism is more prevalent in males while multiple sclerosis is more prevalent in females.
In the past, women have been underrepresented in clinical studies; when the first studies of aspirin for cardiovascular prevention came out, we knew it was effective for men, but we didn’t have enough evidence to recommend it for women. This is changing; researchers today are more aware of the need to include women in their studies. Now the American Heart Association/American Stroke Association (AHA/ASA) has issued the first evidence-based guidelines for reducing the risk of stroke in women. (more…)