Field of Science

The worst scientific idea of the decade: vaccines cause autism

The year and the decade are coming to an end, and top-10 lists are everywhere. These are hard to put together if you want to do it right. I’m opting for a simpler list: the top 1, and I’ll make it for the entire decade.

Of all the bad science, bad medicine, and pseudoscientific nonsense that human beings have come up with over the past decade, which is the worst? Of course, scientists have bad ideas all the time, and most of them never make it out of the lab. So for me, “worst” means a bad scientific notion that has emerged into the public domain and done more damage to civilization, or to public health, than any other idea of the past decade.

To answer this question, I wanted a belief or practice that rose to prominence during the past 10 years, which eliminates a large number of pseudoscientific practices and quack treatments that have been around much longer, including acupuncture, chiropractic, and homeopathy. So what idea has taken hold only recently?

And the worst scientific idea of the 2000's is: vaccines cause autism. This idea has caught on and spread like wildfire during the past ten years, thanks largely to the well-funded, well-publicized efforts of organizations such as Generation Rescue, led by the notoriously mis-informed celebrities Jenny McCarthy and her even more famous boyfriend, the actor Jim Carrey.

Strictly speaking, this terrible idea was first published more than a decade ago, in a now-discredited, notorious 1998 paper in The Lancet by Andrew Wakefield, a British gastroenterologist. This very small study of 12 children seemed to show a link between the measles, mumps, rubella (MMR) vaccine and autism, but it later turned out that the study had multiple flaws: Wakefield recruited the children to the study through a lawyer who was trying to build a case against vaccine makers, Wakefield himself received over $750,000 in consulting frees from the same lawyer, Wakefield didn’t tell his co-authors any of this, Wakefield had filed for a patent on an alternative, “safer” vaccine, and on and on. Although his co-authors repudiated the paper publicly and withdraw their conclusions in 2002, Wakefield has continued to this day to stand by his original claims. (See journalist Brian Deer’s website for a good summary of the Lancet scandal.) He moved to the U.S. after being forced out of his job at a London hospital, and he set up a private business in Texas from which he continues to promote his anti-vaccination claims.

Pfizer wants you to make a New Year’s resolution

“80% of you will fail to quit smoking with Chantix. “ That’s what the ad should say, but it doesn’t. Instead, it shows a smiling woman who “quit smoking with Chantix and support in June ’07” and it promises “with Chantix you can smoke during the first week of treatment.” Nowhere does it say how likely you are to quit smoking.

This is from a very large, full-page ad that’s been running for weeks, almost every day, in the Washington Post and other newspapers. The top 1/3 of the page is the “sell,” and the rest of the page contains the required safety information, which tells you some of the problems, including hostility, depression, suicidal thoughts or actions, and nausea. Naturally, the top of the page is in a larger font with a colorful picture.

Why is Pfizer (Chantix’s manufacturer) running these ads now? Well, quitting smoking is a very popular New Year’s resolution. It’s on many top-10 lists, even one from the U.S. government. Pfizer is trying to grab smokers’ attention now, so they’ll ask their doctors for a prescription, which I have no doubt they’ll get. These direct-to-consumer ads work, big time, and the drug makers know it. The U.S. should never have allowed drug makers to advertise directly to consumers – and Congress should re-institute laws prohibiting these ads.

Alcohol and cancer: journal editors say they got it wrong

In a recent editorial in the Journal of the National Cancer Institute, three scientists point out that I was correct in my February blog post, where I pointed out the errors - and the mistaken scare-mongering - in press reports of a new study on alcohol and cancer.

The JNCI editorial, titled "Promoting Healthy Skepticism in the News: Helping Journalists Get it Right" focuses on two studies, one of which is the article I wrote about. Journalists at the time, including Sanjay Gupta at CNN, reported "there is no level of alcohol consumption that can be considered safe when it comes to cancer." As the editorial points out, the journalists got it wrong. The authors point out that other explanations (other causes besides alcohol) might explain the increased risk. And it's nice to see that even though their own journal was partly to blame for the hype back in February, at least they're making an effort to correct it now.

They could have done more, though. They didn't dig into the article and report, as I did, that the minimum risk levels in the study were for light drinkers, who had 1-2 glasses of wine per week and who had a lower risk than non-drinkers. But at least they pointed out that the absolute increase in risk, even for heavy drinkers, was very small. In fact, they go on to say that under-reporting of absolute risk is a major failing of many biomedical journals.

So my advice for the holiday season is: drink up! The evidence for heart-healthy benefits of wine, especially red wines with high levels of procyanidins (as described in this article from Nature 2006), probably outweighs any risks. Happy holidays!

Crestor gets an undeserved boost from the FDA

The FDA planted a big, wet sloppy kiss on AstraZeneca this week. An FDA scientist told reporters that the benefits of Crestor, a cholesterol-lowering drug, outweighed the risks even for otherwise healthy people. Essentially, millions of healthy people with normal cholesterol levels could find themselves taking Crestor, if they listen to this anonymous FDA scientist and to Crestor’s manufacturer, AstraZeneca. This new recommendation was widely reported on Friday, appearing in the Wall St. Journal, in a widely carried AP report, and in a more skeptical Reuters report.

The new report isn’t based on anything new, though. It’s based on a study published a year ago – a seriously flawed study that I dissected at length on this blog in November 2008. The FDA took a year to review this study and then said yep, we agree. I should mention that the 2008 study has one condition before recommending Crestor: that the patients should have elevated levels of C-reactive protein (CRP). I described in earlier blog post the problems with this recommendation – including the fact that they study’s leader has a patent on the CRP diagnostic test.

Does it matter that, as I explained a year ago, the study was funded by AstraZeneca? How about the fact that this huge study found only a tiny benefit? That’s right: the benefit is so small that you’d have to treat 95 patients for 2 years in order to prevent one heart attack. As I wrote last year, and as others have pointed out, when the number needed (NN) to treat is over 50, the result is probably just statistical noise. Or to put it another way, if you take Crestor for 2 years, you have about a 1% chance of getting any benefit. Compare that to, say, taking vitamin C to treat scurvy, where the NN is about 1. With any decent drug, if you take it, you should have a very high likelihood of benefit.

We know who’s going to benefit here: AstraZeneca. Does it matter to them that there is a significantly higher risk of diabetes in people who take Crestor? There was also a higher number of deaths in the placebo group caused by gastrointestinal disorders, but the FDA dismissed this number because it didn’t reach statistical significance. (Kudos to the WSJ and Reuters reporters for highlighting these problems.) And no one besides me (see my Nov 2008 blog post) seems to have noticed some of the other problems with the study, such as the fact that the placebo group contained an excess in the number of patients with conditions that raise the risk of heart disease.

Does it matter that, as the FDA reported in 2005, “Rhabdomyolysis (serious muscle damage) has been reported in patients taking Crestor as well as other statin drugs.” Or that, as the same report said, “Kidney failure of various types has also been reported in patients treated with Crestor as well as other statins”?

So who the heck are these FDA scientists? After considerable searching, I found the lengthy FDA report here. It’s a “briefing document” for a FDA advisory committee that will meet on Dec. 15. It basically reviews the study in great detail and simply repeats the study results. What became clear to me once I downloaded the document, though, was that it was written by AstraZeneca! [Note: thanks to the first commenter on this blog, I also found the separate FDA-sponsored document - see comments.]

The reports from the AP, Reuters, and the WSJ I cited above mention an anonymous FDA reviewer, but apparently this “reviewer” did not want to be named on the record. It's too bad none of the reporters revealed the name of this anonymous FDA scientist, but the roster of the FDA panel reviewing Crestor is here.

It’s a shame that the FDA’s own scientists can’t take a more critical look at the evidence. Look for AstraZeneca stock to go up next week. Let me close with a video from Stephen Colbert, who had a great skeptical spoof of this last year on his show. Skip forward to about the 2-minute mark in this video to see the Crestor segment.

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As Stephen says in the video, "this is a great breakthrough in the battle to find things to prescribe to people who don't need them".


Read this if you like shrimp

Shrimp are tasty little morsels, but for years I’ve limited my shrimp intake because they’re high in cholesterol, or so I heard. Recently, though, I heard that they might good for you, so I decided to investigate. The results are a bit surprising.

First, shrimp is high in cholesterol, very high in fact. The American Heart Association recommends no more than 300 mg per day for a normal adult, but a 5-ounce serving of steamed shrimp contains 590 mg. For comparison, 2 large eggs contain about 580 mg of cholesterol.

On the other hand, shrimp is quite low in fat. That same 5-ounce (150g) serving of shrimp has just 1.7 grams of fat, while the same amount of beef has 14 grams of fat. So it’s low in fat, but high in cholesterol. What’s a shrimp-lover to do? Luckily, there’s a bona fide scientific study that attempted to answer this question – but with a catch, as we’ll see.

Searching the Web for shrimp and cholesterol, it’s easy to find lots of pages offering health and nutrition advice telling you that shrimp are good for you. But most of these webpages are from dietary advice “experts” who want to sell their books and diet plans, or from shrimp producers. Uh oh.

Science, medicine, and politics mix in new mammography and stem cell guidelines

Today's news included two stories that both illustrate how politicians almost always get science wrong. It never seems to be a good thing when politicians sink their teeth into a scientific or medical question: they are only too happy to distort the facts to achieve their political goals.

First, the new mammography guidelines. This was all over the news two weeks ago: an official federal advisory panel, the U.S. Preventive Services Task Force, recommended that women between 40 and 50, who had no risk factors for breast cancer, not have annual mammograms. This caused a firestorm of criticism from many quarters, because the previous guidelines recommended annual screening. The panel determined, after looking at data from the past decade and more, that the risks of excessive screening (many more false positives, and the resulting biopsies and even surgeries) were not justified by the small number of additional cancers detected.

This is a complex issue, and many other bloggers wrote about it, so I'm not going to discuss it in detail. My overall impression was that the panel weighed the evidence and made their recommendations based on the best available science, and I think their decisions were good ones. I'd also note something that the media seems to have missed: about ten years ago, when another panel was debating similar recommendations, there was tremendous political pressure to make annual screening the official policy.