Junkfood Science: How we know what will kill or cure us

November 19, 2007

How we know what will kill or cure us

With the upcoming conference on the use of homeopathy for HIV/AIDS just weeks away, the homeopathy debate is heating up among the medical and scientific community. As JFS readers will remember, this conference is sponsored by the Society of Homeopaths and its promotional literature claims that with homeopathy, “the AIDS epidemic can be called to a halt.” The current issue of the British medical journal, The Lancet, focuses on this issue. The discussions, however, bring into focus much larger ethical issues about public-funded healthcare.

Udani Samarasekera, Lancet senior editor, reported that pressure from medical and science professionals has been mounting to stop government funding of homeopathy in the UK. Two main concerns are at the root of this movement: the lack of evidence for homeopathy’s effectiveness and its potential dangers.

A meta-analysis published by The Lancet in 2005, and four other large meta-analyses, have all shown that the clinical effects of homeopathy are no greater than placebo, he said. Despite the lack of evidence, it continues to be popular with about 14.5% of the population, and the homeopathic industry is increasingly profitable, with an estimated worth in the UK of over $78 million (U.S. currency). Dr. Michael Baum, professor emeritus of surgery at the University College London, explained that the public support may be due, in part, to the fact that people often confuse homeopathy with herbal medicine. “Although many herbal medicines are unproven, he said, they have scientific plausibility, unlike homeopathy.”

While some suggest that homeopathy could still have usefulness in medicine for its placebo effect, Dr. Baum disagreed, saying it is unethical and patronizing for doctors to deceive patients. Misleading people might seem in their best interest, but ultimately it destroys the relationship between doctors and patients built on trust and honesty.

Dr. Ben Goldacre, a London physician, put it succinctly in an editorial in the same issue of Lancet, writing:

[W]hen a health-care practitioner of any description prescribes a pill which they know is no more effective than placebo — without disclosing that fact to their patient — then they disregard both informed consent and their patient’s autonomy. Some could argue that this cost is acceptable, but such old-fashioned paternalism can ultimately undermine the doctor–patient relationship.

Do people really want their healthcare provider to withhold information from them about their own bodies and take away their ability to make informed choices? Do they really want someone deciding what’s best for them?

The idea that something seemingly as harmless as water could be dangerous might seem improbable. But impugning mainstream medicine is the main reason consumers turn to alternatives, and the results can be deadly. Homeopathic modalities are not uncommonly prescribed for serious illnesses, such as hepatitis and malaria (or HIV/AIDS as this upcoming conference proposes), detracting patients from known effective treatments for life-threatening diseases. Half of homeopaths in one study advised patients not to have their children immunized, based on unsound fears. Children and adults have even died after stopping their medical treatments on the advise of their homeopaths, who are often not medically trained to recognize critical diagnoses.

And simply the act of prescribing pills or potions reinforces the medicalization of life and our fears that every symptom means something is wrong that needs a pill or intervention to fix. It feeds needless anxieties.

But Dr. Goldacre made another powerful argument today in an article for the Guardian. He pointed out an especially troubling consequence of medical and science professionals who collectively condone homeopathy: undermining the public’s understanding of science and clinical research, and what it means to have evidence-based treatment. This leaves people more vulnerable to being harmed and unable to understand enough to be involved with doctors in difficult treatment decisions.

“Evidence-based medicine is beautiful, elegant, clever and, most of all, important,” he wrote. “It is how we know what will kill or cure you.”

The mysteries of the interaction between body and mind are complex, including the placebo effect. It’s more than simply believing a pill or substance can make us feel better (or conversely, sick by means of the nocebo effect), he said. It is “about the cultural meaning of a treatment, our expectation.” In his article, he responded to the most common response he hears from those who believe homeopathy works:

“All I know is, I get better with homeopathy.”

One reason for this common misconception, he explained, is because of “regression to the mean.” What this means is that our aches and pains come and go, our moods rise and fall, a weird rash appears and then goes away, and we get sick and then get better. These cyclical changes would happen, whether we take something for them or not. By taking a pill when we’re feeling our worst, though, the odds are that we’ll get better and then to attribute the feeling better to the pill. And believe that the pill works.

So, how can we know if it was really the pill that helped us or just the placebo effect? Dr. Goldacre described a trial, say for a homeopathic pill:

You take, say, 200 people, and divide them at random into two groups of 100. All of the patients visit their homeopath, they all get a homeopathic prescription at the end (because homeopaths love to prescribe pills even more than doctors) for whatever it is that the homeopath wants to prescribe, and all the patients take their prescription to the homeopathic pharmacy. Every patient can be prescribed something completely different, an “individualised" prescription - it doesn't matter.

Now here is the twist: one group gets the real homeopathy pills they were prescribed (whatever they were), and the patients in the other group are given fake sugar pills. Crucially, neither the patients, nor the people who meet them in the trial, know who is getting which treatment.

This trial has been done, time and time again, with homeopathy, and when you do a trial like this, you find, overall, that the people getting the placebo sugar pills do just as well as those getting the real, posh, expensive, technical, magical homeopathy pills.

What he's described is, of course, a randomized, placebo-controlled clinical trial. The tricky part of understanding the science comes in when these trials aren’t “fair tests.” We see examples of that all the time here, and not just in homeopathy research. For example, if patients are not randomized, the investigator can selectively or unconsciously put sicker people into the placebo group and healthier ones into his modality, thus ensuring his treatment will appear to work better. Or, the trial may not be blinded, so that people and the investigators know who is getting the placebo and who is getting the treatment, thus helping to ensure the therapy is seen more favorably.

“So when doctors say that a trial is weak, and poor quality,” he wrote, “it's not because they want to maintain the hegemony, or because they work for ‘the man:’ it's because a poor trial is simply not a fair test of a treatment.”

Those trying to convince us that their treatment or program works can also pick out just the positive studies to tell us about — this is called “cherry picking” the literature. When it seems that virtually everything we read in the medical literature is in support of something, it can also be due to what’s called “publication bias,” where positive results are much more likely to get published than those null findings that disprove something. While those negative studies are actually the more important ones, they’re seen as less glamorous and exciting to publishers and the media. Those are also the ones that advertisers don’t like — no one wants to support research telling people that what they’re selling doesn’t work!

Currently, on both sides of the Atlantic, we face increasingly limited healthcare resources, so much so that care is being rationed and people are being denied proven therapies that can help them. Simultaneously, our governments are spending billions of dollars on research and initiatives that are implausible or that the science has repeatedly disproven. Together, these trends point to the importance for all of us to recognize good science and sound evidence. This is more than just how our tax dollars are spent, but about lives.

As science and medical professionals, we have a special commitment to understand and stand up for the most careful science and evidence-based medicine, to advocate for patients and point out flawed medical beliefs and practices — no matter how popular they may be­ — and to work to ensure monies and resources are prioritized soundly and people receive the best care possible. On this task, alternative modalities, mainstream medicine, food safety and obesity are no different.

© 2007 Sandy Szwarc

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