I came down with a nasty cold before the holidays – so bad that I briefly thought I had the flu, and was cursing myself for having waited so long to get the flu shot, which I’d received just before the symptoms began.
Amidst all the sniffling and groaning and self-pitying, it occurred to me that, while we’ve spent a lot of time this season talking about influenza, we haven’t much covered the common cold. There are reasons for that of course. Though sometimes as unpleasant as influenza, colds rarely kill. There’s also no organized movement attempting to subvert public health initiatives related to the common cold, as there is with the flu. So the stakes are certainly lower.
Yet there are an awful lot of cold products on the market, and as is often the case when symptoms are inherently self-limiting, many of these treatments are highly questionable. That goes for pharmaceutical products as well as alternative ones, as the following roundup of popular remedies illustrates:
- Vitamin C – the grand-daddy of all cold treatments, taking mega-doses of Vitamin C to fight the cold was popularized by Nobel prize-winning chemist Linus Pauling in the 60’s, proving Ben Goldacre’s maxim that having a PhD is just a risk factor for being correct. Subsequent research over the last 50 years has failed to show any effect – a fact that has been widely covered yet has done only minor damage to the treatment’s appeal.
- Echinacea (Flu Shield, etc.) – popular when I was still wearing Eddie Bauer plaid, Echinacea has very much lost its lustre of late. The evidence was never great, but the recent (and thankfully, widely reported) study published in the Annals of Internal Medicine seems to put the nail in the coffin.
- Cold-FX – this ginseng-based product promises to strengthen the immune system to “stop colds & flu in their tracks”. Scott does a detailed review over at Science-Based Pharmacy, noting that the clinical evidence is mixed, and all of the studies have methodological problems, so it’s hard to separate the data from the noise. However, even on the most charitable read of the evidence, most people won’t get much benefit out of the product for the $400 worth of pills it takes to prevent a single cold.
- Oscillococcinum – the new “it” remedy promises cough, cold and flu relief for children with “no known side-effects, no risk of overdose, no contra-indications”. No wonder – it’s a 200C homeopathic dilution of duck heart and liver – that’s one part in ten thousand trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion. As Scott points out while taking Health Canada to task for approving this product, “It is mathematically impossible that there is any of the original fermented goo in the final product.”
- OTC Remedies for Children – Oscillococcinum’s new children’s version is largely the result of recent evidence showing that OTC pharmaceutical remedies (expectorants, cough suppressants, decongestants, and first generation antihistamines) provide no benefit in children. Children’s doses of these medicines have now been pulled from pharmacy shelves, leaving a void in the market that Oscillococcinum has been all too happy to fill with lactose. (And they say we skeptics only question natural remedies. I guess my cheque for being a Big Pharma shill won’t arrive this month.)
Of course, people are free to spend their money on unsubstantiated treatments if they like. There’s little risk in any of these treatments (with the exception of the children’s OTC products), and I’m the first to admit that cold symptoms are precisely the type that the placebo effect works best on. In some ways ignorance may indeed be bliss, and my intent today is not simply to write a consumer protection piece. Rather, what I’m hoping to explore is the incorrect assumption at the heart of these treatments – an assumption that’s repeated widely and without question both in the media and in the individual discussions we all have about health and illness.
Immune to Evidence
With the exception of the now-removed children’s OTC products, all of the above remedies have one thing in common: they claim to work by boosting the immune system, making it better able to fight off viruses before they can cause unpleasant symptoms. This seems like an inherently reasonable proposition – we have a natural defense system, so why not help it do its job better?
And in fact, that’s exactly what we do when we vaccinate. By injecting dead or critically weakened viruses into our body, our immune system does indeed learn how to fight that virus when it later sees it live and full strength. Of course vaccination isn’t feasible for the common cold – between the healthcare costs and the known risks (however rare), it’s hard to make a case for public health intervention to avoid a benign, if unpleasant, illness.
But immune boosting in common parlance (and in cold product marketing materials) is different from vaccination in a very critical way. Vaccination teaches the body how to respond to a specific threat, whereas these cold products claim to boost the immune system’s general ability to respond to any threat. And that’s where the marketing disconnects from the science.
I was first made aware of this disconnect by the inimitable Mark Crislip, an infectious disease specialist who writes over at Science Based Medicine, in a post from last September. (Skeptoid later took up the topic, but relied primarily on Mark’s original). While I have immense respect for Mark, and am inclined to trust his opinions within his field of expertise, I have to admit I was reticent to accept his assertions because they fly so directly in the face of the “received wisdom” on the subject. So I made a mental note to look more closely at the data at some point…which I then promptly forgot. (Maybe I should have taken my Ginko biloba).
I was reminded again when a co-worker, commenting on my aforementioned cold, began to espouse the wonders of Oil of Oregano — which, he assured me, was the best immune booster on the market. He always takes it at the first sign of cold, and he never gets sick. I knew from the detailed review Scott did over at Science Based Pharmacy that Oil of Oregano was “all anecdotes, no science”, so I smiled politely, thanked him for his advice, and finally finished what I’d intended to do when I read the Crislip article.
Turns out the fact-checking on this wasn’t all that hard – I had to look no further than Harvard Medical School’s 2010 publication, The Truth About Your Immune System: What You Need to Know, from which the title quote is taken. Concise and readable without shying away from the technical details, the report provides a comprehensive overview for the layperson of what the evidence says — and doesn’t say — about how the immune system works and what you can do to improve its function.
Enticing, But Elusive
The report is unequivocal about the current state of the science: simply put, there is no known way to boost one’s immune system other than vaccination. While admitting that there is indeed tantalizing research positing a connection between immune function and various aspects of diet and lifestyle, all of it is preliminary and researchers don’t yet know enough about “the intricacies and interconnectedness of the immune response” to recommend anything more than general healthy-living strategies. Taking aim specifically at marketers that claim otherwise, the report states:
Many products on store shelves claim to boost or support immunity. But the concept of boosting immunity actually makes little sense scientifically. In fact, boosting your immune response is not necessarily a good thing. A hyperactive immune response underlies a number of major diseases, including diabetes, rheumatoid arthritis, and lupus. It is also responsible for allergic reactions to ordinary nontoxic substances.
Even if it were a good thing, attempting to boost the cells of the immune system is especially complicated because there are so many different kinds of cells in the immune system that respond to so many different microbes in so many ways. Which cells should you boost, and to what number? So far, scientists don’t’ know the answer.
The report then goes on to take a close look at the evidence on a wide array of putative immune boosters. Here’s what it has to say:
- On Vitamins: “So far, there is no evidence that taking extra amounts of any vitamin will boost the immune response or protect against infection in any way.”
- On Diet: “There are still relatively few studies of the effects of nutrition on the immune system of humans, and even fewer studies that tie the effects of nutrition directly to the ability to fight off infectious disease.”
- On Exercise: “a direct beneficial link hasn’t been established”
- On Probiotics & Prebiotics: “a direct connection between taking these products and improving immune function has not yet been made scientifically. In fact, changing the balance of bacteria already long established in the human gut may not even be possible.”
- On Herbs & Supplements: “Although a few preparations have been found to alter some components of the immune function, thus far there is no evidence that they actually bolster immunity to the point where they protect against infection and disease….Scientists don’t know, for example, whether an herb that seems to raise the levels of antibodies in the blood is actually doing anything beneficial for the overall immunity.” Similar conclusions are made for the supplements they cover specifically in the report — Astragalus, Echinacea, Ginseng, Licorice Root, and Umckaloabo.
So what’s a body to do? With the claims of marketers (and newscasters) in tatters, the report lists six steps you can take to help your immune system. It’s instructive that five of them – good hygiene, food safety, clean water, insect repellent, and safe sex – are about avoiding pathogens entering your body in the first place, rather than improving your body’s response. The sixth of course is vaccination, still the only known way to make your immune system work better.
Which leaves the cold sufferer reduced to the old standbys – rest, liquids, and the comforting knowledge that it will all be over soon. For as an Egyptian physician I once knew told me, “In my country, they say that without treatment a cold will last for seven days. With treatment — a week.”
Photo courtesy of William Brawley under Creative Commons.