High dose vitamin C does not cure influenza

60 Minutes here in New Zealand presented perhaps the worst science story I have seen all year. Their story on the claimed link between high dose vitamin C and miraculous influenza recovery was absolutely terrible – for reasons I will outline in the next few stanzas (if that is enough to do justice).


Before reading further: The 60 minutes journalist called this story a “controversy”. It is important to note that this is only a controversy among the public and is partly due to the irresponsible reporting in the first episode of this story last month. Rest assured, the role of vitamin C inside the body is well known and there is no scientific controversy around this.


First of all, where did this idea that vitamin C could cure anything other than scurvy come from? It is a pop culture myth that vitamin C (especially in the mega-doses people take it in) has anything to do with curing the common cold or influenza. Linus Pauling published several books in the 1970s about the purported therapeutic effects of vitamin C.

Despite having two Nobel prizes, Pauling’s claims were admonished by the scientific community – Paulings ideas did not stand up to tests. Despite this, he could not let his ideas go and he died in 1994 with the duel distinction of being both a genius and a crank.

When we’re sick, it seems natural to take everything we can to make ourselves feel good. The thing about vitamin C (and other supposed cures like ginseng) is that the “make ourselves feel better” is purely psychological as there is no evidence for the efficacy of these substances. In some cases, vitamin C can be detrimental to the natural healing process because it is a strong antioxidant. In combatting illness, the immune system produces antibodies, which are essentially potent oxidants.

The back story

In the 60 Minutes piece, Alan Smith – a man who, on the brink of death suffering from the infamous H1N1 strain, made a full recovery. At his family’s request, Alan was administered intravenous doses of vitamin C prior to experiencing said miracle

Because of what we know about vitamin C and its action within the human body, we can be certain the vitamin C had nothing to do with the recovery. But this case is a classic case of how beliefs (and alternative medicine generally) veer off the cliff of rationality into the valley of the ‘woo’.

To keep it real, keep it rational

A few points about drawing the inference that there is a causal relationship between the substance (in this case vitamin C) and the recovery. These points are textbook mistakes that lay people make when making health and medical decisions. The style of thinking that embraces the points in the list below account for why large numbers of people believe in unscientific medicine.

  • Confusing correlation with causation – As obvious as this sounds, the journalist asking the questions of the scientist in the story was adamant in her presupposition that vitamin C miraculously cured Mr Smith. The fallacy at work here is that correlation does not necessarily mean causation. This is why we use the scientific method to conduct randomised trials that isolate various factors to see their influence on the outcome. As humans, we make quick judgments about what causation is and then we act as if it is true. It often is impossible to know what causes and observed effect using our reasoning faculties alone and more often than not, we make snap judgments based on prior knowledge and biases. Related fallacy: Post Hoc reasoning – it happened after X therefore it is because of X.
  • Argument from authority – “But these professors in Melbourne use vitamin C to treat patients all the time”. Good for them. The fact they are professors means zero. Even if they worked in the field of expertise in question, the testimony of a professor or a scientist in a lab coat is insufficient to be reliable as an account of reality. Scientists, doctors and engineers are human beings with the same flaws a biases as you and me. Personally, the testimony of one scientist or even a handful, is uninteresting to me. You can find a scientist that will validate any crack pot theory you can dream up. The preponderance of evidence is what we’re interested in when making claims to reality and that can only come from repeated experiments and falsification.
  • Observational selection bias/statistics of small numbers – The nature of news stories is such that a non-event is not news. If 3 people in a 1000 made full recoveries from a particular condition after doses of vitamin C, would you be convinced the 3 were cured by the vitamin C? It would be odd logic if one did. Of course, a news story is only going to focus on the ones that made it while we don’t know how many didn’t make miraculous recoveries. Only a scientific trial can reliably establish whether a treatment is effective or not.
  • False balance – The journalist did not do adequate research. In fact, she gave an open platform to ‘brave crusading alternative practitioners’ who couldn’t care less what is supported by evidence or not. As John Fraser, Head of School of Medical Sciences at Auckland University so aptly put it:

“The consultants were quite right to resist the use of an unproven treatment, and to their credit they did acquiesce to accommodate the family’s wishes because they felt it would do no harm. In this remarkable case the patient did survive but there is no evidence that this was due to the vitamin C. This is a wonderful story of personal survival and it is sad that it has been used to discredit those professionals who were just trying to provide their best for a very sick patient. If the vitamin C had killed him, then the story would have been different. That is the risk of using an unproven treatment.”

Conclusion

In the end, the 60 Minutes story was an apology for cranks who take the ignoance of the lay public and exploit it for their own gain. There  was little attempt to challenge the vitamin C proponents, yet the scientist trying to express why it is improbable that vitamin C cures these illnesses was slated for his rational explanation.

It would be naive to expect anything different from a mainstream news broadcast – the story was always going to be framed around the “experts are strong arming people into their paradigm of medicine” nonsense.

The victims in this story are the people who watched the programme and went away believing the claims of the cranks. After all, taking vitamin C seems to be the common sense solution when we are ill. However, our intuitions and pop myths are poor platforms to determine what is actually effective or not.

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