FOR months now, UK prime minister Boris Johnson and his ministers have been repeating a mantra for tackling the coronavirus pandemic: follow the science. Debates about “the” science aside – the UK government seems to have had too many modellers and not enough public health experts advising it – an approach based on evidence is always a good one.
Evidence, however, can sometimes be lacking. On 29 January, early in the pandemic, the World Health Organization published a guide on the use of medical masks by the general public to slow the spread of the virus. It said that compulsory mask wearing shouldn’t be required, as “no evidence is available on its usefulness to protect non-sick persons”.
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It is easy to read those words and assume that face coverings of any kind are pointless – indeed, that is precisely what many people have done. But as the saying goes, absence of evidence is not evidence of absence. Rigorous studies on mask wearing have simply not been done, so we cannot say for sure that they work. We also cannot say that they don’t.
Now, though, new evidence is trickling in. As a result, official policy in many countries, including in England (see “What are face covering rules in England and why did the policy change?”), is changing. We still don’t have the gold standard of medical evidence – a randomised trial – but as we learn more about how the coronavirus is transmitted, face coverings seem a sensible idea.
“The two pandemics have become interlinked, with obesity a factor in some cases of severe covid-19”
Not content with fighting one pandemic, Johnson has also signalled his intention to begin battle with another: obesity. Of course, the two pandemics have become interlinked, with obesity a factor in the development of some cases of severe covid-19.
However, despite obesity having been around for a great deal longer than covid-19, the evidence on what to do about it remains surprisingly contradictory, with dieticians at loggerheads over whether the most effective approach is to reduce how much fat or carbohydrate we eat (see “What is the best way to lose weight and keep it off for good?”). To find out, we need more long-term research. Only then can we follow the science.
