A Californian judge had enough power to decide that all coffee sold in California has to carry a warning: coffee causes cancer. Starbucks restaurants are among those where you probably encounter the warning everywhere now.
I think it's virtually certain that this regulation will cause much more harm than good – especially because the people get terrified. On top of that, there are serious doubts whether the warning is true in any meaningful sense.
Geoffrey Kabát [Jacket in Czech] works in the Albert Einstein Institute of Medicine – a good enough name for this blog – and he explained some basic facts about coffee and cancer.
The justification of "coffee causes cancer" is based on the fact that 1) roasting creates trace amounts acrylamide, some compound, and 2) in animal experiments, animals served a much larger amount of this compound developed some kinds of cancer.
There exists no evidence based on the observation of the people that would imply that coffee increases the overall cancer risk. In some types of cancer, a weak positive (harmful) signal may exist in the literature. In other types of cancer, coffee was found to reduce the cancer. In both cases, the effects seem weak enough to matter for a pragmatic person.
This must be expected. Everything we do affects us in some ways. Every compound we consume increases the chances of some diseases and decreases the chances of others. It's a very complicated thing because the number of causal mechanisms is so large and complex. The mere existence of "some effect" shouldn't be a justification for a terrifying warning – simply because one would have to be warned about everything because it causes one-half of everything else to arise and one-half of everything else to disappear. ;-)
The consumers react to the warning. Their reaction is in between two extremes. One extreme is that they're terrified and they almost stop drinking coffee – or something else. The other extreme is that they basically ignore the warning. The first option is an overreaction. But the second option is equally bad because people become indifferent to warnings. And there could be warnings that are actually important for the general health, unlike the coffee warning. When the authorities cry wolf too many times, they may lose the ability to warn the people when it matters. The real situation has some amount of the bad effects of the first kind, some amount of the bad effects of the second kind. Does it really have substantial good effects that would make the policy a net benefit?
Cigarettes became a template for these warnings. I am sure that the life expectancy of strong enough smokers is shortened by several years. I am a bit uncertain about the life expectancy of the second-hand smokers – whether it's shortened at all and whether the difference is large enough to be detectable. I quit smoking when I was 5 years old – I tried to inhale once and it was really disgusting. I am no fanatical non-smoker, however: two months ago, I inhaled from a cigarette once again. That's enough for 40 years. ;-) As a kid, I was an avid second-hand smoker, due to my mother. When I returned from school, I often tried not to breath for two minutes and quickly open the windows.
But I think that the cigarette bans are over the edge. And the disgusting pictures that have to be added to packages of cigarettes are disgusting, too. I believe that kids and others should be protected from this kind of ugly visual smog.
A cigarette shortens one's life. The whole process is unpredictable and stochastic but the expectation value is some 11 minutes. That's how much one cigarette subtracts from your life. Some medicine experts who tried to do "the same thing", more or less, that I would be doing ended up with that answer. What does it mean? It means that when you smoke, and it may take those 11 minutes per cigarette as well, your speed of marching towards death doubles. Do you enjoy the life twice as much during those times? I am pretty sure that most smokers will say "yes". A cigarette is often something that dramatically improves their whole afternoon, not just those 10 minutes. When they stop smoking, the march towards death returns to the usual slower rate.
Instead of the "infinitely terrifying" warnings everywhere, I think that the "fairest possible" warnings should be placed there instead. For example, a cigarette package would say:
Because it helps to ignite serious diseases, one cigarette shortens the average smoker's life by 11 minutes.The case of the coffee is much less understood so the warning should be correspondingly fuzzier:
One cup of coffee may shorten the life by 0-3 minutes by helping some kinds of cancers, but it may prolong the life by 0-2 minutes by reducing other kinds of cancers.The true impartial experts similar to Dr Kabat should design "the most honest" summary of this kind and this is what should be written on the coffee cups. Similar comments could be written on many other things related to the public health and safety – safety helmets, air bags, be my guest.
These warnings should simply become more quantitative and honest because a terrifying warning without any numbers may exaggerate the threat much more than no warning understates the threat. In this sense, the alarmist warnings make the market less honest than it was previously.
It may be hard to make such a reform. One reason is that most judges and even lawmakers are scientifically illiterate. In the USA Today news, we read:
He ruled in an earlier phase of trial that companies hadn’t shown the threat from the chemical was insignificant.Note that presumption of guilt, instead of innocence – also known as the precautionary principle – is used here. But if you evaluate the literature rationally, you will conclude that the threat is insignificant. What the literature doesn't show is that the threat is zero. Well, it's because no threat is zero. And with these insanely ambitious standards, you can't prove the harmlessness of anything. I am sure that water also causes some kinds of cancer, in some amounts and under certain circumstances. So far, these activist judges "only" attack coffee (and things like carbon dioxide). But they may attack water or the air or at least the meat, sugar, bread, or vegetables in the future, too.