For years the husband has insisted that chocolate is a health food. He’s also spun me the line that eating it is good for the rainforest, as the mature cacao trees apparently grow in mature forest. So he’ll be happy with the Herald‘s story on his sweet treat, which has the enticing title of “Sweet news: chocolate is good for you”, and comes direct from the Daily Mail, that fount of all things good in science reporting. (Not.)
Me? Not so much. Like cautious investors, I tend to subscribe to the view that if something sounds too good to be true, it probably is.
The item begins:
Just in time for Easter, it’s the news chocolate lovers have dreamt of – official confirmation that their favourite guilty pleasure can be good for you.
New research shows that eating just a single chocolate bar has a direct effect on the brain and may cut the risk of stroke.
The research on which the Daily Mail‘s story is based was published last week in the journal Neurology, to which – alas! – we don’t have a subscription. The brief excerpt I can see indicates that the researchers were building on an earlier publication:
Larsson et al. investigated the association between chocolate consumption and risk of stroke in men, concluding that moderate chocolate consumption may lower the risk of stroke. We performed a prospective mechanistic study that may suggest a potential mechanism for this observation.
A prospective study is one that takes a group of individuals & follows them for some period of time, studying the impact of various factors on that group; ‘mechanistic’ means that the researchers would be looking to explain their findings in terms of physical or biological causes. In this case they were interested in the impact of eating chocolate, & apparently found that this had an impact on blood vessels; specifically, on the stiffness of the vessel walls. It would be interesting to read the actual paper because I’d like to know, for example, which blood vessels were studied, & how they determined the ‘impact’ of chocolate on brain cells. It’s notable that there’s no indication of what constituent of chocolate might be involved in any possible outcomes, so it’s a very broad-brush, preliminary outcome.
In its timing this mirrors an earlier story, published just before Easter 2010. However, the 2010 story is much more balanced in scientific terms, pointing out the shortcomings of the earlier research (and that most newspapers Got It Wrong) & noting that while it was possible that eating a small quantity of chocolate might confer some benefit, the association between choccy consumption & health wasn’t particularly strong. (And in fact, reported chocolate consumption appeared awfully low – the ‘high intake’ group reported eating a mere 7.5g/day!)
In this week’s Daily Mail story, the lead researcher is quoted as saying that
We think a reduction in stroke risk may be caused by chocolate changing how brain blood vessels behave.
It’s a real pity that the DM left this next part of the message until the very end of the tale, but at least the paper does note that
chocolate also has a high sugar and fat content which can cause obesity – a definite risk factor for strokes.
Sounds like swings & roundabouts to me. I hate to dash the husband’s hopes, but it would be a leetle premature to add this putative benefit to his list of reasons to eat his favourite Whitaker’s bar 🙁