Not the first time I’ve talked about chocolate, but what can I say – I like chocolate. Dark chocolate in particular, goes well with my coffee habit. We’re all aware that a lot of the chemicals in natural chocolate give us warm, fuzzy feelings, but there’s all the milk and sugar that might make it less healthy, we know that too. So while some engage in chocolate therapy to heal a metaphorical broken heart, a study recently published in Heart asserts that it may lower the risk of developing a literal broken heart, specifically atrial fibrillation, which I’m calling AFib for the rest of this post because it’s shorter and for the people who know, that’s often how they know about it.
But first, I would like to have a conversation about the heart. Not only associated with love, it is the embodiment of our innermost feelings, particularly those-
Oh, not in this blog, we’re not. This is what I want to talk about:
Specifically, the top half of it, the atria (plural form of atrium; normal hearts have a left and a right atrium), where blood is pumped into the heart. From there, it’s pumped into the ventricles, after which the blood is sent to either the lungs or into the rest of the body, depending on which ventricle it just left. That’s what happens in a single heartbeat, kept in time with regular bursts of electricity. Why do you think your parents told you to (and if you’ve never tried to, DON’T YOU DARE TRY THIS) never stick a fork in an electrical socket? The Cleveland Clinic has some more reading on how the heart’s “electrical system” works.
Anyway, AFib is a Very Bad Thing because the atria and the ventricles must work in sequence so the heart can…well, work. During an AFib episode, the electricity’s gone haywire (so to speak), so now the atria and the ventricles aren’t in sync. This could lead into all sorts of Other Bad Things, including blood clots and strokes. It could either come and go, or it could stay for good, it may even be fatal, but definitely worth seeking medical treatment.
Back to the article – although there has been quite a bit of research that shows that dark chocolate may be heart-healthy (here are some articles). But those are for the blood vessels; what about the heart itself? Think it will do something for AFib? That’s what Mostofsky et al. wanted to investigate, using some more biostatistics. I went over a study that used this method last time – find relationships from a large sample of people (in this case, more than 160,000 people from the Copenhagen and Aarhus metro areas in Denmark) involved in a large study from the mid-1990s. I’d like to think there was more than simple data-mining involved, since the hypotheses they used for this and any other studies that use this data actually make sense; in this case, dark chocolate makes the heart better. Also, it’s Denmark. You know they have access to the good dark chocolate.
By the way, biostatistics has its place – one of the chief issues with biology research is that there aren’t enough samples, and that’s where biostatistics can come in. Smaller-scale experiments have been done in order to see how it works in the body (or cell, or organism, etc.), and biostatistics can be done in order to see how it works in a much larger scale in a more diverse set of people. Remember – we already know that dark chocolate’s good for the heart, there’s research on how it works in the body, we know how it works chemically. Using biostatistics, researchers can look at a larger chunk of a population (especially humans) and pretty much go ‘hey, if we’re seeing the same relationships between these two things with all these people that we did when we did that experiment some time ago, then we can prove that these two things are related.” It’s reproducibility going large, and without having to cut open 100,000 people.
So, does consuming dark chocolate lower the risk of AFib, at least for Danish people living in the two larger metro areas? Short answer – yes. Long answer, yes, which supports the literature on dark chocolate (‘chocolate’ defined as at least 30% solid cocoa, which is getting pretty dark by American standards) and its benefits on the human cardiovascular system. Those who had more than one ounce of chocolate (that’s about six Hershey’s Kisses) had a lower hazard ratio (think of it like a risk) than those who had less. There even seemed to be a trend – the more chocolate consumed (the categories were less than 1 month, 1-3 per month, 1 per week, 2-6 per week, and more than 1 per day), the lower the hazard ratio, particularly for men. Women get the benefits too, but statistics aren’t as strong for more chocolate, less AFib, but don’t let that stop you.
But here’s something that might stop you (both men and women): dark chocolate isn’t alone in each piece. There are all sorts of fillers, as I’ve mentioned up post and before, so just like I mentioned last week, take your bitter (or really any) chocolate in moderation. Also, the study never really explored what kind of dark chocolate it was; they’re not all the same, we don’t know what the cocoa content is – that 30% value I mentioned earlier is pretty much a ballpark figure. You can walk into any decent supermarket and get a bar with at least 70% cocoa powder. There are even bars – not baking chips, mind, bars for eating – that are 100% cocoa. Also, there may be other variables in play such as smoking, obesity, education level (yes, that was a variable in the larger study) that may not be adequately modeled using simple mathematics. At the very least, it’s comforting to know that dark chocolate is heart-healthy, and decreasing AFib risks is just another feather in its cap.
I’m fortunate enough to not have a heart condition, but if my doctor even suspects I’m developing one, I’m moving to Denmark. Between Legos and dark chocolate, I’ll have a healthier, less-stressed ticker, it appears.
Featured Article: Mostofsky E, Johansen MB, Tjønneland A, Chahal HS, Mittleman MA, Overvad K (2017). Chocolate intake and risk of clinically apparent atrial fibrillation: the Danish Diet, Cancer, and Health Study. Heart 0:1-5. DOI: 10.1136/heartjnl-2016-310357.
Featured Image: Public Domain (Author: Alexander Stein, 2013)