(Epic post ahoy!)
Hello, come in, come in, please, come in and make yourself comfortable. How are you? Good? Good. Are those new mittens? They’re lovely. Can I offer you a drink, maybe a Pimms No. 1 with over-sized cucumber garnish? No? Would you like a delicious biscuit? Ok, here’s a delicious biscuit.
Now that you’re comfortable and have a delicious biscuit…
… we need to talk.
Please assume the brace position, as this is heavy news.
Chocolate is probably not that good for you. The antioxidants and all that good-for-you-heart stuff, well… it’s not all it’s made out to be.
There’s been a gargantuan 18-wheeler truckload of stuff in the media about how eating chocolate is good for you. Why is it good for you? It’s got antioxidants! Antioxidants that, well, they stop your body from ageing… and stuff. They stop your cells from getting attacked by, um… nasty things! They prevent cardiovascular problems. Chocolate is full of antioxidants so chocolate prevents cardiovascular problems! Right? Right?
Well, maybe, maybe not. I’m sorry, but it’s just not black and white like that. (It so rarely is with science. Sigh.) There is plenty of research being conducted into the cardiovascular-protective properties of chocolate consumption, and it’s been going on for a fair few years now. Unfortunately, the evidence is not conclusive, and we’re starting to realise that the research that’s gone on so far isn’t anywhere near detailed enough to tell us about whether we should eat chocolate for its cardio-protective qualities, and if so, how much.
It’s true that a fair few studies have found results like “consumption of dark chocolate is correlated with a reduction in blood pressure”. But! (There’s always a but in science, damn it.) When you look at the studies overall, there are a lot of problems.
The number of people in a lot of the studies is quite small, so that increases the chances that we might be seeing false positives in the results, i.e. we think we see a relationship between chocolate consumption and cardiovascular health but actually there isn’t one. The results we have so far just don’t allow us to reliably conclude that chocolate consumption definitely does (or does not) improve cardiovascular health in any specific way.
Some of the studies are conducted over a pretty short time period. These are acute intervention studies that only look at the effects of dark chocolate consumption over a few days (and for those few days, maybe people in the study are paying better attention to their health and stress levels purely by virtue of being in a study that draws attention to those aspects of their lives). These short studies don’t tell us much about the long-term effects of chocolate consumption on either cardiovascular health or other important aspects of health. Need more info.
The amounts of chocolate that should be consumed to achieve any reported improvement in blood pressure or whatever are all over the place. Some studies say you need to eat 2 squares a day to improve blood pressure, but don’t have more than 2 because that doesn’t improve blood pressure. Some studies say you need to eat a few squares daily, whereas others say you only need 10 square per month. It’s a big confusing mess, really. In fact, we’re not even sure if there are enough antioxidants in chocolate to have any impact on overall antioxidant levels in the body — studies that show antioxidants improve cell health in cell cultures in a dish in a lab have used antioxidant concentrations many many times greater than what could be achieved in the human body by eating chocolate. Basically your stomach would be exploding in chocolate pyrotechnics if you ate enough chocolate to get the same concentrations as the cells in the lab were being dosed with. I’d prefer not to explode, quite frankly.
And something that’s emerging as a major flaw in this research is that we don’t know the exact levels of antioxidants in different chocolates. We know dark chocolate is probably highest in antioxidants, but there’s a huge range of variation in the amounts depending not just on percentage cacao, but also how the cacao was treated and processed and where it originally came from. For example, some processing methods can radically reduce the key antioxidant compounds such as catechin and epicatechin. So essentially, when a study is done to see whether chocolate consumption results in improved health measures, we don’t actually know what sort of dose of antioxidants these people in the study are getting!
The upshot of this is that we can’t possibly recommend a particular amount of chocolate to consume in order to get health benefits — we don’t know what amount of antioxidants is in any given chocolate, and we don’t know what the ideal dose of antioxidants is anyway.
Alright, so antioxidants play an undeniably important role in the health of the human body. But here’s the thing: just because something is necessary for health, doesn’t mean that big amounts of it are good for you, and that even bigger amount are better. In fact, it’s usually quite the opposite.
If there’s one thing you learn this year about science and health, make it this: a lot of things are on what’s called an inverted-U curve. It’s not a linear trend of more = better. It’s more like not enough is bad, enough is good, too much is bad again. However, we have to do an enormous amount of research to establish what “enough” actually is. At the moment, we’re trying to work out what “enough” is for antioxidants, but it’s safe to assume that too much is probably a bad thing.
In fact, an enormous review was done of the antioxidant research. Bjelakovic and colleagues did a systematic review and meta-analysis of studies that looked at what happened when people were given antioxidants supplements. This means that they looked at a whole heap of studies, kicked out the ones that weren’t rigorous enough, then tried to figure out the bigger picture that the well-conducted, rigorous studies were painting. They looked at 68 of these good-quality studies, which altogether tested the effects of antioxidant supplementation (in the form of beta carotene, vitamin A, vitamin C, vitamin E or selenium) in 232,606 people. With that many people, surely you’ve got the ability to detect even tiny little relationships between the antioxidant supplementation and health outcomes.
And the results of this enormously powerful meta-analysis? Some antioxidant supplementation might cause bad health outcomes, whereas others still have an unclear effect. Still! After all those studies and all those people! There was no clear benefit to taking extra antioxidants. This could be because: (a) there’s no relationship between extra antioxidants and the health variables being measured, (b) the relationship is so small and subtle it’s difficult to detect or (c) the effects are dependent on other variables that we aren’t taking account. My money’s on (c).
So it’s kind of scary when you think about how frequently the media and various companies (with a financial interest in getting us to buy their products) tell us we should be indiscriminately cramming antioxidants every which-way into our bodies. (Goji berries! You need goji berries! Or was it acai berries that were the latest superfood du jour? Oh god just get some pomegranate before it’s too late! Don’t you want to live forever?) It’s entirely unsurprising that most of us have absorbed the inaccurate message that antioxidants are always good for us and we need as big a dose as we can get.
But even though we don’t know what the right amount of antioxidants is for optimal health benefits (yet), and even though we don’t know what precise levels of antioxidants are in various products, and even though we’re surrounded by products with labels zealously screaming “FULL OF ANTIOXIDANTS!”, and even though we don’t know if we’re getting too little or too much, don’t despair! What should you do? It’s old and tired and not that interesting, but it’s the truth: eat a balanced diet and eat things in moderation. If you do that (along with some exercise) you’ve got a very good chance of getting pretty much everything you need to achieve very good health. If you’re eating tomatoes and carrots and that sort of thing and maybe a bit of dark chocolate here and there, you’re probably getting the antioxidants you need. Don’t fret!
So maybe, eventually, research will be able to pin-point exactly what daily dose of antioxidants we should aim to get, and whether we can eat chocolate to get some of that dose. Until then, don’t use “it’s good for me!” as an excuse to eat chocolate. If you’re leading a generally healthy lifestyle, you can eat it chocolate just because you enjoy it — you don’t need much more justification than that, right?
Thank you for your time. And now: a recipe.
Recipe for not-actually-superfood cookie sandwiches under the cut.
Not-actually-superfood cookie sandwiches (Chocolate chip cocoa nib cookie sandwiches with chocolate raspberry ganache and raspberry mousse)
Chocolate chip cookies
I just used this recipe, which is apparently based on the very popular one that popped up in the New York Times. I halved the amount of chocolate and added 1/2 cup of cocoa nibs instead, though. Also, it made 38 cookies, not 18. Unless your cookies are the size of a hub-cap. Otherwise — excellent recipe, A+, would bake again.
Chocolate raspberry ganache
250g dark chocolate (I used 80% cacao)
1/4 cup cream
3/4 cup frozen raspberries
1/4 cup cocoa nibs
Put the chocolate and cream in a medium saucepan. Crumble in the raspberries (I like how frozen raspberries crumble, as an aside). Melt everything together slowly over a very low heat. Stir until smooth. Remove from heat and stir through cocoa nibs. Transfer into a bowl and leave to cool for half an hour, then put it into the fridge for a couple of hours until it firms up but is not too hard.
1 cup frozen raspberries
250g cream cheese, at room temperature
50g butter, softened
1 tsp vanilla paste
1/4 cup icing sugar, sifted
2-3 tsp xanthan powder
Put the frozen raspberries in a small saucepan and cook over medium heat until they form a sauce. Transfer to a bowl and allow to cool for 30 minutes.
Beat the cream cheese and butter together until smooth. Add the vanilla and raspberries and beat again. Add the icing sugar and beat until well combined. Add the xanthan, one teaspoon at a time, beating for 2 minutes between each addition. The mixture will become slightly elastic and begin to trap air in it during beating.
Assemble the cookie sandwiches by spreading about 2 tbs of the ganache on one cookie, 2 tbs of the mousse on another, then sandwiching them together.
I’ve invented my own referencing style for today.
For most of the info in this post, this is the review paper to read:
Rusconi, M. & Conti, A. (2010). Theobroma cacao L., the Food of the Gods: a scientific approach beyond myths and claims. Pharmacological Research, 61(1), 5-13.
For the systematic review and meta-analysis of those antioxidant supplementation trials:
Bjelakovic, G. et al. (2007). Mortality in randomised trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis. Journal of the American Medical Association, 297(8), 842-857.
For a commentary on the evidence for dark chocolate’s cardiovascular effects:
Egan, B.M. et al. (2010). Does dark chocolate have a role in the prevention and management of hypertension?: commentary on the evidence. Hypertension, 55, 1289-1295.