Chocolate! Oh my god, chocolate. Chocolate! Master/mistress of our hearts! Emperor/empress of all sweet things! Ruler of our minds! Don’t you know, it has chemicals that make us happy! It has compounds that are the ones that also flood your brain when you’re in love! Or during moments of passion! Chocolate contains chemicals of passion! And love! And happiness! And joy! And all of that! Right? Right?
(Can you just imagine my withering gaze right now? You should get a chill up your spine.)
It’s not right, actually. Of course it isn’t. Of course. It’s never that simple. But saying that chocolate contains happy/lovey-dovey/alluring chemicals is a nifty thing to say, even if it’s not necessarily true, or not true to the extent we think it is. It plays into our beliefs, seems to confirm our existing expectations, and makes us all feel warm and fuzzy and comforted – chocolate will always be there for us, to hold us and nurture us and to spur us to neglect urgent work in favour of going on an epic mission to find chocolate, to console ourselves in its melty embrace, to search desperately through the pantry until we are totally convinced there’s not any chocolate in there, and then to search again just to make sure, and then to walk or drive or ride in a horse-drawn carriage to an appropriate vendor of chocolate-related delights.
But what say you, Science? (Science should be the true master/mistress of everyone’s hearts, OK?)
Science says things just aren’t that clear. Unsurprisingly. Oh, Science. Oh, oh, Science.
Firstly, the most widespread inaccuracy: that a chemical in chocolate – phenylethylamine – is the chemical that also responsible for the feeling of love in the brain, or the feeling of passion, or whatever the latest churnalism article in the Daily Mail (yeah, I’m not even in the UK and I’m going to point my finger at it) or whatever hobbling excuse for a newspaper has regurgitated.
While it is true that chocolate contains phenylethylamine, and that phenylethylamine may have effects on cognition, mood and emotion, very little of the chemical could ever get to the brain, since when it is consumed, most of it is converted into a different chemical by the protein monoamine oxidase-B (Suzuki et al. 1981). Barely any phenylethylamine makes it into circulation in the blood and from there into the brain.
Oh and high levels of phenylethylamine are associated with psychosis, particularly in certain individuals with paranoid schizophrenia (Janssen et al. 1999). Just out of interest.
So everyone can quit jabbering about phenylethylamine. It is really not the magical aphrodisiac love-drug that people make it out to be.
Right, moving on. Theobromine! That’s the next chemical to which people ascribe chocolate’s beautiful, bewitching powers.
There’s actually a little bit more validity in that one, although it’s still not totally resolved and is open to debate.
In one study (Smit et al. 2004), participants were given either:
a) pills containing an amount of cocoa power that would have the same theobromine and caffeine amounts as a 50g bar of chocolate
b) pills containing the same amount of theobromine and caffeine as a 50g bar of chocolate (plus some inactive cellulose as filler)
c) pills containing just inactive cellulose as filler (the placebo condition, naturellement)
Participants in conditions (a) and (b) had faster simple reaction times and reported feeling more energetic than those in the (c) condition. That certainly suggests that theobromine and/or caffeine could be having psycho-active effects: they’re doing something to the brain. But it remains unclear whether it’s just theobromine that’s responsible for the effect, just caffeine, or a combination of both.
To make the conditions of the study a little more relevant to the real-world, doses of theobromine/caffeine were also administered in a second experiment using actual pieces of chocolate. The chocolate was made so that it either had no theobromine/caffeine in it (like white chocolate), a small amount of theobromine/caffeine (the same as milk chocolate), or a larger amount of theobromine/caffeine (the same as dark chocolate). When participants ate the chocolate with the large amount of theobromine/caffeine, it greatly improved reaction time. Chocolate with the small and large amounts of theobromine/caffeine improved working memory (tested by getting participants to press a button when they saw 3 odd or even numbers flash up in a row in a constant stream of numbers on a computer screen). The large and small doses of theobromine/caffeine did not result in participants feeling more energetic compared to the chocolate with no theobromine/caffeine or compared to placebo.
Both of the experiments also found, or rather, didn’t find, something rather interesting: there was no strong, clear effect of theobromine/caffeine on “hedonic tone”, a measure of the participants’ levels of contentment and pleasure. So it seems a bit tenuous that theobromine is this magical chemical that so many people assume must be in chocolate in order for chocolate to exert its effects upon us. But people want there to be a chemical in chocolate that explains why so many people love it – I think people get a kick out of imagining that they’re messing with their brain chemistry in order to elevate their mood or to experience enjoyment, thereby associating chocolate consumption (rather loosely) with illicit drug-taking and getting a kick out of the fact that they’re doing something vaguely taboo like that, albeit on a very diluted scale.
Maybe we should, then, look at what other possible ways chocolate could have established its lauded position as reliable and beloved comforter to many. Is it the chemicals? Or is it something else? Or is it the chemicals and something else?
But maybe I’ll get into that next time.
(See, if I leave you with this tremendously epic cliff-hanger, I’ll feel bad for not following it up again soon, so that will give me the impetus to blog again. It’s like training a puppy! But not really like that at all.)
The photos in this post are of the birthday cake I made for Dr Tash PhD last year, and I tried to make said cake as sour as possible (per her predilection for sourness). I can’t actually remember how I made this cake – I think it was a lemon drizzle cake sandwiched in between two layers of white chocolate mud cake, but I could be wrong. I also have no idea what the purple stars are, except that they were some sort of sour agar gel I made and are not, contrary to appearances, slices of beetroot. Just so you know.
Suzuki et al. 1981. Oxidation of beta-phenylethylamine by both types of monoamine oxidase: examination of enzymes in brain and liver mitochondria of eight species. Journal of Neurochemistry, 36(3), 1298-1301.
Janssen et al. 1999. Does phenylethylamine act as an endogenous amphetamine in some patients? International Journal of Neuropsychopharmacology, 2(3), 229-240.
Smit et al. 2004. Methylxanthines are the psycho-pharmacologically active constituents of chocolate. Psychopharmacology, 176(3-4), 412-419.