Everyone can be vulnerable to confirmation bias at some point, and I think people are more vulnerable when they hear "good news" about a favorite food of theirs. If you are one of those people whose favorite food happens to be chocolate, then you were probably happy to see this headline or one of it's permutations: "Stroke Prevention: More Sweet News for Chocolate Lovers." I'll bet many of you were tempted to avoid the advice from a previous post about ignoring the headline, weren't you?
Well, fortunately for science, if not chocolate lovers, the folks over a Medline Plus aren't going to let you get away with it. They bring up several good points which I will expound upon in today's post.
1) This study was observational, so they could notice a correlation between chocolate consumption and stroke risk, but correlation does not equal causation! The only way you might get closer to "proving" cause and effect would be to do a double blind randomized study where some ate chocolate for several years and other people wouldn't be allowed to. So, you can't justify your chocolate purchase on an observation.
2) The researchers, once again, allowed people to self report on their chocolate consumption, so the actual average consumption might be much higher or lower than what was reported. Do any of you remember to the ounce or gram how much chocolate you consumed yesterday? Last week? In the past ten years? Would you be willing to admit it if you did? So, we can't justify a chocolate purchase on someone's faulty human memory either.
3) If you live anywhere other than Sweden, where this particular study was done, you probably have a very different diet. Are you eating gravlax, or ligonberry jam, or artsoppa on a regular basis (or do you have to Google those terms?) along with your chocolate? Did this study account for the complexities of a varied diet on our bodies? And it also says in the study that most of the chocolate consumed in Sweden is milk chocolate, and most other studies look at the impact of dark chocolate, so where does that lead us. So, we can't justify a chocolate purchase based on someone else's diet either.
4) What about the amounts/portion size? Let's, for just a minute, pretend that everyone remembered how much chocolate they consumed for the past ten years or so. The amount was the equivalent of one quarter cup of chocolate chips PER WEEK. Now, unless you are a professionally trained chef, you are most likely going to have to go to your kitchen and look at your quarter-cup dry measure. Not very big is it? And remember it was only that amount PER WEEK and not per day. And if I did my math correctly, that would be roughly four squares of Ghirardelli squares PER WEEK. Anybody else have trouble staying at that amount? More is not necessarily better, so unless you plan on being very strict with your allowance, you probably can't use "Four squares of this per week and I won't have a stroke!" as justification either.
5) This study was done in men aged 49-75, so we don't know if it helps to start eating chocolate earlier, or if it applies to women at all. So ladies, you definitely can't justify your chocolate purchase on this study either.
I know, I know, some of you are thinking, "Well is chocolate ok if it's consumed in moderation?" For those of you who are just tuning in to this blog, let me remind you about how much the term "moderation" drives me crazy because if you ask ten different people what "consuming chocolate in moderation" means you will get about ten different answers. So a better question would be "would it hurt me to eat chocolate if I stay within my calorie/carbohydrate limit and might it help me?"
First of all, you have to know what your carbohydrate/calorie limits are, and figure out how many calories/carbohydrates are in a serving, and then you have to figure out what that serving is! I have found that 85% cocoa has the least amount of added sugar/carbohydrate (when I'm looking for a chocolate bar/chocolate squares to eat), and a tablespoon of cocoa powder only has ~1 gram of net carbohydrates and about 12 calories. So if you can work a few squares of 85-90% chocolate in, or use unsweetened cocoa powder to make your own sugar-free hot chocolate mix or sugar-free pudding, you might actually be able to get your chocolate fix and still stay within your limits. I personally find that I am still better off buying the individually wrapped squares, which means I pay more, but it means I also won't have the other section of the chocolate bar tempting me. Remember what I said before about the evidence pointing toward sugar having addictive qualities? You might want to think about whether or not you resemble that remark before you start in on the chocolate. And of course, if you are adding cocoa powder to your smoothies or making pudding out of it, think about other sources of carbohydrate that you might be getting as well.
Would the chocolate help you if you are able to keep the amount under control? Interestingly enough, when you start looking at double-blinded studies, there are some positive results as in this study here and here. But even the study authors trying to remind people of portion sizes, sugar content, etc.
Take home message--If you like chocolate and feel that you can keep your amounts under control, there might be some benefit. Find the kind with the least amount of sugar that you can tolerate.