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Chocolate. As if we needed any more excuses to indulge in the sweet stuff, there are constantly claims floating around that, hey, chocolate might actually be good for you.

There is some science to back that up but, you guessed it, the devil’s in the details. Most of these claims involve flavonoids, a class of compounds found in lots of plants including cacao, the plant whose seeds are used to make cocoa and chocolate. And some studies have linked flavonoids to a decreased risk of heart disease.

Some experimental studies, which are considered the best type of study for establishing cause and effect, have shown decreases in blood pressure when healthy adults were given specially developed, high-flavonoid cocoa drinks or chocolate. For example, one 2015 study found that 100 adults who drank a high cocoa chocolate drink twice a day for one month had a drop in blood pressure of around 4 millimeters of mercury, which is a measure of pressure. And a drop in blood pressure of just two millimeters has been associated with a decreased risk of stroke or heart problems, at least on average within a population.

There are also a few experiments that hint that flavonoids could improve blood flow to the brain, which in turn might mean better brain function. For example, a 2014 study in Nature Neuroscience found that older adults did better on a memory task, and had increased blood flow to particular memory centres in the brain, if they’d had a high-flavonoid cocoa drink for three months. But there are a bunch of other studies that only show changes in brain blood flow and not improvements in cognition.

And, there are a few key points in these experiments that mean that a candy bar now and then isn’t going to give you any benefit. For one, in most of these trials, it took weeks or months to see any health benefits. And most of the cocoa drinks in the experiments were specially made to have high levels of flavonoids -- between 400 and 1000 milligrams -- using cocoa that’s processed differently than regular supermarket chocolate.

Even 400 mg is more flavonoids than chocolate normally has, and you’d need to eat at least two large bars of regular dark chocolate every day to get that much. Even if you did, the way cocoa is processed to make it less bitter as well as adding milk or sugar has been shown to reduce the levels of flavonoids or the body’s ability to absorb them. Plus, the flavonoid-enriched chocolate used in these types of experiments isn’t particularly tasty.

Some participants were even put off from eating it. Yeah -- these studies managed to make chocolate taste bad. So you won’t be finding these flavonoid-rich drinks and bars at the supermarket.

So, overall, there is evidence that flavonoids in chocolate and other foods have a small, beneficial effect on heart and maybe brain health. But how that works isn’t fully understood yet, and more importantly, these compounds occur in small enough quantities in your average bon-bon or candy bar that to get an effective dose, you’d have to eat quite a bit more chocolate than you should. I mean, all the sugar and fat that comes with that chocolate is going to outweigh any benefits.

So, enjoy chocolate as a treat, but don’t expect to be living longer because of it. Thanks for watching this episode of SciShow, which we couldn’t have made without the help of our community of supporters. Check out patreon.com/scishow to learn more. [♪ OUTRO].