Be My Valentine: Chocolate and the Human Heart
The Most Delicious Bean
Most experts agree: cacao is the most delicious form of bean, very slightly edging out coffee, especially once jelly beans, Mr. Bean, and L. L. Bean were disqualified on eligibility grounds.
Cacao is the un-roasted, raw seed of the Theobroma cacao tree, and looks pretty gross before it’s fermented, roasted, squeezed, and powdered. That process changes both its flavor and its spelling, producing delectable cocoa powder and fatty cocoa butter.
From those two products we get the vast empire of global chocolate, worth some $15 billion and central to no fewer than three otherwise very different holidays. From a cup of cocoa on a cold winter day to chocolate-covered ice cream pops by the beach, this most delicious of beans has found its way into every form of relaxation, celebration, indulgence, and social occasion.
Heart Healthy
Chocolate is also the second-favorite health-related topic of TV pundits, second only to red wine. It is delicious but, reputedly, also healthy.
In fact, there’s a mountain of data on this. Regular consumption of dark chocolate has repeatedly been linked to better cardiovascular health, even in the randomized controlled trials that are the gold standard in health research.
One large study suggests that eating more than 15 grams per day might reduce your overall risk of heart disease and stroke by 12%-14%. A meta-analysis notes widespread agreement, and points out that the numbers are similar for diabetes.
There are some complications to that picture, though.
First, we should say why the type of chocolate matters. There’s a very real sense in which milk chocolate and dark chocolate are fundamentally different foods. Both contain cocoa butter, which is essentially just cocoa-scented plant oil made by pressing cocoa seeds. That pressing process leaves the solids behind, and it’s those solid parts of the seed, processed into cocoa powder, that probably have specific health benefits.
Low-cocoa milk chocolates (and white chocolates) are pure candy: sugar, fat, and a few trace elements of caffeine and theobromine. Dark chocolates, typically 70% cocoa powder or higher, while also rich in fats and sugars, have far more nutritional value and are closer to high-calorie, high-energy snacks like SportBeans or Gu.
(Except that unlike those sorts of products, dark chocolate is both delicious and—wonderfully—made of real food.)
Even more specifically, the health-relevant parts of a chocolate treat belong to a group of complex molecules called flavonoids. The three most common flavonoids in cacao are procyanidin, catechin, and epicatechin, and together they make up the “nonfat cocoa solids” that scientists are interested in.
They have a very wide and very complicated set of biological effects, the net result of which is to improve endothelial function—basically, how well the cells lining your blood vessels are able to regulate blood flow, nutrient exchange, inflammation, and so on. What all those studies are saying is that, by helping keep our endothelium healthy, flavonoids from dark chocolate can reduce blood pressure, help us produce and absorb insulin, and otherwise make our cardiovascular systems work more efficiently.
The complications don’t end there, though. As a new study points out, previous work has looked at many different doses of chocolate. And while we do have a decent guess about the mechanism, a lot of the research is just correlational—this is where we ask people whether they eat chocolate and check their blood pressure, and report the pattern. That doesn’t tell us whether chocolate is actually responsible for what we find.
The new study uses a specialized statistical technique that lets them check whether eating chocolate causes better heart health. The short answer? Sort of. Dark chocolate reduces our risk of getting hypertension, and probably also blood clots, but not 10 other types of cardiovascular disease. That’s not a loss, but it’s also not the end all, be all.
So the hype is real, but probably overstated. Dark chocolate is not a health food. It is dramatically better for you than milk chocolate or white chocolate, but then, so are most things. Moderation is key, think in terms of 30-60 grams per day (about 1-2 ounces), and it’s perfect for athletes like mountaineers and cyclists—people who need high-calorie snacks for quick energy. For a day on the couch, though? It’s an indulgence. And a damn good one.
