Life as a researcher studying the health effects of chocolate must be a pretty “sweet” gig. For one, I suspect you get to do your fair share of tasting (all in the name of science, of course!). And you get to be everyone’s hero when you deliver the good word that chocolate — one of the most beloved foods on the planet — may actually have disease-fighting perks. You can imagine the happy reception that researchers at Columbia University received when they published new research this week showing that compounds in cocoa may help prevent age-related memory loss.
But is rich, delicious chocolate actually deserving of its healthy image? The answer depends on what kind of chocolate you’re eating and how much, along with the type of health benefit you’re looking to achieve.
Chocolate and Blood Pressure
Chocolate is best studied for its effects on heart health. Regularly eating certain types of chocolate or cocoa products may help to modestly lower blood pressure (by about 2 to 3 mm Hg), according to a 2012 systematic research review by the Cochrane group. However, there’s a big caveat: Many of the studies used special chocolates or cocoa drinks that are formulated to contain very high amounts of flavanols, the compounds in cocoa beans that are thought to confer chocolate’s health properties. Flavanols have been shown to help relax and widen blood vessels and improve blood flow, which may help to lower blood pressure.
Among the studies included in the Cochrane review, the average daily dose of flavanols was 545 milligrams. Dark chocolate has significantly more flavanols than milk chocolate, but on average, an ounce of dark chocolate supplies only about 100 mg of flavanols. (This is only a ballpark figure, as the flavanol content varies considerably from brand to brand depending on the cocoa beans, processing methods, percent cacao, and other factors.) That means you would have to eat about five ounces of dark chocolate to match the average flavanol content used in the blood pressure studies. That’s a lot of dark chocolate … about 800 calories worth, to be exact. On a more encouraging note, a few studies have shown that small amounts of dark chocolate (6 grams a day, or one small square) may still help to lower blood pressure.
Chocolate and Memory
More recently, scientists began studying chocolate’s effects on brain health. Researchers hypothesized that chocolate may increase blood flow to areas of the brain involved in memory, and thereby help to protect against mental decline that occurs with aging. In the new Columbia University study I alluded to earlier, researchers found that older adults who drank a high-flavanol cocoa drink for three months showed greater functioning in the dentate gyrus, one of the brain regions that has been linked to age-related memory impairment, compared to participants who consumed a low-flavanol beverage. The people who drank the flavanol-rich cocoa beverage also significantly improved their score on a memory test that involved remembering shapes and patterns.
But the study was small, and the participants weren’t drinking a standard mug of hot cocoa. The chocolate beverage, which isn’t available commercially at this time, provided 900 mg of flavanols a day. At this time, we don’t know if smaller amounts that could be reasonably obtained from regular chocolate or cocoa have any effect on memory, or if these preliminary findings will hold up in larger trials.
For Overall Health, Less Is More
The research on chocolate is fascinating, and makes every decadent bite taste that much more delicious — but it doesn’t mean that chocolate is a magic elixir. Like other plant foods, cocoa beans are a concentrated source of phytochemicals that may deliver health perks, but the minimum amount needed to have an effect on blood pressure or other variables isn’t known.
If you love chocolate and want to maximize your chance of a health return, I recommend nibbling daily on an ounce of dark chocolate that is labeled at least 70 percent cacao. (Dark chocolates with a higher cacao percentage generally have more flavanols. It’s not a perfect indicator, but as consumers, it’s usually the best information we have to go on.) At 160 calories, an ounce of chocolate is a daily treat that fits within most people’s calorie budgets. You can also get a similar or even higher dose of flavanols by adding one to two tablespoons natural cocoa (not Dutch-processed) or cacao nibs to smoothies, oatmeal, or yogurt. But moderation is (as always) key. Eating a giant dark chocolate bar every day, or sugary candy bars with lots of additives, is not the solution to better heart health; it’s a recipe for weight gain.
And if you’re not a fan of chocolate (the rest of us chocoholics will withhold judgement!), you can get a healthy dose of flavanols by eating berries or sipping on green or black tea.