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.
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