If eating dark chocolate is medicine, it’s an easy pill to swallow. Although it might be an overstatement to call dark chocolate medicine, most experts agree it’s a functional food, one that has health benefits that go beyond providing nutrients.
For example, a number of studies show eating moderate amounts of dark chocolate may lower your risk for heart disease. Now, a new study shows dark chocolate could give you an edge when you play sports or work out. Is eating dark chocolate the next ergogenic aid?
Exercise and Eating Dark Chocolate: What a Study Showed
Who doesn’t like the idea of eating dark chocolate before a workout? Researchers at Kingston University in London put the ergogenic potential of dark chocolate to the test. First, they put a group of amateur cyclists through a series of exercise tests to measure their fitness level, including their endurance.
After dividing them into two groups, researchers asked one group of cyclists to replace one of their daily snacks with 40 grams, or about 1.5 ounces of dark chocolate. The other group ate an equivalent amount of white chocolate to serve as a control group. White chocolate doesn’t contain the active ingredients that dark chocolate does. After 7 days, they switched “snacks” and the first group ate the white chocolate and the second the dark.
Over the course of the study, the participants participated in cycling trials. During the tests, the researchers measured how much oxygen they used during sub-maximal exercise and how high their heart rate rose. What they found was cyclists snacking on dark chocolate on a daily basis used less oxygen during their moderate-intensity cycling workouts. Plus, they were able to cycle further during a two-minute time trial. The conclusion is that eating dark chocolate could potentially increase exercise endurance.
Why Dark Chocolate?
You might wonder what it is in dark chocolate that could explain these results. Dark chocolate contains compounds called flavanols that act as potent antioxidants. The researchers in this study believe the flavanols in dark chocolate, particularly one called epicatechin, boost production of a chemical called nitric oxide. In response to nitric oxide, blood vessels that carry oxygen to your hard-working muscles open wider, allowing more exercise-sustaining oxygen to be delivered to contracting muscles. Muscle cells can use this oxygen to make ATP sustain exercise.
Why is this important? The flavanol-induced release of nitric oxide you get after eating dark chocolate also partially explains why dark chocolate lowers the risk of heart disease. For one, nitric oxide lowers blood pressure. In addition, flavanols reduce inflammation along the inner walls of arteries and help reduce platelet “stickiness” that could lead to a heart attack or stroke. So. the three ways in which dark chocolate theoretically improves heart health are:
. By lowering blood pressure
. By reducing inflammation inside the walls of arteries
. By keeping platelets from clumping together to form a clot
Now you know why dark chocolate is so heart healthy.
Active Ingredients in Dark Chocolate
Dark chocolate contains other ingredients that may or may not enhance exercise performance. For one, dark chocolate is a source of caffeine, a compound with ergogenic properties, though the amount in dark chocolate probably isn’t enough to improve exercise performance by itself. Still, even modest quantities of caffeine may enhance exercise endurance in combination with flavanols. The two could act synergistically to improve endurance.
Dark chocolate also contains stearic acid, a type of saturated fat, as well as magnesium, a mineral that plays an important role in heart and bone health. Interestingly, some studies show low levels of magnesium impair endurance and exercise performance. Plus, when you do high-intensity exercise, your body requires more magnesium since you lose this mineral when you sweat or urinate. Therefore, athletes and physically active people may need more magnesium than a sedentary individual.
In addition, studies show magnesium deficiency is more common than previously believed. According to one study, less than half of the U.S. population consumes enough dietary magnesium. That’s concerning since you need magnesium to carry out over 300 chemical reactions in your body, including reactions involved in muscle contraction, blood pressure control, the activity of your heart, nerve function, bone health, and more.
How much magnesium is in dark chocolate? A 100-gram bar supplies almost half of the day’s recommended intake of magnesium (48%), although you probably wouldn’t want to consume that much dark chocolate daily due to the high-calorie content. Still, dark chocolate offers significant quantities of magnesium that when combined with other magnesium-rich foods like green, leafy vegetables, whole grains, and nuts can help you meet your body’s requirement for magnesium. Plus, the magnesium content of dark chocolate may partially explain why it’s heart healthy and improves exercise endurance.
Enjoying the Benefits of Eating Dark Chocolate
Though the link between dark chocolate and exercise performance needs to be explored further, dark chocolate is a heart and blood vessel friendly snack – but choose your bar wisely. You’ll get few health benefits from eating milk chocolate since it contains lower levels of heart-healthy flavanols. Look for a dark chocolate bar that has a cocoa content of at least 70% and is low in sugar.
Unfortunately, the percentage of cocoa isn’t as reliable a measure of flavanol content as it should be. Depending upon how the dark chocolate is processed, the number of active flavanols can vary considerably from bar to bar, even with the same cocoa content. It’s particularly important to avoid chocolate labeled as Dutch processed since it has had most of its flavanols destroyed.
One brand called CocoaVia uses a special technique that preserves the flavanols. They aren’t the only ones that offer high flavanol dark chocolate bars, but you can’t tell how much flavanols you’re getting since manufacturers don’t list the flavanol content on the label – so do your research. Don’t just grab the first dark chocolate bar you see at the supermarket.
The Bottom Line
Eating dark chocolate is not only tasty but it may improve exercise endurance. Combine that with the fact that it lowers blood pressure and is heart healthy and it’s easy to see why dark chocolate is such a potent functional food. Heck, even your cardiologist won’t mind that you eat it. Just remember – if you choose a bar with a low flavanol content, you won’t get the full health benefits – and don’t overdo it. Two squares of dark chocolate are enough to give you the benefits without adding too many calories to your diet.
References:
Science Daily. “Eating Dark Chocolate as a Daily Snack Could Help Boost Athletic Performance”
Magnes Res. 2006 Sep;19(3):180-9.
Oregon State University. “Magnesium”
Authority Nutrition. “7 Proven Health Benefits of Dark Chocolate (No. 5 is Best)”
“Dark Chocolate Supplementation Reduces the Oxygen Cost of Moderate-Intensity Cycling” Journal of the International Society of Sports Nutrition. 2015. 12(1)
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