Chocolate lovers rejoiced when they heard conventional scientific sources report that eating dark chocolate may be good for their health. Of course, there is a catch. Not all chocolate is the same. Some types are high in sugar and low in beneficial nutrients, but if you choose a dark chocolate that’s high in cocoa solids, it's a good source of copper, iron and zinc, plus flavonoids that may lower cholesterol and blood pressure.
All chocolate begins with seeds, or beans, from the cacao tree that are fermented, roasted, shelled and ground into a liquid or paste. This liquid is called cocoa liquor, but you’ll also see it referred to as cocoa solids. Cocoa liquor can be further separated into cocoa butter and powder. Unsweetened, bitter and baking chocolate consist of pure cocoa liquor. Dark chocolate, semi-sweet and milk chocolate contain varying amounts of cocoa liquor, cocoa butter, sugar and other ingredients. Cocoa solids account for 45 to 85 percent of dark chocolate and 5 to 7 percent of milk chocolate. White chocolate doesn’t have any cocoa liquor; instead it’s made with cocoa butter, sugar and milk. As a general guideline, the nutritional benefits go up with higher amounts of cocoa solids.
You don’t need a lot of copper in your diet -- just 0.9 milligram daily -- but it’s still an essential mineral. Copper is an integral part of enzymes that help produce energy and make neurotransmitters. It also helps form two tissues, collagen and elastin, that give your skin strength and suppleness. It even improves the condition of skin when used in topical creams, according to the Cleveland Clinic. Unsweetened baking chocolate has 0.92 milligram of copper in a 1-ounce square. One ounce of dark chocolate with 70 to 85 percent solids has 0.5 milligram of copper. The same portion of semi-sweet chocolate has 0.19 milligram, and milk chocolate has 0.14 milligram.
Iron carries life-sustaining oxygen to all the cells in your body and stores oxygen in muscles so you have extra when your activity level increases. It also regulates the development of immune system cells that fight infections. Women need more iron than men because its lost through menstruation, so your daily diet should include 18 milligrams. But the body retains most of its iron, which means it can become toxic if you consume more than 45 milligrams daily. You’ll get 5 milligrams of iron from 1 ounce of unsweetened baking chocolate, 3.37 milligrams in dark chocolate with 70 to 85 percent solids, 0.89 milligram from semisweet chocolate and 0.67 milligram from milk chocolate.
Much like copper, zinc is an essential component of enzymes. In that role, it’s needed for protein synthesis, to maintain the senses of taste and smell and to support the immune system. Zinc also regulates DNA and is essential for normal growth during pregnancy. Women should consume 8 milligrams of zinc daily, unless they’re pregnant or breast-feeding, and then they need 11 to 12 milligrams. One ounce of unsweetened baking chocolate has 2.79 milligrams, dark chocolate with 70 to 85 percent solids has 0.94 milligram, semisweet chocolate has 0.46 milligram and milk chocolate has 0.65 milligram.
- New York University, Langone Medical Center: True or False: Eating Dark Chocolate Can Lower Your Risk of Cancer and Cardiovascular Disease
- USDA Nutrient Data Laboratory: Candies, Milk Chocolate
- Linus Pauling Institute: Copper
- Cleveland Clinic: Understanding the Ingredients in Skin Care Products
- USDA National Nutrient Database for Standard Reference: Copper Content of Selected Foods
- Office of Dietary Supplements: Iron
- Office of Dietary Supplements: Zinc
- USDA Nutrient Data Laboratory: Baking Chocolate, Unsweetened Squares
- USDA Nutrient Data Laboratory: Candies, Semi-Sweet Chocolate
Sandi Busch received a Bachelor of Arts in psychology, then pursued training in nursing and nutrition. She taught families to plan and prepare special diets, worked as a therapeutic support specialist, and now writes about her favorite topics – nutrition, food, families and parenting – for hospitals and trade magazines.