The most abundant and compelling research for the health benefits of dark chocolate revolves around cardiovascular health.
A review of nine studies involving 157,809 participants, published in 2015, concluded that people who habitual milk and dark chocolate eaters – more than once a week and as often as daily – were significantly less likely to suffer a stroke, develop coronary heart disease or die from heart disease.
The studies analyzed observed associations only and, as such, don’t prove cause and effect. It’s possible that the protective effects were due to other heart-healthy foods in participants’ diets such as fruits and vegetables, whole grains, fish and legumes.
Findings from randomized controlled trials have shown that eating dark chocolate modestly lowers blood pressure in people with hypertension.
Flavonoids in chocolate
Dark chocolate’s potential heart benefits are believed to be due to flavanols, natural chemicals abundant in cocoa beans that give it its dark colour and bitter taste. (Flavanols are a subclass of phytochemicals called flavonoids.)
Research suggests that flavanols serve as antioxidants, lower inflammation, reduce cholesterol, keep arteries elastic, enhance blood flow, inhibit blood clots and improve insulin sensitivity – all of which are related to better heart health.
While dark chocolate's health benefits are mounting, keep in mind that chocolate is a source of calories, fat and sugar. Keep your portion size small: about 30 grams or 1 ounce.
Nutrient information per 30 grams (1 ounce) dark chocolate:
Source: Canadian Nutrient File, 2007b
Dark chocolate can either be sweet, semi-sweet, bittersweet or unsweetened.
Sweet dark chocolate
Compared to other types of dark chocolate, sweet dark chocolate typically contains the least amount of cocoa solids, usually 35 to 45%. It tastes similar to semi-sweet chocolate.
This classic dark baking chocolate can be purchased in most grocery stores. It's often used for cakes, cookies and brownies. It has a good, sweet flavor and typically contains between 40 and 62% cocoa solids.
Good quality bittersweet chocolate contains between 60 and 85% cocoa solids. If the content of cocoa solids is high, bittersweet dark chocolate has a rich, intense and bitter chocolate flavor.
Unsweetened dark chocolate is too bitter to be eaten on its own, and is most often used in baking. Unsweetened chocolate can contain up to 100% cocoa solids.
The quality of chocolate depends both on the quality of the raw ingredients and how they've been processed.
The flavanol content of chocolate can vary considerably depending on the amount of cocoa solids it contains. The more cocoa solids – indicated by a percentage on labels of dark chocolate – the more flavanols. Dark chocolate has more flavanols than milk chocolate; white chocolate – which isn’t chocolate at all – contains none.
But even a chocolate bar that contains 70 per cent cocoa solids can have varying levels of flavanols due to the cocoa bean crop it was made from and the chocolate refining process, which can strip away antioxidants.
Manufacturers are not required to label the flavanol content of chocolate products, so there’s no way to know how much you’re getting. While not perfect, the best indicator of high flavanol content is a higher percentage of cocoa solids and a more bitter taste.
Good quality dark chocolate should be shiny and free of lumps, bubbles and white specks. Avoid chocolate that is discoloured, grey, dull or crystallized, as these are an indication that the chocolate is old or has been improperly stored.
For maximum freshness, wrap opened chocolate in aluminum foil and then again in plastic and store it in a dry, cool place. Properly stored dark chocolate will stay fresh for up to one year. Chocolate is best stored between 20° and 22° C, such as a pantry, or dark cabinet. Avoid storing chocolate in the refrigerator.
Sometimes chocolate will "bloom", which is characterized by white or gray "clouds" or "blooms" on its surface, a grey, streaky, dull finish on the surface and a crumbly texture. Bloom is caused by moisture or temperature fluctuations, but does not mean the chocolate is spoiled. Melted for recipes, it behaves and tastes like any other melted chocolate.
You can freeze chocolate, but it is more likely to bloom, so it is best used in baked goods. Before using frozen chocolate, thaw completely in the refrigerator without removing it from the bag. This will prevent condensation, which will damage the chocolate.
Chocolate easily absorbs odors, so make sure to store it away from any items that might impart strong aromas.
There a number of ways dark chocolate can be prepared, depending on how it is going to be used.
Melting: Place finely chopped dark chcoclate in a bowl over a pan of warm water and stir until melted. Be careful not to get any water in the bowl, as this will cause the chocolate to seize and become solid. To melt chocolate in the microwave, place chocolate in a microwave-safe bowl and heat at 50 percent power. Stir the chocolate several times when melting in the microwave to prevent burning.
Once melted, keep chocolate in a bowl over a pan of warm water to prevent it from solidifying.
Chocolate Curls: Chocolate curls are an elegant way to add chocolate to desserts. To make chocolate curls, use a vegetable peeler to slice curls from a block of chocolate. Alternatively, melt chopped chocolate, pour it onto a flat surface and spread to a thin, even thickness. Let cool. Scrape chocolate off with a very sharp butcher's knife or a wide metal spatula.
If you're like most people, you probable don't need any ideas of how to add dark chocolate to your diet! Good quality dark chocolate is delicious when eaten on its own, but it's also a wonderful addition to cookies, loaves, pancakes and muffins. Dark chocolate is also the perfect accompaniment to fresh fruit.
Healthy ways to enjoy:
- Toss unsweetened dark chocolate chips into pancake or waffle batter for special treat.
- Sprinkle dark chocolate chunks and dried cranberries over warm oatmeal for a flavourful breakfast.
- Enjoy a small square of dark chocolate after lunch to help curb cravings for sweets later in the day.
- Treat yourself to a warm cup of hot cocoa for a satisfying dessert.
- Add a small amount of dark chocolate to a pot of chili - it adds a surprisingly rich and complex flavor.
- Dip strawberries and slices of fresh fruit (e.g. pear, apple and melon) in melted dark chocolate for a heart healthy mid-afternoon snack or dessert. Get a recipe!
- Add unsweetened dark chocolate chunks to muffins, cookies and loaf batters.
- Add semisweet dark chocolate chips to homemade trail mix and granola.
Did you know?
- Cocoa, the main ingredient in chocolate, has been cultivated for at least three thousand years in Mexico, Central and South America, with its earliest documented use around 1100 BC.
- Roughly two-thirds of the entire world's cocoa is produced in Western Africa.
- The Hershey Company is the largest chocolate manufacturer in North America.