Chocolate -- Health Boon or Bust?
February 13, 2009
By Harvey B. Simon, M.D.
It's Valentine's Day. Perhaps you're lucky enough to have someone you care about and who cares about you. Often, the gift you send or receive will be chocolate. It may be a gift from the heart, but what will it do to your heart? Is chocolate a forbidden treat or might it actually be a boon to health?
Chocolate doesn't grow on trees, but cacao beans do. After harvesting, the beans are dried for several days and then roasted. Next, the beans are opened; the shells are discarded, and the nibs are ground and separated into cocoa butter and cocoa powder. The powder is low in fat and is used for baking or to make hot chocolate. The cocoa butter is the heart of chocolate.
Cocoa butter is dark and rich, but it tends to be bitter. To make chocolate sweeter, manufacturers add sugar, which also adds calories. And to make milk chocolate, candy makers really do add milk solids, which include saturated fats. Bottom line: Processing may make chocolate look lighter and taste sweeter, but it also removes healthy ingredients and adds harmful ones.
The cocoa bean is devilishly complex. It contains more than 400 chemicals and substances. Many of them can affect human biology and health.
Scientists from around the world have studied chocolate's effect on people's health. For example:
Given this evidence, chocolate could reduce the risk of heart attack and stroke. But all of these hopeful results are based on short-term experiments in a small number of volunteers. Do these bits and pieces of data apply to real life?
Perhaps. The strongest support for chocolate as a health food comes from a 2006 report from the widely respected Zutphen Elderly Study. Researchers evaluated 470 Dutch men between the ages of 65 and 84. All subjects were free of diabetes, cardiovascular disease, and cancer when the study began in 1985. Each volunteer provided comprehensive dietary information, and had his blood pressure, cholesterol, body fat, and other cardiovascular risk factors evaluated.
Researchers tracked the men for 15 years. They found that the men who ate the most cocoa-containing products had lower blood pressures than those who ate the least. The average difference was 3.7 mm Hg in systolic pressure and 2.1 mm Hg in diastolic. These differences may not seen substantial, but even after taking other risk factors into account, the chocolate lovers also enjoyed a 47% lower death rate. Most of the benefit was due to a sharply decreased risk of heart disease. And the largest single source of cocoa was dark chocolate.
To the ancient Mayans, chocolate was the food of the gods. Many modern Americans agree. But others fear "death by chocolate." They assume that anything tasting so good must be bad for you. Is chocolate a divine food or a devilish temptation?
New research suggests that chocolate may indeed have a role in promoting vascular health. But the devil is in the details. Dark chocolate appears beneficial, but milk chocolate, white chocolate and other varieties are not. Most trials have used 100 grams of dark chocolate, about one and a half chocolate bars of typical size. If you ate that much every day, you'd pack in more than 500 extra calories and gain a pound a week. And if that's not bad enough, remember that chocolate can trigger migraines, heartburn or kidney stones in susceptible people.
If you're a chocolate lover, dark chocolate can be part of a healthy lifestyle. To have the pleasure without the guilt:
In the past few years, modern science has learned a lot about this ancient food. Even so, more chocolate research is needed. Any volunteers?
Harvey B. Simon, M.D. is an Associate Professor of Medicine at Harvard Medical School and a member of the Health Sciences Technology Faculty at Massachusetts Institute of Technology. He is the founding editor of the Harvard Men's Health Watch newsletter and author of six consumer health books, including The Harvard Medical School Guide to Men's Health (Simon and Schuster, 2002) and The No Sweat Exercise Plan, Lose Weight, Get Healthy and Live Longer (McGraw-Hill, 2006). Dr. Simon practices at the Massachusetts General Hospital; he received the London Prize for Excellence in Teaching from Harvard and MIT.