"You really can eat chocolate every day," Penny Kris-Etherton, Penn State distinguished professor of nutrition, told an attentive audience last Wednesday during the final afternoon installment of Research Unplugged's spring season.
Kris-Etherton presented "Healthy indulgences: The benefits of chocolate and wine" at the Penn State Downtown Theatre to a crowd of over fifty community members, who hoped to hear that their guilty pleasures might actually be good for them.
Within the confines of an average diet of 2,000 calories per day, there is room for 200-300 discretionary calories, explained Kris-Etherton. "You can get these calories from solid fats such as butter and cheese, added sugars, or alcohol," she told the group.
But not all discretionary calories are created equal. For example, "some chocolates contain potent antioxidants called flavanols," she said. "Antioxidants scavenge the body in search of free radicals that damage arteries and cells and cause disease." In general, plant foods contain the highest levels of antioxidants, and chocolate—made from seeds of the tropical cacao plant—may have even greater health advantages than most foods, depending on the level of flavanols retained during processing.
Of interest to the 85% of Americans with high blood pressure, "there has been amazing research showing the blood pressure lowering effects of chocolate," reported Kris-Etherton. The Kuna Indians of Panama are currently being studied, as they drink large quantities of a flavonoid rich cocoa. "Members of the tribe do not have age-related increases in blood pressure," she noted.
Chocolate has also been found to reduce platelet stickiness. A study conducted at Johns Hopkins University School of Medicine showed that subjects who consumed a few squares of chocolate a day had slower blood clotting time than those who abstained. The phytochemicals in cocoa seem to relax and dilate blood vessels, Kris-Etherton explained. When platelets flow freely in the blood, the risk of blood clots—which can cause heart attacks and strokes—is greatly reduced. "Chocolate has the same effect as aspirin therapy," noted Kris-Etherton, "but without the negative gastro-intestinal side effects."
The versatile Theobroma cacao (the cocoa plant's botanical name which literally means "food of the gods") seems to also convey benefits to the immune system, reducing the instances of arthritis and other autoimmune diseases. Chocolate also decreases blood glucose levels and increases insulin sensitivity, thereby reducing the risk of diabetes. And research is currently being done on the effects of chocolate on cancer. "Cancer cell growth has slowed when chocolate is introduced in vitro," she said. "There's much more research to do, so stay tuned."
When one audience member asked about the difference between milk chocolate and dark chocolate, Kris-Etherton said that typically, more bioactive compounds are found in chocolates with the highest percentages of cocoa. "Most chocolate contains less than 50 percent cocoa," she pointed out, "but chances are that if you eat dark chocolate, you'll get a higher level of flavonoids." Nevertheless, since some people don't like the more intense, less sweet taste of dark chocolate, Kris-Etherton encouraged audience members to "eat what you enjoy."
She also said that sometimes when chocolate is processed, the flavonoids are destroyed. But some companies, such as M&M/Mars and Hershey's, are working to preserve the health benefits during processing. One audience member, a food scientist and former chocolatier, pointed out that "it is a delicate balance between preserving both the flavor and the health benefits." The recent trend of the general public towards dark chocolate consumption suggests that tastes are changing, Kris-Etherton said.
"It tastes so good, there must be something wrong with it," expressed one audience member. Not so, said Kris-Etherton. It's a myth that chocolate causes migraines, acne, cavities, and hyperactivity. What's more, she added, since chocolate is not an addictive substance, there is no biological basis for craving chocolate. "Studies have shown that people like the texture of chocolate. If you crave anything, it is the creamy texture." The bottom line? As long as it is eaten in moderation as part of a healthy lifestyle, chocolate can be a therapeutic—and delicious—part of one's diet.
The idea of moderation carried over into Kris-Etherton's next topic of discussion: wine. The nutritionist quoted the 16th century physician, Paracelsus, who said, "Whether wine is a nourishment, a medicine, or a poison is a matter of dosage."
Kris-Etherton said that "alcohol in moderation is okay," explaining that cardiovascular benefits can be obtained when men drink two servings (of five ounces each) per day and women drink one. In addition to cardiovascular benefits, alcohol also can increase HDL ("good" cholesterol), decrease platelet stickiness, increase blood flow and circulation, and decrease risk of stroke. "It may also be linked to increased longevity," she added.
But she also warned that when alcohol consumption increases, so does mortality, citing evidence of a J-curve, in which only alcohol in moderation is shown to have positive effects. And she reminded the audience that any alcohol increases cancer risk. "It is important to weigh both the positive and negative effects," Kris-Etherton said.
She also said that though both red and white wines are considered powerful antioxidants, "if you're not drinking alcohol already, don't start," adding that you can get the same antioxidant effects from non-alcoholic beverages like grape juice.
Yet there are definite benefits associated with alcohol when consumed smartly. "Dark ales, whiskeys, and stout beers may also be advantageous," she pointed out. "It is up to you to decide which options work best within your diet and lifestyle. If you want to increase your HDL, either go out and exercise, or drink alcohol," she joked. It is this balance between diet and indulgences that makes incorporating our favorite guilty pleasures a healthy alternative. The take-home message: "You don't have to feel badly about eating chocolate or drinking wine," said Kris-Etherton, "because, within the context of a healthy diet, both confer a lot of health benefits."
Penny Kris-Etherton, Ph.D., is distinguished professor of nutrition in the College of Health and Human Development. She can be reached at email@example.com.