The bittersweet truth about chocolate and your health

Is there a health benefit to that Valentine chocolate treat?

Mounting evidence has indicated so, linking certain forms of chocolate to improved cardiovascular health, lower blood pressure, enhanced glucose tolerance, and even stronger teeth. Candy-makers, as well as “health-oriented” companies, have even developed chocolate products they claim are good for you.

But not so fast, says Jeffrey B. Blumberg, PhD, director of the Antioxidants Research Laboratory at Tufts University’s Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) in Boston. He cautions that not all forms of chocolate have health benefits. Dark chocolate with a cocoa content of at least 70 percent has been shown to be most beneficial. And although Blumberg acknowledges the growing number of chocolate studies, and has participated in research that shows some healthful benefits of cocoa in the diet, he warns that it’s still important to consume the confection in moderation.

“Chocolate is not a health food,” Blumberg emphasizes. “A health food would be one with positive attributes, which we know chocolate has, but it should also have absent negative attributes. When we look at chocolate, we need to acknowledge the fat and the calories. The question is: Can we really get the benefits without paying the price in calories and fat?”

Some producers of chocolate products would like us to think so. In 2003, Mars Inc., the maker of M&Ms and Snickers, launched the CocoaVia snack bar, a candy product that delivers 100 milligrams of cocoa flavonols plus 1.1 grams of canola esters in its 100 calories per serving. Now, a new product, “The Doctor’s Chocolate,” promises to “lower daily stress and tension” and reduce sugar cravings while delivering a sweet load of antioxidants and amino acids — at only 20 calories per diabetic-friendly piece of raspberry-flavored chocolate.

The Flavonol Factor

This drive to produce something delicious and delightfully marketable stems not only from the average person’s willingness to swallow a bite of chocolate instead of, say, a clump of sautéed kangkong, but also from the rash of hopeful reports linking the sweet treat with health benefits. One recent study, published in the Journal of the American Medical Association (JAMA), showed that eating about 30 calories a day of dark chocolate was associated with a lowering of blood pressure, without weight gain or other adverse effects.

“Cocoa is a good source of magnesium and contains many phytochemicals, including plant sterols and theobromine,” Blumberg notes, “but most of the excitement is directed to its flavonoid content.” For example, he adds, dark chocolate is rich in proanthocyanidins that are potent antioxidants — but blueberries, cranberries, and tea are likewise rich in proanthocyanidins.

The focus of Blumberg’s work with chocolate has been on the antioxidants, specifically in dark chocolate high in flavonol-rich cocoa. “In one Italian study, for instance, we saw a significant decline in LDL (“bad”) cholesterol,” he says. It’s the flavonol factor, he notes, that is behind the promising findings of a recent Spanish study in which cocoa was found to increase antioxidant activity in all body tissues. Notably, the cocoa flavonols strengthened the thymus, an organ situated in the upper part of the chest that plays a role in the body’s immune response. Publishing their findings in the Journal of Agricultural and Food Chemistry, researchers from the University of Barcelona reported that feeding a cocoa-rich diet to rats boosted the animal’s antioxidant enzyme defenses. While the researchers wrote that more study is needed to determine if there would be the same results in humans, the initial findings are promising. (And it probably wouldn’t be hard to find humans willing to sign on to take part in such a research!)

Chocolate News To Smile About

Have some chocolate each day to keep the dentist away? It seems to fly in the face of common sense: A cocoa extract is more effective at protecting teeth than fluoride? But that’s the word from researchers who found that an ingredient in chocolate can fight cavities and promote dental health.

Arman Sadeghpour, PhD, led the Tulane University arm of the research team, which also included scientists from the University of New Orleans and Louisiana University’s School of Dentistry. They compared a cocoa extract versus fluoride, side by side on the enamel surface of human teeth. The key to cocoa’s dental benefits, according to Sadeghpour, is a substance called theobromine. A water-soluble, crystalline bitter powder, theobromine is an alkaloid of the cocoa plant, and is therefore found in chocolate along with teas and other foods. Its chemical makeup is similar to caffeine. Theobromine helps harden tooth enamel, making teeth less susceptible to decay. The cocoa extract could offer the first major innovation in commercial toothpaste since manufacturers began adding fluoride in 1914. Sadeghpour has since started up a biotech company, Theodent, and created a prototype of peppermint-flavored toothpaste with the cavity-fighting cocoa extract. “We are now working on the steps for approval” toward a marketable product, he says. His cocoa-enhanced toothpaste could hit the supermarket shelves within two to four years.

In the meantime, Sadeghpour adds that consuming foods containing theobromine also boosts dental health. “Consumers do receive some benefit to all their bone tissues just from eating chocolate, thanks to the theobromine,” he says. Chocolate candy doesn’t come close to matching the hoped-for benefits of Sadeghpour’s toothpaste, however. You get only about three percent theobromine even in high-quality dark chocolate, he explains, which is far outweighed by the tooth-decaying effects of sugar.

Dark Chocolate Helps Blood Pressure

Another new study has found that small amounts of dark chocolate were as effective at lowering blood pressure as other non-pharmaceutical interventions. While not a substitute for hypertension medications, a small daily dose of chocolate brought results significant enough to be considered beneficial to overall health, the researchers said. In previous short-term studies, consumption of 100 grams of cocoa daily has been shown to improve the function of the endothelial cells lining blood vessels — thereby reducing blood pressure. Polyphenols — specifically flavonols — in the cocoa are thought to be responsible.

Writing in JAMA, lead author Dirk Taubert, MD reported that at the end of the test period, those who have consumed 30 calories worth (about one-quarter ounce) of dark chocolate daily for 18 weeks saw modest reductions in their systolic and diastolic pressure. Dr. Taubert noted that on a population basis, it is equivalent to a reduction of relative risk of stroke mortality by eight percent, of coronary artery disease mortality by five percent, and of all-cause mortality by four percent. The blood pressure benefit was not accompanied by weight gain or other related bodily changes such as elevated lipids or sugar in the blood. The researchers suggested the positive blood pressure results were due to cocoa’s flavonols. These naturally occurring compounds promote the production of nitric acid in the cells lining the vascular system, leading to better blood vessel dilation. But subjects who ate white chocolate saw no changes in their blood pressure or other markers in their blood. White chocolate is made from cocoa-butter, the natural fat of the cocoa bean, and lacks the beneficial polyphenols of cocoa.

Variety For Vitality

Scientists, however, are quick to caution that it’s best to obtain our nutrients from a varied, healthful diet, getting a wide range of flavonoids from many sources — particularly those that don’t have the fats and calories of chocolate. Blumberg explains, “I don’t think there’s a ‘best’ flavonoid. To focus on just a couple of them is short-sighted. It’s important to get a wide range of them into your diet, and the best way to do that is to eat a whole variety of antioxidant-rich foods, like green tea, fruits and vegetables, and red wine if you enjoy that.”

But a bite of high-quality dark chocolate, even on a regular basis, can indeed be a good thing. “It’s certainly worth having for its healthful components, like the flavonols,” Blumberg says. “I think it’s reasonable to say that cocoa and high-quality dark chocolate can be beneficial when included as some of one’s discretionary calories. It’s a lovely indulgence that can contribute to a whole healthy diet.”