In Search of the Healing Power of Chocolate
Mars chemist Harold Schmitz holds a chemical model of a flavanol. These compounds give chocolate its taste and might also provide some healthful benefits, such as lowering blood pressure. Joanne Silberner, NPR hide caption
In a fresh cacao pod, beans, wrapped in a sweet pulp, have a very bitter taste. Roasting the beans softens their flavor. However, it's during this roasting process that the beans can lose their flavanols. Joanne Silberner, NPR hide caption
Chocolate Science
Several studies have looked for the health benefits of flavanols, compounds naturally occurring in cocoa, as well as in green tea, black tea, red wine, grapes and raspberries. Chocolates high in flavanols appear to have some benefit to the heart -- by improving blood flow.
The challenge is how to capture that without ingesting daily doses of high fat, high calorie candy bars. A look at some of the latest research on chocolate and health:
COCOA & SMOKING
Study: University of California, San Francisco/Heinrich-Heine University, Germany
Publication: Journal of the American College of Cardiology
Finding: Cocoa may reverse smoking-related impairments of blood vessel function. A dozen smokers in their early 30s where given doses of specially prepared cocoa. The cocoa was found to increase nitric oxide and thus blood flow. (Nitric oxide triggers vessels' inner linings to expand.)
Caveat: Improvements were only looked for immediately after the cocoa was consumed. Are there any long-term benefits?
COCOA & BLOOD PRESSURE
Study: Harvard Medical School/Brigham and Women's Hospital
Published: Hypertension
Finding: Five days of drinking a special brew of flavanol-rich cocoa seemed to activate the production of nitric oxide in study involving 27 participants. Nitric oxide causes blood vessels to relax and expand, and thus improves blood flow to the brain.
Caveat: Flavanol levels in most commercial chocolates are much lower than those used in the experiment. And to really prove flavanol-rich cocoa helps the heart, studies of larger groups of people over a longer period of time are needed.
COCOA & CHOLESTEROL
Study: Tufts/USDA/University of L'Aquila
Publication: Hypertension
Finding: Eating 3 1/2 ounces of dark chocolate daily for 15 days reduced participants' blood pressure. Levels of LDL, the so-called "bad" cholesterol, also dropped in study subjects.
Caveat: How much chocolate must be consumed to provide a long-term benefit?
HEALTHIEST CHOCOLATE
Study: Cornell University, Funded by Hershey
Presented: Cornell Functional Foods, Bioactive Compounds and Human Health Conference
Finding: The levels of flavanols in chocolate directly relate to the amount of natural cocoa in a product. The highest levels were found in natural cocoa powder, followed by unsweetened baking chocolate, dark chocolate, milk chocolate and chocolate syrup.
Caveat: Can enough flavanols be preserved in processed cocoa to be of benefit?
-- Vikki Valentine
At a Mars factory in Elizabethtown, Pa., an assembly line moves millions of pieces of Dove dark chocolate.
The factory's secret -- and it's a proprietary secret -- is a method of processing chocolate that maintains something called flavanols, a class of chemicals found in raw cocoa beans, red wine and green tea.
It's all about roasting the beans for the right amount of time, and at the right temperature. "It's a much gentler process," says plant manager Bob Harvey. "You can destroy the flavanols if you don't know what you're doing."
Mars makes two products high in flavanol, Dove dark chocolate and CocoaVia. The latter has a soybean-based ingredient known to lower cholesterol.
More than 20 years ago, Mars scientists were trying to figure out what gives chocolate its flavor. Mars chemist Harold Schmitz says they focused on flavanols. And then they started to understand that flavanols might have more to offer than just taste.
"As we started to understand the chemistry of these molecules," Schmitz explains, "we realized they could have biological attributes not just related to the tongue and flavor, but to other parts of the body in the context of health."
Harvard scientist Norman Hollenberg discovered that natives on an island off Panama had low blood pressure when drinking their favorite drink made from cocoa that had been minimally processed. Together Mars and Hollenberg determined that the key factor was flavanols.
So Mars has been working for years to figure out how to manufacture chocolate high in flavanols. Schmitz says starting with the right kind of cocoa pod is key.
He compares a football-sized, red, yellow and black pod to a rounder, yellow pod about half the size to show how much pods can differ from one another. Genetics is one of the key factors for the difference. And genetics can lead to greatly differing flavanol levels.
Schmitz says Mars has spent many years and a lot of money figuring out the right genetics and growing conditions that will lead to maximum levels of flavanols.
So at the Elizabethtown plant, manager Bob Harvey is very careful. He knows a mistake in processing can destroy flavanols.
But he won't give details about the manufacturing process, or say how high the flavanol levels are in the finished chocolate. He will say that he loves the end result; he eats a half dozen Dove dark chocolates a day.
Mars and Harvard's Hollenberg have shown flavanols increase blood flow, but they haven't yet proven their chocolate lowers blood pressure and heart attack risk.
There are those who doubt the magic of Dove chocolate and CocoaVia.
Alice Lichtenstein won't comment on the Mars products specifically. She's a nutrition professor at Tufts University. She will talk about what concerns her with any "healthy" chocolate. It's the calories. CocoaVia bars are 90 calories apiece. A serving of Dove dark has 190 calories. "About two-thirds of Americans are overweight or obese," says Lichtenstein, "and the last thing that we want to do is actually add food and extra calories to the diet on a daily basis."
Lichtenstein won't rule out the possibility that flavanols may prove to be helpful. But if that happens, she says, calorie-free pills would be a better option.
Mars chemist Schmitz counters that people are more likely to eat candy bars than take pills.
Dove chocolate is available across the United States, but CocoaVia is in more limited distribution, at some Wal-Marts, Targets and Walgreens, and online. How well the products are selling is a mystery. Mars is a family owned company and doesn't have to tell.