chocolate and your heart

Chocolate's Natural Power 

Despite chocolate's indulgent reputation, scientists believe it may actually do your heart (and your whole cardiovascular system) good. Good heart health depends on wide open, flexible arteries that are free of blockages and can deliver blood efficiently throughout your body. Studies have shown that consumption of dark chocolate or cocoa may help with all those vital functions.

Natural compounds in cocoa and dark chocolate may aid the cardiovascular system by improving blood flow and reducing blood pressure.Scientists have also discovered that cocoa may help maintain healthy arteries.

Yale University Associate Professor Dr. David Katz recently tested the blood pressure of 45 adults before and after eating dark chocolate. The results were impressive: just two hours after eating dark chocolate the subjects' blood pressure dropped and their blood flow improved. "This clearly suggests that dark chocolate isn't just good; it's good for you," Dr. Katz said of his 2005 study, one of more than the 20 conducted in the past decade on the health value of cocoa and chocolate.

Chocolate's Promising Effects

While more research is needed to determine the long-term effects on people with high blood pressure, the research on cocoa and chocolate is accumulating quickly. Recent research shows that dark chocolate and cocoa may:

Antioxidants and Your Heart

Scientists attribute the power of dark chocolate and cocoa to their surprisingly high amount of antioxidants, plant-based compounds also found in red wine and green tea. People sometimes forget that chocolate, like wine and tea, starts out as a natural product. Chocolate comes from the cacao bean (the seed of the fruit of the cacao tree) which is a particularly potent source of antioxidants.

The antioxidants in chocolate are called polyphenols, a large class of compounds found in fruits and vegetables like oranges, soybeans and berries. Dark chocolate and cocoa are particularly high in a sub-class of these compounds called flavanols, which are also found in red wine and tea.

The flavanols in dark chocolate and cocoa are key to heart health because they deactivate unstable molecules in your blood called free radicals. Free radicals can aggravate the bad cholesterol in your blood and lead to the clogged arteries. Flavanols have also been shown to stimulate the production of nitric oxide, a key gas inside artery walls that relaxes and widens arteries, allowing for the easy flow of blood and reduced blood pressure.

It's the role these flavanols play in promoting heart health that has grabbed researchers' attention.

Reduced Risk of Heart Disease

On the heels of studies showing that moderate consumption of red wine and tea can lead to a reduced risk of heart disease, Dutch researchers tested the power of chocolate and cocoa, which contains similar flavanol antioxidants.

The results, published in 2006, were stunning. The researchers divided a group of 470 elderly men according to how much cocoa-containing food they consumed and tracked them over 15 years. The men who consumed the most cocoa-containing products, the researchers discovered, were half as likely to die from cardiovascular disease as those who consumed the least. In addition, they were half as likely to die from any cause as those who ate the least cocoa-or chocolate-containing foods.

The researchers suspect that the longevity and reduced cardiovascular risk may be associated with a slight, yet sustained, lower blood pressure in those consuming cocoa and chocolate. Targeted studies on the effects of cocoa on the cardiovascular function may help explain why.

Open Wide — Good Blood Flow

Both cocoa and dark chocolate have been shown to help your arteries relax, widen and maintain their flexibility, which may aid in lowering blood pressure.

Consider the Kuna Indians who live on the San Blas Islands off the coast of Panama. They, like most Americans, consume a diet high in sodium. But unlike Americans, the Kuna Indians do not develop high blood pressure as they grow older. Researchers from Harvard University at first thought the Kuna might have a unique genetic makeup, but noticed that when the Kuna moved to urban Panama and stopped eating their regular diet their blood pressure rose. One component of the traditional Kuna diet is drinking 5 or 6 cups of a cocoa-based beverage every day. Researchers finally concluded that the high intake of cocoa may be the reason for the Kuna's stellar blood pressure.

The researchers went on to further study the effects of cocoa on vascular health and blood pressure. Scientists determined that chocolate triggers the production of nitric oxide in the blood. Nitric oxide is responsible for relaxing and dilating blood vessels which allows more blood to pass through them and thereby lowers blood pressure.

Other studies have investigated these effects. In one study published in the Journal of the American Medical Association, people who ate dark chocolate every day for a week saw their blood pressure drop and the lower blood pressure was maintained as long as they continued to eat dark chocolate. However, once they stopped eating it their blood pressure rose again.

Plaque Attack

Dark chocolate and cocoa may help prevent the build-up of plaque that can clog arteries.

There is good cholesterol (HDL) and bad cholesterol (LDL) in your blood. When the LDL cholesterol meets the unstable molecules in your blood called free radicals, it becomes oxidized. The oxidization of LDL cholesterol is a significant threat to the health of arteries because it begins the process of plaque build-up, lesions and, ultimately, "hardening of the arteries."

When LDL cholesterol becomes oxidized, it attracts other LDL cholesterol particles and clumps start to grow. This mass can adhere to the artery walls, become lodged and damage the artery. Like healing a cut on your skin, your body's immune system then sends out platelets to try to repair the injury. But these platelets, while trying to help, can end up creating a larger mass which clings to your arterial walls causing blockages which can turn into a blood clot.

Both arterial blockages and blood clots can result in heart attack and stroke

The antioxidants in dark chocolate and cocoa work to slow down the process of LDL oxidation and thus may help prevent this whole escalation of arterial injury from happening. They neutralize the free radicals before they oxidize the LDL. Five studies to date show that consuming a cocoa-based beverage for 2 to 4 weeks reduced the rate at which the LDL cholesterol was oxidized.

Sticky Situation

Platelets are crucial for the ability of blood to clot, form scabs and heal wounds. But problems happen when these naturally sticky cells build up along the walls of your arteries. They contribute to plaque and blood clots which can cause arterial blockages. As you may know, baby aspirin is often prescribed to prevent heart attacks because of its anti-clotting properties. In more than 8 clinical trials, chocolate and cocoa were shown to have similar beneficial effects on blood platelets. One trial directly compared taking a baby aspirin to drinking a cocoa beverage and found that cocoa's effect was similar to baby aspirin's but at a slightly lower magnitude. The best results were obtained when baby aspirin and a cocoa-based beverage were taken together.