Chocolate: It Does a Heart Good

Fledgling U.K. study aims to prove cocoa and soy components can stave off heart disease for at-risk women.

By
Joanna Cosgrove
Online Editor

Mounting evidence is lending credence to the fact that chocolate can do much more than just taste great. Cocoa flavonoids—bitter tasting, polyphenolic compounds that occur naturally in the cocoa bean—have demonstrated antioxidant activities that researchers believe have the potential to reduce certain risk factors for cardiovascular disease.

A new study, funded by U.K. charity Diabetes U.K. and currently underway at the University of East Anglia in Norwich, U.K., is testing a specially formulated chocolate to determine if it can exert a beneficial effect on post-menopausal women with diabetes. While most studies begin with healthy test subjects, this study is pragmatic in nature. Each of the 60 initial test subjects are women with “a real risk” who are already on an established drug therapy.

“Type 2 diabetes is a predominant problem for menopausal women, as opposed to younger women because of the age-related effect,” explained Aedín Cassidy, lead researcher and professor at the University of East Anglia’s School of Medicine, Health Policy & Practice. “Women who are diabetic are three to five times more likely to develop heart disease than healthy women.

“Very few studies have addressed the potential benefit of diet in addition to conventional drug therapy, so here in the U.K. all women are on statins and aspirin already, but they still seem to have a disproportionate risk for heart disease,” she added. “The study participants are not newly diagnosed; they have been on established aspirin therapies and statin therapies for some time.”

The “chocolate therapy” the women will be testing revolves around the consumption of specially formulated chocolates that are nutritionally optimized far beyond anything found on the candy shelf. Each day, study participants will receive two 15 gram pieces of chocolate. This 30 gram daily dose contains a total of 75 mg of epicatechin and 100 mg isoflavones (a-glycone equivalents), as well as 500 milligrams of cocoa extract—three times more of the compounds than one could get in a commercial bar of even dark chocolate.

“The chocolate was specially developed by a Belgian chocolate manufacturer to contain the specific levels (of soy isoflavones and cocoa flavonoids), which we believe to be the optimal levels, according to short term trials on healthy people and also from laboratory experiments, to be beneficial for cardiovascular health,” commented Professor Cassidy. “(The chocolate) is a very small component of total energy which is important for us because we don’t want the women gaining weight. We give them dietetic advice, to make sure that they maintain their weight. The chocolate is to replace an existing snack.”

Professor Cassidy’s previous experience with flavonoids drew her to this new opportunity to specifically study soy isoflavones and cocoa polyphenols (procyanidins). “We’re looking at a whole range of cardiovascular risk factors from blood bio-markers like inflammatory markers; effects on lipids; carotid intima-media thickness where we measure the thickness of the carotid artery and plaque volume; pulse wave velocity (which obtains a measure of arterial stiffness between two locations in the arterial tree) and vascular function; effect on blood biomarkers, which we know are established markers of cardiovascular risk,” she said.

“A successful outcome of this research would hopefully mean being able to offer people at high risk better protection over and above that provided by conventional drugs,” said Dr. Iain Frame, director of research, Diabetes U.K.

The study, just underway, recently recruited its first 60 test subjects. The goal is to enlist 150 women under the age of 70 with type 2 diabetes who have not had a menstrual cycle for at least one year, and who have been taking cholesterol-lowering statin drugs for at least 12 months. The study is expected to span one year.

“We hope to show that adding flavonoids to (the) diet will provide additional protection from heart disease and give women the opportunity to take more control over reducing their risk of heart disease in the future,” said Professor Cassidy, who noted that the precursor to this study was a large systematic review of flavonoids and their correlation to cardiovascular risk. “It’s the best evidence to date and comes from soy and cocoa polyphenol (chocolate) trials,” she said. The systematic review will be published in the July issue of American Journal of Clinical Nutrition.