Maintaining a healthy blood pressure is critical to reduce your heart disease risk. There are various ways to do this, and diet and lifestyle changes come with the most benefit in comparison to medication and surgery, which have higher physical and financial costs. One food that may seem contrary to typical dietary advice for lowering blood pressure is chocolate. Chocolate shows potential at reducing blood pressure. Moderation is the key when consuming chocolate, since it has substantial fat and calories.
ACE Inhibition
Cocoa flavonoids in chocolate assist with keeping angiotensin-converting enzyme, or ACE, from constricting blood vessels, which increases blood pressure. A study in the January 2011 "Journal of Cardiovascular Pharmacology" reports a significant decrease in ACE activity following intake of 75 g of dark chocolate by 16 healthy study participants. The chocolate in this study was dark chocolate and 72 percent cocoa.
Improves Endothelium Function
Cocoa in dark chocolate reduces blood pressure by improving the endothelium, the inner covering or lining of the blood vessels. Researchers in a study in the August 2005 "Hypertension" journal provided participants who had high blood pressure with 100 g per day of dark chocolate for 15 days. Following the 15 days, their blood pressure decreased. The flavonols in the chocolate caused an increase of the enzyme that increases synthesis of nitric oxide and its secretion from the walls of blood vessels. Nitric oxide helps clean up remnants from cell turnover and cell injury to prevent blood clots. When the blood is free of clots, blood pressure is decreased. Dark chocolate also promoted relaxation of the blood vessels in this study.
Dark Chocolate Versus White Chocolate
Dark chocolate shows more benefit than white chocolate, according to research in a March 2005 study in the "American Journal of Clinical Nutrition." For 15 days, the researchers gave one group of healthy young adults 100 g of dark chocolate, and gave 100 g of white chocolate to another group. Each group then took a break and ate no chocolate for seven days, and then each group switched to the other chocolate for 15 days. The dark chocolate improved blood pressure, but the white chocolate showed no effect.
Word of Caution
It's important to remember to eat chocolate in moderation, since saturated fat, calories and sugar are primary components in chocolate. The main idea is to consume chocolate with the highest amount of cocoa possible; aim for a minimum of 70 percent cocoa content, advises "Today's Dietitian." Dark chocolate should be eaten only as part of a healthy diet.
References
- "Journal of Cardiovascular Pharmacology"; Effects of Cocoa Extract and Dark Chocolate on Angiotensin-converting Enzyme and Nitric Oxide in Human Endothelial Cells and Healthy Volunteers--A Nutrigenomics Perspective; Ingrid Persson, et al.; 2011
- "Hypertension"; Cocoa Reduces Blood Pressure and Insulin Resistance and Improves Endothelium-Dependent Vasodilation in Hypertensives; David Grassi, et al.; 2005
- "American Journal of Clinical Nutrition"; Short-term Administration of Dark Chocolate is Followed by a Significant Increase in Insulin Sensitivity and a Decrease in Blood Pressure in Healthy Persons; Grassi, et al.; 2005
- "Today's Dietitian"; 5 Functional Foods and Why They Work for Women; Victoria Shanta-Retelny, RD, LD
