Your ears may be buzzing having heard news that cocoa, the key ingredient in chocolate, may have beneficial effects on blood pressure. There is definitely reason to take notice. However, if you're thinking about indulging your favorite confection for health purposes, it's important that you consult with your doctor first.
Dark Chocolate Benefits
According to researchers reporting in the January 2007 issue of the "Journal of the American Medical Association," one small serving of dark chocolate every day, containing just 30 calories, can lower blood pressure. The researchers enrolled 44 adults with stage-one hypertension and randomly assigned them to receive either a square of dark chocolate containing 30 mg of cocoa polyphenols or polyphenol-free white chocolate for 18 weeks. At the end of the study, the dark chocolate group had significantly lower blood pressure and didn't suffer any weight gain.
Cocoa Beverage
It turns out that drinking cocoa also has blood pressure--lowering effects. Researchers reporting in the April 2007 issue of the "Archives of Internal Medicine" analyzed five cocoa studies involving 173 participants who had high blood pressure. In four of the studies, both systolic and diastolic blood pressure was reduced. Systolic is the top number when the heart contracts, and diastolic is the bottom number when the heart relaxes. According to the researchers, the results were comparable to prescription medicine.
Cocoa Medicine
Captopril is a well-known prescription medicine for reducing blood pressure. Researchers reporting in the July 2009 issue of the "Journal of Agriculture and Food Chemistry" pitted Captopril against cocoa in a rat study. Rodents fed 300 mg of cocoa experienced a reduction in blood pressure equivalent to a 50 mg dose of Captopril. The cocoa contained 139 mg of cocoa polyphenols. According to the researchers, the results pave the way for cocoa food product manufacturers to petition the Food and Drug Administration for a health claim.
Research Review
While the news is mostly positive about the ability of cocoa to help lower blood pressure, a scientific review of studies reported in the June 2010 issue of "BMC Medicine" concludes the jury is still out. The researchers reviewed published trials conducted between 1955 and 2009 and found 15 that met their inclusion criteria. The pooled data did show a blood pressure--lowering benefit, but the researchers asserted that genetic factors may have influenced the results. They concluded that additional trials are needed to distinguish between dietary habits and genetic considerations.
References
- "Journal of the American Medical Association"; Effects of Low Habitual Cocoa Intake on Blood Pressure and Bioactive Nitric Oxide -- A Randomized Controlled Trial; Dirk Taubert, et al., January 2007
- "Archives of Internal Medicine"; Effect of Cocoa and Tea Intake on Blood Pressure; Dirk Taubert et al.; April 2007
- "Journal of Agricultural and Food Chemistry"; Antihypertensive Effect of a Polyphenol-Rich Cocoa Powder Industrially Processed to Preserve the Original Flavonoids of the Cocoa Beans; Elena Cienfuegos-Jovellanos, et al.; July 2009
- "BMC Medicine"; Does Chocolate Reduce Blood Pressure? a Meta-Analysis; Karin Ried, et al.; June 2010
