Heart Healthy Blog by Boston Heart

“It’s OK. It’s good for you”

Posted by Peggy G. Daly, ND, FNP-BC, FNMM, ABAAHP, MBA on Feb 14, 2017 12:00:00 PM


“Not that one….get the one that’s 70% or higher,” are words of wisdom when it comes to chocolate!  Chemicals called polyphenols found in the cocoa of chocolate have tremendous health benefits.  Flavanols and flavanoids are sub-categories of polyphenols that act as antioxidants in the body. They have been shown to cause dilatation of the arteries (meaning the arteries become wider) by increasing a substance called nitric oxide. When nitric oxide is released, the arteries open up and blood pressure goes down.1 Studies show that cocoa intake can reduce blood pressure by 2-3 mm/hg. What if we combined modest exercise (30-40 mins/day), which lowers systolic blood pressure by 4-9 mm/hg, with cocoa polyphenols? 2,3 There are no clinical studies to tell us what the combination would do, but sometimes it’s the little changes that cause dramatic effects.  

So what would happen if someone had high blood pressure and had issues with their blood sugar and ate dark chocolate?  You guessed it, in one study insulin resistance improved helping blood sugar to stabilize and blood pressure to go down. 4 So how much of that wonderful chocolate packed with cocoa can you enjoy to get these benefits? One ounce of chocolate that contains at least 70-85% cocoa has enough flavonoids to do the trick. Remember that too much of a good thing may not get the desired effect. Chocolate not only contains the beneficial cocoa, but often contains sugar and is high in fat so it would be easy to pack on extra pounds if one consumes too much!

Can the cocoa in chocolate help prevent heart disease? The answer is yes! It was found that cocoa has an aspirin-like effect in the body to decrease clot formation.5 Blood platelets have a very important role in the body. These are the particles of our blood that prevent us from bleeding to death when we get a cut. The platelets are sent to the site of injury to stick together and form a clot to stop the flow of blood. It’s the same in the heart. When the body perceives a problem with an artery, it sends out an alert. Platelets are activated to respond. When they arrive on the scene, platelets begin to clump together and recruit other substances that eventually turn into a blockage in the coronary artery. 5 This is the making of a heart attack!

Cocoa has yet another way it helps to prevent heart disease. Cocoa actually helps increase the good HDL cholesterol in our bodies. When the good cholesterol is high it helps prevent the bad cholesterol, called LDL, from oxidizing, which is similar to corroding. When the LDL oxidizes, it can create inflammation in the body and start the whole process of damaging the vessel lining which then sends a message to send platelets and the whole process spins into motion with the end result being a blockage in the coronary artery.6

Is cocoa heart healthy? I vote YES to good dark rich chocolate that contains 70-85% cocoa, and of course organic fair trade. Now you have all the reasons you need to enjoy a LITTLE bit of luscious dark chocolate without hiding in the closet.


  1. Tuabert D, Roesen R, Schomig E.  Effects of Cocoa and Tea Intake on Blood Pressure. A meta-ananlysis. Arch Intern MED/Vol 167, Apr 9, 2007: 626-634.
  2. Glynn RJ, L’Itallien GJ, Sesso HD, Jackson EA, Buring JE.  Development  of predictive models for long-term cardiovascular risk associated with systolic and diastolic blood pressure. Hypertension 2002;39 (1): 105-110.
  3. Mancia G, DeBacker G, Dominiczak A Cifkova R, Fagard R, Germano G, et al. Guidelines for the management of arterial hypertension:  the task force for the management of arterial hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC).  J Hypertens 2007 2007;25(6):1105-87.
  4. Grassi D, Desideri G, Necozione S, Lippi C, Casale R,  Properzi G,  Blumberg J, Ferri C.. Blood Pressure Is Reduced and Insulin Sensitivity Increased in Glucose- Intolerant Hypertensive Subjects after 15 Days of Consuming High –Polyphenol Dark Chocolate. Journal of Nutrition and Disease. 138:1671-1676, 2008.
  5. Rein D, Paglieroni T, Wun T, Pearson D, Schmitz H, Gosselin R, Keen C. Cocoa inhibits platelet activation and function. Am J Clin Nutr 2000;72:30-5.
  6. Baba S, Osakabe N, Kato Y, Natsume M, Yasuda A, Kido T, Fukuda K, Muto Y, Kondo K. Continuous intake of polypenolic compounds containing cocoa powder reduces LDL oxidative susceptibility and has beneficial effects on plasma HDL-cholesterol concentrations in humans. Am J Clin Nutr 2007;85:709-717.

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