Dark Chocolate and Blood Flow

by Stephanie Kramer

While many believe that chocolate is an unhealthy option, dark chocolate is often considered a healthier food due to its antioxidant content. Dark chocolate is considered chocolate that has > 60% cocoa (1). It contains flavonoids, which are antioxidants known to reduce the amount of pro-inflammatory molecules in the blood, increase HDL (“good” cholesterol) and lower LDL (“bad” cholesterol) levels in the blood, and improve blood flow throughout the body. These antioxidants are also found in red wine, and many fruits and vegetables such as strawberries, blueberries, and broccoli (1)!

Most people feel pretty good after they eat chocolate (I know I do!), and past studies have already shown that dark chocolate does in fact improve blood flow in the body; however, little is currently known about the health benefits directly after the consumption of dark chocolate.


A recent study published in the Journal of Nutrition Research looked at if the same benefits of eating chocolate long-term would also occur immediately after consumption (2). This study compared the effects of dark chocolate and milk chocolate on red blood cell deformability (the ability of red blood cells to change shape during stress without rupturing), nitric oxide (NO) production (the neurotransmitter that causes blood vessels to dilate and increases blood flow), and antioxidant concentration in the blood immediately after consumption.

Since red blood cell deformability is something usually impaired in people with diabetes, peripheral vascular diseases, and a variety of other diseases, foods that would increase this deformability would improve blood flow and overall health (3).

The study consisted of fifty-one young, healthy students. These students were randomly assigned to either the experimental group (dark chocolate, 85% cocoa) or the control group (milk chocolate, 30% cocoa), and were all given a standardized diet during the study.

After analysis of the blood drawn before and after chocolate consumption, results showed that with acute consumption of dark chocolate, red blood cell deformability was improved but NO production and antioxidant concentration in the blood was unchanged. The milk chocolate group showed no change in any of the outcomes.

Looking at previous studies analyzing chronic dark chocolate consumption and this study that analyzed acute consumption, it can be said that dark chocolate consumption does have a significant effect on blood flow in the body. Remember though, the benefits come from the cocoa in the chocolate, so white chocolate and milk chocolate unfortunately won’t cut it!

Below are some recipes that make use of dark chocolate’s delicious taste and health benefits.

Dark Chocolate Almond Butter Cups with Smoked Sea Salt (source)

Dark Chocolate Orange Pudding (source)



  1. Dark chocolate. The University of Michigan Integrative Medicine Web site. http://www.med.umich.edu/umim/food-pyramid/dark_chocolate.html. Published 2005. Updated 2009. Accessed March, 2017.
  2. Radosinska J, Horvathova M, Frimmel K, Muchova J, Vidosovicova M, Vazan R, et al. Acute dark chocolate ingestion is beneficial for hemodynamics via enhancement of erythrocyte deformability in healthy humans. J Nut Res. 2017. doi: 10.1016/j.nutres.2017.03.002
  3. Mohandas N, Chasis JA. Red blood cell deformability, membrane material properties and shape: regulation by transmembrane, skeletal and cytosolic proteins and lipids. Semin Hematol. 1993; 30 (3): 171-92.
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