Chocolates are good for the heart? — The power of flavonoids Chocolates are good for the heart? — The power of flavonoids – SOMETHING ABOUT SCIENCE

Chocolates are good for the heart? — The power of flavonoids

Last week, I emphasized that chocolates are toxic to dogs and may have given you a bad impression of eating cocoa products. This week, I will discuss the potential benefit of eating chocolates to maintain a healthy heart. Does it sound too good to be true? Read on and find out!

Ok, not exactly the gift, but something for he...

Photo credit: Chrys Omori on Wikimedia Commons

The concept that cocoa products are beneficial to our health is not new. Even before the time of Christopher Columbus, cocoa had been revered in the Mesoamerica as a plant with magical powers. In Europe, the plant was used for diverse medicinal purposes, including the treatment of heart pain. However, the medicinal value of cocoa has been nearly forgotten until recent years.

Today, with the high incidence of cardiovascular disease, researchers are re-evaluating the power of cocoa as a cardio-protective agent. In fact, cardiovascular disease is the leading cause of death and disability in the developed countries, and high blood pressure affects 20-30% of adult population worldwide.

Chemical structure of Flavanol (Flavan-3-ol). Image credit: Wikimedia Commons

Chemical structure of Flavanol (Flavan-3-ol). Image credit: Wikimedia Commons


Cocoa beans are rich in various types of polyphenols, especially flavanols, a subclass of flavonoid. High content of flavanols is also found in grapes (and so in wine), apples, pomegranates, and tea. Multiple studies have shown health benefits of consuming foods rich in flavanols, such as chocolates and cocoa beverages. In particular, flavanols are associated with lowered levels of low-density lipoprotein (LDL) cholesterol and decrease in blood pressure, reducing the risk for the development atherosclerosis (thickening of artery walls due to accumulation of fats, such as cholesterol) and cardiovascular disease. Moreover, cocoa reduces blood clotting, thus lowering the risk of stroke and cardiovascular disease.

The mechanism of the protective role of flavonoids against cardiovascular disease is still largely uncertain. One of the speculations is the antioxidant activities of flavonoids. Oxidation in the body creates free radicals that lead to various pathologies. For example, free radicals can oxidize LDL cholesterol which promotes atherosclerosis and hypertension. Flavonoids get rid of free radicals and protect us against oxidative damages. One major limitation with this hypothesis is that the concentration of flavanols in the body cannot reach that high, and their presence in the body is only transient, lasting only 2-4 hours. Therefore, other mechanisms are likely associated with the antioxidant effect of flavanols. Also, the amount of flavonoids needed to obtain health benefits is not certain. More studies are needed to understand the beneficial chemistry of flavonoids.

This image was selected as a picture of the we...

Photo credit: André Karwath on Wikimedia Commons

Some caveats:
1)      White chocolates do not contain cocoa (and flavanols) and so do not have cardio-protective effect.
2)      The amount of flavanols in chocolates largely depends on the manufacturing process of cocoa which often damages flavonoids, so that cocoa products available on the market may contain only little flavonoids. In general, cocoa powder and dark chocolate contain more flavanols than milk chocolate.
3)      Chocolates should be eaten in moderation. Over eating may defeat the purpose of being healthy since high sugar content of chocolates may result in diabetes and heart failure.

Also, just to remind you that although chocolates may be beneficial to our health, cocoa is still toxic to animals, such as dogs and cats!

Lastly, even though we do not fully understand the chemistry of flavonoids, it’s good to have an excuse at hand for reaching over to that box of chocolates and indulging to some treats.

Thank you for reading this post, and see you in a week! 🙂


Cocoa, Chocolate, and Cardiovascular Disease
Chocolate and Cardiovascular Health: Is It Too Good To Be True?
Cocoa and chocolate flavonoids: Implications for cardiovascular health
Blood pressure and cardiovascular risk: What about cocoa and chocolate?

Lynn Kimlicka

I am a scientist-turned writer and editor, who loves to read and write (more than doing experiments). I have a PhD in biochemistry and molecular biology, with a specialization in structural biology. My interests range widely, from life sciences to pop culture and arts to music. I am bilingual in English and Japanese.

6 Responses

  1. There’s so much to learn about the science behind the good things we eat. Thanks for posting!

  2. akilambigai says:

    Happy to know such a thing about chocolates….tnks for post..

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