Drinking red wine provides a degree of protection against coronary heart disease. Alcohol as such has some advantages that could explain the positive influence on coronary heart disease but probably red wine has greater anti-atherosclerotic or antithrombotic actions than alcohol alone because it contains a variety of polyphenols with their own profile of protective properties. As such red wine is comparable to dark chocolate.
One of the possible mechanisms for polyphenolen to have a positive influence on the cardiovascular system is it’s antioxidant properties.
But the general conclusion from studies over the past few years is that the absorption of polyphenols is insufficient for exerting any antioxidant effect.
You can read about the other possible mechanisms on how polyphenolen can protect the cardiovascular system in a recent post on this blog: How Does Chocolate protect the Heart.
In a recent editorial a common mechanism for both red wine and dark chocolate is discussed. According to the author it is most probable that procyanidine, a flavanol, triggers an endothelial response thereby improving the endothelial function and decreasing the risk on cardiovascular disease. However these claims are based on in vitro research, done in the lab that is. This hypothesis has to be proven in vivo, in real humans and patients. It isn’t even clear how much and what kind of flavanols are absorbed to the bloodstream.
Clinical trials of red wine leading to health claims are unlikely on ethical and safety grounds. Nevertheless, some carefully controlled studies in volunteers could provide useful insights into the relative importance of alcohol versus polyphenol constituents on vascular function
and antithrombotic effects.
As in chocolate not every wine or red wine has a high content of flavanols. White wine has a lower content of flavanols approximately 8 times less and white wines do not contain procyanidins because the juice is fermented without seeds or skin. Procyanidins in red wine are derived mainly from the grape seeds, but owing to their poor solubility, seeds need to be present in the fermenting for at least 10–14 days for extraction of maximum amounts. So most cheap mass produced red wine isn’t fermented during two weeks and lack procyanidins. Manufacturing processes also affect levels of flavanols in chocolate products.
It is frequently stated that dark chocolate is a richer-source of flavonoids (often just referred to as antioxidants) than red wine. This is misleading because if it is based on a serving of similar calorific value this difference is no longer apparent. There are also large variations for both red wine and dark chocolate, so a generalisation that one is a better choice is unreliable. A future requirement for product labels to include information on flavanol content is essential for consumers.
It is a pity chocolate with red wine doesn’t taste so well, except port wine but the flavanols content of port wine is not very well known, less attention has been paid to this subject.
You can always take your dark chocolate with green tea.
By the way he recommends no more than 25 gram, or 2.5 squares of dark chocolate, a day. That is much more than the 6 grams advised in another post on this blog: How much chocolate is good for your health.
Based on the evidence to date, there should be a degree of optimism that well-characterised flavanol-rich products will appear with a body of evidence to support meaningful benefits and justify health claims.
The author of this editorial Roger Corder also recently published a book: The Red Wine Diet.
The book is reviewed on The Wine Cask Blog;
He lists specific types of wine and regions of the world where one can generally expect procyanidin rich wine. Therein is the value of the book as a resource.
You can read an interview with the author on Telegraph.co.uk: It’s a diet but not as we know it.
Jim’s Chocolate Mission: reviews of all kind of chocolate.
Chocolate Obsession, news reviews and thoughts on the most perfect of foods.
R. Corder (2008). Red wine, chocolate and vascular health: developing the evidence base Heart, 94 (7), 821-823 DOI: 10.1136/hrt.2008.143909