With the Easter weekend over for another year and the family festivities drawing to a close, we can sit and contemplate one thing…just how much chocolate have I eaten the past few days?!
As one of the world’s best loved and most indulgent treats, we often regard chocolate as one of those “a little of what you like” foods. But are we just kidding ourselves? Is there any truth behind the phrase we all long to hear: “chocolate is good for your health”?
Well hold on to your bunny ears because there a few nuggets of good news, but that doesn’t mean you can go out and stuff your mouth with Mini eggs!
As offspring of the Theobroma cacao tree, cocoa beans –and the products from them – have been consumed for over a millennium (although strictly speaking cocoa is the seed of the fruit from the tree). Only recently, however, have the possible health benefits of chocolate been exploited. As you might have imagined, therapy-related weight gain was amongst the first most common of uses.
Along with fibre and lipids, chocolate contains a decent amount of polyphenol compounds which have the ability to act as antioxidants against free radical compounds, and is particularly plentiful in flavonol (sometimes spelled flavanol) in particular. Flavonols belong to a family of chemicals called flavonoids, molecules which are found in a number of fruit and veg as well as tea and red wine. Containing benzopyran and benzene aromatic carbon rings, flavonols are partly responsible for the bitterness of some chocolates. It is these rings that are free radical-neutralising, something that protects endothelia from oxidative stress and subsequent cardiovascular risks. These protective effects have been shown in dark chocolate rather than milk or white chocolate which have lower levels of flavonol due to their reduced cocoa content, which is a shame for those of us partial to a bar of dairy milk!
Studies in 2006 saw an inverse relationship between chocolate consumption and blood pressure in a population of 470 men and a similar relationship between consumption and cardiac mortality in a separate investigation. The many facets of cardiovascular disease constitute a major disease burden. Similar flavonols that are thought to be valuable antioxidants are also anti-inflammatory and vasoprotective. Polyphenols such as flavonols interfere with NF-κB, a transcription factor involved in control of the inflammatory pathway whereby leukocyte adhesion and tissue invasion –hallmarks of the inflammatory process – are stunted.
The modulation of these processes can also go some way in altering the effects of carcinogenesis, as cell adhesion and invasion as a result of NF-κB signalling are essential steps a tumour must undertake to become malignant. In addition, the fact that cocoa constituents can merely reduce oxidative stress levels may give rise to lowered stress-mediated mutations leading to DNA damage if not properly repaired. Interestingly, cocoa has consistently been shown to interfere with extrinsic apoptotic mechanisms, the process of controlled cell death. Cancer cells express ways in which to avoid apoptosis and therefore continue to survive. Unfortunately they also have a plethora of other ways to exhibit carcinogenesis, so I’m afraid a chocolate bar a day probably won’t be protective against cancer.
From reducing mental stress to oxidative stress, chocolate and its chemical constituents have a whole range of advantageous and detrimental effects. But it’s not all doom and gloom…so don’t feel too bad if you’re half way through your fourth Easter egg of the day whilst reading this!
For more information about the health benefits of cocoa and flavonols, these articles are a great place to start!
Katz, D., Doughty, K., & Ali, A. (2011). Cocoa and Chocolate in Human Health and Disease Antioxidants & Redox Signaling, 15 (10), 2779-2811 DOI: 10.1089/ars.2010.3697
Franco R, Oñatibia-Astibia A, & Martínez-Pinilla E (2013). Health benefits of methylxanthines in cacao and chocolate. Nutrients, 5 (10), 4159-73 PMID: 24145871
Selmi C, Cocchi CA, Lanfredini M, Keen CL, & Gershwin ME (2008). Chocolate at heart: the anti-inflammatory impact of cocoa flavanols. Molecular nutrition & food research, 52 (11), 1340-8 PMID: 18991246
Ellam S, & Williamson G (2013). Cocoa and human health. Annual review of nutrition, 33, 105-28 PMID: 23642199
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