Dark chocolate contains polyphenols – the group of antioxidants that are present in various foods like purple & red grapes, dark berries, oranges, vegetables, tea and red wine. Flavonoids are a group of polyphenols and form the major source of polyphenols in our diet.
Dark Chocolate Bar
How do flavonoids in cacao protect against ageing?
Mainly plant pigments, flavonoids help fight aging by protecting cells from inflammation and damage. Procyanidins and Epicatechins are flavonoids in dark chocolate that help to slow down or reverse cell oxidation. While flavonoids are widely present in various plants, cacao contains a sub-class of flavonoids known as flavanols that have shown to have particular benefits for the heart namely in blood circulation, blood platelet function, endothelial (blood vessel lining) function, and blood pressure.
Epicatechins are known to enter the brain and stimulate cerebral blood flow to the brain. They promote the birth of new brain cells as well as new blood vessels and changes in neuron structures. Epicatechins help to improvecognitive functions and memory. Flavonoids in chocolate have been shown to preserve cognitive functions in rat studies and reduce the risk of Alzheimer's disease. Chocolate is also a well known mood enhancer and can reduce stress.
The flavonoids in chocolate are also known to react with protein signaling cascades that prevents neurons from dying, improves their survival and also strength of synapses.9
Benefits of Dark Chocolate that help prevent ageing related diseases
Suppresses inflammation causing immune response
In a study published in the American Journal of Clinical Nutrition it was shown that chocolate procyanidins reduced the synthesis of eicosanoids like prostaglandins which are compounds that signal the immune system of body. When activated, prostaglandins induce pain, inflammation and fever which is the body’s immune response to injury or infection. Chronic inflammation leads to degenerative disease and loss of youthful functions.
A 2012 study showed that daily consumption of dark chocolate could be used as preventative measure to protect against cardiovascular related diseases.
The study was conducted on over 2000 hypertensive patients with metabolic syndrome and no heart disease. The benefits were derived from properties of dark chocolate to lower blood pressure and cholesterol.
In the Dec 2013 publication of the Journal of the Federation of American Societies for Experimental Biology, it was shown that flavonol enriched chocolate promoted vasodilation or widening of blood vessels, reduced white blood cell count and adhesion of white blood cells. This prevents inflammation of the endothelium or the lining of blood vessels.
In a study conducted at the University of Illinois, consumption of flavanol-containing dark chocolate on a daily basis was shown to reduce systolic blood pressure by 5.8 mmHg.
Blood pressure and endothelial function
A study of mice published in IUBMB Life 2013, showed that epicatechins in chocolate helped reduce blood pressure by 27 mm Hg and also increased Nitric Oxide Synthases by 173%. Nitric Oxide Synthases or NOSs are enzymes that synthesize nitric oxide from L-Arginine. These enzymes strengthen heart vessels, manage insulin secretion, digestive tract movements and also in generating brain cells and neurons.
Brain cell protection and neurogenesis
Flavonoids may also be helpful in improving mental processes and protect from age related diseases of the brain like dementia and Alzheimer’s.
In a study published in the Neuroscience Biobehaviour Review 2013 the neuromodulatory and neuroprotective actions of chocolate flavonoids was
researched. It was found that the flavonoids accumulate in the hippocampus of the brain which is the center of learning and memory. The flavonoids acted in two ways. One was to directly interact with cells to produce proteins that aid in generating neurons, enhance functions of neurons and promote brain connectivity. The second was by improving blood flow and production of new blood vessels in the brain and sensory systems.
Animal studies also showed protective effects of chocolate flavonols against cognitive decline caused by ageing and disease.
Oxidative stress and cognitive decline increase with age. In addition due to increasing inactivity and changes in diet, it is common for obesity to set in during mid-life. This combined with type 2 diabetes is considered to add to the risk of Alzheimer's disease and cognitive decline in later life. In a study on aged rats in whom obesity was induced, it was found that consumption of dark chocolate containing 70% cocoa solids and 4% polyphenols, blood sugar levels could be reduced. Additionally spatial memory related tasks were performed better by the rats.
Protection against cancers
Polyphenolic compounds like flavonoids found in chocolate donate electrons to free radicals and thereby act as chemopreventive agents. Polyphenols inhibit development and propagation of cancer cells as in colon and rectal cancer.
Research studies have also shown flavonoids to reduce the growth of lung and prostate cancers.
Skin protection and visible ageing signs
According to a study published in the Journal of Cosmetic Dermatology, chocolate can protect against the harmful effects of ultraviolet rays. 30 adults who were approximately 42 years of age were recruited. Half were given 20 grams of high flavonol chocolate and the other half 20 grams of normal chocolate. They were exposed to a daily dose of UV rays. After 3 months, those who took the flavonol enriched chocolate showed that their skin stood up much better to the sun’s rays than those who took the regular chocolate.
How dark should chocolate be to give you health benefits?
Chocolate needs to be at least 70% cacao to give you the health benefits discussed above. The more cacao content the better. Of course you will have to contend with the bitter taste.
Avoid chocolate that contains milk or which is processed with alkali as that lowers flavonol content. Just a one ounce square daily is enough for health benefits.
1. Centers for Disease Control and Prevention 2011;
2. Neuroscience Biobehaviour Review 2013 (Sokolov AN, Pavlova MA, Klosterhalfen S, Enck P.)
3. International Union of Biochemistry and Molecular Biology (IUBMB) Life. 2013 Aug;
(-)-Epicatechin reduces blood pressure and improves vasorelaxation in spontaneously hypertensive rats by NO-mediated mechanism.
Galleano M, Bernatova I, Puzserova A, Balis P, Sestakova N, Pechanova O, Fraga CG.
4. Federation of American Societies for Experimental Biology (FASEB) Journal. 2013 Dec 4.
Dark chocolate consumption improves leukocyte adhesion factors and vascular function in overweight men.
Esser D, Mars M, Oosterink E, Stalmach A, Müller M, Afman LA.
5. British Medical Journal (BMJ). 2012 May 30;
The effectiveness and cost effectiveness of dark chocolate consumption as prevention therapy in people at high risk of cardiovascular disease: best case scenario analysis using a Markov model.
Zomer E, Owen A, Magliano DJ, Liew D, Reid CM.
6. Asia Pacific Journal of Clinical Nutrition. 2008;
Effects of cocoa flavanols on risk factors for cardiovascular disease.
Erdman JW Jr, Carson L, Kwik-Uribe C, Evans EM, Allen RR.
7. Biotechnology Advances. 2013 Sep-Oct;
Nanoencapsulation of polyphenols for protective effect against colon-rectal cancer.
Santos IS, Ponte BM, Boonme P, Silva AM, Souto EB.
8. Journal of Dietary Supplements 2016;13(4):449-60. doi: 10.3109/19390211.2015.1108946. Epub 2015 Dec 16.
The Neuroprotective Effect of Dark Chocolate in Monosodium Glutamate-Induced Nontransgenic Alzheimer Disease Model Rats: Biochemical, Behavioral, and Histological Studies.
Madhavadas S1, Kapgal VK2, Kutty BM2, Subramanian S1.
9. British Journal of Clinical Pharmacology 2013 Mar;75(3):716-27. doi: 10.1111/j.1365-2125.2012.04378.x.
The neuroprotective effects of cocoa flavanol and its influence on cognitive performance.