Health and longevity benefits of dark chocolate

I like this anti-aging medicine so much that I sometimes feel guilty when I eat it. There are some 380 distinct known chemicals in chocolate and many of those are bioactive.  However, the main beneficial ingredient in chocolate is the flavonoid Epicatechin.  “Cocoa, the major ingredient of dark chocolate, contains relatively high amounts of epicatechin and has been found to have nearly twice the antioxidant content of red wine and up to three times that of green tea in in-vitro tests(ref)(ref).”   Epicatechin is also found in other foods including tea and grapes.   Some research findings re chocolate:

• Promotes cardiovascular health:  From a 2006 report Chocolate and prevention of cardiovascular disease: a systematic review:  “The body of short-term randomized feeding trials suggests cocoa and chocolate may exert beneficial effects on cardiovascular risk via effects on lowering blood pressure, anti-inflammation, anti-platelet function, higher HDL, decreased LDL oxidation.” “–flavonoids are likely protective against CHD (cardiovascular heart disease) mortality. The highest priority now is to conduct larger randomized trials to definitively investigate the impact of chocolate consumption on long-term cardiovascular outcomes(ref).”  Several other research publications reinforce the same viewpoint.  For example, a 2008 review study report states “While flavonoids are ubiquitous in plants, cocoa can be particularly rich in a sub-class of flavonoids known as flavanols. A number of human dietary intervention trials with flavanol-containing cocoa products have demonstrated improvements in endothelial and platelet function, as well as blood pressure. These studies provide direct evidence for the potential cardiovascular benefits of flavanol-containing foods and help to substantiate the epidemiological data.– Together the results of these human dietary intervention trials provide scientific evidence of the vascular effects of cocoa flavanols and suggest that the regular consumption of cocoa products containing flavanols may reduce risk of CVD(ref).”
• Cuts death risk for coronary heart disease patients who have had a heart attack:  A study reported a couple of weeks ago, was based on following 1,169 non-diabetic patients hospitalized with a confirmed first acute myocardial infarction (AMI) between 1992 and 1994 in Sweden as part of the Stockholm Heart Epidemiology Program.  Patients were followed for 8 years and reported on chocolate consumption as part of a standard questionnaire.  “Chocolate consumption had a strong inverse association with cardiac mortality. [More chocolate, less mortality.” —  “Chocolate consumption was associated with lower cardiac mortality in a dose dependent manner in patients free of diabetes surviving their first AMI(ref).”

·        Helps prevent age-related dementia: Back in the post Warding off Alzheimer’s Disease and things in my diet, I quoted about my daily chocolate  snack: “Oxidative stress induced by reactive oxygen species has been strongly associated with the pathogenesis of neurodegenerative disorders, including Alzheimer’s disease.  In this study, we investigated the possible protective effects of a cocoa procyanidin fraction (CPF) and procyanidin B2 (epicatechin-(4beta-8)-epicatechin) – a major polyphenol in cocoa – against apoptosis of PC12 rat pheochromocytoma (PC12) cells induced by hydrogen peroxide.  — These results suggest that the protective effects of CPF and procyanidin B2 against H(2)O(2)-induced apoptosis involve inhibiting the downregulation of Bcl-X(L) and Bcl-2 expression through blocking the activation of JNK and p38 MAPK(ref).” 

·        Is neuroprotective and modulates brain functioning: The epicatechin in chocolate like other flavonoids is neuroprotective.  “Flavonoids exert a multiplicity of neuroprotective actions within the brain, including a potential to protect neurons against injury induced by neurotoxins, an ability to suppress neuroinflammation, and the potential to promote memory, learning and cognitive function(ref).” Another study report states “dietary flavonoids might have potential as protective agents against neuronal apoptosis through selective actions within stress-activated cellular responses, including protein kinase signalling cascades(ref).”  And yet-another report states “Emerging evidence suggests that dietary phytochemicals, in particular flavonoids, may exert beneficial effects on the central nervous system by protecting neurons against stress-induced injury, by suppressing neuroinflammation and by improving cognitive function(ref).”   I often experience a rush of good feeling and what seems to be an ability to think more clearly after a chocolate fix,  but usually attribute that to being a sugar rush or perhaps a quirk of my imagination.  Quite possibly that effect is biochemically driven by the chocolate itself and real.

·        Reverses vascular dysfunction in diabetes:  This publication reports on two studies looking at the feasibility and efficacy of dietary intervention based on daily intake of flavanol-containing cocoa for improving vascular function in diabetic patients.  The feasibility study involved 10 diabetic patients and the follow-up efficacy study 41 medicated diabetic patients. Both studies were double-masked, randomized, controlled trials.  The study found sustained benefits and concludes “Diets rich in flavanols reverse vascular dysfunction in diabetes, highlighting therapeutic potentials in cardiovascular disease(ref).”

·        Lowers blood pressure in overweight adults: The conclusions of a randomized, placebo-controlled, single-blind crossover trial of 45 healthy adults state “The acute ingestion of both solid dark chocolate and liquid cocoa improved endothelial function and lowered blood pressure in overweight adults. Sugar content may attenuate these effects, and sugar-free preparations may augment them(ref).” 

·        Lowers blood pressure in normal adults: Another study Effects of low habitual cocoa intake on blood pressure and bioactive nitric oxide: a randomized controlled trial concludes. “Data in this relatively small sample (44 adults aged 56 through 73 years) of otherwise healthy individuals with above-optimal BP (blood pressure) indicate that inclusion of small amounts of polyphenol-rich dark chocolate as part of a usual diet efficiently reduced BP and improved formation of vasodilative nitric oxide(ref).”  See also Effect of dark chocolate on arterial function in healthy individuals: cocoa instead of ambrosia? and Effect of dark chocolate on arterial function in healthy individuals.

·        May help prevent artery hardening due to smoking: “Researchers compared the effects of dark (74% cocoa solids) and white chocolate on the smoothness of arterial blood flow in 20 male smokers.” – “After two hours, ultrasound scans revealed that dark chocolate significantly improved the smoothness of arterial flow, an effect which lasted for eight hours. Blood sample analysis also showed that dark chocolate almost halved platelet activity. Antioxidant levels rose sharply after two hours.” – “Only a small daily treat of dark chocolate may substantially increase the amount of antioxidant intake and beneficially affect vascular health,” conclude the authors(ref).”

Other interesting findings related to chocolate are:

·        Brain awareness benefits of chocolate consumption are visible in MRI scans: “The present study employed functional magnetic resonance imaging based on blood oxygenation level-dependent (BOLD) contrast to explore the effect of flavanols on the human brain. Magnetic resonance imaging was used to measure BOLD responses to a cognitive task in 16 healthy young subjects. The data presented show an increase in the BOLD signal intensity in response to a cognitive task following ingestion of flavanol-rich cocoa (5 days of 150 mg of cocoa flavanols). This may arise either as a result of altered neuronal activity, or a change in vascular responsiveness, or both –(ref).”

·        Benefits of chocolate consumption may be greater for older people:  This publication reports study “of blood pressure and peripheral arterial responses to several days of cocoa in 15 young (< 50 years) and 19 older (> 50) healthy subjects.” Conclusions: Flavanol-rich cocoa enhanced several measures of endothelial function to a greater degree among older than younger healthy subjects. Our data suggest that the NO-dependent vascular effects of flavanol-rich cocoa may be greater among older people, in whom endothelial function is more disturbed(ref).”  Also, in another report “Observations point to a favorable response among the older. Together with peripheral vascular disease, cerebrovascular disease is responsible for significant mortality with advancing age. An association of decreased cerebral perfusion with dementia has been recently highlighted. The prospect of increasing cerebral perfusion with cocoa flavanols is extremely promising(ref).”

·        Endothelial and cardiovascular benefits of cocoa consumption are due in some large measure to induction of nitric oxide vasodilation: Several studies make this point; for example: “ Therefore, ingested flavonoids may reverse endothelial dysfunction through enhancement of NO bioactivity(ref).” As stated in another research report, “In healthy humans, flavanol-rich cocoa induced vasodilation via activation of the nitric oxide system, providing a plausible mechanism for the protection that flavanol-rich foods induce against coronary events(ref).”  This is the sex aspect of consuming chocolate.  Inducing vasodialation via activation of the nitric oxide system is what the erectile dysfunction drugs Viagra (Sildenafil), Cialis (Tadalafil), and Levitra (Vardenafil) do in their own somewhat-similar ways(ref).         

On the whole is eating chocolate good for you?  Of course it depends on the chocolate product you eat.  These products can vary widely in both polyphenol/flavonoid, fat and sugar content(ref)(ref).  And in some cases the health hazards of the sugar and fat can outweigh the health benefits of the chocolate flavonoid content.  However,  the large-population studies mentioned above are based on consumption of commercial chocolate products.  Personally, I have been eating 72% cocoa solids Belgian Chocolate available in a big red-wrapped bar from Trader Joe’s and am now increasingly eating enhanced-flavonoid chocolate products that are now becoming commercially available.  Preparing to put this blog post online, I have just rewarded myself with two squares from a big red bar.