Cocoa, the principal component of chocolate, is derived from the cacao tree. Cocoa and chocolate are rich in polyphenols, particularly flavonoids, exhibiting the highest concentrations of flavonoids (chiefly epicatechin, catechin, and procyanidins) among many commonly consumed foods. Processing of cocoa induces flavonoid losses of 60 percent or more, however.
A wide range of beneficial health effects has been attributed to the consumption of cocoa and chocolate, and robust evidence suggests that cocoa flavonoids…
Some of the beneficial effects of cocoa and chocolate may be related to their capacity to promote the production of nitric oxide, a potent endogenous vasodilator that plays important roles in blood pressure regulation. Cocoa and chocolate also contain anandamide, a cannabinoid compound that binds to receptors in the brain and alters brain activity and mood, and methylxanthine compounds, including theobromine and caffeine, which exert potent antioxidant activity and stimulant effects.
When adults with high blood pressure took cocoa flavonoid capsules (providing 862 milligrams of cocoa flavonoids) for eight consecutive days, their systolic blood pressure dropped by as much as 1.7 mmHg, and their pulse wave velocity decreased by as much as 0.14 m/s. The greatest effects occurred in the first three hours after consuming the cocoa, with the blood pressure dropping approximately 5 mmHg. Blood pressure dropped again at approximately eight hours after consuming the cocoa supplement, likely due to bacterial metabolism of the flavonoids in the gut.
In a double-blind, randomized clinical trial involving 44 adults with peripheral artery disease (PAD), participants who drank a cocoa beverage daily for six months showed marked improvement in their walking performance, increasing their walking distance by nearly 43 meters immediately after consumption of the beverage and by nearly 18 meters 24 hours afterward. Biopsies of the participants' calf muscles revealed that cocoa improved mitochondrial function, blood flow, and capillary density, suggesting that cocoa shows promise as a therapeutic strategy for people who have PAD.
In a crossover intervention study involving healthy young males, participants consumed a cocoa beverage prepared with either high- or low-flavanol cocoa powder dissolved in water before taking a test that promoted mental stress. Participants' vascular function improved after consuming the high-flavanol beverage, and the improvement was maintained even at 90 minutes post-stressor.
When healthy young adults consumed cacao that contained L-theanine, an amino acid found in tea and mushrooms, their diastolic and systolic pressures decreased by as much as 8 mmHg. In addition, their brain activity related to arousal increased, but brain activity related to brain deactivation decreased.
Q: Is the heavy metal content of certain chocolates cause for concern?
A: A 2022 Consumer Reports analysis of widely available cocoa and chocolate products revealed that most of the products tested contained quantities of heavy metals that exceed acceptable California Proposition 65 limits. However, heavy metal concentrations varied across brands, with some brands showing lesser or greater amounts.
Heavy metals are ubiquitous, naturally occurring elements and are commonly present in regularly consumed foods. High blood lead and cadmium levels are associated with lower intelligence in children and infertility in adults, as well as many other health concerns. Whether the quantity of heavy metals found in a serving of dark chocolate is cause for concern, especially for vulnerable groups like children and pregnant women is unclear. Elimination of certain heavy metals from the body can be enhanced by lifestyle behaviors such as sauna use, which enhances excretion through sweat.
Polyphenols - a broad family of bioactive plant compounds that exert a wide range of health effects in humans, including notable compounds like anthocyanins found in berries, and EGCG (epigallocatechin gallate), found in green tea, and many more.
Quercetin - a flavonol found in apples, onions, and other edible plants that exerts antioxidant, anti-inflammatory, and anti-aging properties across multiple organ systems.
Resveratrol - a polyphenolic compound found in red grapes, peanuts, and other edible plants that has demonstrated beneficial cardiovascular effects.
Sulforaphane - a bioactive compound derived from some cruciferous vegetables that exerts potent antioxidant and anti-inflammatory properties and may be beneficial against a wide range of chronic and acute diseases.
Clips and episodes
Resveratrol, a polyphenol in grapes, mimics some of the effects of fasting (Mark Mattson interview)
Resveratrol's effects on the cardiovascular system (David Sinclair interview)