Cocoa and cocoa products – particularly dark chocolate, contain high levels of flavonols, a potent type of antioxidant.
A team from University of Milan (Italy) assessed the effect
of a dark chocolate composed of 860 mg polyphenols and containing 58 mg
epicatechin, a specific type of antioxidant polyphenol. The team
assigned 20 healthy men and women, average age 24.2 years, to consume a
balanced diet for 4 weeks, midway through which one-half of the
subjects were asked to additionally consume dark chocolate. The
researchers observed that catechin levels increased just two hours
after the consumption of the dark chocolate, a rise that coincidentally
correlated to decreases in DNA damage on the order of 20% that were
observed in blood cells.
Researchers from the Laboratory of Genetic and Environmental Epidemiology at Catholic University (Italy) studied a group of 5,000 subjects in generally good health over a one-year period. Specifically, the evaluated the anti-inflammatory properties of dark chocolate, as measured by serum levels of C-reactive protein (CRP), a blood marker of inflammation. The team found that those subjects who consumed 1 serving (20 g) of dark chocolate every 3 days had serum CRP concentrations that were significantly lower than those who did not eat any chocolate. According to the researchers, these reductions in CRP translate to a 33% risk reduction of cardiovascular disease in women and 26% reduction in men.
A team from Karolinska Institute (Sweden) followed 1,169 non-diabetic patients hospitalized with a confirmed first acute myocardial infarction (AMI), surveying them for their chocolate consumption during the preceding 12 months and conducting a health examination 3 months after discharge. Participants were followed for hospitalizations and mortality with national registries for 8 years. The researchers found that chocolate consumption was strongly inversely associated with cardiac mortality, observing that eating chocolate two or more times a week slashes cardiac death by 66%, but less frequent consumption is also associated with smaller decreased risks.
German Institute of Human Nutrition (Nuthetal, Germany) researchers studied 19,357 people, ages 35 to 65 years, enrolled in the Potsdam arm of the European Prospective Investigation into Cancer (EPIC) study. Following the subjects for at least ten years, the team found that those who ate the most amount of chocolate -- an average of 7.5 grams a day -- had lower blood pressure and a 39% lower risk of having a heart attack or stroke, as compared to those who ate the least amount of chocolate -- an average of 1.7 grams a day. The researchers observed that the difference between the two groups amounted to six grams of chocolate, or the equivalent of less than one small square of a 100g bar.
A team from Nestle Research Center (Switzerland) reported that a small portion of dark chocolate can ward off stress. The team studied 30 men and women, each of whom were classified by anxiety level. The study subjects consumed 20 grams of dark chocolate in the mid-morning and again in the afternoon. Noting that those subjects with high anxiety traits had a distinct metabolic profile, the researchers observed that after two weeks of consuming 40 grams of dark chocolate daily, levels of stress hormones and other stress-related biochemical markers were reduced.
McMaster University (Canada) researchers analyzed various studies involving chocolate consumption to ascertain its effects on stroke risk. One study revealed an association with stroke for chocolate consumption once a week as opposed to none per week, with another study suggesting that flavonoid intake from eating chocolate weekly lowered death caused by a stroke.
Researchers from Beth Israel Deaconess Medical Center (Massachusetts, USA) observed that 13 men and women (average age 72 years) who consumed flavonol-rich cocoa (900 mg per day) for two weeks demonstrated a 10% increase in cerebral blood flow.]
Indulge in dark chocolate, but modestly. Twenty grams twice a week may help improve your cardiovascular risk profile.