How lovely to hear that a beloved food is also good for you, and how much lovelier it is that it happens to be true!

Dark chocolate contains plentiful antioxidants, especially one called epicatechin, with a variety of positive effects. Research suggests that small doses of dark chocolate are associated with lower blood pressure and better insulin sensitivity, the healthful opposite of insulin resistance. These benefits and others help to protect the heart.

It is a prebiotic food, nourishing a range of “good” bacteria among our body’s microorganisms, known collectively as the microbiome (Zugravu et al., 2019). Remarkably, its antioxidant power is stable: one analysis concluded that even 80-year-old cocoa powder packed a punch (Hurst et al., 2009). 

Of course, gobbling a box of sugary milk chocolate bonbons won’t have the same good effect on your health.  According to the Food and Drug Administration, milk chocolate must contain at least 10 percent chocolate liquor, and at least 12 percent milk (FDA, 2019), which means much of the remaining weight can consist of sugar.

In dark chocolate, you’ll find a range from 50 percent chocolate liquor on up to 100 percent. The darker varieties tend to have much less sugar and - allergy alert! - they often contain milk, even if milk isn’t on the ingredients list.

Sugary or not, all chocolate is fairly high in calories. Even just 3.5 ounces of dark chocolate could supply a quarter of your desirable calorie intake for the day! Instead, enjoy one or two ounces a day of dark chocolate that contains at least 80 percent cocoa (the only kind available at Vital Choice).

Chocolate was one of the first recognized super-foods, beloved by the Aztec king Montezuma, who considered it an aphrodisiac that would also enhance fertility and longevity. In 1737, the Swedish naturalist Linnaeus named the cocoa tree Theobroma, “Food of God.” Over the centuries, people touted cocoa to calm agitation, improve energy, relieve asthma, and cut fever (Zugravu et al., 2019). In our scientific age, we can trace benefits to the antioxidant effects of compounds called flavonoids.

A natural experiment

The Kunu, who live on islands in the Caribbean near Panama, traditionally fetched water by boat from a mainland river every day. Lacking refrigeration, they always boiled their water and drank it hot with either homegrown or Colombian cocoa powder rich in antioxidants. On any one day, they might drink more than five cups.

In the early 1990s, a team from Boston’s Brigham and Women’s Hospital and Harvard (led by Norman Hollenberg, who became renowned for this work) noticed that Kuna elders enjoyed admirably low blood pressure. In several hundred Kuna over age 60, the average systolic blood pressure was less than 110 mm Hg, and the average diastolic blood pressure less than 70 mm Hg. These numbers were too good to be explained by known dietary factors, so the team suspected the Kuna had a protective gene (Hollenberg et al., 2009).

However, when islanders migrated to the mainland, they cut back on drinking cocoa and their blood pressure rose. Alarmingly, their rates of death from heart disease, cancer and diabetes became much higher than those of island-dwellers. It seemed that cocoa made the difference (Hollenberg et al., 2009). 

Many later studies support the idea that cocoa promotes healthy low blood pressure. One of the clearest tests was a double-blind, controlled study of 90 elderly individuals in L’Aquila, Italy, who were randomly assigned into three groups: a group that drank a high-flavonoid cocoa every day, one that drank a less potent version and one that drank an even weaker one. After eight weeks, the volunteers showed improvements in blood pressure, and the more potent their cocoa, the greater the improvement (Mastroiacovo et al., 2015).    

Does chocolate increase insulin sensitivity?

It may sound odd that chocolate would lower blood sugar, but again, remember we’re not talking about sugary bonbons (Greenberg, 2014, Veronese et al., 2019). The L’Aquila study is again a good example, as it found improvements in insulin sensitivity linked to flavonoid power.  

Its primary purpose, however, was to test if cocoa would make the elders mentally sharper, and indeed the more potent cocoas pushed up their performance on cognitive tests (Mastroiacovo et al., 2015). The researchers proposed that the improvement was most likely a positive effect of better insulin sensitivity. 

Should you eat dark chocolate on a date?

Why not? A dose of good chocolate could boost your performance in any stressful situation. In one study, researchers put healthy men through standard tests of psychological stress that included public speaking and doing mental arithmetic. Two hours earlier, they had been dosed with either dark chocolate or the same amount of chocolate stripped of its flavonoids. The men who ate the real stuff were much less stressed, according to measurements of blood chemicals (von Kanel et al., 2014). Young women also benefited from a dose of 85 percent chocolate in another stress test. This time researchers compared measures of heart function and found the women buoyed by dark chocolate were less reactive than a group that ate milk chocolate instead (Regecova et al., 2019).

Overall, it’s likely that chocolate is good for your heart, and not only as a red heart-shaped gift from your true love. In a study following nearly 21,000 participants over around 12 years, dark-chocolate lovers enjoyed lower chances of heart disease and stroke (Kwok et al.,2018). A meta-analysis of 23 studies published through June, 2018, concurred, as long as you don’t eat more than about 3.5 ounces a week (Ren et al., 2019). The effect may be stronger for women, other research has found (Gianfredi et al., 2017). 

Anecdotally, I can confirm all of the above. I recall bringing extra-dark chocolate with me on a hike, a date with a promising man. I brought enough for both of us, and so did he. “Women need chocolate,” he said, confessing that he liked only the sweeter kinds. Crediting me with my “chocolate independence” became one of his ongoing jokes. 


CFR - Code of Federal Regulations Title 21. Accessed July 23, 2020.

Djoussé L, Hopkins PN, North KE, Pankow JS, Arnett DK, Ellison RC. Chocolate consumption is inversely associated with prevalent coronary heart disease: the National Heart, Lung, and Blood Institute Family Heart Study. Clinical nutrition (Edinburgh, Scotland). Published April 2011.

Gianfredi V, Salvatori T, Nucci D, Villarini M, Moretti M. Can chocolate consumption reduce cardio-cerebrovascular risk? A systematic review and meta-analysis. Nutrition. E-published September 25, 2017.

Grassi D, Desideri G, Necozione S, et al. Blood pressure is reduced and insulin sensitivity increased in glucose-intolerant, hypertensive subjects after 15 days of consuming high-polyphenol dark chocolate. The Journal of nutrition. Published September 2008.

Greenberg JA. Chocolate intake and diabetes risk. Clinical nutrition (Edinburgh, Scotland). Published February 2014.

Hollenberg NK, Fisher ND, McCullough ML. Flavanols, the Kuna, cocoa consumption, and nitric oxide. J Am Soc Hypertens. E-published February 20, 2019.

Hurst WJ, Payne MJ, Miller KB, Stuart DA. Stability of cocoa antioxidants and flavan-3-ols over time. Journal of agricultural and food chemistry. Published October 28, 2009.

Kwok CS, Boekholdt SM, Lentjes MAH, et al. Habitual chocolate consumption and risk of cardiovascular disease among healthy men and women. Heart (British Cardiac Society). Published August 2015.

Magrone T, Russo MA, Jirillo E. Cocoa and Dark Chocolate Polyphenols: From Biology to Clinical Applications. Published May 24, 2017.

Mastroiacovo D, Kwik-Uribe C, Grassi D, et al. Cocoa flavanol consumption improves cognitive function, blood pressure control, and metabolic profile in elderly subjects: the Cocoa, Cognition, and Aging (CoCoA) Study--a randomized controlled trial. Am J Clin Nutr.  E-published December 24, 2017.

Neitzel AL, Smalls BL, Walker RJ, Dawson AZ, Campbell JA, Egede LE. Examination of dietary habits among the indigenous Kuna Indians of Panama. Nutrition journal. Published August 1, 2019.

Regecova V, Jurkovicova J, Babjakova J, Bernatova I. The Effect of a Single Dose of Dark Chocolate on Cardiovascular Parameters and Their Reactivity to Mental Stress. J Am Coll Nutr. E-published September 17, 2019.

Ren Y, Liu Y, Sun XZ, et al. Chocolate consumption and risk of cardiovascular diseases: a meta-analysis of prospective studies. Heart. E-published July 30, 2018.

Veronese N, Demurtas J, Celotto S, et al. Is chocolate consumption associated with health outcomes? An umbrella review of systematic reviews and meta-analyses. Clin Nutr. E-published June 1, 2018.

von Känel R, Meister RE, Stutz M, et al. Effects of dark chocolate consumption on the prothrombotic response to acute psychosocial stress in healthy men. Thrombosis and haemostasis. Published December 2014.

Williams S, Tamburic S, Lally C. Eating chocolate can significantly protect the skin from UV light. Wiley Online Library. Published September 1, 2009.

Zugravu C, Otelea MR. Dark Chocolate: To Eat or Not to Eat? A Review. J AOAC Int. Published September 1, 2019