This Valentine’s Day, Remember Chocolate May Protect the Heart Against Heart Disease

During the month of February, society is surrounded by abundant reminders of the presence of love, roses, and chocolate—symbols of the Valentine’s Day holiday. On February 14, consumer data has shown that Americans purchase approximately 58 million pounds of chocolate each year.¹ Considering chocolate’s potential benefits for the heart, this might not be such a bad thing.

Although chocolate has long been proposed to possess benefits in lowering heart disease morbidity and mortality, not everyone may be familiar with exactly how chocolate impacts this disease, which is one of the nation’s leading causes of death. As an integral member of patients’ care teams, pharmacists can help to educate patients on the multifaceted effects of lifestyle factors in addition to medications that treat chronic conditions such as heart disease.

Historically, the practices of Kuna Indians sparked much interest in the use of chocolate for health purposes.^2,3 Native to islands of Panama, the Kuna Indians have low rates of hypertension, atherosclerosis, and diabetes. In fact, the average blood pressure of this population is only 110/70 mmHg. Due to these findings, researchers have speculated whether this may be due to their diet, which is gilded in cocoa.

On average, the Kuna population frequently consumes 5 cups of cocoa daily. Though some have argued that the low rates of hypertension in the population is due primarily to genetics, research has now demonstrated that a diet rich in cocoa plays a stronger role. Specifically, this became clear after some of the population native to the coast of the islands of Panama moved inland, leading to a decrease in their daily cocoa intake. Following this move, those living inland began to demonstrate higher rates of cardiovascular comorbidities as compared to those living on the coast.^2,3

Chocolate contains a complex mix of ingredients that may provide a range of health advantages. Cocoa, and its similar counterpart cacao, are likely the main source of these beneficial effects. Cocoa contains large concentrations of flavanols, which yield tremendous antioxidant effects, increase nitric oxide and subsequent vasodilation, and support endothelial function.^2,4 Cocoa also contains nitrogenous compounds such as theobromine and caffeine, which produce mild stimulant, diuretic, and muscle relaxant effects.^2,4 Lastly, cocoa is a natural source of potassium, phosphorous, copper, iron, zinc, and magnesium, which all play a variety of roles within the cardiovascular system, including muscle function, nerve signaling, and overall cardiac function.^2,4,5

Additionally, although cocoa butter contains predominantly saturated fats, one-third of that fat is a monounsaturated fat called oleic acid.2 Monounsaturated fats such as oleic acid are known to lower LDL cholesterol levels and can help decrease the risk for heart disease. Although the exact mechanism of how these compounds potentiate cardioprotective effects is unknown, experts in the field have speculated that they play a major role in preventing heart disease by reducing blood pressure, improving endothelial function, decreasing atherosclerosis, and modulating inflammation.

While chocolate and its constituents have been historically criticized for their high fat, sugar, and caloric density, research has shown that its unhealthy reputation may be unfounded, at least when consumed in moderation. A study conducted in 2006 showed that cocoa intake, primarily from dark chocolate, was inversely related to blood pressure, cardiovascular mortality, and all-cause mortality.⁶ Additionally, the mean systolic blood pressure (SPB) and mean diastolic blood pressure (DBP) were lower in the higher intake group (4.2g of cocoa daily) compared to the lowest intake group (0g of cocoa daily) by 3.7mmHg and 2.1mmHg, respectively.

Furthermore, another study in 2009 indicated cocoa could be associated with lower cardiovascular morbidity and all-cause mortality.⁷ Following this, in 2017, a meta-analysis of the data from this research analyzed the short-term effects of daily cocoa consumption on blood pressure. The active group received an average of 670 mg of flavanols in cocoa products, while the control group received an average of 55 mg of flavanols daily. The results showed a statistically significant mean decrease of 1.8 mmHg in both SBP and DBP.⁸

However, more intensive randomized controlled trials are needed to establish causality and solidify cocoa’s potential role in adjunctive therapy. Current guidelines still recommend using traditional blood pressure medications in addition to lifestyle modifications, such as physical activity, tobacco cessation, alcohol limitation, and the Dietary Approaches to Stop Hypertension diet.⁹ Pending further studies, it remains unknown whether chocolate could be added to this list.

Although incorporating chocolate into the diet may be a healthy choice, the type and amount are an important contributing factor. Dark chocolate is likely the best choice since it contains more cocoa and approximately 2 to 3 times more flavanol-rich cocoa solids than milk chocolate.¹⁰

On the other hand, white chocolate does not contain cocoa solids and most likely lacks the healthy properties found in other chocolates. When choosing the healthiest chocolate, patients can decide by checking the label for the percent of cacao present, which can identify for patients the amount of the chocolate that’s from cocoa solids.¹¹

Generally, bittersweet or extra bittersweet chocolate contain around 70% cacao and provide a favorable ratio of cocoa solids to sugar.¹¹ Although recommended consumption amounts have not been determined, one study showed eating 2 to 6 one-ounce servings of chocolate weekly reduced the rate of atrial fibrillation by 20% (HR 0.80, 95% CI 0.71 to 0.91).¹² During the trial, the study investigators estimated that the chocolate likely contained at least 30% cocoa solids.

However, it remains important to keep in mind that moderation is key. Not only can chocolate add extra sugar, fat, and calories to the diet, it also contains caffeine that can complicate sleep disorders, anxiety, tachycardia, and cardiac arrhythmias when consumed in large amounts.⁴

There is much yet to learn about this popular treat so commonly associated with Valentine’s Day. With further research into verifying its cardiovascular benefits, dark chocolate could find its way into guidelines for use as nonpharmacological therapy. Additionally, it could be valuable in novel nutritional counseling, and even result in the potential innovation of a chocolate pill, if such a need arose.¹³

For now, pharmacists can remind patients this Valentine’s Day that they may no longer need to feel guilty when they indulge in a small piece of chocolate for the sake of their heart.

About the Authors

Sarah Johnson is a PharmD Candidate in the Class of 2024 at the Auburn University Harrison School of Pharmacy.

Marilyn N. Bulloch, PharmD, BCPS, FCCM, is an associate clinical professor and director of strategic operations at the Auburn University Harrison School of Pharmacy.

References

1. Milena, N. Valentine's Day Sales Statistics 2021 [Internet]. Balancing Everything. 2021 [cited 2021Dec29]. Available from: https://balancingeverything.com/valentines-day-sales-statistics/
2. Latif R. Chocolate/Cocoa and Human Health: A Review [Internet]. The Netherlands Journal of Medicine. U.S. National Library of Medicine; 2013 [cited 2021Dec29]. Available from: https://pubmed.ncbi.nlm.nih.gov/23462053/
3. K. Hollenberg, Norman MD. Vascular Action of Cocoa Flavanols in Humans: The Roots of the Story, Journal of Cardiovascular Pharmacology: June 2006 - Volume 47 - Issue - p S99-S102. [cited 2021Dec29]. Available from: https://journals.lww.com/cardiovascularpharm/Fulltext/2006/06001/Vascular_Action_of_Cocoa_Flavanols_in_Humans__The.2.aspx
4. Gammone MA, Efthymakis K, Pluchinotta FR, Bergante S, Tettamanti G, Riccioni G, D'Orazio N. Impact of chocolate on the cardiovascular health. Front Biosci (Landmark Ed). 2018 Jan 1;23:852-864. doi: 10.2741/4620. PMID: 28930576.
5. Minerals [Internet]. MedlinePlus. U.S. National Library of Medicine; 2021 [cited 2022Jan18]. Available from: https://medlineplus.gov/minerals.html#summary
6. Buijsse B, Feskens EJ, Kok FJ, Kromhout D. Cocoa intake, blood pressure, and cardiovascular mortality: the Zutphen Elderly Study. Arch Intern Med. 2006 Feb 27;166(4):411-7. doi: 10.1001/archinte.166.4.411. PMID: 16505260.
7. Janszky I, Mukamal KJ, Ljung R, Ahnve S, Ahlbom A, Hallqvist J. Chocolate consumptionand mortality following a first acute myocardial infarction: the Stockholm Heart Epidemiology Program. J Intern Med. 2009 Sep;266(3):248-57. doi: 10.1111/j.1365-2796.2009.02088.x. PMID: 19711504.
8. Ried K, Fakler P, Stocks NP. [Internet]. Effect of cocoa on blood pressure. Cochrane; 2017 [cited 2021Dec29]. Available from: https://www.cochrane.org/CD008893/HTN_effect-cocoa-blood-pressure
9. Whelton PK, Carey RM, Aronow WS, et al. ACC/AHA/AAPA/ABC/ACPM/AGS/apha/ash/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines [Internet]. Journal of the American College of Cardiology. 2018. https://www.jacc.org/doi/10.1016/j.jacc.2017.11.006?_ga=2.202736081.1724495363.1640710933-104056250.1640710933
10. Dark chocolate [Internet]. The Nutrition Source. Harvard T.H. Chan School of Public Health; 2021 [cited 2022Jan19]. Available from: https://www.hsph.harvard.edu/nutritionsource/food-features/dark-chocolate/
11. Sagon C. Dark chocolate helps lower blood pressure, heart disease risk - AARP bulletin [Internet]. AARP. [cited 2021Dec29]. Available from: https://www.aarp.org/health/medical-research/info-03-2011/dark-chocolate-can-help-lower-your-blood-pressure.html
12. Mostofsky E, Johansen MB, Tjønneland A, Chahal HS, Mittleman MA, Overvad K. Chocolate intake and risk of clinically apparent atrial fibrillation: The Danish diet, Cancer, and Health Study [Internet]. Heart. 2017. https://heart.bmj.com/content/103/15/1163
13. Aubrey A. Eating chocolate, a little each week, may lower the risk of a heart flutter [Internet]. NPR. 2017 [cited 2021Dec29]. https://www.npr.org/sections/thesalt/2017/05/24/529843647/eating-chocolate-a-little-each-week-may-lower-the-risk-of-a-heart-flutter