Cocoa, Dark Chocolate

Introduction:

Chocolate comes from the cacao plant. Cacao is extraordinarily rich in flavonols, which act as antioxidants. The many evidence-based health benefits of consuming dark chocolate will be discussed below.

 

Chocolate consumption and hypertension:

Blood pressure and chocolate intake: In a study involving 14,310 adults from various regions of Jordan, higher intake of dark chocolate was found to be associated with lower blood pressure. No particular effects on heart rate were found. Subjects were divided into 3 categories according to dark chocolate intake: 1) mild (1-2 bars/wk); 2) moderate (3-4 bars/wk); and 3) high (more than 4 bars/wk), and results showed that higher intakes of dark chocolate were associated with lower systolic and diastolic blood pressure, regardless of age or family history of hypertension. These results suggest that intake of dark chocolate may be associated with lower blood pressure. (1)

Dark chocolate and nitric oxide (NO) levels:

A study looked at the effects of dark chocolate on nitric oxide (NO) for fifteen days with regards to blood pressure in people with prehypertension. Thirty-two individuals were recruited and divided into 2 groups of 16 each. The treatment group received 30 g/day of dark chocolate daily (containing 70% cocoa) and dietary counseling. Those in the placebo group received 25 g/day of white chocolate daily and dietary counseling. After 15 days, dark chocolate increased NO blood levels compared to placebo (7.70 vs 1.92, respectively) and decreased systolic blood pressure (120.64 vs 131.19). (2)

 

Dark chocolate and blood pressure:

For 2 weeks, participants (n=13) were randomly assigned to receive 480 kcal bars containing either 100-g dark polyphenol-rich chocolate (PRC) bars per day containing 500 mg of polyphenols or 90-g white chocolate (polyphenol-free chocolate [PFC]). At the end of the study, when compared to the PFC group, those in the PRC group experience an average decrease in systolic and diastolic blood pressure (BP) of 5.1 mmHg and 1.8 mmHg, respectively. After the intervention was stopped, BP returned to pre-study values within 2 days. (3)

 

Chocolate consumption in pregnancy:

Chocolate and pregnancy complications: To investigate whether chocolate’s possible cardiovascular benefits may prevent pre-eclampsia, researchers looked at 2,291 women who delivered a single infant, and asked them about how much chocolate they consumed in their first and third trimesters. The researchers also tested levels of theobromine, used as a biomarker for chocolate consumption, in infants’ umbilical cord blood. Women who consumed the most chocolate and those whose infants had the highest concentration of theobromine in their cord blood were the least likely to develop preeclampsia. Women in the highest quarter for cord blood theobromine were 69% less likely to develop the complication than those in the lowest quarter. Women who ate five or more servings of chocolate each week in their third trimester of pregnancy were 40% less likely to develop pre-eclampsia than those who ate chocolate less than once a week. A similar, but weaker, relationship between chocolate consumption and preeclampsia risk was seen in the first trimester, with women eating five or more servings of chocolate each week at 19% lower risk than those who ate chocolate less than once a week. (4)

 

Chocolate and risk of complications in pregnancy:

Researchers examined whether regular chocolate consumption during pregnancy is associated with reduced risks of pre-eclampsia and gestational hypertension. A total of 2,508 women who had hospital delivery records available were included in this study. The researchers found that a higher chocolate intake in the first or third trimester was associated with a lower risk of pre-eclampsia and in the first three months of pregnancy with a lower risk of high blood pressure. Of those who developed pre-eclampsia, 37.5% did not consume chocolate regularly, compared to 19.3% of women who had normal blood pressure and 24.2% of those with high blood pressure. Women who reported regular chocolate consumption had a 45% reduced risk of pre-eclampsia during the first trimester (odd ratio [OR] 0.55) and a 46% reduction during the the third trimester (OR 0.56). (5)

 

Cocoa and cholesterol:

Cocoa and the lipid profile:

In a study, scientists recruited 42 volunteers (19 men, 23 women) with a mean age of 70 to participate in a randomized trial. All the participants received 500 mL of skim milk/day with or without 40g of cocoa powder for 4 weeks. Cocoa powder contains polyphenol, which acts as an antioxidant protecting cells against damage. At the end of the study the researchers found that milk plus cocoa was associated with an increase in HDL (good) cholesterol levels by 2.67 mg/dL, compared to only milk. In addition, cocoa plus milk was associated with a reduction in oxidized LDL cholesterol levels of -12.3 U/L, compared to milk only. In conclusion, the authors suggest that a combination of cocoa and skimmed milk may beneficially affect cholesterol levels in the blood. (6)

 

Cocoa and lipid levels:

Eating cocoa could help reduce LDL cholesterol, according a 4-week study conducted by Baba S, et al in which 160 adults with either normal or raised cholesterol levels (hypercholesterolemic) were randomly assigned to receive either a daily placebo compound or a high-polyphenol cocoa powder. Three different levels of cocoa powder were tested all consumed as a beverage after the addition of hot water, twice each day: 13g, 19.5g or 26g per day. In all the cocoa groups, blood levels of LDL cholesterol decreased significantly compared with levels seen at the beginning of the study. Subjects with clinically raised cholesterol levels seem to benefit specifically from the cocoa supplementation, in that LDL cholesterol levels fell, while levels of HDL cholesterol rose. Specifically, among subjects administered the high dose cocoa total cholesterol, LDL, and triglycerides decreased by 1.15%, 3.77%, and 5.11%, respectively. HDL increased by 9.52%. In addition, there was less oxidation of LDL cholesterol. It is believed that cocoa is rich in polyphenol antioxidants that are believed to help protect cells from oxidation and may improve blood pressure control. (7)

 

Chocolate and coronary heart disease:

Chocolate intake and coronary heart disease (CHD): Researchers studied the effects of total chocolate intake on coronary heart disease (CHD) in 4,970 men and women, ages 25 to 93 years, looking at the frequency of dark chocolate consumption and assessing for the onset of CHD. The researchers found evidence suggesting an inverse association between frequency of chocolate consumption and coronary heart disease: specifically, consumption of chocolate 1-4 times per week was associated with a 26% lower risk of CHD and consumption of chocolate more than five times a week was associated with 57% lower risk of CHD, as compared to those subjects who did not consume chocolate. Additionally, consumption of non-chocolate candy was associated with a 49% higher risk of CHD comparing 5 or more times per week vs. none per week. (8)

 

Chocolate consumption and atherosclerosis:

A large study on chocolate consumption suggests that chocolate might help maintain healthy arteries. Researchers analyzed data from food frequency questionnaires of 2217 subjects. Healthy arteries were assessed by rate of calcified atherosclerotic plaque in the coronary arteries (CAC) (measured by cardiac computer tomography). Using non-eaters of chocolate as a baseline, the researchers concluded that those who ate 1-3 servings per month had a 6% reduced CAC. For 1/week chocolate eaters, a 22% reduction was observed, and consuming chocolate at least 2 times per week was associated with a 32% reduced CAC. (9)

 

Chocolate consumption and risk of stroke:

Consumption of chocolate has been found to significantly reduce the risk of both ischemic stroke and hemorrhagic stroke in a large cohort study on women who ate a median of 66.5 grams per week of chocolate (13). In a large cohort study on men, a median intake of 62.9 grams of chocolate per week was associated with a decrease in risk of stroke by about 17% (14).

 

Flavanol-rich cocoa and endothelial function:

In a study, 15 healthy adults under the age of 50 and 19 healthy adults over the age of 50 drank a specially made flavonol-rich cocoa every day for four to six days. Flavonols naturally occur in plants and possess antioxidant characteristics. Blood pressure and peripheral arterial responses were recorded. The results showed that blood vessel response to nitric oxide and endothelial function improved among both younger and older adults after the cocoa phase. These improvements were more significant in the older group. (10)

 

Chocolate and chronic fatigue syndrome:

High cocoa polyphenol rich chocolate may reduce the burden of the symptoms in chronic fatigue syndrome. Results of a small double-blind, randomized crossover study with 10 individuals indicate that daily consumption of high cocoa liquor/polyphenol rich chocolate (HCL/PR) significantly improved symptoms of chronic fatigue, as measured using the Chalder Fatigue Scale, after 8 weeks, compared with a placebo made to look like chocolate. (11)

 

Chocolate and asthma:

Cocoa and chocolate have a significant effect on lung function due to the theobromine and theophylline content. Simons FE et al found that an average dose of 468 mg of theobromine and an average dose of 249 mg of theophylline each separately promoted significant improvements in all pulmonary function tests (15). 468 mg of theobromine is equivalent to about 50 grams of a dark chocolate bar containing 70-90% cocoa (standard chocolate bars contain 100 grams of dark chocolate). Dark chocolate is less palatable than milk chocolate, but contains much more theobromine per given amount of fat content. Cocoa powder may also be mixed into a drink or used in a recipe of choice. Chocolate and cocoa is also known to act as a cough suppressant (16).

 

 

Assessment and Plan: Cocoa, Dark Chocolate

• Cocoa and chocolate contains caffeine and theobromine. Caffeine intake up to 300 mg per day is generally safe for healthy adults. Older patients or those with hypertension, cardiovascular disease, or cerebrovascular disease should avoid more than 1-2 cups of caffeinated beverages per day (no more than 100-200 mg of cafeine intake per day). One cup of coffee contains on average, about 100 mg of caffeine. Each standard sized milk chocolate bar such as Hershey’s contains about 10 mg of caffeine, and each standard size dark chocolate bar contains about 31 mg of caffeine. Standard caffeine intake is generally recognized as safe by the FDA and AMA but can be dangerous with adverse effects such as high bp, stroke, and arrythmias reported. If more than 1-2 cups of caffeinated beverages are consumed per day, it is prudent to seek physician and/or pharmacist approval of caffeine consumption with any medications or supplements. Please see caffeine section for more detail. Cocoa and chocolate also contains theobromine which is known to act as a stimulant, vasodilator, and diuretic which may be responsible for some of the therapeutic action of cocoa (12). Theobromine and cocoa may intensify the blood pressure lowering effects of any blood pressure medications. Therefore a physician should oversee the care of a patient taking cocoa or chocolate for high blood pressure.

 

• Hypertension:

 

• Higher intakes of dark chocolate were associated with lower systolic and diastolic blood pressure, regardless of age or family history of hypertension (1).

 

• Sudarma V et al found that 30 g/day of dark chocolate daily (containing 70% cocoa) plus dietary counseling for 15 days resulted in increased nitric oxide blood levels over placebo (7.70 vs 1.92, respectively) and decreased systolic blood pressure (120.64 vs. 131.19) (2).

 

• A 100-g dark polyphenol-rich chocolate bar once per day containing 500 mg of polyphenols showed an average decrease in systolic and diastolic blood pressure (BP) of 5.1 mmHg and 1.8 mmHg compared to white chocolate, respectively, but after the intervention was stopped, BP returned to pre-study values within 2 days (3).

 

• Pregnancy:

 

• Triche EW et al determined the following: 1) Women who consumed the most chocolate an highest concentrations of theobromine in cord blood were 69% less likely to develop preeclampsia; 2) 5 or more servings of chocolate per week in the 3rd trimester were 40% less likely to develop pre-eclampsia than once per week; and 3) Women in the 1st trimester eating 5 or more servings per week of chocolate had a 19% lower risk of preeclampsia (4)

 

• Saftlas, AF et al noted that a higher chocolate intake in the 1st or 3rd trimester was associated with a lower risk of pre-eclampsia, and that a higher intake in the 1st trimester was related to a lower risk of high blood pressure (5).

 

• Cholesterol:

 

• Elderly adults who took 500 mL of skim milk daily with 40g of cocoa powder for 4 weeks found that milk plus cocoa increased HDL (good) cholesterol levels by 2.67 mg/dL, and reduced oxidized LDL cholesterol levels of -12.3 U/L compared to milk only (6).

 

• Cocoa powder was tested as a beverage with hot water at a dose of 13g, 19.5g or 26g per day resulted in the following improvements: total cholesterol, LDL, and triglycerides decreased by 1.15%, 3.77%, and 5.11% respectively, and HDL increased by 9.52% (7).

 

• Coronary artery disease:

 

• Total chocolate intake by 4,970 men and women, 25-93 years old was studied and it was found that chocolate intake 1-4 times per week lowered risk of coronary artery disease by 26%, and chocolate intake over 5 times a week lowered risk 57% compared with controls. Also, non-chocolate candy was associated with a 49% higher risk of CHD when comparing 5 or more times per week vs. none per week. (8)

 

• Djoussé, L et al measured calcified atherosclerotic plaque in coronary arteries by cardiac computer tomography, and after comparing non-eaters of chocolate as a baseline with those who consumed 1-3 servings per month had a 6% reduced size of coronary artery plaque. Also, once per week chocolate eaters had a 22% reduction, and twice per week chocolate eaters had a 32% reduction. (9)

 

• Chocolate and stroke: Consumption of chocolate has been found to significantly reduce the risk of both ischemic stroke and hemorrhagic stroke in a large cohort study on women who ate a median of 66.5 grams per week of chocolate (13). In a large cohort study on men, a median intake of 62.9 grams of chocolate per week was associated with a decrease in risk of stroke by about 17% (14).

 

• Endothelial function: After cocoa intake, blood vessel response to nitric oxide and endothelial function improved, but the vessels of older adults responded to a greater extent (10).

 

• Chronic Fatigue Syndrome: Results of a small double-blind, randomized crossover study indicated that consumption of a 15 gram bar of 85% cocoa, 3 times daily significantly improved symptoms of chronic fatigue (10).

 

• Chocolate and asthma: Cocoa and chocolate have a significant effect on lung function due to the theobromine and theophylline content. Simons FE et al found that an average dose of 468 mg of theobromine and an average dose of 249 mg of theophylline each separately promoted significant improvements in all pulmonary function tests (15). 468 mg of theobromine is equivalent to about 50 grams of a dark chocolate bar containing 70-90% cocoa (standard chocolate bars contain 100 grams of dark chocolate). Dark chocolate is less palatable than milk chocolate, but contains much more theobromine per given amount of fat content. Cocoa powder may also be mixed into a drink or used in a recipe of choice. Chocolate and cocoa is also known to act as a cough suppressant (16).

 

 

References:

1.Al-Safi SA, Ayoub NM, Al-Doghim I, Aboul-Enein FH. Dark Chocolate and Blood Pressure: A Novel Study from Jordan. Curr Drug Deliv. 2011 Jun 22. http://www.ncbi.nlm.nih.gov/pubmed/21696359

 

2.Sudarma V, Sukmaniah S, Siregar P. Effect of dark chocolate on nitric oxide serum levels and blood pressure in prehypertension subjects. Acta Med Indones. 2011 Oct;43(4):224-8. http://www.ncbi.nlm.nih.gov/pubmed/22156352

 

3.Taubert D, Berkels R, Roesen R, Klaus W. Chocolate and blood pressure in elderly individuals with isolated systolic hypertension. JAMA. 2003 Aug 27;290(8):1029-30. http://www.bluefrogchocolates.com/Chocolate&BPJAMA8~27~03.pdf

 

4.Triche EW, Grosso LM, Belanger K, Darefsky AS, Benowitz NL, Bracken MB. Chocolate consumption in pregnancy and reduced likelihood of preeclampsia. Epidemiology. 2008 May;19(3):459-64. doi: 10.1097/EDE.0b013e31816a1d17. http://www.ncbi.nlm.nih.gov/pubmed/18379424

 

5.Saftlas AF, Triche EW, Beydoun H, Bracken MB. Does chocolate intake during pregnancy reduce the risks of preeclampsia and gestational hypertension? Ann Epidemiol. 2010 Aug;20(8):584-91. http://www.ncbi.nlm.nih.gov/pubmed/20609337

 

6.Khan N, Monagas M, Andres-Lacueva C, Casas R, Urpí-Sardà M, Lamuela-Raventós RM, Estruch R. Regular consumption of cocoa powder with milk increases HDL cholesterol and reduces oxidized LDL levels in subjects at high-risk of cardiovascular disease. Nutr Metab Cardiovasc Dis. 2011 May 5. http://www.ncbi.nlm.nih.gov/pubmed/21550218

 

7.Baba S, Natsume M, Yasuda A, Nakamura Y, Tamura T, Osakabe N, Kanegae M, Kondo K. Plasma LDL and HDL cholesterol and oxidized LDL concentrations are altered in normo- and hypercholesterolemic humans after intake of different levels of cocoa powder. J Nutr. 2007 Jun;137(6):1436-41. http://www.ncbi.nlm.nih.gov/pubmed/17513403

 

8.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. Clin Nutr. 2011 Apr;30(2):182-7. http://www.ncbi.nlm.nih.gov/pubmed/20858571

 

9.Djoussé L, Hopkins PN, Arnett DK, Pankow JS, Borecki I, North KE, Curtis Ellison R. Chocolate consumption is inversely associated with calcified atherosclerotic plaque in the coronary arteries: the NHLBI Family Heart Study. Clin Nutr. 2011 Feb;30(1):38-43. http://www.ncbi.nlm.nih.gov/pubmed/20655129

 

10.Fisher ND, Hollenberg NK. Aging and vascular responses to flavanol-rich cocoa. J Hypertens. 2006 Aug;24(8):1575-1580. http://www.ncbi.nlm.nih.gov/pubmed/16877960

 

11.Sathyapalan T, Beckett S, Rigby AS, Mellor DD, Atkin SL. High cocoa polyphenol rich chocolate may reduce the burden of the symptoms in chronic fatigue syndrome. Nutr J. 2010 Nov 22;9:55. http://www.ncbi.nlm.nih.gov/pubmed/21092175

 

12.Sudano I, Flammer AJ, Roas S, Enseleit F, Ruschitzka F, Corti R, Noll G. Cocoa, blood pressure, and vascular function. Curr Hypertens Rep. 2012 Aug;14(4):279-84. http://www.ncbi.nlm.nih.gov/pubmed/22684995

 

13.Larsson SC, Virtamo J, Wolk A. J Am Coll Cardiol. Chocolate consumption and risk of stroke in women. 2011 Oct 18;58(17):1828-9. http://www.ncbi.nlm.nih.gov/pubmed/21996399

 

14.Larsson SC, Virtamo J, Wolk A. Chocolate consumption and risk of stroke: a prospective cohort of men and meta-analysis. Neurology. 2012 Sep 18;79(12):1223-9. http://www.ncbi.nlm.nih.gov/pubmed/22933736

 

15.Simons FE, Becker AB, Simons KJ, Gillespie CA. The bronchodilator effect and pharmacokinetics of theobromine in young patients with asthma. J Allergy Clin Immunol. 1985 Nov;76(5):703-7. http://www.ncbi.nlm.nih.gov/pubmed/4056254

 

16.Halfdanarson TR, Jatoi A. Chocolate as a cough suppressant: rationale and justification for an upcoming clinical trial. Support Cancer Ther. 2007 Jan 1;4(2):119-22. http://www.ncbi.nlm.nih.gov/pubmed/18632476