The Effect of Chocolate Consumption on Cardiovascular Disease Risk Factors Stephanie Becker November 24, 2014

Outline Purpose Background Methods Findings Conclusions Implications Future Research Required

Purpose To examine the relationship between chocolate consumption and cardiovascular disease risk.

Cardiovascular Disease (CVD) Leading cause of death for Americans equating to 34% of all deaths. 60,000 Americans die from CVD every year. Every 1 in 4 deaths is CVD related. (Center for Disease Control, 2014)

Cardiovascular Disease Risk Factors Hypertension High LDL-C Low HDL-C Oxidative Stress High BMI Lack of Physical Activity Poor Diet

How Can Chocolate Help? Polyphenols: – A phytochemical found in chocolate thought to be responsible for combating CVD risk factors. – Found in teas and fruit juices as well. Chocolate has been found to have one of the highest polyphenol contents compared to other foods.

Methods Simmons College Library Network – Medline, CINAHAL, Web of Science, Academic Search Complete Keywords – Chocolate OR Cocoa OR Cacao – AND Cardiovascular disease OR Cardiovascular risk factors Techniques – Thesaurus, Boolean operators, Citation Index

Methods Inclusion Criteria: – Published in 2010 or later – Peer Reviewed Academic Journal Exclusion Criteria: – Language other than English – Literature reviews – Animal subjects A total of 15 studies were used for this literature review.

Results Topic# of StudiesDesignAssociation (Yes) Association (No) CVD Risk and CVD Mortality 2(1) Prospective Cohort (1) Cross- Sectional 20 Blood Pressure5(4) Randomized Controlled Trials (1) Longitudinal 50 Serum Cholesterol 3(3) Randomized Controlled Trials 30 Other CVD Risk Factors 8(6) Randomized Controlled Trials (1) Cross- sectional (1) Intervention Clinical Trial 71

Chocolate Consumption, CVD Risk, and CVD Mortality Topic# of StudiesDesignAssociation (Yes) Association (No) Chocolate Consumption, CVD Risk, and CVD Mortality 2(1)Prospective Cohort (1) Cross- Sectional 20 Both studies used food frequency questionnaires to access chocolate intake. The prospective cohort study had a 7 year follow up when the National Death Index was used in order to access mortality. Both studies recruited subjects from previous cohort studies

Chocolate Consumption, CVD Risk, and CVD Mortality Author/DateDesign/# of SubjectsResults Djousse et al., 2011Cross- sectional/ 4,970Those who consumed chocolate had a lower risk of CVD (P trend <0.0001) McCullough et al., 2012Prospective Cohort/98,469Those in the top quartile of flavonoid intake compared to the bottom quartile had a lower risk of fatal CVD (p trend= 0.01)

Strengths and Limitations Strengths: – Large sample sizes – Accurate dietary software – Drop off rate for prospective cohort was only 11% Limitations: – Self-Reporting – Diets not controlled during the follow up period

Chocolate Consumption and Blood Pressure Topic# of StudiesDesignAssociation (Yes) Association (No) Chocolate Consumption and Blood Pressure 5(4) Randomized Controlled Trials (1) Longitudinal 50 All clinical trials provided their own chocolate products The longitudinal study was based on a food frequency questionnaire.

Chocolate Consumption and Blood Pressure Author/DateDesign/# of subjectsResults Almoosawi et al., 2010Randomized cross-over/14SBP and DBP both significantly lower then baseline (SBP: p=0.001, DBP: p=0.001) Almoosawi et al., 2012Randomized cross-over/42SBP reduced in normal weight and overweight group (NW: p=0.014, OW: P=0.016) DBP reduction in overweight group (p<0.001) Bogaard et al., 2010Randomized 3-period cross-over/ High dose theobromine showed a reduction in both SBP and DBP compared to placebo (SBP: P<0.01, DBP: p=0.04)

Chocolate Consumption and Blood Pressure Author/DateDesign/# of SubjectsResults Sudarma et al., 2011Parallel Randomized Clinical Trial/32 Significant difference in SBP in treatment vs. control (p=0.001). No significant difference in DBP (p=0.308) Buijsse et al., 2010Longitudinal/19,357Significant difference in SBP and DBP in the top quartile for chocolate consumption vs. the bottom quartile (SBP: p< , DBP: p=0.014)

Strengths and Limitations Strengths: – Majority of trials used a standard cocoa product – Strict inclusion criteria – Longitudinal study had a large sample size Limitations: – Clinical trials had small sample sizes – All studies were done on people with different CVD risk factors

Chocolate Consumption and Serum Cholesterol Levels Topic#of studiesDesignAssociation (Yes) Association (No) Chocolate Consumption and Serum Cholesterol Levels 3(3) Randomized Controlled Trials 30 All studies provided chocolate products to participants

Chocolate Consumption and Serum Cholesterol Levels Author/DateDesign/# of SubjectsResults Anuzzi, et al., 20102x2 factorial/86A significant reduction was shown in VLDL-C in treatment vs. control (p=0.016) Khan et al., 2011Randomized cross-over/47A significant reduction in LDL-C (p=0.001 and a significant increase in HDL- C (p=0.008) was found in treatment vs. control. Sola et al., 2012Parallel multi-centered/113Reduction in LDL-C and Apo B/Apo A ratio in treatment vs. control (p=0.002, p=0.0085)

Strengths and Limitations Strengths: – Diets were kept uniform in all studies (Sola et al., kept participants on a low saturated fat diet) – Large sample size compared to other clinical trials Limitations: – Short trial periods – Compliance to these specific diets is unknown

Chocolate Consumption and Other CVD Risk Factors Topic# of StudiesDesignAssociation (Yes) Association (No) Chocolate Consumption and Other CVD Risk Factors 8(6) Randomized Controlled Trials (1) Intervention Trial (1) Cross- sectional 71 Various CVD Risk factors were tested including: Nitric Oxide levels, fasting glucose levels, DNA methylation, arterial stiffness, and endothelial function. 3 studies in this section were also used in other sections

Chocolate Consumption and Other CVD Risk Factors Author/DateDesign/# of SubjectsResults Crescenti et al., 2013Randomized Controlled Trial/254 Peripheral leukocyte DNA methylation status was significantly lower in the treatment group vs. control (p< 0.001) Flammer et al., 2011Randomized Controlled Trial/22 No significant results found. West et al., 2013Randomized cross-over/ 30Hyperaemic blood flow increased post treatment (Basal: p=0.04, peak: p=0.03). Augmentation Index at 75bpm was decreased in women post treatment (p=0.01)

Chocolate Consumption and Other CVD Risk Factors Author/DateDesign/# of SubjectsResults Nogeuria et al., 2012Intervention Trial/20Significant increase in endothelial function after intervention (p=0.01) Djousse et al., 2011Cross-Sectional/2,217Increased chocolate consumption decreased calcified atherosclerotic plaque in coronary arteries (p trend= 0.022) Sudarma et al., 2011*Parallel Randomized Clinical Trial/32 Nitric Oxide Serum levels significantly higher in treatment vs. control group (p=0.001) * Represents a study that was also used in a previous section

Chocolate Consumption and Other CVD Risk Factors Author/DateDesign/# of SubjectsResults Almoosawi et al., 2010*Randomized cross-over/14Significant reduction on fasting glucose levels in treatment vs. control group (p=0.026) Almoosawi et al., 2012*Randomized cross-over/42Fasting glucose and HOMA- IR were reduced from baseline in participants with a BMI ≥ 25 kg/m 2 (FG: p<0.001, HOMA-IR: p=0.041)

Strengths and Limitations Strengths: – Multiple risk factored studied to get a broader view on the effect that chocolate has on CVD risk. – Different study designs used. Limitations: – Very few studies were done on each individual risk factor, therefore it is difficult to draw significant conclusions.

Conclusions All studies, with the exception of the study conducted by Flammer et al. showed an association between chocolate consumption and CVD risk. Chocolate consumption reduced systolic blood pressure more significantly then diastolic blood pressure. Polyphenols in chocolate were shown to reduce various CVD risk factors.

Implications Regular consumption of dark chocolate may help to lower CVD risk factors in those individuals who already have a higher then average CVD risk. In order to prevent other CVD risk factors it is recommended to add chocolate to a low saturated fat diet.

Future Research Research needs to be done on healthy subjects without any CVD risks. The exact mechanism of how chocolate lowers CVD risk is unknown. Further research needs to be done on the biological level to find the exact mechanism. There is now a chocolate shortage, how to counteract that?

Thank you for your time! Questions?