The Effect of Chocolate Consumption on Cardiovascular Disease Risk Factors Stephanie Becker November...
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Transcript of The Effect of Chocolate Consumption on Cardiovascular Disease Risk Factors Stephanie Becker November...
The Effect of Chocolate Consumption on Cardiovascular Disease Risk Factors
Stephanie BeckerNovember 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.
ResultsTopic # of Studies Design Association
(Yes)Association
(No)CVD Risk and CVD Mortality
2 (1) Prospective Cohort(1) Cross-Sectional
2 0
Blood Pressure 5 (4) Randomized Controlled Trials(1) Longitudinal
5 0
Serum Cholesterol
3 (3) Randomized Controlled Trials
3 0
Other CVD Risk Factors
8 (6) Randomized Controlled Trials(1) Cross-sectional(1) Intervention Clinical Trial
7 1
Chocolate Consumption, CVD Risk, and CVD Mortality
Topic # of Studies Design Association (Yes)
Association (No)
Chocolate Consumption, CVD Risk, and CVD Mortality
2 (1)Prospective Cohort(1) Cross-Sectional
2 0
• 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/Date Design/# of Subjects Results
Djousse et al., 2011 Cross- sectional/ 4,970 Those who consumed chocolate had a lower risk of CVD (P trend <0.0001)
McCullough et al., 2012 Prospective Cohort/98,469 Those 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 Studies Design Association (Yes)
Association (No)
Chocolate Consumption
and Blood Pressure
5 (4) Randomized Controlled Trials(1) Longitudinal
5 0
• All clinical trials provided their own chocolate products
• The longitudinal study was based on a food frequency questionnaire.
Chocolate Consumption and Blood Pressure
Author/Date Design/# of subjects Results
Almoosawi et al., 2010 Randomized cross-over/14 SBP and DBP both significantly lower then baseline (SBP: p=0.001,
DBP: p=0.001)Almoosawi et al., 2012 Randomized cross-over/42 SBP 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., 2010 Randomized 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/Date Design/# of Subjects Results
Sudarma et al., 2011 Parallel 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., 2010 Longitudinal/19,357 Significant difference in
SBP and DBP in the top quartile for chocolate consumption vs. the
bottom quartile (SBP: p<0.00001, 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 studies Design Association (Yes)
Association (No)
Chocolate Consumption
and Serum Cholesterol
Levels
3 (3) Randomized Controlled Trials
3 0
• All studies provided chocolate products to participants
Chocolate Consumption and Serum Cholesterol Levels
Author/Date Design/# of Subjects Results
Anuzzi, et al., 2010 2x2 factorial/86 A significant reduction was shown in VLDL-C in
treatment vs. control (p=0.016)
Khan et al., 2011 Randomized cross-over/47 A 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., 2012 Parallel multi-centered/113 Reduction 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 Studies Design Association (Yes)
Association (No)
Chocolate Consumption
and Other CVD Risk Factors
8 (6) Randomized Controlled Trials(1) Intervention Trial(1) Cross-sectional
7 1
• 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/Date Design/# of Subjects Results
Crescenti et al., 2013 Randomized Controlled Trial/254
Peripheral leukocyte DNA methylation status was
significantly lower in the treatment group vs. control
(p< 0.001)Flammer et al., 2011 Randomized Controlled
Trial/22No significant results
found.West et al., 2013 Randomized cross-over/ 30 Hyperaemic 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/Date Design/# of Subjects Results
Nogeuria et al., 2012 Intervention Trial/20 Significant increase in endothelial function after
intervention (p=0.01)Djousse et al., 2011 Cross-Sectional/2,217 Increased 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/Date Design/# of Subjects Results
Almoosawi et al., 2010* Randomized cross-over/14 Significant reduction on fasting glucose levels in
treatment vs. control group (p=0.026)
Almoosawi et al., 2012* Randomized cross-over/42 Fasting glucose and HOMA-IR were reduced from
baseline in participants with a BMI ≥ 25 kg/m2 (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?