Effectiveness of Mediterranean Diet vs. DASH Diet in Reducing Cardiovascular Risk Factors

1. Effectiveness of Mediterranean Diet vs. DASH Diet in Reducing Cardiovascular Risk Factors Hannah Lapkin GNUR 450

2. Background • More than 2, 200 Americans die daily from CVD • One death every 39 seconds • Cause of 1/6 deaths in U.S. in 2007 • Major risk factors: • Hypertension (>120/80 mmHg): 33.5% • High Cholesterol (>240 mg/dl): 15% • Obesity (BMI > 30 kg/m2): 33.7% • Financial Implications • Estimated cost of CVD: $268 billion • Cardiovascular operations/procedures increased 27% from 1997

3. PICOT Question • In patients with the cardiovascular disease risk factors of hypertension and elevated cholesterol, how does the Mediterranean diet compare with the DASH diet in effectively reducing blood pressure and serum cholesterol levels over six months with bi-monthly counseling with an RD? • P: High-risk CVD patients • I: Mediterranean diet • C: DASH diet • O: Reduced blood pressure and cholesterol • T: 6 months • Significance

4. Literature Review • DASH Diet • High consumption of fruits, vegetables, whole grains, nuts/legumes, low-fat dairy products • Low consumption of sodium, red/processed meats, saturated/total fat • Used in U.S. for prehypertensive/hypertensive individuals • Studies show significant reductions in total/LDL cholesterol and estimated CHD risk • Mediterranean Diet • Composed of: • Abundance of plant foods • Minimal red and processed foods • Moderate amount of dairy products • Olive oil as main lipid source • Low-moderate consumption of wine with meals • Evidence demonstrates: • Lower serum triglycerides, cholesterol, and systolic/diastolic blood pressure

5. Table of Relevant Studies

6. Databases EbscoHost Ovid Pub Med Search Terms Cardiovascular disease Heart disease DASH diet Mediterranean Cholesterol Hypertension Study inclusion Criteria English-language Years 2007-2012 Search Strategy

7. Design • Pretest-Posttest experimental design • Randomized into two diet arms • Each of 50 individuals • Stratified equally into men and women • 6 months • Bi-monthly counseling with a trained RD • Evaluation • BP readings at baseline, monthly, and at end • Serum cholesterol values assessed at baseline, 3-month mark, and end • Food frequency questionnaires bi-monthly • Adherence test

8. Sample • Method • Research nurses will recommend study to patients at a cardiac unit that meet inclusion/exclusion criteria • Stratified random sampling by gender • Size • 50 men/50 women • 50/each diet arm • Inclusion/Exclusion

9. Methods for Data Collection • Blood pressure readings • Baseline • Monthly • Serum cholesterol blood draws • Baseline • Month 3 • End of Month 6 • 2008 NHANES Food Frequency Questionnaires • 110-food item list • Bi-monthly with counseling sessions • Ensure adherence • Food Diaries • To review with RD and ensure accurate FFQ responses

10. Intervention Protocol • Two RDs working in a cardiology unit will deliver intervention through bi-monthly counseling • Assigned to either DASH/Mediterranean Diet arm • Must be similar in personality • Will take personality test to ensure similarity • Training program to ensure fidelity • Trained on specifics of each diet, nutrient composition and energy requirements, optimal methods to implement the goals • Ensure RDs are equally knowledgeable on their assigned diet arm and can adequately counsel participants.

11. Procedures for Data Collection • Bi-monthly counseling sessions • Review and analyze food diaries • Offer suggestions on improving adherence to assigned diet • Provide assistance on following assigned diet • RD will chart on each counseling session using de-identified data (identification numbers for participants) • Food Frequency Questionnaires completed by participants at time of counseling session • Trained laboratory technician will: • Take blood pressure readings monthly • Do blood draws at baseline, 3-month mark, end to assess cholesterol values • Research analysts will assess • RD chart notes • Food Frequency Questionnaires • Blood pressure readings • Serum cholesterol values

12. Measures for Data Collection • Blood pressure readings and blood tests • Reliability: extremely reliable • Laboratory technicians will also be highly-trained to enhance reliability • Validity: extremely valid • Highly-trained lab technicians also enhances validity • Food Frequency Questionnaires • Reliability: Moderately reliable • Hindered due to self-reporting; may report what they think researchers want to see • Validity: Deemed valid sources of adherence in a number of nutritional experiments

13. Proposed Data Analysis Plan • Independent t-test • Comparing different diet arms in two groups • Repeated measures analysis of variance (ANOVA) • Study participants will be assessed at 3 different points of time

14. Human Subjects Issues • Approved by Loyola IRB • Informed of study through research nurse • De-identified data to minimize potential biases • Identification numbers received at time of consent • Participants will consent to participation through signed waiver • Informed consent waiver • Statement of participant status • Study goals • Type of data collected and procedures used • Nature of commitment • Sponsorship of study • Method of participant selection • Potential risks and benefits • Alternative treatments • No diet therapy was unethical

15. Study Challenges • Financially difficult • Bi-monthly counseling for 100 participants • Time commitments • Bi-monthly counseling appointments • Food logging • Small sample size • Maybe too small for statistical power • Potential limited diversity • Consequently limiting generalizability • Selection bias due to convenience sampling • Threat to validity • Self-reporting inaccuracies of food frequency questionnaires • Only provide broad, general view of adherence

16. References Fundacion Dieta Mediterranea. (2011). The FDM presents the new Mediterranean diet pyramid. Retrieved from http://fdmed.org/en/the-fdm-presents-the-new-mediterranean-diet-pyramid/ Kastroini, C., Milionis, H., Esposito, K., Guigliano, D., Goudevenos, J., & Panagiotakos, D. (2011). The effect of Mediterranean diet on metabolic syndrome and its components: A meta-analysis of 50 studies and 534,906 individuals. Journal of the American College of Cardiology, 57(11), 1299-1313. Levitan, E., Wolk, A., & Mittleman, M. (2009). Relation of consistency with the dietary approaches to stop hypertension diet and incidence of heart failure in men aged 45 to 79 years. American Journal of Cardiology, 104, pp. 1416-1420. Roger, V., Go, A., Lloyd-Jones, D., Adams, R., Berry, J., Brown, T., Carnethon, M., Dai, S., de Simone, G., Ford, E., Fox, C., Fullerton, H., Gillespie, C., Greenlund, K., Hailpern, S., Heit, J., Ho, P., Howard, V., Kissela, B., Kittner, S., Lacklund, D., Lichtman, J., Lisabeth, L., Makuc, D., Marcus, G., Marelli, A., Matchar, D., McDermott, M., Meigs, J., Moy, C., Mozaffarian, D., Mussolino, M., Nichol, G., Paynter, N., Rosamond, W., Sorlie, P., Stafford, R., Turan, T., Turner, M., Wong, N., & Wylie-Rosett, J. (2010). Heart disease and stroke statistics—2011 update: A report from the american heart association. Circulation, 123, pp. e18-e209. San Vincente, R., Perez, I., Ibarra, J., Berranondo, I., Uribe, F., Urraca, J., Samper, R., Aizpurua, I., Almagro, F., Andres, J., & Ugarte, R. (2008). Clinical practice guideline on the management of lipids as a cardiovascular risk factor. Retrieved from http://www.guideline.gov/content.aspx?id=15711&search=basque+mediterranean+diet Serra-Majem, L., Roman, B., Estruch, R. (2006). Scientific evidence of interventions using the Mediterranean diet: A systematic review. Nutrition Reviews, 64 (2), p. S27-S47. Sofi, F., Abbate, R., Gensini, G., & Casini, A. (2010). Accruing evidence on benefits of adherence to the Mediterranean diet on health: An updated systematic review and meta-analysis. American Journal of Clinical Nutrition, 92, pp. 1189-1196. Swain, J., McCarron, P., Hamilton, E., Sacks, F., Appel, L. (2008). Characteristics of the diet patterns tested in the optimal macronutrient intake trial to prevent heart disease (omniheart): Options for a heart-health diet. Journal of the American Dietetic Association, 108, pp. 257-265. Tyrovolas, S. & Panagiotakos, D. (2010). The role of Mediterranean type of diet on the development of cancer and cardiovascular disease in the elderly: A systematic review. Maturitas, 65, pp. 122-130. U.S. Department of Health and Human Services (2006). Your guide to lowering your blood pressure with DASH: Dash eating plan. NIH Publication No. 06-4082.