After my ST elevation myocardial infarction in 2012 and emergent deployment of left anterior descending stents, the first book I read was Prevent and Reverse Heart Disease by Caldwell Esselstyn, M.D. After reading other sentinel scientific studies on nutrition and heart disease, I realized the answer to the question of whatâ€™s necessary, statins, percutaneous coronary intervention (PCI) or nutrition is all three.
Pharmaceuticals, intervention and diet all play important roles in preventing, treating and reversing the No. 1 killer in the United States, heart disease. There is much evidence for using diet for primordial prevention as well as treating and reversing advanced cardiovascular disease.
Any diet discussion begins with the gut. A whole food, plant- based (WFPB) diet â€“ fruits, vegetables, whole grains, legumes, nuts and seeds â€“ contains soluble and insoluble fiber. There is an inverse association between dietary fiber intake and risk for cardiovascular and coronary heart disease. In a 2013 meta- analysis, Threapleton, et. al. found that for each increase of 7g/day intake of fiber, separate risks for cardiovascular disease and coronary heart disease were each 9 percent lower.
Total dietary fiber intake should be 25 to 30g a day from whole foods. Current intake in the United States averages 15g a day. Meeting the dietary recommendation could low- er our risk of cardiovascular disease by 18 percent.
Fiber molecules decrease the re-absorption of bile acids leading to increased low-density lipoprotein cholesterol (LDL) uptake by the liver. This lowers serum total and LDL cholesterol. Highly processed foods (think cake and cookies) contain minimal fiber while animal-based foods contain no fiber. Fruits, vegetables, whole grains, beans and nuts are the only food source of health-promoting fiber. The total spectrum of health benefits (reduced risks of stroke, cancer, all- cause mortality) from consuming fiber is beyond the scope of this article, but fiber, arguably, may be the most important nutrient for positive health outcomes.
The microbiome in our colon affects our health either positively or negatively depending on the species of bacteria, the degree of diversity and which substrates are presented to the colonic cultures. A molecule associated with cardiovascular risk and atherogenesis is trimethylamine N-oxide (TMAO). Colonic bacteria convert carnitine and choline-containing compounds into trimethylamine (TMA). The TMA produced is absorbed by colonocytes into the enterohepatic circulation and becomes oxidized in the liver to trimethylamine N-oxide (TMAO). The oxidized TMA enters the endothelial cell, increases the inflammatory response and promotes foam cell formation leading to atherosclerotic plaques.
Numerous clinical studies have shown â€œelevated plasma TMAO concentrations were strongly associated with long- term mortality in heart failure patients, with advanced left-ventricular diastolic dysfunction, and with atherosclerosis burden in patients with atherosclerotic coronary artery diseaseâ€ (Ziesel, 2017). Heart failure patients in the highest serum TMAO tertiles had the highest risk for all-cause mortality (Schuett, 2017).
Carnitine is found in meat, fish, poultry and milk. Cho- line is found in eggs. Persons eating a WFPB diet have a predicable fecal microbiota profile different than persons eating the standard American diet. The plant-based microbiota contains a higher ratio of anti-inflammatory bacterium and abundant butyrate producers, which plays a protective role for colonocytes. When a vegan volunteer is given meat, TMA is not produced since the required bacteria species are absent. There is no serum elevation of TMAO in vegan WFPB persons, which occurs routinely in people eating meat and dairy.
Heart failure rates in the U.S. are increasing with hypertension, diabetes and coronary artery disease (CAD) the leading risk factors. Lara, et al. (2018) observed the relationship between five dietary eating patterns and incident heart failure (HF) in an observational cohort study over 8 years. The self-reported eating patterns were Convenience, Plant-based, Sweets, Southern and Alcohol/Salads.
Using Cox multivariable-adjusted models, they were able to show that higher adherence to plant-based eating resulted in lower incidence of HF. Adjusted for confounding factors, there was a 42 percent reduction in risk of incident HF in the plant-based cohort compared to reference population. According to the authors, â€œeating a diet of mostly dark green leafy plants, fruits, beans, whole grains and fish, while limiting processed meats, saturated fats, trans fats, refined carbohydrates and foods high in added sugars, is a heart-healthy lifestyle and may specifically help prevent heart failureâ€.
Twenty one years ago, Dr. Dean Ornish published 5-year data from the Lifestyle Heart Trial. The trial randomized patients with known CAD into a control group receiving usual standard of care and routine lifestyle recommendations; the other half into an experimental group. This group participated in an intensive lifestyle intervention program centered on a low-fat, whole food, plant-based diet (and aerobic exercise and stress management). No participants in the experimental group took lipid-lowering medication. At 5 years, the experimental group showed a relative stenosis reduction in their coronary arteries of 7.9 percent. The control group showed a relative increase in stenosis of 27.7 percent. The control group not on lipid-lowering medication had increase in stenosis by 46.7 percent.
This trial demonstrated that lifestyle modification substituting fruits, vegetables, whole grains and legumes instead of refined and animal-based foods can reverse CAD. In 2010, The Centers for Medicare and Medicaid Services (CMS) determined the Ornish Program for Reversing Heart Disease met the intensive cardiac rehabilitation (ICR) program requirements and became a covered service by Medicare.
For patients concerned about taking statins, Jenkins et al (2003) demonstrated a diet high in plant-based foods was equally as effective at lowering LDL as statins. Patients were randomized into one of three groups; a diet low in saturated fat, same diet plus 20mg of lovastatin, or a diet high in plant sterols, soy, viscous fiber and almonds.
This later portfolio of foods was chosen based on recommendations from The American Heart Association, National Cholesterol Education Program and the U.S. Food and Drug Administration. The results at one month demonstrated 8 percent reduction in LDL in the control group but a 30.9 percent and 28.6 percent reduction in the statin and portfolio diet groups respectively.
C-reactive protein dropped 10 percent in the control group, 33.3 percent in the statin group and 28.2 percent in the portfolio diet group. There were no statistically significant differences in treatment efficacy between statin and portfolio diet groups.
Parenthetically, our medical group has conducted three separate 21-Day Plant Power Challenges for employees and medical staff. Participants eat a WFPB diet for 21 days with education and community support provided. We consistently observe an average 30 percent or more reduction in total cholesterol levels in participants that provide their lipid profiles pre- and post-challenge.
Hypertension can be mediated with a plant-based diet. Chuang et. al. (2016), using a prospective matched cohort study, demonstrated that vegetarians had a 34 percent lower risk for hypertension than non-vegetarians. Results were statistically significant and consistent after adjusting for age, sex, C-reactive protein, waist circumference and fasting glucose. Epidemiological and controlled studies consistently demonstrate a drop in systolic blood pressure upon changing to a vegetarian diet. This is true for both normotensive and hypertensive populations.
In a systemic review and meta-analysis in 2014, Yokoyama pooled the effects of vegetarian versus omnivorous diets and demonstrated a vegetarian mean reduction of systolic BP -4.8 mm Hg in controlled trials and -6.9 mm Hg in observational studies. In controlled trials, there was a reduction of diastolic BP -2.2 mm Hg and -4.7 mm Hg in observational studies. Lower BMI typically seen in vegetarians did not account for the effect since the trials controlled for weight differences.
In a comprehensive review by Yu, et. al. (2018) regarding cardiovascular disease prevention using diet modification, the authors state â€œ… the impact of dietary composition is consistent for primordial, primary and secondary prevention of CVD with certain dietary factors that reduce CVD incidence also being important for secondary prevention among myocardial infarction survivors.â€
In their summation analysis, they found those with the highest adherence to diets rich in fruits, vegetables, legumes, whole grains, fish and poultry had a 31 percent lower risk of CVD compared to persons with the lowest adherence. Adherence to a typical Western dietary pattern, including processed meats, French fries, desserts, red meat and high fat dairy had a 14 percent increase in risk.
The authors recommend that physicians become knowledgeable about which food groups and dietary patterns are healthiest. They encourage becoming familiar with how to read, interpret and understand peer-reviewed nutrition published reports.
Physicians are rightfully skeptical of changing practice patterns without high-quality randomized controlled trials. That research methodology is appropriate when studying new pharmaceuticals and procedures. However, nutrition research is different and relies on longitudinal observational cohort and cross-sectional studies.
While we like to say that correlation is not causation, when the preponderance of evidence from good nutritional research indicates the same results repeatedly, it is appropriate for us to accept the results.
We have known for a long time that food can heal. Albert Einstein said â€œnothing will benefit human health and increase our chances of survival for life on earth as much as the evolution to a vegetarian diet.â€
While many of our patients may not be contemplating a change to a WFPB diet, studies have demonstrated even small tweaks over time have a positive impact. The data supporting heart health and a plant-strong diet is very convincing. We need to offer this information to our patients, have a reliable referral network of plant-based knowledgeable dieticians, and keep informational resources readily available for those patients that are receptive. You may be surprised at the increasing number of patients in your practice who will accept the challenge of lifestyle modification if it means preventing, treating and reversing heart disease through food.
Chuang, S.-Y., Chiu, T. H. T., Lee, C.-Y., Liu, T.-T., Tsao, C. K., Hsiung, C. A., & Chiu, Y.-F. (2016). Vegetarian diet reduces the risk of hypertension independent of abdominal obesity and inflammation. Journal of Hypertension, 34(11), 2164â€“2171. doi:10.1097/hjh.0000000000001068
Esselstyn, C.B. (2007). Prevent and Reverse Heart Disease. New York, New York: Penguin Books.
Glick-Bauer, M., & Yeh, M. C. (2014). The health advantage of a vegan diet: exploring the gut microbiota connection. Nutrients, 6(11), 4822-38. doi:10.3390/ nu6114822
Jenkins DJA, Kendall CWC, Marchie A, et al. (2003). Effects of a Dietary Portfolio of Cholesterol-Lowering Foods vs Lovastatin on Serum Lipids and C-Reactive Protein. JAMA. 290(4):502â€“510. doi:10.1001/jama.290.4.502
Lara KM, Levitan EB, Guitterrez OM, et al. Dietary patterns and incident heart failure in adults with no known coronary disease or heart failure. Presented at: American Heart Association 2017 Scientific Sessions; November 11-15, 2017; Anaheim, California. Abstract M2081.
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Zeneng Wang, Nathalie Bergeron, Bruce S Levison, Xinmin S Li, Sally Chiu, Xun Jia, Robert A Koeth, Lin Li, Yuping Wu, W H Wilson Tang, Ronald M Krauss, Stanley L Hazen (2018). Impact of chronic dietary red meat, white meat, or non-meat protein on trimethylamine N-oxide metabolism and renal excretion in healthy men and women, European Heart Journal. https://doi.org/10.1093/eurheartj/ehy799
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