Can Changing Your Diet Actually Reverse Heart Disease? What a Cleveland Clinic Study Reveals About Plant-Based Nutrition

Table of Contents

• Key Points
• Background: Why This Research Matters
• The Earlier Research: A 1985 Program That Started It All
• Study Methods: How the Research Was Conducted
• The Intervention: What Patients Were Asked to Eat (and Avoid)
• Key Findings: What Happened to the Patients
• Outcomes for Nonadherent Patients: A Stark Contrast
• Outcomes for Adherent Patients: Strong Evidence of Benefit
• Why Did the Results Look So Favorable?
• What Larger Studies Say About Nutrition and Heart Disease
• Clinical Implications: What This Means for Patients
• Study Limitations: What This Research Could Not Prove
• Recommendations for Patients
• Frequently Asked Questions
• Source Information

Key Points

• In a study of 198 patients with heart disease, 89% adhered to a strict plant-based diet for an average of 3.7 years.
• Adherent patients had a 99.4% rate of avoiding major cardiac events, while 62% of nonadherent patients had adverse events.
• The diet eliminated added oils, animal products, dairy, fish, avocado, nuts, and sugary foods, emphasizing whole grains, legumes, and vegetables.
• Among 112 adherent patients with angina, 93% reported improvement or complete symptom resolution during follow-up.
• Patients continued their prescribed cardiac medications; dietary change was an adjunct to standard care, not a replacement.

Background: Why This Research Matters

Coronary artery disease (CAD) occurs when the blood vessels that supply the heart muscle become narrowed or blocked by plaque buildup. It remains the leading cause of death in Western countries, despite 40 years of aggressive medical and surgical interventions.

Current treatments, including medications and procedures like stent placement, can be lifesaving during an acute heart attack. However, the researchers point out that the elective use of percutaneous coronary intervention (PCI) — the procedure where a small mesh tube called a stent is inserted to hold open a blocked artery — "shows little protection from future heart attacks or prolongation of life." These palliative treatments also carry significant risks of complications and lead to unsustainable healthcare costs.

The problem, according to the research team led by Dr. Caldwell B. Esselstyn Jr., is that these approaches "do not treat the major cause of this disease." The researchers argue that getting at the root cause requires a fundamentally different approach.

CAD begins with progressive injury to the endothelium — the thin layer of cells lining the inside of blood vessels. This is followed by inflammatory oxidative stress, a reduction in nitric oxide production (a molecule crucial for blood vessel health), the formation of foam cells, and the development of plaques that may rupture and cause a myocardial infarction (heart attack) or stroke.

This damaging cascade, the authors write, is "set in motion in part by, and is exacerbated by, the western diet" — specifically foods containing added oils, dairy, meat, poultry, fish, and sugary foods such as sucrose, fructose, and drinks containing those sweeteners. These foods injure or impair endothelial function with each meal, making food choices "a major, if not the major, cause of CAD."

The Earlier Research: A 1985 Program That Started It All

This follow-up study builds on earlier work. In 1985, the Cleveland Clinic initiated a program to examine whether plant-based nutrition could arrest or reverse advanced coronary artery disease in 22 patients.

Remarkably, one patient with restricted myocardial blood flow — documented by positron emission tomography (PET), an imaging test that shows how well blood is flowing through the heart — showed restored normal blood flow on a repeat scan just 3 weeks after starting the nutritional intervention. Within 10 months of starting treatment, another patient with severe right calf claudication (leg pain caused by poor circulation) and a measurably diminished pulse volume experienced total pain relief and showed a measurable increase in pulse volume.

That small cohort was followed for 5 and 12 years, with cholesterol-lowering drugs added to the protocol in 1987. Of the 22 patients, 17 were adherent to the protocol, and their disease progression halted. In 4 of 12 patients, angiograms (X-ray imaging of the blood vessels) confirmed actual disease reversal — in some cases dramatically. One such image showed a diseased distal left anterior descending artery that, after 32 months of plant-based nutritional intervention without cholesterol-lowering medication, regained its normal configuration.

This earlier success raised an important question: Could this approach work in a larger, broader group of patients? Skeptics doubted it. The current study was designed to answer that question.

Study Methods: How the Research Was Conducted

This follow-up study reviewed the outcomes of 198 consecutive nonsmoking patients with cardiovascular disease who voluntarily asked for counseling in plant-based nutrition. These were not patients recruited from a clinic waiting room — they were self-selected participants who sought out the program after learning about it through the Internet, the media, prior scientific publications, the lead author's book, supportive comments from other authors, or word of mouth.

The patients had multiple coexisting health conditions, known in medical terms as comorbidities:

• Hyperlipidemia (elevated cholesterol/fats in the blood): 161 patients
• Hypertension (high blood pressure): 60 patients
• Diabetes: 23 patients

The participants were mostly men (180 of 198, or 91%), with an average age of 62.9 years. They were followed for an average of 44.2 months (about 3.7 years), with some patients tracked for up to 13 years.

Before the program, each participant completed a 25- to 30-minute telephone screening that established disease presentation and severity. This included gathering information about symptoms, history of heart attacks, stress test and angiogram results, previous interventions, family history, lipid profiles, and any chronic conditions.

Patients were considered adherent if they eliminated dairy, fish, and meat from their diets and did not use added oils. The research team considered it especially important that patients avoid added oils, since even plant-based oils can injure endothelial cells.

The Intervention: What Patients Were Asked to Eat (and Avoid)

Each participant attended a single-day, 5-hour counseling seminar in a group of at most 12 participants. Spouses or partners were encouraged to attend. The seminar was intensive and covered the science behind the diet in considerable detail.

The core diet consisted of whole grains, legumes, lentils, other vegetables, and fruit. The researchers reassured patients that a balanced and varied plant-based diet would cover all their needs for amino acids (the building blocks of protein). Patients were also encouraged to:

• Take a multivitamin and a vitamin B12 supplement
• Use flax seed meal as an additional source of omega-6 and omega-3 essential fatty acids

The prohibited foods included:

• All added oils and processed foods containing oils
• Fish, meat, poultry, and dairy products
• Avocado and nuts
• Excess salt
• Sugary foods: sucrose, fructose, drinks containing them, refined carbohydrates, fruit juices, syrups, and molasses
• Subsequently, caffeine and fructose were also excluded

Exercise was encouraged but not required. The program did not require meditation, relaxation, yoga, or other psychosocial support approaches. Patients continued their cardiac medications as prescribed, monitored by their regular physicians.

The 5-hour seminar profiled plant-based cultures that have virtually no cardiovascular illness, contrasted with non-plant-based cultures where CAD is everywhere (confirmed even by autopsies of young adults). Participants learned about the plummeting death rates from strokes and heart attacks in Norway during World War II, when German occupying forces confiscated livestock and limited Norwegians to plant-based nutrition.

The seminar included a 44-page recipe handout, two scientific articles confirming the effectiveness of plant-based nutrition, and, after 2007, a copy of the book Prevent and Reverse Heart Disease. Participants watched angiograms showing actual CAD reversal from prior participants. An associate with decades of experience discussed how to buy and prepare plant foods, including how to read food labels and convert common recipes to meet program standards. Each seminar concluded with a testimonial from a prior participant, a plant-based meal, and a question-and-answer session.

After the seminar, participants were asked to complete and return a 3-week diet diary. They were invited to communicate concerns via email or phone and to share subsequent lipid profiles, stress tests, cardiac events, angiograms, and information about any interventions.

Key Findings: What Happened to the Patients

Of the 198 patients with cardiovascular disease in the study, 177 (89%) were adherent to the plant-based nutritional intervention. Only 21 patients (11%) were nonadherent.

Baseline characteristics showed the severity of illness in this group:

• 195 of 198 patients (98%) had a confirmed diagnosis of coronary artery disease
• Angiography or CT angiography confirmed the diagnosis in 180 patients (92%)
• The remaining patients were diagnosed through electrocardiography, failed stress tests, or a history of enzyme-documented myocardial infarction
• 44 of the 195 patients (23%) had already suffered a heart attack (MI) prior to counseling
• 3 patients had noncoronary vascular disease: one with cerebral (brain) vascular disease, one with carotid (neck artery) disease, and one with peripheral arterial disease

Before entering the program, 119 adherent patients had already undergone significant interventions: 75 had received PCI with stent placement, and 44 had suffered a heart attack. This was a seriously ill population.

Outcomes for Nonadherent Patients: A Stark Contrast

The 21 patients who did not sustain the dietary changes experienced markedly worse outcomes. Thirteen of 21 nonadherent participants (62%) experienced at least one adverse event, including:

• 2 sudden cardiac deaths
• 1 heart transplant
• 2 ischemic strokes (caused by blockage of blood flow to the brain)
• 4 percutaneous coronary interventions (PCIs) with stent placement
• 3 coronary artery bypass graft surgeries (CABGs, or "heart bypass" operations)
• 1 endarterectomy (surgical removal of plaque from an artery) for peripheral arterial disease

Outcomes for Adherent Patients: Strong Evidence of Benefit

The adherent group of 177 patients told a very different story. Among the 112 adherent patients who reported angina (chest pain) at baseline, 104 (93%) experienced improvement or complete resolution of their symptoms during the follow-up period. An additional patient with claudication (leg pain from poor circulation) also experienced symptom relief.

Among adherent patients with coronary artery disease, radiographic or stress testing results were available to document actual disease reversal in 39 patients (22%). Furthermore, 27 patients were able to avoid PCI or CABG procedures that had previously been recommended for them.

The researchers also evaluated whether adherent patients could avoid major cardiac events. Among all 177 adherent patients, there was only 1 major cardiovascular event related to disease progression: a single stroke. This represents a recurrent event rate of just 0.6% — meaning 99.4% of adherent patients avoided major cardiac events during the follow-up period.

Statistical analysis confirmed the significance of these findings: adherent patients experienced worse outcomes significantly less frequently than nonadherent patients (P<.001, by Fisher's exact test). In plain language, there is less than a 0.1% probability that this difference occurred by random chance.

There were 5 deaths in the adherent group, all noncardiac: 3 from cancer, 1 from a pulmonary embolus (blood clot in the lungs), and 1 from pneumonia. No adherent patient died of a cardiac cause.

Some adherent patients did require vascular interventions, but these were largely unrelated to disease progression:

• 1 patient required CABG for disease progression
• 1 patient had CABG for malpositioned dissecting stents placed just before enrollment
• 2 patients had CABG to qualify for heart valve repair surgery
• 2 patients had stenting procedures to correct closing grafted arteries
• 2 asymptomatic patients with stable CAD were persuaded by their primary care physicians to undergo CABG
• 1 patient experienced a nonfatal stroke after refusing warfarin for atrial fibrillation (an irregular heart rhythm)
• 1 patient had a stroke due to progression of CVD
• 1 patient experienced stent thrombosis (clotting of a stent) with acute heart attack after discontinuing clopidogrel as advised by their primary care physician
• 1 patient had a previously placed stent occlude 3 years into the study, requiring another stent

Even when counting all of these events as potentially diet-related, the researchers note that the overall event rate of 10% (18 out of 177 patients in the "Worse" category) over an average of 3.7 years remains far below the 62% event rate seen in the nonadherent group and below rates reported elsewhere in the medical literature.

Additionally, among 135 adherent patients for whom body weight data were available, the average weight loss was 18.7 pounds.

Why Did the Results Look So Favorable?

The researchers offer several explanations for why their results were particularly favorable compared to other nutrition intervention studies.

First, the strictness of the diet. No other nutrition study has completely eliminated all oils (including food products that may contain even small quantities of added oil of any kind) along with all animal, fish, and dairy products. This approach avoids foods known to injure endothelial cells, as well as exogenous cholesterol and saturated fat.

The authors also note that by avoiding exposure to lecithin and carnitine found in eggs, milk, dairy products, liver, red meat, poultry, shellfish, and fish, participants were unlikely to develop the intestinal bacteria capable of producing trimethylamine oxide (TMAO) — a recently identified compound that promotes atherosclerosis (hardening of the arteries). Interestingly, vegan eaters do not possess these particular detrimental gut bacteria, which are unique to omnivores.

Second, the intensity of the counseling. The single-day, 5-hour seminar was designed to convey the message of nutritional intervention with depth, clarity, power, and completeness. The researchers educated participants in detail about the importance of the endothelial cell and its product, nitric oxide. Patients came to understand exactly which foods injure their blood vessels and how transitioning to a whole-food, plant-based diet empowers them to halt and potentially reverse their disease.

The pre-seminar phone consultation, the seminar itself, and follow-up psychological support resulted in the remarkable 89% adherence rate sustained over 3.7 years.

What happens in the body? The researchers postulate several mechanisms for why plant-based nutrition works. When foods that injure or cause endothelial dysfunction are removed, the body readily restores the capacity of endothelial tissue to produce nitric oxide. This reduces the production of vasoconstricting (blood-vessel-narrowing) substances called endothelin and thromboxane by injured endothelial cells.

The daily consumption of generous portions of green leafy vegetables also appears to improve the population of endothelial progenitor cells — the cells that help repair and regenerate the lining of blood vessels. Additionally, reductions in lipid (fat), homocysteine, and triglyceride levels, along with improved insulin resistance, enhance the body's ability to produce nitric oxide.

Interestingly, while blood levels of HDL cholesterol (the so-called "good" cholesterol) may actually decrease with this anti-inflammatory, plant-based nutrition, the researchers note that the function of HDL cholesterol — its ability to remove cholesterol from tissues (efflux capacity) — may be more important than its blood concentration. This functional capacity could be significantly enhanced by the intervention, helping to enable disease arrest or reversal.

What Larger Studies Say About Nutrition and Heart Disease

The Cleveland Clinic study also places its findings in the context of large epidemiological research supporting the power of nutrition for preventing and treating cardiovascular disease.

Dehghan and colleagues followed 31,546 participants with cardiovascular disease or diabetes over 4.5 years, dividing them into five groups (quintiles) based on nutritional quality. Within the healthiest dietary group, the reduction in cardiovascular-related risk was:

• 35% for death
• 14% for myocardial infarction (heart attack)
• 19% for stroke

Importantly, this protective association was maintained whether or not patients were receiving medications.

Crowe and colleagues followed 44,561 men and women enrolled in the European Prospective Investigation into Cancer and Nutrition study. Thirty-four percent (15,151 participants) were vegetarian, consuming neither meat nor fish. During an 11.6-year follow-up, vegetarians had:

• A lower mean body mass index (BMI)
• Lower non-HDL cholesterol levels
• Lower systolic blood pressure
• A 32% lower risk of developing ischemic heart disease

Combined, these two large studies involving 76,107 individuals strongly support the power of nutrition for both primary and secondary prevention of cardiovascular illness.

By contrast, the researchers cite the findings of Wilkins and colleagues, who assessed lifetime risk of cardiovascular disease by reviewing data from 905,115 person-years accumulated from 1964 to 2008. While lifetime risk estimates for total cardiovascular disease for all individuals exceeded 30%, even men and women aged 55 with optimal risk factors still had a 40% and 30% likelihood, respectively, of developing cardiovascular disease by age 85. The authors conclude that even optimal risk factors are no guarantee that a typical Western diet won't eventually lead to heart disease.

Clinical Implications: What This Means for Patients

This study offers a powerful message: patients with established cardiovascular disease who are willing to change how they eat can take control of their disease in a way that drugs and procedures alone may not achieve.

The authors emphasize that "food may be the most important lifestyle factor in establishing the presence or absence of disease." For the 82% of adherent patients (146 out of 177) who avoided both required interventions and interventions that were recommended but found to be unnecessary, the implications are substantial: fewer procedures, fewer hospitalizations, and a dramatically lower risk of future cardiac events.

Perhaps most striking is the suggestion that successful nutritional treatment of cardiovascular disease — coupled with standard medical therapy — "may extinguish major cardiac event progression in the vast majority of patients." The researchers even question the need for elective stent deployment, noting the prompt improvement in myocardial perfusion within just 3 weeks of starting the diet, the resolution of angina, and the angiographic evidence of disease reversal.

This matters because it suggests that patients previously told they "need" a stent or bypass surgery might reasonably explore a period of intensive dietary change as an alternative — provided they work with their physicians and understand that this approach requires serious commitment.

Study Limitations: What This Research Could Not Prove

It's important to view these findings with appropriate scientific caution. This was not a randomized controlled trial — the gold standard of medical research. Patients were self-selected volunteers who actively sought out the program, which may mean they were more motivated and health-conscious than the average patient.

There was no control group of patients who continued their usual Western diet. Instead, the researchers compared outcomes against historical data from other studies and against the nonadherent patients within the study itself. The nonadherent group was also quite small (21 patients), which limits the strength of statistical comparisons.

The study relied on patient self-reporting of dietary adherence. Patients who invested time and effort in the program may have been inclined to report better adherence than actually occurred. Additionally, some data points (such as weight loss) were only available for a subset of patients (135 of 177).

The authors acknowledge that the disease burden and presence of comorbid conditions in their patients may not be directly comparable to those in other published studies of nutrition interventions. They also note that even in their worst-case analysis — attributing all negative events in adherent patients to the diet — the event rate was still only 10% over 3.7 years, which is far below historical norms.

Finally, this study enrolled patients who were already interested in dietary change. It does not answer the question of whether such adherence can be sustained in broader, less motivated populations. The authors themselves identify this as an area for future research: "The test is to see if adherence can be sustained in broader populations."

Recommendations for Patients

Based on this research and the supporting studies it cites, patients with or at risk for coronary artery disease may want to consider the following:

1. Talk to your doctor first. Dietary changes should be made in partnership with your healthcare team, especially if you are taking medications for blood pressure, cholesterol, diabetes, or blood thinners. Changes in diet can affect how these medications work, and doses may need adjustment.
2. Understand the scope of the commitment. The diet used in this study was strict: no meat, poultry, fish, dairy, eggs, avocado, nuts, or added oils of any kind, along with avoidance of sugary foods, refined carbohydrates, fruit juices, syrups, and molasses. Even small amounts of added oil in processed foods were discouraged.
3. Build a strong support system. The high adherence in this study was attributed in part to the intensive counseling and ongoing support. If you're considering this approach, consider working with a registered dietitian, joining a support group, and involving your spouse or partner in the process.
4. Learn the "why." Participants were educated about how foods injure the endothelium (the lining of blood vessels) and how plant-based nutrition restores the body's ability to heal. Understanding the mechanisms helped participants stay motivated over years. Knowledge is a powerful tool for sustained behavior change.
5. Be patient and consistent. The benefits in this study developed over months and years. By 3 weeks, one patient's PET scan showed restored blood flow. By 32 months, another patient's angiogram showed the artery had regained its normal appearance. But many of the most important benefits, like avoiding heart attacks and strokes, unfolded over 3.7 years of follow-up.
6. Take supplements as recommended. The researchers advised a multivitamin, vitamin B12, and flax seed meal to ensure nutritional completeness. Anyone following a strict plant-based diet should pay attention to vitamin B12, which is not found naturally in plant foods.
7. Remember that this is an adjunct to care, not a replacement. Patients in this study continued their cardiac medications as prescribed. The authors' message is not that patients should abandon their medications, but that nutritional intervention combined with standard medical therapy offers the best chance of halting or reversing disease.

This study's message is ultimately an empowering one. It suggests that the food on your plate is not merely fuel — it is information that your body uses to build health or create disease. For patients with coronary artery disease, the fork may be a more powerful tool than the scalpel.

Frequently Asked Questions

What is coronary artery disease and can a plant-based diet actually reverse it?

Coronary artery disease (CAD) is narrowing of heart blood vessels by plaque. In a Cleveland Clinic study of 198 patients with established heart disease, those who strictly followed a whole-food, plant-based diet for about 3.7 years had a 99.4% rate of avoiding major cardiac events. Some patients showed actual disease reversal on angiograms.

What happened to patients who did not stick to the diet?

Among 21 nonadherent patients, 62% experienced at least one adverse event during follow-up. These included sudden cardiac deaths, strokes, heart transplants, stents, bypass surgery, and surgery for peripheral artery disease. This contrasted sharply with adherent patients, who had far fewer cardiac events.

Is this strict plant-based diet safe and nutritionally complete?

The study's authors advised a multivitamin, vitamin B12 supplement, and flax seed meal to ensure nutritional completeness. They noted that a balanced and varied plant-based diet covers protein needs. Anyone following such a diet should pay special attention to vitamin B12, which is not found naturally in plant foods.

How quickly can a plant-based diet improve heart health?

In one study patient, a PET scan showed restored blood flow to the heart just 3 weeks after starting the diet. Another patient's angiogram after 32 months showed an artery regained its normal appearance. However, most benefits, like avoiding heart attacks and strokes, unfolded over several years of follow-up.

What were the study's limitations?

This was not a randomized controlled trial. Patients volunteered because they wanted dietary change, and there was no control group. Dietary adherence was self-reported, and only 21 patients were nonadherent for comparison. The study cannot prove cause and effect, but it showed significantly fewer cardiac events in adherent patients.

My doctor recommended a stent for my blocked arteries. Should I get a second opinion on whether a plant-based diet could work instead?

Before proceeding with a recommended stent or bypass, a second opinion can help weigh whether the procedure is truly necessary or whether intensive dietary change is a viable alternative. Patients with established coronary artery disease who strictly followed a plant-based diet for an average of 3.7 years had a 99.4% rate of avoiding major cardiac events, and 27 patients were able to forgo previously recommended stents or bypass surgery. Elective stent placement did not show clear protection from future heart attacks or prolonged life. Discuss risks and benefits with your cardiologist. Diagnostic Detectives Network provides independent expert second opinions.

Source Information

This patient-friendly article is based on peer-reviewed research originally published in The Journal of Family Practice (July 2014, Volume 63, Number 7, pages 356-364).

Original article title: potential conflict of interest

Corresponding author: Caldwell B. Esselstyn Jr., MD

Authors: Caldwell B. Esselstyn Jr., MD; Gina Gendy, MD; Jonathan Doyle, MCS; Mladen Golubic, MD, PhD; Michael F. Roizen, MD

Affiliation: The Wellness Institute of the Cleveland Clinic, Lyndhurst, Ohio

The authors reported no potential conflict of interest relevant to this article. This patient-friendly translation was created to make the research accessible to a broader audience while preserving all numerical data, statistical findings, and clinical conclusions from the original publication.