Coronary artery disease is the most common type of heart disease in the United States, affecting over 18 million adults, and is a major cause of heart attack and death worldwide (1, 3). Coronary artery disease develops over many years and is strongly influenced by dietary and lifestyle choices. Early detection and diagnosis and prompt lifestyle interventions that address cardiovascular risk factors are important in reducing cardiovascular morbidity and mortality.
This article will discuss a typical functional medicine approach to coronary artery disease, from diagnostic lab testing to integrative and holistic therapeutic interventions that successfully manage the condition and support cardiovascular vitality.
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What is Coronary Artery Disease?
Coronary artery disease (CAD), or coronary heart disease (CHD), is a common heart condition involving plaque formation in the coronary arteries, leading to impaired blood flow and oxygen delivery to the cardiac muscles. CAD is the most common form of heart disease and the leading cause of death in the United States. (1-3)
Atherosclerosis is the buildup of plaques within the arteries, consisting of fat, cholesterol, and calcium. Atherosclerosis progresses over a lifetime, often starting in childhood, accelerated by high cholesterol, high blood pressure, cigarette smoking, and diabetes. Not only does atherosclerosis contribute to the development of CAD, but it can also lead to peripheral artery disease and chronic kidney disease. (4)
Two primary forms of coronary artery disease are stable ischemic heart disease and acute coronary syndrome. Stable ischemic heart disease is a chronic manifestation of heart disease; arterial plaques build, and coronary arteries narrow over many years. This results in a gradual decrease in the flow of oxygen-rich blood to your heart, causing chronic and often low-grade cardiovascular symptoms. Acute coronary syndrome is an emergent scenario in which a coronary plaque ruptures, forms a blood clot, and impedes blood flow to the heart, resulting in a heart attack. (5)
Coronary Artery Disease Symptoms
CAD can present without symptoms for a long time. For some, a heart attack may be the first sign of CAD. As coronary atherosclerosis progresses and coronary arterial narrowing occurs, you may notice mild symptoms that reflect poor blood flow to and oxygenation of the heart. (4)
Stable angina, or temporary chest pain and discomfort, is the most common symptom of CAD. Stable angina typically occurs during physical or emotional exertion, like during exercise or psychological stress, and is relieved with rest. Shortness of breath with physical exertion is also common.
Typical symptoms of a heart attack include (6):
- Acute crushing chest pain or heaviness, which may radiate down the left arm or into the shoulder, neck, jaw, and back
- Indigestion
- Heart palpitations
- Anxiety and a feeling of impending doom
- Sweating
- Lightheadedness and dizziness
- Research indicates that women are more likely to experience symptoms less commonly associated with heart attacks, such as fatigue, shortness of breath, insomnia, nausea/vomiting, and abdominal pain.
What Causes Coronary Artery Disease?
CAD is a multifactorial disease; etiologic factors can be categorized into modifiable and non-modifiable factors. These factors predispose an individual to arterial damage, inflammation, advanced development of atherosclerosis, and, ultimately, CAD. These risk factors often occur together, making CAD even more likely. (7)
Non-modifiable risk factors include age, sex, family history, and genetics. Atherosclerosis develops over time; aging increases the risk of damaged and narrowed arteries. Men are more likely to develop CAD than women; however, the relative risk for women increases after menopause. A family history of CAD in a primary family member (i.e., biological parents and siblings) increases the risk of developing it yourself. This risk is enhanced if a family member has a history of premature onset of atherosclerotic cardiovascular disease, defined as disease onset before age 55 in men and 65 in women. (7-9)
Modifiable risk factors for CAD include a sedentary lifestyle, unhealthy diet, chronic stress, smoking, excessive alcohol consumption, lack of sleep, and obesity. (7-9)
Chronic diseases can also contribute to CAD risk by negatively impacting the health of arteries, causing arterial stiffness and inflammation that impairs healthy blood flow to the heart. Traditional CAD risk factors include dyslipidemia (high LDL cholesterol and triglycerides, low HDL cholesterol), diabetes, and hypertension. Other diseases impacting arterial and cardiac health include sleep apnea, preeclampsia, autoimmune diseases, and chronic kidney disease (CKD). (8)
Functional Medicine Labs to Test for Root Cause of Coronary Artery Disease
Functional medicine labs are valuable tools that go beyond the basic lipid panel in identifying and managing risk factors for CAD, along with monitoring patient progress and success once therapeutic interventions have been implemented.
Advanced Lipid Panel
An advanced lipid panel provides a more detailed dissection of cholesterol-carrying lipoproteins. Lipoprotein fractionation includes markers of a traditional lipid panel (total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides) but also provides additional information regarding LDL and HDL particle size, number, and density. These markers can be used to categorize a patient's risk for CAD, as they influence the development and progression of atherosclerosis.
Apolipoprotein B (ApoB)
Circulating cholesterol-containing lipoproteins contain one apoB molecule. ApoB measures the concentration of apoB-containing lipoproteins in plasma. ApoB is now recognized to be superior to LDL cholesterol and non-HDL cholesterol levels as a predictor of cardiovascular events.
Lipoprotein (a) (Lp(a))
Lp(a) is an LDL-like lipoprotein with an apoB bound to an apo(a) protein. 20-25% of the global population has an elevated Lp(a), which increases the risk of atherosclerotic cardiovascular disease, independent of other traditional risk factors. Elevated Lp(a) precipitates vascular inflammation, atherosclerosis, calcification, and blood clotting. (10)
Inflammatory Markers
Elevations in inflammatory markers are strong risk factors for CAD (7). High-sensitivity CRP (hs-CRP), homocysteine, Lp-PLA2, and myeloperoxidase are well-documented markers of cardiac-related inflammation associated with atherosclerosis and cardiovascular events.
Conventional Treatment for Coronary Artery Disease
Conventional interventions for treating and managing CAD include lifestyle modifications and pharmacotherapy to reduce and modify atherosclerotic risk factors. The emphasis lies on dietary and exercise changes to achieve optimal body weight and prescription medications, as indicated, to manage blood pressure, cholesterol, and blood sugar. More advanced stages of CAD may require surgical procedures to open blocked coronary arteries. (11)
Functional Medicine Treatment Protocol for Coronary Artery Disease
The goals of a functional medicine CAD protocol are similar to conventional ones. Emphasis is placed on dietary interventions and natural alternatives to prescription medications to manage cardiovascular risk factors, reverse atherosclerosis, and prevent cardiovascular events.
Therapeutic Diet and Nutrition Considerations for Coronary Artery Disease
Heart-healthy dietary patterns, such as Mediterranean or DASH diets, are indicated for CAD. These diets outline nutritional choices and habits that promote a healthy balance of cholesterol levels, stabilize blood sugar, and reduce cardiovascular inflammation.
Fruits and Vegetables
Fruits and vegetables are rich in fiber, phytosterols, vitamins, minerals, and antioxidants, which protect the cardiovascular system. Numerous studies show that increased intake of fruits and vegetables is associated with reduced risk of cardiovascular disease. For optimal heart health, the AHA recommends a goal of eating 4-5 servings of fruits and vegetables each every day.
Fiber
Meta-analyses indicate that a higher intake of dietary fiber decreases the incidence and mortality from cardiovascular disease. While dietary fiber intake may be a marker for fruit and vegetable intake (along with other anti-inflammatory dietary patterns), soluble and insoluble fiber both have other known cardioprotective effects, like assisting in eliminating excess serum cholesterol and stabilizing blood sugar. Patients should aim to eat at least 25-35 grams of fiber daily.
Unsaturated Fats
Trans and saturated fats are more likely to become oxidated in the body, leading to vascular inflammation and increased LDL cholesterol. Shifting dietary choices away from foods high in saturated and trans fats and instead replacing them with dietary sources of mono- and polyunsaturated fats can favorably shift lipid profiles and reduce the risk of cardiovascular disease. The 2020-2025 Dietary Guidelines for Americans recommends that no more than 10% of daily calories come from saturated fats. (17, 18)
Food sources of monounsaturated fats include olive, avocado, sesame and pumpkin seeds, and almonds. Sources of polyunsaturated fats include flax seeds, walnuts, and fish. (17)
Supplements Protocol for Coronary Artery Disease
Like a conventional strategy, a natural supplemental protocol should focus on managing cardiovascular risk factors predisposing an individual to atherosclerosis and CAD. Protocols should be customized to the patient's medical history and lab results, and will vary accordingly. Additionally, dietary and herbal supplements can be prescribed to support vascular integrity and reduce cardiovascular inflammation. Below is a sample protocol for a patient with CAD, high cholesterol, elevated blood pressure, and dysglycemia.
Berberine
Berberine is an excellent antilipemic and hypoglycemic herbal option used alone or with prescription therapy. This 2015 meta-analysis indicated that berberine has a comparable therapeutic effect on type 2 diabetes, hyperlipidemia, and hypertension to first-line prescription therapies. Favorable outcomes have been measured in fasting and postprandial blood glucose, HbA1c, and lipid profiles in patients taking berberine. (12, 13)
Dose: 500 mg 2-3 times daily, taken at the beginning of meals
Duration: 3 months
*Note: Caution should be taken with prolonged supplementation of berberine as it is strongly antimicrobial and can induce unfavorable changes to the gut microbiome over prolonged periods.
Magnesium
Magnesium has many valuable effects for preventing and treating cardiovascular disease. It is a cofactor in cardiac energy production, inhibits platelet aggregation, promotes vasodilation, exerts anti-inflammatory effects, and can lower blood pressure.
Dose: 500-1,000 mg daily, or dosed to bowel tolerance. Decrease the dose if the patient experiences loose stools.
Duration: 1-6 months
Fish Oil
Fish oil provides numerous benefits in treating atherosclerosis and promoting cardiovascular health. The omega-3 fatty acids in fish oil lower triglyceride levels, inhibit platelet aggregation, decrease blood viscosity, lower blood pressure, and reduce endothelial inflammation. Trials using fish oil for the primary and secondary prevention of cardiovascular disease have resulted in beneficial results, including reductions in all-cause mortality and heart attack rates. (14)
Dose: 3-6 grams daily
Duration: 1-4 years
Nattokinase
Nattokinase is an enzyme extracted from natto, a fermented soybean product. It has been consumed for thousands of years in Japan and studied extensively in Japan, Korea, and China. Nattokinase has proven potent anti-clotting effects and the ability to reverse atherosclerosis and reduce cholesterol levels. (15, 16)
Dose: 4,000-10,000 FU daily, in split doses
Duration: 1 year
Flavonoids
Plant flavonoids are concentrated in fruits and vegetables and possess potent antioxidant capacity. They can improve lipid profiles by decreasing LDL oxidation and support endothelial integrity by reducing inflammation and promoting vasodilation. Dr. William Mitchell's Fruit Anthocyanins is an evidence-based flavonoid-rich formula used regularly by functional medicine providers.
Dose: 1 tbsp daily
Duration: 3 months
When to Retest Labs
Patients can expect to see changes in lab results as soon as four weeks after implementing an integrative treatment protocol for CAD. For convenience and to allow the treatment plan to have maximum effect, many doctors recommend postponing repeat labs for 6-12 weeks after starting a supplemental regimen.
Treatment protocols can be modified as needed per the patient's response. While higher supplemental doses may be required in the earlier stages of treatment, it is reasonable to expect that some supplements can be decreased or discontinued over time, especially as health-promoting dietary and lifestyle habits are implemented.
Summary
As the most common heart disease and the leading cause of death in America, CAD cannot go unmanaged. The good news is that CAD is a preventable and modifiable disease. Using functional medicine labs to understand a patient's overall cardiovascular risk, along with an in-depth evaluation of lifestyle factors known to contribute to atherosclerosis and CAD, risk factors can be identified, and a functional medicine protocol implemented to halt the progression of CAD and prevent associated adverse health complications.