Nutritional Supplements and Cardiovascular Health
Author: Yvette C. Terrie, BSPharm, RPh
Because cardiovascular disease (CVD) continues to be the leading cause of death among men and women in the United States, many patients elect to take a proactive approach in augmenting and protecting their cardiovascular health.
A host of nutritional supplements are marketed for protecting against CVD and promoting overall cardiovascular health. Before taking any of these supplements, patients, especially those taking medications for chronic medical conditions, should check with their primary health care provider to ascertain the appropriateness of using these products, learn of contraindications, and avoid drug interactions.
Patients should be advised that these supplements should never be used as a replacement for prescription antihyperlipidemic agents. Patients with hyperlipidemia or with risk factors for CVD should be encouraged to consult their primary healthcare provider for a thorough medical evaluation and treatment. Patients should also be reminded that a healthy diet and lifestyle, including exercise and lifestyle modifications (eg, lowfat, low-cholesterol, low-sugar, high-fiber diet; smoking cessation; limited use of alcohol), are the best defenses against CVD. Pharmacists should stress that there is no substitution for a healthy diet and lifestyle and that patients should always discuss the use of nutritional supplements with their physician.
The most common ingredients marketed for promotion of cardiovascular health include omega-3 fatty acids, plant sterols, coenzyme Q10 (CoQ10), and garlic. These nutritional supplement products include single-entity or combination products and are often incorporated in multivitamin supplements formulated for cardiovascular health, such as Centrum Specialist Heart (Pfizer). While many of these supplements are available in capsule form, some new products include Nature Made Fish Oil in fruit-flavored gummy form. Other new supplements include Nature Made CholestOff Complete and CholestOff Plus as well as Cholestra Flavored Chews (Quest Consumer).
Omega-3 and -6 Fatty Acids
Many dietary supplements that are specifically formulated for cardiovascular health contain omega-3 fatty acids alone or in conjunction with omega-6 fatty acids. Omega-6 and omega-3 fatty acids found in fattier fish such as tuna, mackerel, and salmon) are referred to as polyunsaturated fatty acids (PUFAs). Some studies suggest that these supplements may provide health benefits when consumed in the recommended amounts, especially when used to replace saturated fats or trans fats in the diet.1 Omega-6 and -3 PUFAs play a crucial role in heart and brain function and in normal growth and development.1 PUFAs are classified as essential fats that the body needs but can’t produce, so they must be obtained through dietary means or supplements.1
The consumption of omega-3 fatty acids through dietary means is preferred to supplementation. However, patients may elect to use omega-3 dietary supplements due to convenience or the inability to consume enough omega-3 fatty acids through dietary means alone. Patients with chronic medical conditions or who are taking pharmacologic agents should always discuss the use of these supplements with their primary healthcare provider before taking them. Common adverse effects associated with the use of omega-3 supplements include acid reflux/heartburn/indigestion, nausea, diarrhea, and increased burping.2-4
Gastrointestinal side effects can be minimized by taking fish oil with meals and by starting with a low dose and gradually increasing it.2-4 Patients with allergy or hypersensitivity to any of these products should avoid their use. The use of omega-3 supplements is associated with potential interactions with drugs or supplements (eg, aspirin, anticoagulants, antiplatelet agents, some herbal supplements).4-6 Diabetic patients should exercise caution when using these supplements because they may slightly lower the blood glucose level.2-4 Pharmacists should remind patients that they should not ingest more than 3 g of omega-3 fatty acids in supplement form daily unless approved by their physician, because large intakes may result in excessive bleeding or worsen heart rhythm in individuals with arrthymias.2-4 Patients should be reminded that prolonged use of fish oil supplements may also cause vitamin E deficiency; therefore, vitamin E is added to many commercial fish oil products.2-4 Regular use of vitamin E–enriched products may lead to elevated levels of this fat-soluble vitamin, so patients should be monitored rotuinely.2-4
Plant Sterol Products
Clinical studies have evaluated the health benefits associated with the use of plant sterols (phytosterols). Plant sterols are classified as naturally occurring, plant-based ingredients that have been proved to lower low-density-lipoprotein (LDL) cholesterol levels, thus possibly decreasing the risk of CVD.5-7 The most common plant sterols include betasitosterol, campesterol, and stigmasterol.6,7 Sitostanol, which is a saturated derivative of sitosterol, is the most common plant stanol.7 Plant sterols and stanols are chemically related and structurally comparable to cholesterol and have been shown to reduce total and LDL cholesterol by decreasing dietary and biliary cholesterol absorption via the displacement of cholesterol from the micelles, thus decreasing the solubility of cholesterol in the intestine.6,8 Plant sterols are added to many margarine spread products and are available in a few supplements as well.
According to the American Heart Association’s Nutrition Committee, although few adverse effects have been reported regarding the short- or long-term consumption of plant stanol/sterol ester– containing fats, there has been some concern regarding observations of decreased levels of plasma alpha-tocopherol plus beta-carotene, alpha-tocopherol, and/or lycopene due to the consumption of foods containing stanol and sterol esters.9 Further investigation is needed to establish the long-term safety of recommended doses of stanols and sterols and to evaluate their potential bioavailability in foods, beverages, and supplements as well as their effects.6,9
CoQ10 is found in many cardiovascular supplements and is naturally found in every human cell, with the greatest concentrations in the mitochondria of the heart, liver, pancreas, and kidneys.4
Supplements are used in the treatment of various cardiovascular conditions, including heart failure, cardiomyopathy, and hypertension.4 Dosages range from 100 to 200 mg daily.
The most common adverse effects include nausea, gastrointestinal distress, anorexia, headache, dizziness, and irritability.4,10 Prior to using this supplement, patients taking warfarin should consult their physician because the structure of CoQ10 is similar to the synthetic form of vitamin K (menaquinone), possibly providing procoagulant effects comparable to those of vitamin K.4 The use of supplements containing CoQ10 may also interact with some chemotherapeutic and antihypertensive agents.4,11 The use of CoQ10 is contraindicated in pregnant and lactating women due to a lack of clinical information regarding the safety of its use in these patient populations.4
The use of CoQ10 has become popular for managing the adverse effects of myopathy, which is often associated with the use of statin drugs.12 In general, CoQ10 is well tolerated and has not been associated with serious adverse effects.12 However, more research is needed to determine whether CoQ10 is useful for treatment of statin myopathy, and there is no research regarding the effectiveness of CoQ10 for the prevention of statin myopathy.4,12
Garlic supplements are marketed to treat conditions such as hyperlipidemia, hypertension, and type 2 diabetes mellitus, and to prevent various cancers.4 Garlic supplements are typically manufactured from dried or fresh bulbs of the plant.4 Animal and in vitro studies report that garlic possesses hypotensive, hypolipidemic, and antiplatelet properties.4
The most common adverse effects, including nausea, vomiting, and heartburn, occur mostly at high doses. Body odor and halitosis are common complaints among consumers using these supplements, but odorless formulations are available.4 Due to antithrombotic effects, patients should discontinue use of these supplements at least 7 to 10 days before any surgical procedure.4 Prior to using garlic supplements, patients taking warfarin, other platelet active agents, or ginkgo supplements should be advised to consult their primary healthcare provider because of potential bleeding risks.4 Studies have reported that the use of garlic supplements may decrease concentrations of saquinavir by an estimated 50%; therefore, the combination of garlic supplements and agents that treat HIV infection should be avoided.4
Some research demonstrates that garlic can decrease blood pressure in individuals with hypertension by as much as 7% or 8%.11 Other studies report promising modest short-term effects of garlic supplements on lipid and antithrombotic factors; however more clinical research is needed.4,7