A Comprehensive Review of the Research Behind Scores of Nutraceutical Ingredients That Help Keep a Heart Healthy and Happy
Consumers probably don’t need to hear again that heart disease is the leading cause of death in the U.S. Nor do they need to hear that the World Health Organization (WHO) estimates some 17 million people die worldwide each year from cardiovascular disease (CVD)—accounting for about one-third of all deaths. A healthy heart is critical for survival, but what many people may not realize is that nature provides a treasure chest of various nutrients to keep the heart and cardiovascular system healthy.
Last year functional foods for heart health grew nearly 250% from the year before, according to global market research firm Mintel, Chicago, IL. The Global New Products Database, which Mintel uses to track new product introductions in various product segments throughout the world, recorded almost 150 new functional food launches in the heart health category. It seems the high awareness of the importance of maintaining a healthy heart has prompted companies to act and consumers to reach into their wallets for these heart healthy concoctions, many of which contain nutraceutical ingredients proven to support some aspect of cardiovascular health.
The Anatomy of CVD
The heart is a complex machine, and its health is tied to a full-body orchestration of nerves, muscles, valves, arteries, capillaries, neurotransmitters, hormones and enzymes. The brain’s vasomotor center fires sympathetic pulses to coordinate this symphony, blending blood vessel dilation and contraction, fluid level, volume, pressure, heart rate and stroke. The signaling ligand messengers include epinephrine, norepinephrine, acetylcholine, vasopressin, renin, angiotension and aldosterone. Secondary cardiovascular ligands include cortisone, dopamine, serotonin, insulin, leptin and thyroid hormones. Receptors for primary ligands include alpha-1, alpha-2, beta-1, and beta-2 types, located throughout the anatomy, including heart muscle cells and artery epithelial cells. These receptors are responsible for regulating and balancing everything from stroke volume and heart rate to the contraction and relaxation of blood vessels. Epinephrine, for example, stimulates alpha-1 and specialized beta-2 receptors to constrict blood vessels. Meanwhile acetylcholine, working in conjunction with nitric oxide, stimulates beta-2 adrenergic receptors, initiating dilatation and increased blood flow.
The orchestration between ligands and receptors enables the homeostasis of blood pressure and flow throughout the circulatory system. Although the heart is the cardiovascular command center, cardiovascular health is directly related to the elasticity and strength of the blood vessel walls as well as the balance of ligands and receptors. This means the health of the blood and the blood vessel walls is essential. The heart’s health is intimately tied to these because healthy blood and elastic blood vessels are required to deliver nutrients and oxygen to the heart muscle, along with every other vital organ and tissue system.
The most common heart disease is ischemia, which is linked to elevated cholesterol, hypertension and atherosclerosis. Atherosclerosis is a narrowing and hardening of artery walls thought to be caused by artery wall damage from oxidized low-density lipoprotein (LDL), or “bad cholesterol,” and free radicals. This artery damage stimulates an inflammatory response resulting in plaque build-up, fibrin and thickened lumen. With increased plaque build-up comes the deadly risk of thrombosis events like stroke and myocardial infarction.
Some of the obvious causes of artery damage and plaque build-up include obesity, diabetes, a sedentary lifestyle and a diet high in saturated fats and/or fried foods. High blood pressure and fast or irregular heart rate, especially in persons over 40 years old, are strong markers. Higher levels of total cholesterol, LDL and very low-density lipoprotein (VLDL) cholesterol, and total triglycerides are also key markers. The exception appears to be in the case of the elderly, where recent studies have illustrated that moderately high total cholesterol among the elderly may be linked with lower mortality1,2. Nonetheless, a link between small LDL particle size and atherosclerosis has been made3, and the oxidation of LDL particles seems to be on center stage. There appear to be multiple causes for the LDL oxidation cascade. Hyperperoxides appear to be instigated, as they readily form oxidative radicals. The cascade toward LDL oxidation also seems to be accelerated by lipooxygenases like 15-LOX-2 along with cyclooxygenases.
Additional diagnostic markers for artery damage include increased homocysteine, fibrinogen and C-reactive protein levels4. These indicate the likelihood of inflammation and clotting events, with the eventual risk of thrombosis. Increased homocysteine levels may indicate problems with trans-methylation—the liver-regulated glutathione process of exchanging methyl groups to reduce oxidative stress. Methylation problems can be the result of a lack of bioavailable methyl groups such as vitamin B12. Damaged and cholesterol-laden artery walls also appear to block the production of nitric oxide from epithelial cells. This contributes to the constrictive hardening of arteriosclerosis and reduced blood flow.