According to the Centers for Disease Control, nearly one million Americans per year die of CVD. Thatís more than 40 percent of all deaths, at a rate of nearly two per minute.
By Mark Anthony, Ph.D. | 12/05/2005
The core of CVD is the buildup of plaque in arteries, the thick-walled vessels that carry oxygenated blood. Accounting for much of the thickness is a layer of smooth muscle that helps to propel the blood along. The interior vessel wall is lined with endothelial cells, a sort of inside skin. According to the most popular theory, the ďresponse to injury hypothesis,Ē plaque begins with damage to the endothelial layer.
The injured artery lining undergoes a complex series of changes that can narrow the passageways and reduce the flow of blood. Defensive cells attach to the injured walls, secreting growth factors, which attract wound-healing proteins. The smooth muscle layer then expands into the artery and this highly inflammatory process invites the attachment of cholesterol. This is because the injured wall has more cholesterol receptors.
|Because the risk factors for CVD are complex, the effective heart-health diet must be anti-inflammatory, anti-oxidant, anti-obesity and anti-hypertensive all at the same time. Image courtesy of NutriBody.com.|
The growing mass becomes vulnerable to rupture and the formation of a deadly clot, which if lodged in a narrowed artery that feeds the heart, can halt blood flow and starve a portion of the heart muscle. That is a heart attack.
The risk factors for CVD are complex. What causes the original injury is uncertain, but risk factors such as smoking, elevated blood pressure and high blood cholesterol are the usual suspects. Risk factors are perceived as individual contributors, but frequently risk factors are clustered.
For example, the metabolic syndrome that is a precursor to type II diabetes is characterized by a variety of symptoms, like elevated blood sugar and high LDL cholesterol, insulin resistance, obesity and hypertension. Obesity is a heart disease risk, and generally carries with it hypertension, increased markers of inflammation and elevated cholesterol.The Diet Connection
The complex nature of CVD means that for diet to be protective, it must address many factors and do so consistently. Itís not enough to call a diet ďheart-healthyĒ simply because itís low in fat or results in lower cholesterol. Half of all heart attacks happen in people who do not have elevated cholesterol levels.
The effective heart-health diet must be anti-inflammatory, anti-oxidant, anti-obesity and anti-hypertensive all at the same time. Anti-diabetic also comes in. And of course, it has to taste good and be convenient, otherwise nobody will stick with it long enough for it to be effective.
Sound impossible? Actually, itís not difficult at all, just a matter of balance. A balanced, heart-healthy diet begins with a generous supply of fruits and vegetables. Numerous studies have revealed that a diet rich in fruits and vegetables tends to reduce blood pressure, lower cholesterol and dial down markers of inflammation. Itís associated with lower body weight and less incidence of type II diabetes. In other words, all the biggies.
The effectiveness of a diet rich in fruits and vegetables was confirmed by the DASH studies (Dietary Approaches to Stop Hypertension) sponsored by the NHLBI (National Heart Lung Blood Institute). A diet that included 10 servings per day of fruits and vegetables, whole grains, beans, nuts and low-fat dairy products significantly reduced hypertension. In fact, simply adding more fruits and vegetables to a standard American diet lowered hypertension, though not quite as dramatically as the full-blown DASH diet.
Many fruits and vegetables are rich in potassium and magnesium. And although the DASH diet was also high in calcium and low in sodium, the significant change in the balance of electrolytes is considered by many researchers to be more effective at lowering hypertension than simply reducing salt intake.
While fruits and vegetables are naturally low in sodium, their ability to reduce hypertension exceeds that which can be accomplished by simply altering electrolyte balance with supplements. Also, a diet rich in fruits and vegetables initiates many positive changes all at once that can go beyond lowering hypertension.
The Phytochemical Factor
|Grapes provide a wealth of phytochemicals, especially resveratrol. Photo courtesy of USDA's Agricultural Research Service.|
Fresh fruits and vegetables teem with heart-protective chemicals called phytochemicals. Phytochemicals can act as antioxidants, accompanying cholesterol during transport and protecting it from oxidation. Itís believed oxidized cholesterol is more likely to bind to injured artery walls.
These compounds work alone and in concert and number in the thousands, ranging from antioxidant vitamins, such as C and E, to carotenoids, such as beta-carotene, and lycopene. There are also polyphenols, which include phenolic acids (cinnamic acids, benzoic acids).
Resveratrol, the polyphenol from grapes, also appears to protect the artery walls from oxidation, inflammation, platelet aggregation and clot formation. Other phytochemical classes include flavonoids (of which there are over 6,000); stilbenes and lignans; organosulfur compounds and phytosterols.
The total cost to the nation in health care and lost productivity from heart disease is projected to be over $350 billion in 2005. Nearly 61 million people have been diagnosed with some form of cardiovascular disease (CVD), and not just seniors. Coronary heart disease (CHD), the main type of CVD and the number one cause of death in the U.S., is a major cause of disability among men and women in the prime of life.