The China Study - T. Colin Campbell and Thomas M. Campbell

Broken Hearts

PUT YOUR HAND on your chest and feel your heart beat. Now put your hand where you can feel your pulse. That pulse is the signature of your being. Your heart, creating that pulse, is working for you every minute of the day, every day of the year, and every year of your entire life. If you live an average lifetime, your heart will beat about 3 billion times.l
Now take a moment to realize that during the time it took you to read the above paragraph an artery in the heart of roughly one American clogged up, cut off blood flow and started a rapid process of tissue and cell death. This process is better known, of course, as a heart attack. By the time you finish reading this page, four Americans will have had a heart attack, and another four will have fallen prey to stroke or heart failure.2 Over the next twenty-four hours, 3,000 Americans will have heart attacks,2roughly the same number of people who perished in the terrorist attacks of September 11, 200l.
The heart is the centerpiece of life and, more often than not in Ameri- ca, it is the centerpiece of death. Malfunction of the heart and/or circula- tion system will kill 40% of Americans,3 more than those killed by any other injury or ailment, including cancer. Heart disease has been our number one cause of death for almost one hundred years.4 This disease does not recognize gender or race boundaries; all are affected. If you were to ask most women what disease poses the greatest risk to them, heart disease or breast cancer, many women would undoubtedly say breast cancer. But they would be wrong. Women's death rate from heart disease is eight times higher than their death rate from breast cancer. 5, 6
If there is an "American" game, it is baseball; an "American" dessert, apple pie. If there is an "American" disease, it is heart disease.
EVERYONE'S DOING IT
In 1950, Judy Holliday could be seen on the big screen, Ben Hogan dominated the world of golf, the musical South Pacific won big at the Tony Awards and on June 25, North Korea invaded South Korea. The American administration was taken aback but responded quickly. With- in days, President Truman sent in troops on the ground and bombers overhead to push back the North Korean army. Three years later, inJuly of 1953, a formal cease-fire agreement had been signed and the Korean War was over. During this period of time, over 30,000 American sol- diers were killed in battle.
At the end of the war, a landmark scientific study was reported in the Journal of the American Medical Association. Military medical investiga- tors had examined the hearts of 300 male soldiers killed in action in Ko- rea. The soldiers, at an average age of twenty-two years, had never been diagnosed with heart problems. In dissecting these hearts, researchers found startling evidence of disease in an exceptional number of cases. Fully 77.3% of the hearts they examined had "gross evidence" of heart dis-
ease.? (In this instance, "gross" means large.)
That number, 77.3%, is startling. Coming at a time when our number
one killer was still shrouded in mystery, the research clearly demon- strated that heart disease develops over an entire lifetime. Furthermore, almost everyone was susceptible! These soldiers were not couch-potato slouches; they were in top condition in the prime of their physical lives. Since that time, several other studies have confirmed that heart disease is pervasive in young Americans.s
THE HEART ATTACK
But what is heart disease? One of the key components is plaque. Plaque is a greasy layer of proteins, fats (including cholesterol), immune sys- tem cells and other components that accumulate on the inner walls of the coronary arteries. I have heard one surgeon say that if you wipe your finger on a plaque-covered artery; it has the same feel as wiping your finger across a warm cheesecake. If you have plaque building up in your coronary arteries, you have some degree of heart disease. Of the autopsied soldiers in Korea, one out of twenty diseased men had so much plaque that 90% of an artery was blocked.? That's like putting a kink in a garden hose and watering a desperately dry garden with the resulting trickle of water!
Why hadn't these soldiers had a heart attack already? After all, only 10% of the artery was open. How could that be enough? It turns out that if the plaque on the inner wall of the artery accumulates slowly, over several years, blood flow has time to adjust. Think of blood flowing through your artery as a raging river. If you put a few stones on the sides of a river every day over a period of years, like plaque accumulating on the walls of the artery, the water will find another way to get to where it wants to be. Maybe the river will form several smaller streams over the stones. Perhaps the river will go under the stones forming tiny tunnels, or maybe the water will flow through small side streams, taking a new route altogether. These new tiny passageways around or through the stones are called "collaterals." The same thing happens in the heart. If plaque accumulates over a period of several years there will be enough collateral development that blood can still travel throughout the heart. However, too much plaque buildup can cause severe blood restriction, and debilitating chest pain, or angina, can result. But this bUildup only
rarely leads to heart attacks.9, 10
So what leads to heart attacks? It turns out that it's the less severe ac-
cumulations of plaque, blocking under 50% of the artery, that often cause heart attacks.l l These accumulations each have a layer of cells, called the cap, which separates the core of the plaque from the blood flOwing by. In the dangerous plaques, the cap is weak and thin. Consequently, as blood rushes by, it can erode the cap until it ruptures. When the cap ruptures, the core contents of the plaque mix with the blood. The blood then begins clotting around the site of rupture. The clot grows and can qUickly block off the entire artery. When the artery becomes blocked over such a short period of time, there is little chance for collateral blood flow to develop. When this happens, blood flow downstream of the rupture is severely reduced and the heart muscles don't get the oxygen they require. At this point, as heart muscle cells start to die, heart pumping mechanisms begin to fail, and the person may feel a crushing pain in the chest, or a searing pain down into an arm and up into the neck and jaw. In short, the victim starts to die. This is the process behind most of the l.1 million heart at- tacks that occur in America every year. One out of three people who have a heart attack will die from it.
We now know that the small to medium accumulation of plaque, the plaque that blocks less than 50% of the artery, is the most deadly.
So how can we predict the timing of heart attacks? Unfortunately, with existing technologies, we can't. We can't know which plaque will rup- ture, when, or how severe it might be. What we do know, however, is our relative risk for having a heart attack. What once was a mysterious death, which claimed people in their most productive years, has been "demystified" by science. No study has been more influential than that of the Framingham Heart Study.
FRAMINGHAM
After World War II, the National Heart Institutel3 was created with a modest budget4 and a difficult mission. Scientists knew that the greasy plaques that lined the arteries of diseased hearts were composed of cho- lesterol, phospholipids and fatty acids,14 but they didn't know why these lesions developed, how they developed or exactly how they led to heart attacks. In the search for answers, the National Heart Institute decided to follow a population over several years, to keep detailed medical re- cords of everybody in the population and to see who got heart disease and who didn't. The scientists headed to Framingham, Massachusetts.
Located just outside of Boston, Framingham is steeped in American history. European settlers first inhabited the land in the seventeenth century. Over the years the town has had supporting roles in the Revo- lutionary War, the Salem Witch Trials and the abolition movement. More recently, in 1948, the town assumed its most famous role. Over 5,000 residents of Framingham, both male and female, agreed to be poked and prodded by scientists over the years so that we might learn something about heart disease.
And learn something we did. By watching who got heart disease and who didn't, and comparing their medical records, the Framingham Heart Study developed the concept of risk factors such as cholesterol, blood pressure, phYSical activity, cigarette smoking and obesity. Because of the Framingham Study, we now know that these risk factors playa prominent role in the causation of heart disease. Doctors have for years used a Framingham prediction model to tell who is at high risk for heart disease and who is not. Over 1,000 scientific papers have been pub- lished from this study, and the study continues to this day, having now studied four generations of Framingham residents.
The shining jewel of the Framingham Study is its findings on blood cholesterol. In 1961, they convincingly showed a strong correlation be- tween high blood cholesterol and heart disease. Researchers noted that men with cholesterol levels "over 244 mgldL (milligrams per deciliter) have more than three times the incidence of CHD (coronary heart dis- ease) as do those with cholesterol levels less than 210 mgldL."15The contentious question of whether blood cholesterol levels could predict heart disease was laid to rest. Cholesterol levels do make a difference. In this same paper, high blood pressure was also demonstrated to be an important risk factor for heart disease.
The importance given to risk factors signaled a conceptual revolu- tion. When this study was started, most doctors believed that heart disease was an inevitable "wearing down" of the body, and we could do little about it. Our hearts were like car engines; as we got older, the parts didn't work as well and sometimes gave out. By demonstrating that we could see the disease in advance by measuring risk factors, the idea of preventing heart disease suddenly had validity. Researchers wrote, " . .. it appears that a preventive program is clearly necessary."15 Simply lower the risk factors, such as blood cholesterol and blood pressure, and you lower the risk of heart disease.
In modern-day America cholesterol and blood pressure are house- hold terms. We spend over 30 billion dollars a year on drugs to control these risk factors and other aspects of cardiovascular disease.2 Almost everyone now knows that he or she can work to prevent a heart attack by keeping his or her risk factors at the right levels. This awareness is only about fifty years old and due in large measure to the scientists and subjects of the Framingham Heart Study.
OUTSIDE OUR BORDERS
Framingham is the most well-known heart study ever done, but it is merely one part of an enormous body of research conducted in this country over the past sixty years. Early research led to the alarming conclusion that we have some of the highest rates of heart disease in the world. One study published in 1959 compared the coronary heart disease death rates in twenty different countries (Chart 5.1).16
These studies were examining Westernized societies. If we look at more traditional societies, we tend to see even more striking disparities in the incidence of heart disease. The Papua New Guinea Highlanders, for example, pop up in research quite a bit because heart disease is rare in their societyY Remember, for example, how low the rate of heart dis- ease was in rural China. American men died from heart disease at a rate almost seventeen times higher than their Chinese counterparts.