UNIT 2 |
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OBJECTIVES:
Discuss the primer of heart disease Describe the role of endothelium Is Moderation enough? Is it Coronary or Culinary Disease? Article review
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REFERENCES:
Prevent and Reverse Heart Disease, Caldwell Esselstyn, MD
Nutrition Facts, Michael Greger, MD
Nutrition Guide for Clinicians, Neal Barnard, MD
Prevent and Reverse Heart Disease, Caldwell Esselstyn, MD
Nutrition Facts, Michael Greger, MD
Nutrition Guide for Clinicians, Neal Barnard, MD
The Heart Disease Primer
There was a clarion example of those parts of the world where cardiovascular disease is nearly nonexistent: in those areas, cholesterol levels are consistently below 150 mg/dL. Cornell University professor emeritus Colin Campbell, an expert in biochemistry and nutrition, was the director of a twenty-year project that involved Cornell, Oxford University, and the Chinese Academy of Preventive Medicine - one of the most comprehensive studies of nutrition ever. Among other things, the project found that the normal range of cholesterol among residents of rural China, were coronary artery disease is rarely seen, falls below 90 and 150 mg/dL. Comparing those levels with levels in the United kingdom, where cholesterol levels are far closer to those in the United States.
Perhaps the most important was the Framingham Heart Study, the fifty-year project - run by the National Heart, Lung and Blood Institute, Boston University, and other academic collaborators - that has collected and analyzed medical data from several generations of residents of Framingham, Massachusetts. Dr. William Castelli, former medical director of the study, put it quite badly: over all those years, no one in Framingham who maintained a cholesterol level lower than 150 mg/dL has had a heart attack.
So why is your cholesterol level so important to your health? Let's take a look at some of the basics.
Perhaps the most important was the Framingham Heart Study, the fifty-year project - run by the National Heart, Lung and Blood Institute, Boston University, and other academic collaborators - that has collected and analyzed medical data from several generations of residents of Framingham, Massachusetts. Dr. William Castelli, former medical director of the study, put it quite badly: over all those years, no one in Framingham who maintained a cholesterol level lower than 150 mg/dL has had a heart attack.
So why is your cholesterol level so important to your health? Let's take a look at some of the basics.
Cholesterol is a white, waxy substance that is not found in plants - only in animals. It is an essential component of the membrane that coats all our cells, and it is the basic ingredient of sex hormones. Our bodies need cholesterol, and they manufacture it on their own. We do not need to eat it. But we do, when we consume meat, poultry, fish, and other animal-based foods, such as dairy products and eggs. In doing so, we take on excess amounts of the substances. What's more, eating fat causes the body itself to manufacture excessive amounts of cholesterol, which explains why vegetarians who eat oil, butter, cheese, milk, ice cream, glazed doughnuts, and French pastry develop coronary disease despite their avoidance of meat.
Medicine subsides cholesterol into two types. High-density lipoprotein, or HDL, is sometimes known as "good" cholesterol. Medical experts do not know precisely how, but it seems to offer some protection against heart attacks - by collecting excess cholesterol and carrying it away from the arteries to the liver, which can break it down and dispose of it. As total blood cholesterol rises, you need more and more of the HDL cholesterol to protect you against heart disease.
Low-density lipoprotein, or LDL, is "bad" cholesterol. When too much of it is present in the bloodstream, it tends to build up along artery walls, helping to form the plaques that narrow blood vessels and ultimately may clog them altogether. As described in Unit 1, the coronary arteries are the blood vessels that supply oxygen and nutrients to the muscle of the heart. They get their name from the Latin word for "crown" because they encircle the heart almost like a royal headpiece. They are relatively small, but exceedingly important: without the nourishment they bring to the incredibly efficient pump they serve, the heart becomes injured, begins to fail, and may die.
Low-density lipoprotein, or LDL, is "bad" cholesterol. When too much of it is present in the bloodstream, it tends to build up along artery walls, helping to form the plaques that narrow blood vessels and ultimately may clog them altogether. As described in Unit 1, the coronary arteries are the blood vessels that supply oxygen and nutrients to the muscle of the heart. They get their name from the Latin word for "crown" because they encircle the heart almost like a royal headpiece. They are relatively small, but exceedingly important: without the nourishment they bring to the incredibly efficient pump they serve, the heart becomes injured, begins to fail, and may die.
The Endothelium
The innermost lining of all blood and lymph vessels and the heart is called the endothelium. Far more than a simple membrane, the endothelium is actually the body's single largest endocrine organ. Of all endothelial cells in your body were laid out flat, one cell thick, they would cover an area equal to 2 tennis courts.
Healthy arteries are strong and elastic, their linings smooth and unobstructed, allowing a free flow of blood. But when the levels of fats in the bloodstream become elevated, everything begins to change. Gradually, the endothelium, the white blood cells, and the platelets, the blood cell adheres to and eventually penetrates the endothelium, where it attempts to ingest the rising numbers of LDL cholesterol molecules that are being oxidized from the fatty diet. That white blood cell sends out a call for help to other white blood cells. More and more of them converge on the site, becoming engorged with bad cholesterol and eventually forming a bubble of fatty pus -- an ATHEROMA, or PLAQUE, the chief characteristic of atherosclerosis.
Old plaques contain scar tissue and calcium. As they enlarge, they severely narrow and sometimes block the arteries. A significantly narrowed artery cannot give the heart muscle a normal blood supply, and the heart muscle, thus deprived, causes chest pain, or angina. In some cases, the coronary arteries actually perform their own bypasses, growing extra branches -- called COLLATERALS -- that go around the narrowed vessels.
However, it is not the old, larger plaques that put you most at risk for heart attacks. The most recent scientific evidence indicates that most heart attacks occur when younger and smaller fatty plaques rupture their outer lining, or cap, and bleed into the coronary artery.
As the plaque is formed, a fibrous cap develops as its roof, which is covered by a single layer of endothelium about as thick as a cobweb. For a while, thus protected, plaques lie quietly in place, doing little perceptible harm to the artery's owner. But an insidious process is nonetheless under way. The white blood cells that raced to the rescue, now engorged with oxidized LDL cholesterol, are called FOAM CELLS, and begin to manufacture chemical substances that erode the cap of the plaque. The cap weakens to the thickness of a cobweb. And eventually, the shearing force of blood flowing over the weakened cap may cause it to rupture.
This is catastrophic. Plaque content now oozes into the flowing bloodstream, and that constitutes a thrombogenic event: nature wants to heal the rupture, and so platelets are activated. They try mightily to stop the invading garbage by clotting the rupture. Thus begins a lethal cascade. The clots is self-propagating, and within minutes, the entire artery may become blocked.
With no more blood flowing through the blocked artery, the heart muscle that was nourished by it begins to die. This is the definition of myocardial infarction, or HEART ATTACK. If the person survives this attack, the dead portion of heart muscle scars. Multiple heart attacks and widespread scaring weaken the heart, sometimes causing it to fail. That condition is known as congestive heart failure. If the heart attack is extensive, if it results in an abnormal rhythmical contraction, or if the congestive heart failure is prolonged the person may die.
If the same process pf plaque formation occurs in a noncoronary artery, it can be just as dangerous. Whatever tissue the artery supplied - it could be the leg muscles or even the brain - will not receive its full measure of blood. What's more, a piece of a plaque or a clot can break loose and be carried through the blood stream, ultimately obstructing an artery far from its source.
Traditional cardiology has approached this disease primarily by relying on mechanical interventions. But we can do better. We can go right to the source of the disease. We can cut off the supply of fatty substances that accumulate in the arteries to such catastrophic effect. We can go directly to the bottom line.
This is it: if you follow a plant-based nutrition program to reduce your total cholesterol level to below 150 mg/dL and the LDL level to less than 80mg/dL, you cannot deposit fat and cholesterol into your coronary arteries.
The innermost lining of all blood and lymph vessels and the heart is called the endothelium. Far more than a simple membrane, the endothelium is actually the body's single largest endocrine organ. Of all endothelial cells in your body were laid out flat, one cell thick, they would cover an area equal to 2 tennis courts.
Healthy arteries are strong and elastic, their linings smooth and unobstructed, allowing a free flow of blood. But when the levels of fats in the bloodstream become elevated, everything begins to change. Gradually, the endothelium, the white blood cells, and the platelets, the blood cell adheres to and eventually penetrates the endothelium, where it attempts to ingest the rising numbers of LDL cholesterol molecules that are being oxidized from the fatty diet. That white blood cell sends out a call for help to other white blood cells. More and more of them converge on the site, becoming engorged with bad cholesterol and eventually forming a bubble of fatty pus -- an ATHEROMA, or PLAQUE, the chief characteristic of atherosclerosis.
Old plaques contain scar tissue and calcium. As they enlarge, they severely narrow and sometimes block the arteries. A significantly narrowed artery cannot give the heart muscle a normal blood supply, and the heart muscle, thus deprived, causes chest pain, or angina. In some cases, the coronary arteries actually perform their own bypasses, growing extra branches -- called COLLATERALS -- that go around the narrowed vessels.
However, it is not the old, larger plaques that put you most at risk for heart attacks. The most recent scientific evidence indicates that most heart attacks occur when younger and smaller fatty plaques rupture their outer lining, or cap, and bleed into the coronary artery.
As the plaque is formed, a fibrous cap develops as its roof, which is covered by a single layer of endothelium about as thick as a cobweb. For a while, thus protected, plaques lie quietly in place, doing little perceptible harm to the artery's owner. But an insidious process is nonetheless under way. The white blood cells that raced to the rescue, now engorged with oxidized LDL cholesterol, are called FOAM CELLS, and begin to manufacture chemical substances that erode the cap of the plaque. The cap weakens to the thickness of a cobweb. And eventually, the shearing force of blood flowing over the weakened cap may cause it to rupture.
This is catastrophic. Plaque content now oozes into the flowing bloodstream, and that constitutes a thrombogenic event: nature wants to heal the rupture, and so platelets are activated. They try mightily to stop the invading garbage by clotting the rupture. Thus begins a lethal cascade. The clots is self-propagating, and within minutes, the entire artery may become blocked.
With no more blood flowing through the blocked artery, the heart muscle that was nourished by it begins to die. This is the definition of myocardial infarction, or HEART ATTACK. If the person survives this attack, the dead portion of heart muscle scars. Multiple heart attacks and widespread scaring weaken the heart, sometimes causing it to fail. That condition is known as congestive heart failure. If the heart attack is extensive, if it results in an abnormal rhythmical contraction, or if the congestive heart failure is prolonged the person may die.
If the same process pf plaque formation occurs in a noncoronary artery, it can be just as dangerous. Whatever tissue the artery supplied - it could be the leg muscles or even the brain - will not receive its full measure of blood. What's more, a piece of a plaque or a clot can break loose and be carried through the blood stream, ultimately obstructing an artery far from its source.
Traditional cardiology has approached this disease primarily by relying on mechanical interventions. But we can do better. We can go right to the source of the disease. We can cut off the supply of fatty substances that accumulate in the arteries to such catastrophic effect. We can go directly to the bottom line.
This is it: if you follow a plant-based nutrition program to reduce your total cholesterol level to below 150 mg/dL and the LDL level to less than 80mg/dL, you cannot deposit fat and cholesterol into your coronary arteries.
And although some patients may need cholesterol-lowering drugs to help them achieve those safe, low cholesterol levels, drugs alone are not the answer. Nutrition is the real key to saving your life in the long term. Eating the right way not only will help reduce your cholesterol levels, but also can work additional wonders you may never imagined.
IS MODERATION ENOUGH?
In science, a review of many studies on the same subject is referred to as meta-analysis. Such a review of studies on coronary artery disease was done in 1988, when researchers in Wisconsin analyzed ten clinical trials involving 4,347 patients. Half of the patients had received cardiac rehabilitation, which generally consists of advice to lose weight, exercise, control high blood pressure, control diabetes, stop smoking, and eat less fat. The other half of the patients did not receive such assistance. The results:
In early 2006, a report published in the Journal of American Medical Association resulted in national headlines suggesting that low-fat diets do not decrease health risks. The JAMA article was based on a study, part of the Women's Health Initiative of the National Institutes of Health, which followed nearly 49,000 women over eight years, and it found that those prescribed a "low-fat" diet turned out to have the same rates of heart attacks, strokes, and cancers of the breast and colon as those who ate whatever they wanted.
Almost buried in the news reports about this latest, largest most expensive study ever was this incredibly important fact: the women who were supposedly consuming a low-fat diet were actually getting 29 percent of their daily calories from fat. For those on the front lines of nutritional research, that is not "low fat" at all. It is three times the level - around 10 percent of daily caloric intake - that researchers recommend through plant-based nutrition.
The Women's Health Initiative study were quoted as saying that their results "do not justify recommending low-fat diets to the public to reduce their heart disease and cancer risk." True, they certainly do not justify recommending diets containing 29 percent fat, the level currently endorsed in the US Dietary Guidelines. The Women's Health Initiative study simply conforms guidelines are not optimal enough: we should be recommending diets far lower in fat than those featured in the research.
Over the years the meta-analyses, such as the one conducted by the Wisconsin researchers, have consistently shown that coronary patients who reduce their fat intake do somewhat better than those who do not. But almost always, the best outcome is a slowing of the rate of progression of disease in patients who receive treatment - not putting an absolute stop to it.
These results are not good enough. We should be aiming much higher: at arresting coronary artery disease altogether, even reversing its course. And the key to doing this, is not simply reducing the amount of fat and cholesterol you ingest, but eliminating cholesterol and any fat beyond the natural, healthy amounts found in plants, from your diet. The key is PLANT-BASED NUTRITION.
- The rehabilitated group had slightly fewer fatal heart attacks than those who did not get the same advice. But the researchers found "no significant difference" between the two groups in the number of nonfatal heart attacks. In fact, the rehabilitated group suffered slightly more nonfatal attacks than those who made no lifestyle changes.
In early 2006, a report published in the Journal of American Medical Association resulted in national headlines suggesting that low-fat diets do not decrease health risks. The JAMA article was based on a study, part of the Women's Health Initiative of the National Institutes of Health, which followed nearly 49,000 women over eight years, and it found that those prescribed a "low-fat" diet turned out to have the same rates of heart attacks, strokes, and cancers of the breast and colon as those who ate whatever they wanted.
Almost buried in the news reports about this latest, largest most expensive study ever was this incredibly important fact: the women who were supposedly consuming a low-fat diet were actually getting 29 percent of their daily calories from fat. For those on the front lines of nutritional research, that is not "low fat" at all. It is three times the level - around 10 percent of daily caloric intake - that researchers recommend through plant-based nutrition.
The Women's Health Initiative study were quoted as saying that their results "do not justify recommending low-fat diets to the public to reduce their heart disease and cancer risk." True, they certainly do not justify recommending diets containing 29 percent fat, the level currently endorsed in the US Dietary Guidelines. The Women's Health Initiative study simply conforms guidelines are not optimal enough: we should be recommending diets far lower in fat than those featured in the research.
Over the years the meta-analyses, such as the one conducted by the Wisconsin researchers, have consistently shown that coronary patients who reduce their fat intake do somewhat better than those who do not. But almost always, the best outcome is a slowing of the rate of progression of disease in patients who receive treatment - not putting an absolute stop to it.
These results are not good enough. We should be aiming much higher: at arresting coronary artery disease altogether, even reversing its course. And the key to doing this, is not simply reducing the amount of fat and cholesterol you ingest, but eliminating cholesterol and any fat beyond the natural, healthy amounts found in plants, from your diet. The key is PLANT-BASED NUTRITION.
IS IT CORONARY OR CULINARY DISEASE?
Let's use science to explain this. Heart disease develops in susceptible persons when blood cholesterol levels rise higher than 150 mg/dL and a person who maintains blood cholesterol under 150 mg/dL for a lifetime will not develop coronary artery disease - even if he or she smokes, has family history of coronary disease, suffers from hypertension, and is obese!
THE PAPUA HIGHLANDERS OF NEW GUINEA
These people are traditionally heavy smokers. Even nonsmokers among them breathe in lethal doses of secondhand smoke in communal hutches. Not surprisingly, the Papua highlanders suffer many lung disorders. But studies of those who live into their sixties and beyond have shown that despite the well-documented risk to health health that is posed by smoking, they have no coronary artery disease. They are protected by their diet, which consists almost entirely of nineteen separate varieties of sweet potatoes.
Nutrition impinges on cardiovascular health in several critical ways. The most obvious, of course, is that a diet in fat and cholesterol causes blood lipid levels to rise, thus setting off the process of plaque formation. Every segment of our bodies is comprised of cells, and every individual cell is protected by an outer coat. This cell membrane is almost unimaginably delicate - just one hundred thousandth of a millimeter thick. Yet it is absolutely essential to the integrity and healthy functioning of the cell. And it is extremely vulnerable to injury.
Every mouthful of oil and animal products, including dairy foods, initiates an assault on these membranes and, therefore, on the cells they protect. These foods produce a cascade of free radicals in our bodies - especially harmful chemical substances that induce metabolic injuries from which there is only partial recovery. Year after year, the effects accumulate. And eventually, the cumulative cell injury is great enough to become obvious, to express itself as what physicians define as disease. plants and grains do not induce the deadly cascade of free radicals. Even better, in fact, they carry an antidote. Unlike oils and animal products, they contain antioxidants which help to neutralize the free radicals and also, recent research suggests, may provide considerable protection against cancers.
These people are traditionally heavy smokers. Even nonsmokers among them breathe in lethal doses of secondhand smoke in communal hutches. Not surprisingly, the Papua highlanders suffer many lung disorders. But studies of those who live into their sixties and beyond have shown that despite the well-documented risk to health health that is posed by smoking, they have no coronary artery disease. They are protected by their diet, which consists almost entirely of nineteen separate varieties of sweet potatoes.
Nutrition impinges on cardiovascular health in several critical ways. The most obvious, of course, is that a diet in fat and cholesterol causes blood lipid levels to rise, thus setting off the process of plaque formation. Every segment of our bodies is comprised of cells, and every individual cell is protected by an outer coat. This cell membrane is almost unimaginably delicate - just one hundred thousandth of a millimeter thick. Yet it is absolutely essential to the integrity and healthy functioning of the cell. And it is extremely vulnerable to injury.
Every mouthful of oil and animal products, including dairy foods, initiates an assault on these membranes and, therefore, on the cells they protect. These foods produce a cascade of free radicals in our bodies - especially harmful chemical substances that induce metabolic injuries from which there is only partial recovery. Year after year, the effects accumulate. And eventually, the cumulative cell injury is great enough to become obvious, to express itself as what physicians define as disease. plants and grains do not induce the deadly cascade of free radicals. Even better, in fact, they carry an antidote. Unlike oils and animal products, they contain antioxidants which help to neutralize the free radicals and also, recent research suggests, may provide considerable protection against cancers.
VIDEO AND ARTICLE REVIEW
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