DONATE
FOR PHYSICIANS
HEALTH AND NUTRITION
  Action Alerts
  Breaking Medical News
  Continuing Education
  Health Topics
  Cancer Resources
  Diabetes Resources
  Food for Life Classes
  Healthy School Lunches
  Vegetarian and Vegan Diets
  Reports and Surveys
  Clinical Research Studies
  Health Care Professionals
ETHICAL RESEARCH & EDUCATION
MEDIA CENTER
LEGISLATIVE FOCUS
CLINICAL RESEARCH
EDUCATIONAL LITERATURE
MEMBERSHIP
SHOP

CONNECT WITH PCRM

 

 

    



Section One: Preventing and Reversing Heart Disease

Heart attacks bring patients into the emergency room in crisis. When blood flow through the coronary arteries is blocked by plaques or blood clots, part of the heart muscle loses its source of oxygen and dies. The worse the damage, the lower the chances of survival.

In Western countries, artery blockages are common, even in asymptomatic young adults. A review of post-mortem examinations of American soldiers killed in the Korean War at an average age of just 23 years, showed that artery blockages were already present in 77 percent of the men. Their Asian counterparts were much less likely to have atherosclerosis, probably due to differences in diet.1,2

Artery blockages can be treated surgically, using either angioplasty to destroy the plaque or a coronary artery bypass graft, in which arteries or veins from another part of the body are transplanted onto the heart to route blood around the blockage. Both are usually only temporary or palliative measures, however, since blockages progress in the newly opened vessels. A second bypass is usually necessary after six to eight years. Ultimately, heart disease kills half of our patients.

Diet and lifestyle changes, however, can prevent and usually reverse heart disease, and are now the cornerstone of heart disease treatment.

What Is Heart Disease?

Common heart disease, or atherosclerosis, is the growth of raised lesions on the inside of arteries. These lesions, called plaques, are composed of overgrowing cells from the artery’s muscle layer, along with cholesterol, fat, and cellular debris. It is believed that this process begins when a low-density lipoprotein particle (LDL, the so-called “bad cholesterol”) is damaged by free radicals in the bloodstream. The cells lining the artery remove the LDL particle from the blood, leading to the accumulation of a fatty streak in the artery wall and the gradual formation of plaques.

Defining the Terms for Your Patients

Angina means chest pain caused by an inadequate blood supply to the heart.

Atherosclerosis, sometimes called “hardening of the arteries,” is when small bumps, or plaques, slow the flow of blood. These plaques are made of cells growing from the muscle layer that sheathes the artery, along with cholesterol, fat, and cellular debris.

Claudication means leg pains that come when the arteries to the legs are narrowed by plaques. The symptoms arrive during walking or climbing stairs and are relieved by resting.

Coronary arteries nourish the heart muscle. Their name comes from the fact that they ring the heart like a crown.

A myocardial infarction is a heart attack. The coronary arteries become blocked and a portion of the heart muscle dies from lack of oxygen.

A stroke is when a part of the brain dies due to a blockage or break in the arteries.

Risk Factors

The following risk factors are associated with the development of atherosclerosis:

  • high cholesterol levels
  • obesity
  • smoking
  • family history of heart disease
  • high blood pressure
  • “Type A” personality (a need to excel, bossiness, and impatience)
  • sedentary lifestyle
  • chronic stress
  • diabetes
  • elevated levels of stored iron

Different Types of Cholesterol

Cholesterol is a waxy substance made in the liver for use as a biological raw material. It is used as a structural part of cell membranes and as a precursor to estrogen, testosterone, and other hormones. Cholesterol is not the same as fat.

When cholesterol is transported in the bloodstream, it is packed into LDL and very low density lipoprotein (VLDL) particles.

LDL delivers cholesterol to various parts of the body. It is sometimes called the “bad cholesterol,” because, although it is necessary in limited quantities, high LDL cholesterol levels can dramatically increase the risk of a heart attack.

When cholesterol is released from dead cells, it is picked up for disposal in another kind of particle called high density lipoprotein (HDL, the “good cholesterol”). The more HDL a person has, the lower the risk of a heart attack.

Cholesterol: The 150 Goal

Ideally, total cholesterol levels should be below 150 mg/dl.* For 35 years running, not a single person in the Framingham Heart Study whose cholesterol level was below this value had a heart attack.

However, for every 1 percent increase in the amount of cholesterol in the blood, the risk of a heart attack rises by about 2 percent. This association can be used clinically: lowering a patient’s serum cholesterol level is rewarded by a two-for-one improvement in risk. If a patient lowers his or her cholesterol level by 20 percent, for example, by dropping from 200 mg/dl down to 160 mg/dl, the risk of a heart attack diminishes by roughly 40 percent.


* In the U.S., most clinicians measure cholesterol levels in milligrams of cholesterol per deciliter of blood serum (mg/dl), a system still reflected in government guidelines. Most other countries and medical journals report cholesterol levels in millimoles per liter (mmol/L).
          To convert cholesterol measurements from mg/dl to mmol/L, simply multiply by 0.02586. To convert triglyceride measurements from mg/dl to mmol/L, multiply by 0.0113.


How to Read a Cholesterol Test

The total cholesterol level combines all forms of cholesterol in the blood.

Above 240 mg/dl (6.2 mmol/L):

High risk**

205-240 mg/dl (5.3-6.2 mmol/L):

Above average risk

205 mg/dl (5.3 mmol/L):

Average for U.S. adults

150 mg/dl (3.9 mmol/L) or less:

Very low risk

If the total cholesterol level is 150 mg/dl (3.9 mmol/L) or below, heart disease risk is extremely low.

If the total cholesterol is above 150, you should check how much of the cholesterol is in the form of high density lipoprotein (HDL). For most North Americans, only about 20 percent of their total cholesterol is HDL. This means that not enough of the cholesterol in the body is leaving. Ideally, the HDL level should be one-third or more of the total.


** The National Cholesterol Education Program has set the following guidelines for risk of coronary artery disease based on the total cholesterol level:

 

high risk

200-239 mg/dl (5.2-6.2 mmol/L):

borderline-high risk

Below 200 mg/dl (5.2 mmol/L):

desirable

However, approximately one-third of all heart attacks occur at cholesterol levels of 150-200 mg/dl, making the designation “desirable” for these levels controversial.


How Much Is “Good Cholesterol”?

The following figures from the Framingham Heart Study show how much of the total cholesterol is in the HDL form for various groups.3 HDL is the “good” form of cholesterol that is leaving the body.

Ideal:

near 33%

Average vegetarian:

34%

Average Boston Marathon runner:

29%

Average female without heart disease:

23%

Average male without heart disease:

20%

Average female with heart disease:

19%

Average male with heart disease:

17%

Triglycerides

Triglycerides is a term that refers to the type of fat the body stores. After a meal, triglyceride molecules are assembled in the liver, packed into VLDL, and sent via the bloodstream to fat storage areas.

Triglyceride levels above 150 mg/dl (170 mmol/L) are considered elevated. Some studies have linked high triglyceride levels to increased risk of heart disease, particularly if accompanied by low HDL levels. Triglyceride levels that are extremely high (greater than 1,000 mg/dl) are associated with other risks, such as pancreatitis, and medical treatment is necessary.

Reversing Heart Disease

One of the most important recent innovations in heart disease was published in the July 21, 1990, edition of The Lancet. Research findings of Dean Ornish, M.D., demonstrated that heart disease can actually be reversed without surgery or medicines.4

Dr. Ornish studied 47 patients, all of whom had atherosclerotic plaques that were clearly visible on angiograms. He assigned half the research subjects to a control group in which they received the standard care that doctors prescribe (e.g., a diet centered on “lean” meat, poultry, and fish, along with various medications and advice not to smoke).

The remaining patients were assigned to an experimental group that followed a very different regimen, including the following four steps:

  1. Low-fat, vegetarian diet
  2. Brisk walking for one-half hour per day or one hour three times per week
  3. Avoidance of tobacco
  4. Stress management exercises

The prescribed diet excluded red meat, poultry, and fish, virtually eliminating cholesterol and animal fat. It also minimized vegetable oils, because all oils contain at least some traces of saturated fats.

One year later, all patients had a second angiogram to measure the blockages in their coronary arteries. The results showed that the control group patients, who had been following the more traditional medical routine, had not improved. In fact, the blockages in their coronary arteries were worse, on average, than at the beginning of the study. They still had chest pain and still needed medications.

For the patients in the special intervention group, however, chest pain diminished within weeks. Their cholesterol levels dropped dramatically without cholesterol-lowering drugs. At the end of one year, 82 percent of the patients showed measurable reversal of their coronary artery blockages.

These results gave doctors a new tool for reversing heart disease. It cost much less than surgery, had no side effects, was surprisingly easy to follow, and could help keep patients healthy over the long run.

Vegetarian Diets for Heart Patients

Dr. Ornish used a vegetarian diet, which has marked advantages over other diets. It avoids cholesterol and animal fat.

Cholesterol is not needed in the diet at all, since the liver makes all the cholesterol that the body needs. The optimal amount of cholesterol in the diet is zero. However, all animal products contain cholesterol. Every 100 milligrams of cholesterol in a person’s daily routine adds roughly five points to the serum total cholesterol level. (Everyone is different, and this number is an average.) In practical terms, 100 milligrams of cholesterol are found in four ounces of beef, four ounces of chicken, half an egg, or three cups of milk. Most Americans consume 500 to 600 milligrams of cholesterol each day.

Note that chicken has about the same cholesterol content as beef, approximately 25 milligrams per ounce, something that may surprise your patients, because they have heard that chicken has slightly less cholesterol.  For poultry (without the skin), the figure is near 20 percent. In contrast, beans are only 4 percent fat, rice is between 1 percent and 5 percent, depending on the variety, and potatoes are less than 1 percent fat. Nearly all grains, beans, vegetables, and fruits derive less than 10 percent of their calories from fat, and none have any cholesterol at all.

Fish vary, but like all other animals, contain cholesterol and fat. Of the fat in fish, about 15 percent to 30 percent is saturated fat. This is lower than beef and chicken, but much different from plant products, which never contain cholesterol and tend to be very low in fat.

The “White Meat” Myth

Many patients have come to believe that if they switch from “red meat” to chicken and fish, they will keep their arteries clear. It is important for them to understand that such a diet does not usually lead to a major lowering of cholesterol levels nor does it stop artery blockages from progressing in most patients.

The April 29, 1993, New England Journal of Medicine showed the weakness of the diets that many doctors and the popular press often promote for heart patients. In this case, the diet was the National Cholesterol Education Program Step II Diet, which recommends modest portions of fish and skinless poultry and non-fat cooking methods. Even among patients with good adherence, this diet reduces LDL by only about 5 percent.5 For a patient with a cholesterol level of 250 mg/dl (6.5 mmol/L), for example, a 5 percent drop leads only to about 235 mg/dl (6.1 mmol/L), which is still far too high for safety. Not only does such a diet not lower cholesterol levels effectively, it does not reverse arterial blockages and, in fact, allows blockages to gradually worsen for most patients. Such diets are no longer justified for heart patients.

Some doctors resist using more effective diets because of the mistaken idea that patients are unwilling to make more substantial changes. Recent studies have addressed this issue, as is discussed below.

Animal protein may have an effect on cholesterol levels that is independent of fat. When researchers substitute plant protein for animal protein, while holding dietary fat and cholesterol constant, serum cholesterol levels fall. Soy protein, in particular, lowers cholesterol levels, independent of the effect of fat or cholesterol.6

Animal Products VS. Plant Foods

Source

Cholesterol
(mg)

Fat
(% of calories)

Beef top round, lean, 4oz.

103

25

Pork tenderloin, lean, 4 oz.

106

26

Chicken breast, skinless, 4 oz.

97

23

Turkey breast, skinless, 4 oz.

79

18

Halibut, 4 oz.

47

19

Chinook Salmon, 4 oz.

96

52

 

Baked beans

0

4

Cauliflower

0

6

Lentils

0

3

Rice

0

2

Potato

0

1

Spaghetti noodles

0

4

Spinach

0

9

Sweet potato

0

1

Source: Pennington JAT. Bowes and Church’s Food Values of Portions Commonly Used. 16th Edition, Philadelphia, J.B. Lippincott, 1994.


* The name saturated fat comes from the fact that all of the binding sites on the carbon chain are covered with hydrogen atoms. Monounsaturated fats have one double bond, and polyunsaturated fats have two or more. Saturated fats stimulate the liver to make more cholesterol, while unsaturated fats do not.


How Much is Saturated Fat?

Figures show, of the fat in each product, how much is saturated:

Animal Fats:

Vegetable Oils:

Beef tallow

50%

Canola oil

7%

Chicken fat

30%

Corn oil

13%

Pork fat (lard)

39%

Cottonseed oil

26%

Turkey fat

30%

Olive oil

13%

 

Peanut oil

17%

Tropical Oils:

Safflower oil

9%

Coconut oil

87%

Sesame oil

14%

Palm oil

49%

Soybean oil

15%

Palm kernel oil

82%

Sunflower oil

10%

Source: Pennington JAT. Bowes and Church’s Food Values of Portions Commonly Used. 16th Edition, Philadelphia, J.B. Lippincott, 1994.

Soluble Fiber

Many plant products are rich in soluble fiber which has special cholesterol-lowering properties. The liver converts cholesterol into bile and sends it down the bile ducts and into the intestine. There, fiber carries it away along with the digestive contents.7 In order to replace these lost bile acids, the liver pulls cholesterol from the blood to make new bile acids. The result is lower cholesterol levels. If there is insufficient fiber in the diet, however, the bile acids moving along the intestinal tract can be broken back down into cholesterol and reabsorbed into the blood. Fiber may also block some of the absorption of fat from the digestive tract and reduce cholesterol synthesis in the liver.8,9

Although soluble fiber is a well-known part of oat bran, it is also found in many other foods, particularly beans, vegetables, and fruits. As little as four ounces of beans daily has been shown to lower cholesterol and triglyceride levels more than 10 percent in just three weeks.9 Chick peas, canned beans, and other whole beans and bean extracts, such as guar gum (a bean extract often used in commercial food products) are all effective.9-14 Fruits, particularly apples and citrus fruits, are rich in pectins, a form of soluble fiber which has been shown to reduce cholesterol levels.15,16 Barley, which is commonly used in soups, also contains soluble fiber and effectively reduces cholesterol levels.

The Effect of Exercise

Regular exercise, such as walking, leads to a substantial reduction in heart disease risk, compared to a sedentary lifestyle, and the more physical activity patients engage in (within the limits of their cardiovascular capacity), the greater benefit they achieve.17,18 A simple starting regimen is a half-hour walk each day or a one hour walk three times per week.

Patients should be reminded, however, that exercise alone cannot undo the effects of a fatty diet. As noted above, soldiers in peak form have been found to have atherosclerosis.19 Physical activity adds to the benefits of a healthful lifestyle, but does not replace it.

The Effect of Stress

Stress can contribute to heart disease.20,21  Stress management can involve meditation, yoga, or breathing exercises, as well as adjustments in work habits. Stress in the workplace usually results from a combination of high demands and little worker control over the workload. Reducing stress means keeping challenges within manageable limits.

For Patients with Heart Disease

  1. Be sure patients understand all their options, including the benefits of lifestyle modification.
  1. An optimal diet and lifestyle program includes all of the following elements:
    1. A low-fat, vegetarian diet
    2. A half-hour brisk walk each day or one hour three times per week
    3. Smoking cessation
    4. Stress management exercise
  1. The physician and the patient’s family should remain involved with the program and should follow the same healthful lifestyle as the heart patients.
  1. Be sure that patients include a source of vitamin B12 in their routine, such as any common daily multiple vitamin.

Helping Patients Adapt to a Healthier Diet

Research studies have shown that heart patients are often motivated to make significant changes in their diets, and they appreciate clinicians who help them do so. A review of clinical trials using low-fat and vegetarian diets for heart patients showed that the following factors help patients achieve dietary goals.22,23

  • Involving other family members
  • Close monitoring (e.g., weekly visits with the dietitian)
  • Use of stricter, more effective diet
  • Group support
  • Providing food for patients to try

An easy way to incorporate all these elements is to refer the patient to a dietitian or cooking instructor for a short series of weekly cooking classes. The spouse or partner should attend as well, and the experience is often a very memorable one for all involved.

It helps to focus on the short term. Rather than make a long-term commitment to a diet change, the patient simply needs to follow the diet for eight weeks or so, by which time the effect on serum lipids will be evident. At that point, the motivation to continue is usually much stronger than at the outset. A short-term focus improves compliance, without compromising dietary goals.

Preventing and Reversing Heart Disease Study Questions

  1. How will a plant-based diet achieve reductions in dietary fat and cholesterol intake? Why is this important?
  2. What is the importance of the results of the study by Dr. Dean Ornish?
  3. What results have been found with patients using the National Cholesterol Education Program’s Step II Diet? What type of diet would be more effective?
  4. What role does fiber play in reducing cholesterol levels? What are some good sources of soluble fiber?
  5. What steps can your patients take to change to a healthier lifestyle?
  6. When addressing a patient with heart disease, how will you approach the subject of diet and the role of a plant-based diet in decreasing the risk for heart disease?
  7. What kinds of resistance will patients have towards changing their diets?

References
1. Enos WF, Holmes RH, Beyer J. Coronary disease among United States soldiers killed in action in Korea. JAMA 1953;152:1090-3.
2. Enos WF, Beyer J, Holmes RH. Pathogenesis of coronary disease in American soldiers killed in Korea. JAMA 1955;158:912-4.
3. Castelli WP. Epidemiology of coronary heart disease. Am J Med 1984;76:4-12.
4. Ornish D, Brown SE, Scherwitz LW, et al. Can lifestyle changes reverse coronary heart disease? Lancet 1990;336:129-33.
5. Hunninghake DB, Stein EA, Dujovne CA. The efficacy of intensive dietary therapy alone or combined with lovastatin in outpatients with hypercholesterolemia. N Engl J Med 1993;328:1213-9.
6. Anderson JW, Johnstone BM, Cook-Newell ME. Meta-analysis of the effects of soy protein intake on serum lipids. N Engl J Med 1995;333:276-82.
7. Kesaniemi YA, Tarpila S, Miettinen RA. Low vs high dietary fiber and serum, biliary, and fecal lipids in middle-aged men. Am J Clin Nutr 1990;51:1007-12.
8. Anderson JW. Dietary fiber, lipids, and atherosclerosis. Am J Cardiol 1987;60:17G-22G.
9. Anderson JW, Gustafson NJ, Spencer DB, Tietyen J, Bryant CA. Serum lipid response of hypercholesterolemic men to single and divided doses of canned beans. Am J Clin Nutr 1990;51:1013-9.
10. Mathur KS, Khan MA, Sharma RD. Hypocholesterolemic effect of Bengal gram: a long-term study in man. Br Med J 1968;1:30-1.
11. Grande F, Anderson JT, Keys A. Effect of carbohydrates of leguminous seeds, wheat and potatoes on serum cholesterol concentration in man. J Nutr 1965;86:313-7.
12. Bingwen L, Zhaofeny W, Wahshen L, Rongjue Z. Effects of bean meal on serum cholesterol and triglycerides. Chin Med J 1981;94:455-8.
13. Hellendoorn EW. Beneficial physiologic action of beans. J Am Dietetic Asso 1976;69:248-53.
14. Jenkins DJA, Wolever TMS, Kalmusky J, et al. Low-glycemic index diet in hyperlipidemia: use of traditional starchy foods. Am J Clin Nutr 1987;46:66-71.
15. Life Sciences Research Office, Federation of American Societies for Experimental Biology. Physiological effects and health consequences of dietary fiber. Washington, DC, 1987.
16. American Heart Association. Dietary guidelines for healthy Americans: a statement for physicians and health professionals by the Nutrition Committee. Arteriosclerosis 1988;8:218A-21A.
17. Leon AS, Connett J, Jacobs DR, et al. Leisure-time physical activity levels and risk of coronary heart disease and death. The multiple risk factor intervention trial. JAMA 1987;258:2388-95.
18. Blair SN, Kohl HW, Paffenbarger RS, et al. Physical fitness and all-cause mortality. JAMA 1989;262:2395-401.
19. Sibai AM, Armenian HK, Alam S. Wartime determinants of arteriographically confirmed coronary artery disease in Beirut. Am J Epidemiology 1989;130:623-31.
20. Rozanski A, Bairey CN, Krantz DS, et al. Mental stress and the induction of silent myocardial ischemia in patients with coronary artery disease. N Engl J Med 1988;318:1005-12.
21. Schnall PL, Pieper C, Schwartz JE, et al. The relationship between ‘job strain,’ workplace diastolic blood pressure, and left ventricular mass index. JAMA 1990;263:1929-35.
22. Barnard ND, Scherwitz LW, Ornish D. Adherence and acceptability of a low-fat, vegetarian diet among patients with cardiac disease. J Cardiopulmonary Rehabil 1992;12:423-31.
23. Barnard ND, Akhtar A, Nicholson A. Factors that facilitate compliance to lower fat intake. Arch Fam Med 1995;4:153-8.



 

Table of Contents

Study questions included at the end of each section

Introduction

Section One:
Preventing and Reversing Heart Disease

Section Two:
Cancer Prevention

Section Three:
Cancer Survival

Section Four:
Diabetes

Section Five:
Foods and Blood Pressure

Section Six:
Nutrition and Renal Disease

Section Seven:
Preventing and Reversing Osteoporosis

Section Eight:
Nutrition and Arthritis

 
This site does not provide medical or legal advice. This Web site is for informational purposes only.
Full Disclaimer | Privacy Policy

Physicians Committee for Responsible Medicine
5100 Wisconsin Ave., N.W., Ste.400, Washington DC, 20016
Phone: 202-686-2210     Email: pcrm@pcrm.org