Nutritional Advice for the Patient With Heart Disease
What Diet Should We Recommend for Our Patients?
Cardiovascular disease is the number one cause of death in the United States (the Table).1 The question stated in the title of this patient page is one of the most commonly asked queries by patients with cardiovascular disease in the offices of primary care physicians and cardiologists. Similarly, residents often ask, “What diet should we order for our inpatients with atherosclerosis?” Clearly, the American public believes that we are what we eat. It is not surprising that in our society, with its abundant supply of inexpensive, high-calorie food, this is a subject of consummate interest.
There can be little doubt that the Western diet is closely tied to the development of atherosclerosis. The mechanisms leading to atherosclerosis, or hardening of the arteries, involve, among other factors, elevated blood lipid (fat) values that, in part, reflect both the quantity and quality of fat in an individual's diet. Large amounts of saturated fat in the diet, combined with obesity, predict elevated blood lipids and a high chance of developing atherosclerotic vascular disease, which leads to heart attacks and strokes.
For more than 50 years, population studies and experiments in animals have supported the idea that the Western diet, rich in saturated fat, was a major factor leading to atherosclerosis, heart attacks, and stroke. When the relationship between diet and atherosclerosis was first understood, cardiologists, internists, family physicians, and dieticians recommended that all Americans, and particularly those with elevated blood lipid values or a family history of coronary heart disease at younger ages, follow a diet reduced in saturated fat and cholesterol. Later studies demonstrated that it was the degree of saturated fat more than the amount of cholesterol in the diet that led to atherosclerosis. The amount of cholesterol in the diet was shown to play only a minor role in the development of atherosclerotic arterial disease.
Debate continues to this day as to how severely saturated fat should be restricted in the diet, with recommendations ranging from moderate (20% to 30% of total calories as saturated fat) to marked restriction (5% to 10% of total calories as saturated fat) of fat intake. Because of the challenging nature of human studies involving restricted diets, it has been difficult to prove that lowering the dietary intake of saturated fat prevents heart attacks and strokes. Nevertheless, studies performed during the last 20 years involving highly effective drugs that lower blood lipid levels, for example, statins, fibrates, and high dose niacin, have convinced most physicians that decreasing levels of lipids in the blood is an effective strategy for reducing the risk of heart attack and death from vascular disease. Many carefully designed and executed randomized, double-blind, controlled trials have demonstrated that lowering of low-density lipoprotein (LDL), so-called bad cholesterol, and/or elevation of high-density lipoprotein (HDL), so-called good cholesterol, results in marked clinical benefit. Death from heart disease and nonfatal heart attacks and strokes can be significantly reduced with these lipid-lowering drugs.
Following dietary recommendations from the American Heart Association (AHA) and the federal government will promote a heart-healthy lifestyle that seeks to minimize the occurrence of atherosclerotic vascular disease. The AHA and various federal agencies suggest that drug therapy to lower cholesterol levels in the blood should be combined with dietary guidelines, such as a low intake of saturated fat. Controversy among experts continues relative to how strict a diet should be recommended by physicians for individuals with established vascular disease or who are at risk for vascular disease.
One diet often recommended is the Mediterranean diet, which was used in the Lyon Diet Heart Study.2 This study grew out of an observation termed the French paradox, in which citizens living in southern France near the Mediterranean Ocean appeared to have significantly fewer coronary heart disease deaths compared with citizens living in northern France. The Lyon Diet Heart Study compared 2 groups of matched patients with established atherosclerotic coronary heart disease. One group consumed a standard northern French diet rich in saturated animal fat. The second group ate a Mediterranean diet rich in fruits, vegetables, seafood, and olive oil. Both groups drank alcoholic beverages, usually wine; however, the consumption of wine was higher in the Mediterranean group. Interestingly, the patients following the Mediterranean diet had markedly fewer heart attacks compared with their northern French compatriots.
The second diet that has captured the attention of Americans is the so-called Atkins weight-reducing diet, named for the physician who popularized this low-carbohydrate, high-fat diet. Scientific studies have repeatedly documented that ingestion of foods containing simple carbohydrates, such as those found in white flour, white rice, sugar, pasta, and potatoe,s leads to a rapid rise in blood sugar, which results in vigorous insulin secretion from the pancreas and into the bloodstream. This insulin wave causes blood sugar levels to fall quickly, and this stimulates an individual's appetite, resulting in increased food consumption.3 Clinical studies performed over the last 30 years have demonstrated that a diet low in carbohydrates and high in fat and protein produces a chemical state in the blood called ketosis, and this state suppresses appetite in those individuals who follow a low-carbohydrate/high–fat and protein dietary regime. It has been proven that the low-carbohydrate/high–fat and protein diet is effective in some individuals, leading to impressive weight loss. However, other studies suggest that the high fat content of the Atkins diet can lead to increased levels of blood lipids, which might be harmful to blood vessels. However, individuals who lose weight on the Atkins diet eventually do lower their blood lipid levels.4
A third diet often used by patients with atherosclerotic heart disease is the well-established AHA restricted saturated fat diet, in which patients restrict the amount of saturated fat in their diet but continue to eat moderate amounts of carbohydrates and other fats, such as monounsaturated oils (an example is olive oil) and polyunsaturated fats (an example is canola oil). This diet is featured in the AHA cookbooks, which are available from the AHA on their Web site at http://www.heart.org. The AHA diets emphasize seafood and vegetarian sources of protein alongside portion and hence calorie control. These diets also advocate that individuals include multiple portions of fruits and vegetables in their daily food consumption.
It is sad that obesity is epidemic in the United States5 and Europe.6 Citizens on both continents generally enjoy remarkable prosperity with an overabundance of relatively high-calorie high-fat food. The fat in many of these products is saturated fat, often animal fat, such as lard. The level of obesity in the United States has reached staggering proportions, particularly in areas where inexpensive high-fat fast foods have become a major component of the diet. Physicians, public health authorities, and the media have focused a great deal of attention on the percentage of the American population that is obese. Not surprisingly, many obese Americans have tried to stick to the Atkins diet, unfortunately, with varying degrees of long-term success and with variable effects on their blood lipids.
Given this background information, what do I personally tell patients with clinical atherosclerosis or individuals who are at risk for developing atherosclerosis about the best diet for them? In addition, what diet do I follow myself? To friends, colleagues, and patients, I first tell them about the experience of the Lyon Diet Heart Study, and I continue with a short discourse on the ability of the low-carbohydrate diet to suppress appetite. If these individuals have high low-density lipoprotein cholesterol levels in their blood or are trying to lose weight (or both), I suggest that they try to eat a diet that I call either the American Heart Association version of the Atkins diet or the Mediterranean Atkins diet. It is the diet that I try to follow myself. The major precepts of this diet are as follows7:
Markedly decrease the volume of simple carbohydrates (foods containing white flour such as bread, as well as white rice, pasta, sugar, and potatoes) in the diet. If weight reduction is not required, modest intake of simple carbohydrates is allowed, but individuals should attempt to eat complex carbohydrates (see No. 2 below) in place of the simple ones.
Try to eat foods containing complex carbohydrates, such as beans, whole-grain foods, and nuts. These foods raise blood sugar more slowly than those with simple carbohydrates, thereby moderating pancreatic insulin secretion.
Decrease or eliminate the intake of foods containing animal fats (beef, lamb, and pork) in the diet, emphasizing lean cuts if you must eat red meat. Prepare these animal products by broiling or baking. Do not fry them. Some special cuts of pork can be quite lean.
Use liberal quantities of olive oil or peanut oil in the diet. These oils are monounsaturated and seem to have a particular beneficial effect on blood lipid levels. Polyunsaturated oils such as canola oil are second best. Strenuously avoid hydrogenated or partially hydrogenated (so-called trans fatty acids). These fats are often labeled as partially hydrogenated vegetable oils, although they are solid at room temperature. These latter fats are commonly found in commercially available baked goods and margarines.
Eat liberal quantities of fruits and vegetables each day. Most nutritional experts recommend 6 to 9 servings of fruits and/or vegetables daily.
Use seafood as the main source of protein in the diet. Particularly useful are oily fish from northern oceans, for example salmon, mackerel, tuna, sardines, anchovies, and Alaskan halibut. Other seafood is also an excellent dietary choice and should be preferred over red and white meat. White meat from chicken and turkey is preferred over red meat (beef, lamb, and pork) and the dark meat of chicken and turkey. Shellfish contain a cholesterol-like substance, but this is not really something to worry about, because dietary cholesterol is not the major determinant of blood cholesterol. Rather, the amount of saturated animal fat in the diet is a major factor in raising bad low-density lipoprotein cholesterol levels in the blood.
Bean curd products such as tofu are highly recommended sources of protein and complex carbohydrate.
Ingest only modest quantities of foods containing sugar or corn syrup, because this can lead to rapid rises in blood sugar with a resultant vigorous pancreatic insulin response resulting in appetite stimulation.
Try to be as much of a pescetarian/vegetarian as possible.
Finally, I am a firm advocate for daily exercise.8 This has definitely been proven to improve cardiovascular health. Individuals should exercise for 40 or more minutes per day. Aerobic exercise such as walking, jogging, swimming, rowing, etc. are ideal. Some weight training is also a good idea and can be performed two to three times per week for approximately 30 minutes. If you are not someone who exercises habitually, it would be prudent to consult a physician and a trainer before initiating an exercise program.
These 10 simple dietary and lifestyle tenets reflect sound practical advice based on knowledge available today.
Dr Alpert has consulted for Elsevier Publications Inc, Sanofi-aventis, Merck, Bristol-Myers-Squibb, Pfizer, Astra-Zeneca, McNeill, Organon, Berlex, Novartis, Ciba-Geigy, Servier, Boehringer-Ingleheim, Bayer, Johnson & Johnson, Exeter Continuing Medical Education; North American Center for Continuing Medical Education, and the FRANCE Foundation.
- © 2011 American Heart Association, Inc.
American Heart Association Statistics Committee and Stroke Statistics Subcommittee: Heart disease and stroke statistics: 2008 update. Circulation.2008;117:e25–e146.
- deLorgeril M,
- Salen P,
- Martin JL,
- Monjaud I,
- Delaye J,
- Mamelle N
- Alfenas RC,
- Mattes RD