WHAT IS HEART DISEASE? Acquired heart disease in western cultures involves progressive narrowing in the blood vessels supplying blood to the major organs such as the heart. The narrowing is caused by slow, persistent build-up of cholesterol, fat, inflammatory cells and smooth muscle. This process, termed atherosclerosis, causes abrupt closure of these blood vessels by blood clots (leading to heart attack, stroke) and chronic narrowing of blood vessels (leading to progressive dementia, kidney disease and angina). Recently, inflammation in the inside of the blood vessel has been recognized as an important mediator of this process. That is, the more “irritable” the inside of the blood vessel, the more atherosclerosis moves forward and the more likely an abrupt closure could occur. While smoking is by far the most important factor, “bad” cholesterol, saturated fat, trans-fat, obesity and diabetes also increase the irritability of the blood vessel wall.
WHAT IS THE MOST IMPORTANT NUTRITIONAL FACTOR IN HEART DISEASE? The single most important issue in American nutrition is weight control. Maintaining an ideal body weight cannot be underestimated. Excess weight and body fat…
1. Cause hypertension (high blood pressure).
2. Predispose to diabetes.
3. Elevate cholesterol.
4. Increase cardiac workload – chronic overworking of heart.
5. Increase likelihood of sleep apnea (low oxygen at night).
6. Stress the joints and impair mobility, which enhances the obesity spiral (less movement leads to less calorie burning, which leads to more fat).
The solution? One’s total intake of calories should not exceed the daily expenditure of calories, which includes the basal metabolic rate (calories burned at rest simply maintaining the normal body functions) plus the calories burned with movement of the body (exercise). Basal metabolic rate is higher in lean individuals as muscle burns more calories than fat. More muscle means higher metabolism. There are two ways to decrease calorie intake. Eat less overall and eat less high-calorie food. It is important to note that many “low-fat” foods have more calories than their regular counterparts. Plus, many have higher sugar content. This is a critical issue. Sugary high-carbohydrate foods that are easily digested have a high glycemic index. Low-fat foods such as bread, bagels, cereals, pasta and potatoes result in quick absorption from the gut (high glycemic index) and a subsequent immediate rise in insulin levels. Insulin, a hormone released from the pancreas, is required to maintain adequate blood sugar. However, high insulin levels induced by ingestion of these simple carbohydrates cause significant deleterious effects. First, insulin causes immediate lowering of blood sugar, resulting in the “sugar low” 2-3 hours after ingesting simple carbohydrates, thereby, stimulating the need for more food intake. Second, insulin promotes fat storage. This is why high sugar intake results in fat weight gain. Third, high insulin levels are atherogenic. That is, insulin promotes hardening and thickening of the blood vessel wall. The take-home message is that high-sugar, easily digested, high-glycemic foods, which cause elevated insulin levels, predispose to cardiovascular disease and should be limited. Low glycemic index carbohydrates, such as vegetables, whole grains, lentils and legumes are absorbed slowly and do not cause spiking insulin levels.
SHOULD WE AVOID FRUITS BECAUSE THEY ARE HIGH GLYCEMIC CARBOHYDRATES? No. Fruits are natural (not-processed) and full of important nutrients such as vitamins and minerals. Active individuals need carbohydrates for energy. A balanced diet, including mostly slow-absorbing, “quality” carbohydrates with small doses of fast-absorbing carbohydrates, mostly in the form of fruits, is ideal. More fruit, less white bread and pasta!
WHAT’S THE STORY ON FATTY FOODS? Saturated fats, such as animal and dairy, are clearly associated with blood vessel hardening and narrowing. More recently, an even bigger health problem has surfaced in the trans-fatty acids. These are probably more dangerous than the saturated fats. Formed through a process called hydrogenation, trans-fats do not occur in nature, and thus, are foreign to the body. When the body has to process foreign material inflammation occurs. All “hydrogenated” oils and fats, including margarine, are detrimental to the body, probably through this inflammatory mechanism. Remember, inflammation plays a significant role in atherogenesis (blood vessel disease). Hydrogenated fats are the backbone of the processed food industry. Nearly all snack-foods contain hydrogenated or trans-fatty acids. Most cooking oils other than virgin olive oil are hydrogenated. While it has been a gradual process in mainstream medicine, it is now recognized that consumption of “good” fats is highly beneficial. Good fats are termed mono- and poly-unsaturated fats. Good fats contain essential fatty acids such as omega-3 and linoleic acid and are found in legumes, seeds, nuts and the oily fishes (salmon, tuna, etc.). These good fats are important for cell structure, energy, insulin control and satiety. They likely have a protective effect on the blood vessel wall, thereby lessening the chance of cardiac events.
WHAT ABOUT PROTEIN INTAKE AND THE ATKINS DIET? While the real scientific answer is unknown, weight loss does occur, primarily because of decreased intake of calories that accompanies the elimination of carbohydrates. Some studies have shown cholesterol levels can actually improve. The problem is that some individuals increase their intake of saturated fat and trans-fat. Protein intake is critically important, but should come from quality sources – non-animal protein such as legumes, nuts and seeds. Soy is a great source of protein and should be increased in the American diet. Animal protein intake should be high in the oily fishes and lean poultry and less in red meat. The primary benefit of the Atkins Diet is the exposure of the danger of high-glycemic-index carbohydrates.
WHAT SHOULD OUR DIETARY GOALS BE? First, good nutrition should limit inflammation. Foods high in good fat should be increased, and processed foods should be eliminated. Second, high-glycemic, simple carbohydrates that cause spiking insulin levels should be decreased. Less insulin means less fat and less heart disease. For most Americans this step will likely be the most challenging, as it means curtailing our staples – pasta, bagels, white bread, ice cream, donuts and, say it isn’t so, the beloved French fry. Third, our diet should include enough fruits and vegetables for adequate vitamin and mineral intake. Eliminating processed foods and decreasing high-glycemic carbohydrates will allow room in the diet for more fruits and vegetables without increasing daily calorie intake. Finally, for most, eating less is paramount. This is applicable to more than 90 percent of us. Even the physically fit can get by with fewer calories. It is likely that lower calorie intake slows the aging process and promotes longevity. Here’s the best part. Good nutrition is not just about longer life. It’s also about feeling better. Good nutrition promotes an improved energy level, improved sleep and better training and racing. So, eat right … at least most of the time!
John Mandrola, M.D., is a cardiac electrophysiologist (doctor who treats heart rhythm disorders). He is in private practice with Cardiovascular Associates. He is active in masters swimming, cycling, running and when time permits, an occasional triathlon. John is a member of Kentuckiana HealthFitness Magazine’s Editorial Advisory Board.
Nutrition Strategies for Keeping Your Heart Healthy By Barbara Day, M.S., R.D., C.N.
v Add at least 25 grams of soy per day to your diet.
v Eat plant-sterol enriched margarine such as Take Control® or Benecol® if you have high blood cholesterol.
v Limit the amount of trans-fatty acids.
v Eat 20-25 grams of dietary fiber per day. At least 10 grams should be from functional (soluble) fiber such as oats, legumes and the fleshy portion of apples, pears, citrus fruits and bananas. A good source of dietary fiber should contain 3-5 grams per serving. Read food labels for fiber content.
v Limit foods high in saturated fat and/or cholesterol such as full-fat milk, fatty meats, tropical oils, partially hydrogenated vegetable oils and egg yolks. Choose foods with 2 grams or less of saturated fat per serving. Foods high in saturated fat are meats, butter, dairy products and desserts. Read food label for saturated fat content.
v Eat at least two servings of fish per week. Increase the consumption of omega-3 fatty acids found in fish oil or plant sources such as soybeans or canola oil and flaxseed.
v Eat a variety of fruits and vegetables. Choose five or more servings per day. The more colorful the fruit or vegetable, the more nutrients it has.
v Consume adequate amounts of folic acid and Vitamin B6 daily.
