Is a vegetarian diet good for heart health?
A vegetarian diet is mostly based on plant foods: grains, vegetables, fruits, legumes, seeds, and nuts, but eggs and dairy products may also be included (lacto-ovo-vegetarianism). Epidemiologic studies have consistently found a decreased risk for coronary heart disease among lacto-ovo-vegetarian Seventh Day Adventists.31 Despite more favourable lipid profiles in vegetarians, a recent study showed no difference in fat intake between vegetarians and non-vegetarians.32 Higher intakes of other nutrients, such as fibre and antioxidant nutrients could explain the reduced risk of cardiovascular disease.33 Besides diet, this may also be related to lifestyle factors, such as maintaining a healthy weight, regular physical activity, and abstinence from smoking and alcohol.33 A heart-healthy lifestyle, rather than diet alone, helps explain why vegetarians have a lowered heart disease risk compared to non-vegetarians. Positive dietary aspects of a vegetarian lifestyle, such as eating plenty of fibre and antioxidant-rich foods, along with other important lifestyle components, such as regular physical activity, are important to help prevent heart disease.
How can I adopt a more Mediterranean style of eating?
To adopt a Mediterranean foodstyle: Emphasize whole-grain products, fresh vegetables, fruits, and legumes. Choose meat less often, with more frequent use of meat substitutes like cheese, fish, poultry, and eggs. Use a good quality monounsaturated oil (e.g. olive or canola) as the preferred fat, instead of butter, ghee or shortenings. Achieve and maintain a healthy body weight by remaining physically active. Give yourself plenty of time to prepare and enjoy meals.
How can I improve my diet in order to lower my risk of heart disease?
Rather than limit nutrient-dense foods, such as eggs, meat, and cheese from your diet, registered dietitians suggest that it is more important to reduce your saturated and trans fats intake. Below are some suggestions: Eat more grain products, vegetables and fruits. Cut down on fried foods and use a non-stick fry pan. Trim or drain fat from meat and remove the skin from chicken and turkey. Limit fatty luncheon meats, bacon, and sausages. Use less butter, margarine, spreads, and salad dressings. Select lower fat milk and milk products (less than 2%) more often. Exercise more. Achieve and maintain a healthy body weight.
What is the French Paradox and its relevance to heart disease?
High fat diets are usually associated with increased risk of coronary heart disease (CHD). However, epidemiological evidence shows that the mortality rate from CHD is lower in France than expected, based on saturated fat intake and serum cholesterol levels of the French.27 This "French Paradox" cannot be explained by differences in other risk factors, although it has been linked to the regular consumption of red wine.28, 29 Moderate alcohol consumption has been shown to protect from CHD.30 Phenolic compounds found in red wine could explain this protection since they have been found in in-vitro studies to inhibit oxidation of LDL-cholesterol, rendering it less atherogenic, and to lower platelet aggregability.27 The protective effect of wine may be prolonged if consumed during meals since it is then absorbed more slowly.28 A moderate intake (1-2 glasses per day) of red wine, preferably during meals, can be beneficial as one strategy to help protect against heart disease.
What are antioxidants and how do they decrease my risk of heart disease?
Antioxidants are chemical substances that help trap and prevent oxidative damage to cells and the formation of free radicals. When present in excess, various substances, including free radicals can inactivate enzymes, damage DNA (the genetic makeup of cells) and oxidize lipids. Aging, cancer, arthritis, heart disease, cataracts and colitis have all been linked with oxidative damage.14 The vitamins C, E and beta-carotene (the plant form of vitamin A) are called antioxidants because they help make free radicals harmless and prevent oxidation of low-density lipoproteins. The oxidation of LDL's can cause fatty streaks to be deposited in arteries, which could be the beginning of atherosclerosis.14 Increased intakes of antioxidant nutrients has been found to protect against heart disease.14, 15, 16 Vitamin E, taken for 2 years in supplement form (100 IU/day), has been found to have beneficial effect on reducing risk or coronary heart disease in men and women.17, 18 Most of the beneficial effects of antioxidant nutrients, for example vitamin C and beta-carotene, come from eating combinations of foods, such as dark green or orange vegetables, and dark orange fruits. These foods also contain phytochemicals and non-nutritive substances, such as indoles, phenols, flavones, and isothiocyanthes, which help protect against heart disease. To get vitamin E in your diet, choose margarine and vegetable oils in moderation, whole grain cereals, wheat germ, nuts, and seeds.
What role does vitamin E play in protecting against heart disease?
Oxidation of low-density lipoproteins (LDL) is involved in the development and progression of atherosclerosis.19 Vitamin E is a potent antioxidant shown to protect LDLs from oxidative damage.19 Recent results from large clinical intervention trials confirm a potentially important role of vitamin E supplementation in heart disease prevention. The Alpha Tocopherol Beta-Carotene Cancer Prevention Study (ATBC), a double-blind placebo controlled primary prevention study involving 29,133 male smokers, showed that supplementation with 50 mg/day of vitamin E was associated with a minor decrease in the incidence of angina pectoris.20 Another randomized double-blind trial, the Cambridge Heart Antioxidant Study (CHAOS), found that treatment with a large dose (268-537 mg) of vitamin E of patients with established coronary heart disease (CHD), reduced the rate of non-fatal myocardial infarction by 77%, with beneficial effects apparent after 200 days of treatment.21 On the basis of these results, it appears that vitamin E may be an important component of secondary prevention of CHD. To increase your intake of vitamin E, choose foods, such as vegetable oils, almonds, whole grain cereals, sweet potatoes, peaches, and eggs. Your physician or a registered dietitian can determine if you need additional vitamin E in the form of a supplement.
How does the Mediterranean diet protect against heart disease?
In the early 1960's, mortality rates from CHD in Greek men were one seventh those of Americans of the same age.23 This was confirmed in the Seven Countries study.22, 23 More recently a secondary prevention intervention trial comparing the effect of a Mediterranean-inspired diet to the usual post-infarct prudent diet resulted in a markedly reduced rate of recurrence of myocardial infarction, other cardiac events and overall mortality.24 Protective effects of the traditional Mediterranean diet may be related to its high proportion of MUFAs (e.g. mainly from olive oil), found to lower low-density lipoprotein (LDL)25, which tend to make LDLs more resistant to oxidation26 and decrease platelet aggregation.25 Health benefits could also be explained by the abundant supply of antioxidant nutrients, in particular beta-carotene, vitamin C, and vitamin E, which are associated with a reduced risk of chronic disease.25 Other diet-related factors and physical activity may also explain the higher adult life expectancy and lower chronic disease rates found in specific Mediterranean areas in the early 1960's. People in these regions were generally much more active and leaner than we are in Canada today. Other lifestyle factors may also have contributed to the health enhancing effect of the traditional Mediterranean diet, such as the enjoyment and relaxation associated with the careful preparation and leisurely consumption of meals. This slower style of food preparation and enjoyment of food provide relief from stress, a factor associated with increased cardiovascular morbidity.
How useful are egg substitutes?
Egg substitutes are marketed as a "low-fat, yolk-replaced egg" product and promoted as a healthy alternative to eggs. Egg substitutes are made with egg whites, and contain significant amounts of protein, little fat and no cholesterol34, making them potentially attractive to those who must reduce their serum cholesterol level. On the other hand, the addition of several additives and the high cost (almost triple the cost of fresh shell eggs) tend to limit their appeal. Eggs are a nutritious and economical source of high-quality protein, and can thus be included in a cholesterol-lowering program, in accordance with the prescribed amount. Egg whites can be substituted for whole eggs in most egg-based recipes (1 or 2 egg whites for a whole egg). A natural egg substitute (see below) can also be used to replace 2 or 3 eggs in most recipes. Commercial egg substitutes may therefore be useful only for those with high blood cholesterol who are not responding to the prescribed low-fat diet and who choose to pay the added cost for convenience. Natural Egg Substitute Recipe for Patients with High Serum Cholesterol 3 egg whites 3 ¼ cup skim milk 50 mL 1 tbsp skim milk powder 15 mL 1 tsp vegetable oil 5 mL Pinch turmeric Beat egg whites lightly with a fork. Stir in milk, milk powder, oil, and turmeric, beating until well blended. Makes about 6 tbsp / 90 mL. Can be used to replace 2 or 3 eggs in most recipes. Keep in airtight container in the refrigerator for a maximum of 4 days.
I've heard that eating more fish can help decrease my risk of heart disease. How is this so?
A moderate intake of omega-3 fatty acids, found in fish, can provide some protection against cardiovascular disease.12 A controlled study of men who had recently recovered from myocardial infarction found that fish with a high omega-3 content reduced mortality rather than incidence of heart disease.13 Likely mechanisms include a reduction in blood clotting, prevention of arrhythmia and protection of the ischemic myocardium against infarction. Consumption of two to three servings per week of omega-3-rich fish, such as mackerel, herring and salmon are recommended as part of a healthy balanced diet. Lean white fish, such as cod and flounder contain only small amounts of omega-3 fatty acids. If you don't like fish, try omega-3 enriched eggs sold in many of the larger grocery stores.
What is the Mediterranean diet and its relationship to coronary heart disease?
Mortality rates from coronary heart disease (CHD) in the early 1960's were reported to be low in Mediterranean populations. Besides genetic influences, the so-called Mediterranean diet was one of the most important lifestyle factors implicated in these statistics. The "Mediterranean diet" refers to dietary patterns found in olive-growing areas of the Mediterranean region, particularly Greece and Southern Italy, about 30 years ago.22 The traditional Mediterranean diet included whole wheat products, legumes, an abundance of home-grown vegetables, seasonal fruits, milk and milk products. Consumption of meat and fish was limited and the major source of calories was provided by home-baked, whole-wheat bread, olives and olive oil.23 This diet was rich in fibre and antioxidant nutrients, low in saturated fat, with total fat ranging from less than 25% to nearly 40% of energy depending on the region.22 Most of the fat consumed was in the form of monounsaturated fatty acids (MUFAs) mainly from olive oil.