Healthy and Fit   

General Guidelines

The goals of a heart-healthy diet are to eats foods that help obtain or maintain healthy cholesterol and lipid levels: to reduce overall levels and low-density lipoproteins (LDL) and to increase high-density lipoproteins (HDL). Reducing other lipids, such as triglycerides and lipoprotein(a) (lp(a)) are also important. Any diet should also help keep blood pressure under control.

Fats and Oils

General Recommendations for Fat Intake. About two-thirds of cholesterol in the body does not come from cholesterol in food but is manufactured by the liver, its production stimulated by saturated fat (mostly found in animal products). The dietary key to managing cholesterol, then, lies in understanding fats and oils. When it comes to studying the effects of fat on the body, however, the problem is compounded by its complex nature. All fats found in foods are made up of chains of molecules composed of carbon and glycerol called fatty acids. Fats and oils are composed of three major chains: are monounsaturated, polyunsaturated, and saturated fatty acids. Taken together, they are called a triglyceride. Monounsaturated and polyunsaturated fatty acids are found in plant products and saturated fatty acids are found in animal products and some tropical oils. The oils and fats that people and animals eat are nearly always mixtures of all three fatty acids, but one type usually predominates. In addition, there are three chemical subgroups of polyunsaturated fatty acids: omega-3, omega-6, and omega-9 fatty acids. To complicate matters, there are also trans-fatty acids. These are not natural fats but are manufactured by adding another hydrogen molecule, a process known as hydrogenation, to polyunsaturated fatty acids. These subgroups are being heavily researched for their specific effects on health. All fats, both good ones and bad, add the same calories. Although there is much controversy on the overall effects of fat on health, virtually all experts strongly advise limiting intake of saturated fats and trans-fatty acids (found in commercial baked goods and fast foods). Other fatty acids, however, may offer benefits. In order to calculate daily fat intake, multiply the number of fat grams eaten by 9 (one fat gram is equal to 9 calories, whether it's saturated or unsaturated) and divide by the number of total daily calories desired. One teaspoon of oil, butter, or other fats equals about five grams of fat.

Harmful Fats. Reducing consumption of saturated fats and trans-fatty acids is the first essential step in managing cholesterol levels through diet. Saturated fats are found predominantly in animal products, including meat and dairy products. Saturated fats in the diet increase blood cholesterol levels. The so-called tropical oils, palm, coconut, and cocoa butter, are also high in saturated fats. Evidence is lacking, however, about their effects on the heart. The countries with the highest palm-oil intake, Costa Rica and Malaysia, also have much lower heart disease rates and cholesterol levels than Western nations.

Trans-fatty acids are also dangerous for the heart, and they may pose a risk for certain cancers. They are created during a process aimed at stabilizing polyunsaturated oils to prevent them from becoming rancid and to keep them solid at room temperature. Some experts believe that these partially hydrogenated fats are even worse than saturated fats because they both increase LDL and reduce HDL cholesterol levels and may have unhealthy effects on the linings of the arteries. One study of 80,000 nurses reported that women whose total fat consumption was 46% of total caloric intake had no greater risk in general for a heart attack than did those for whom fat represented 30% of calories consumed. Women whose diets were high in trans-fatty acids, however, had a 53% increased risk for heart attack compared to those who consumed the least of those fats. Hydrogenated fats are used in stick margarine and in many fast foods and baked goods, including most commercially-produced white breads. (Liquid margarine is not hydrogenated and is recommended, as is margarine labeled "trans-fatty acid free.") The FDA has now required that food labels include information on trans-fatty acids.

Beneficial Fats and Oils. It should be noted that some fat is essential for health and fat is essential for healthy development in children. Public attention has mainly focused on the possible benefits or hazards of monounsaturated (MUFA) and polyunsaturated (PUFA) fats. Polyunsaturated fats are found in safflower, sunflower, corn, cottonseed oils, and fish, while monounsaturated fats are mostly present in olive, canola, and peanut oils and in most nuts. Studies, however, do not all agree on their effects. For example, early studies indicate that monounsaturated fats help to maintain healthy HDL levels while polyunsaturated fats reduce them. A 2000 study comparing olive oil (high in MUFA) with sunflower oil (high in PUFA) reported that olive-oil rich diets were strongly associated with lower blood pressure while sunflower diets had only a small effect. Researchers are most interested in the smaller fatty-acid building blocks contained in these oils called essential fatty acids, which may have more specific effects on lipids: three important fatty acids are omega-3, omega-6, and omega-9. Food oils often contain a combination of these building blocks, which may account for the mixed results observed in people consuming them.

Omega-3 fatty acid sources include canola oil, soybeans, flaxseed, olive oil, and many nuts and seeds. Studies have indicated that vegetable oils containing alpha-linolenic acids are heart protective. Fish oils, which contain docosahexaenoic and eicosapentaenoic acids do not have much effect on cholesterol but they may benefit the lining of blood vessel (the endothelium) and therefore improve blood flow.

Omega-6 fatty acid sources are flaxseed, corn, soybean, and canola oil. Many hydrogenated fats are made from oils rich in omega-6 fatty acids. Omega-9 fatty acid source is olive oil. The bottom line, then, is to try to obtain a better balance of fatty acids without consuming too many calories.

Fat Substitutes. Fat substitutes added to commercial foods or used in baking deliver some of the desirable qualities of fat, but do not add as many calories. Some replacers, such as the cellulose gel Avicel, Carrageenan (made from seaweed), guar gum, and gum arabic, have been used for decades in many commercial foods. New, synthetic fat substitutes are now available, but little is known about their long-term effects. Olestra (Olean) passes through the body without leaving behind any calories from fat. (It should be noted, however, that foods containing olestra still have calories from carbohydrates and proteins.) Early reports of cramps and diarrhea after eating food containing olestra have not proven to be significant. Of greater concern is the fact that even small amounts of olestra deplete the body of certain vitamins and nutrients that are important for protection against serious diseases, including cancer. The FDA requires that the missing vitamins be added back to olestra products, but not other nutrients.

A sterol called sitostanol, also called stanol, is now being used in margarines (Benecol, Take Control). Benecol is derived from pine bark and Take Control from soybeans; both are effective. Studies on stanol margarines have reported lower LDL and total cholesterol with their use, including children with inherited high cholesterol levels, although not all studies are positive. In one 1999 study, sitostanol was significantly effective in reducing cholesterol absorption, but only when it was mixed in a solution containing lecithin. Of concern is the possibility that stanol may block absorption of important fat-soluble nutrients. One study suggested that it may impair absorption of beta carotene and vitamin E but has no effect on vitamins A and D, two other fat soluble vitamins. In people already on a low-fat diet, the addition of this margarine may not add much benefit.

You should try to limit even reduced-fat foods and fat substitutes in your diet. Although one might believe that eating reduced-fat or fat substitute products means consuming fewer calories, this is often not the case. Many commercial, lowered-fat products have extra calories from sugar and other carbohydrates. A study has found that people who consume foods that contain fat substitutes do not learn to dislike fatty foods, while people who learn to cook using foods naturally lacking or low in fat eventually lose their taste for high fat diets.

Complex Carbohydrates and Fiber

Foods that are high in complex carbohydrates and fiber are as important as reducing harmful fats in maintaining a healthy diet.

Fresh Fruits and Vegetables. Regular consumption of fresh fruit and raw vegetables reduces deaths from stroke and coronary artery disease, may lower blood pressure, and may be protective against certain cancers. Substances found in them called phytochemicals have been found to be important, such as flavonoids, sterols, phenol, and sulfur-containing compounds. In addition, man foods, generally dark-colored fruits and vegetables, that contain these nutrients also provide fiber. Flavonoids, found in red wine, onions, and apples, may protect against damage done by cholesterol and prevent blood clots. Many dark colored berries (blueberries, sweet cherries, strawberries, and blackberries) are particularly potent antioxidants. Some studies have suggested that a chemical in garlic called S-allyl cysteine produces a cholesterol lowering effect, although two well-conducted recent studies found no heart-benefits from taking capsules containing garlic oil or powder equivalent to between one and one and half cloves a day. The preparation of these products, however, may be responsible for the lack of effect. Another recent study reported that heating garlic blocks its health-protective effects. By allowing crushed fresh garlic to stand 10 minutes before heating, however, S-allyl cystein and other beneficial chemicals are released and are not lost when the garlic is cooked. In any case, adding garlic to a meal is an option for those who enjoy its flavor.

Fiber: Whole Grains and Nuts. Dietary fiber is an important component in achieving a healthy cholesterol balance. One study indicated that people on a reduced-fat diet consuming 25 grams of fiber a day lowered their cholesterol by 13% compared to 9% in another group that consumed less fiber. Other studies have reported a lower risk for heart disease in both men and women who ate more fiber, particularly from grain products. Fiber also helps weight reduction and may fight cancer. Simply adding breakfast cereal regularly to a diet appears to reduce cholesterol levels.

Fiber passes through the intestines undigested. It draws water with it and is eliminated as part of feces content. Fiber can be soluble or insoluble. Fiber is found only in plants, particularly vegetables, fruits, whole grains, nuts, and legumes (beans and peas), which offer other health benefits as well. Many studies have singled out nuts, which contain omega-3 fatty acids, fiber, and other important substances as being particularly beneficial for the heart by lowering LDL and total cholesterol without increasing triglycerides. Soluble fiber (found in nuts, oat bran, beans and other legumes, barley, prunes, and various fruits and vegetables) is particularly useful for lowering cholesterol levels, possibly because it removes bile acids from the intestine. Soluble fiber also improves blood glucose levels and appears to reduce blood pressure. Oats may be a particularly beneficial source of soluble fiber. In one study, women who had six to 11 servings of whole grains a day reduced their risk of heart disease by a third. Insoluble fiber (found in rye, wheat bran, whole grains, seeds, and fruit and vegetable peels) may also reduce fat absorption and even aid in weight reduction. It is best to obtain dietary fiber, soluble or insoluble, in foods. If it proves difficult to do so, use a soluble fiber supplement. Gas and bloating often accompany a high-fiber diet; to combat them, drink at least 8 glasses of water a day and use enzymes that help digest fiber. People who increase their levels of soluble fiber should also increase water and fluid intake. BiosLife2, a natural high fiber powder, is showing promise in helping control blood glucose levels, cholesterol, and blood pressure.

Protein

Fish. A number of studies have reported that eating fish or shellfish at least once a week reduces the risk of sudden death from dangerous heart-rhythm abnormalities by more than one half. Oily fish, such as salmon, halibut, swordfish, and tuna, appear to be particularly beneficial. (Studies of people who take fish oil supplements, which contain omega-3 fatty acids, have found no similar benefits, indicating that fish contain other protective substances.) Other research indicates that eating fish reduces triglycerides and lipoprotein(a). Eating fish also appears to protect the nervous system and may reduce risks for other disorders, including rheumatoid arthritis, asthma, ulcerative colitis, and some types of cancers. At this time, most studies indicate that eating moderate amounts (one or two servings weekly) of fish offers the most benefits. Some studies found that very high amounts (five or six servings weekly) can be harmful. This risk may be due to the presence of mercury in many kinds of fish (salmon is one exception).

Soy. Soy is an excellent food. It is rich in both soluble and insoluble fiber, omega-3 fatty acids, and provides all essential proteins. Soybeans also contain natural estrogens called isoflavones, which have positive effects on lipid levels. A number of studies have indicated that subjects that consume about 40 grams of soy protein each day reduce LDL by 13%, triglycerides by 11%, and increase HDL by 2%. Four ounces of tofu equals about eight to 13 grams of soy, and a soy burger contains about 18 grams. Powdered soy protein that contains at least 60 mg of isoflavones may provide similar benefits. Tablets of individual isoflavones found in soy, however, do not appear to offer any advantages. (Note: soy sauce contains only a trace amount of soy and is very high in sodium.) Of possible concern, a high intake of soy during pregnancy may have some adverse effect on the fetus, although only animal studies have suggested this. More research is important.

Meat. The fat content of meat varies depending on the type and cut. It is best to eat skinless chicken or turkey the leanest cuts of pork (loin and tenderloin), veal, and beef are nearly comparable to chicken in calories and fat and their effect on LDL and HDL levels. It should be noted, however, that even chicken and lean meat do not improve cholesterol levels, and, in terms of cardiac health, fish is a more desirable choice.

Some sodium is essential to protect the heart, but most experts agree that most Americans consume far more than is necessary. Diets high in salt accelerate the increases in blood pressure that occur as people age. Simply eliminating table and cooking salt can be somewhat beneficial, and salt substitutes, such as Cardia, containing mixtures of potassium, sodium, and magnesium are now available. Cardia is costly, however, and because most (about 75%) of the salt in people's diets comes from processed or commercial foods, the benefits of table-salt substitutes are likely to be very modest.

Sugar adds calories and increases blood glucose levels quickly. It provides no other nutrients. One study found that sugar was a risk factor for heart disease, possibly because sugar fuels obesity, which boosts very low density lipoproteins and triglycerides that are dangerous for the heart. Artificial sweeteners include saccharin, aspartame (Nutra-Sweet), and acesulfame K (Sweet One). Sucralose (Splenda), a new sweetener, may also prove to be a good alternative to sugar.

Dietary Cholesterol

The story on cholesterol found in the diet is not entirely straightforward. Cholesterol is found only in animal tissues, with high amounts occurring in meat, dairy products, egg yolks, and shellfish. American Heart Association recommends no more than 300 mg of cholesterol per day. One study estimated, however, that reducing dietary cholesterol intake by 100 mg/day would only produce a 1% decrease in cholesterol levels. Avoiding foods high in cholesterol will also not make much of a dent in high LDL levels. Eggs are also a good source of protein, are rich in very beneficial nutrients, and low in saturated fat. One study of people who ate eggs regularly indicated that certain people with high cholesterol experienced lower LDL levels and even a modest increase in HDL; people with high triglycerides appeared to fare badly. A 1998 study on rabbits suggested, however, that when cholesterol contained in food is heated, it becomes oxidized and accelerates atherosclerosis. Of note, one study indicates that although dietary cholesterol itself does not appear to increase the risk for heart disease in most people, people with diabetes, especially type 2, may be an exception. Until more research is done, they should consider avoiding eating eggs or other high-cholesterol foods (such as shrimp) more often than once a week.

Vitamins and Supplements

Antioxidant Vitamins and Supplements. Currently, many researchers are studying vitamins C, E, and A and beta carotene and other nutrients for their role as antioxidants, which are scavengers of particles known as oxygen-free radicals. These unstable particles are by-products of many of the body's normal chemical processes and are increased by smoking, environmental toxins, and stress. They can damage cell membranes and interact with genetic material, contributing to the development of a number of disorders including cancer and heart disease.

Evidence for heart-protective benefits from vitamin E are stronger than other antioxidants. Although not all studies on vitamin E are positive, some experts believe that most are promising enough to recommend daily vitamin E supplements (400 to 80 IU) in patients with coronary artery disease. For example, laboratory studies have indicated that vitamin E has properties that inhibit blood clots and the formation of fatty plaques and cell proliferation on the walls of the arteries. Some studies have suggested that vitamin E may protect against ischemic stroke (caused by blocked arteries) and an animal study reported that high levels of vitamin E in the diet reduced the amount of brain tissue injured by a stroke. The evidence for heart protection from vitamin C is weaker. In two major studies that demonstrated some benefit from vitamin E, vitamin C was not protective. Vitamin C may help maintain blood vessel flexibility and so have benefits on blood pressure. One study found some benefits against stroke but not heart disease.

Of concern, however, are studies reporting that antioxidant supplements may actually be harmful in people with existing diseases, particularly cancer, since the same properties that protect healthy cells also may protect cancerous ones. In fact, there is some evidence that in high doses, vitamin C, vitamin E, and beta carotene have pro-oxidant effects that can be harmful. Beta carotene and vitamin A supplements in particularly have no benefits for heart disease, and, in fact, a number of studies are reporting a higher incidence in lung cancer in smokers in those who take them.

Everyone should eat plenty of dark colored fresh fruits and vegetables, which contain teams of these and other antioxidant vitamins and nutrients.

B Vitamins. Niacin (Vitamin B3) is currently prescribed for lowering both LDL-cholesterol and triglyceride levels and for raising HDL levels. Although niacin is available over the counter, a physician should prescribe it in order to ensure its safety and effectiveness. Vitamins B6, B12, and folic acid are important in protecting against elevated blood levels of homocysteine, an amino acid that is a possible factor in coronary artery disease. However, it is not clear yet whether homocysteine is a cause or simply a marker of heart disease and it is not known if vitamin B supplements will actually reduce the risk of cardiovascular disease.

Other Supplements. One study indicated that calcium may protect against heart attack if it is obtained in products that do not contain fat (such as whole milk). Chromium, found in brewer's yeast, peanuts, whole grains, and dried beans, may boost HDL levels. Although supplements are not recommended at this time, the foods that contain chromium are. Supplements with L-arginine may help prevent atherosclerosis in people with high cholesterol, but more research is needed. Magnesium may possibly benefit both cholesterol levels and blood pressure and adequate amounts are critical for preventing excess calcium in the arteries, which can cause hardening of the endothelium (blood vessel lining).

Alcohol, Caffeine, and Chocolate

Alcohol. Many studies have reported that alcohol increases HDL levels and may protect against heart disease and possibly stroke. Anyone on medication should ask their physician about potential interactions with alcohol. Women who are pregnant or have a risk for breast cancer or those at risk for alcohol abuse should avoid alcohol to avoid the many hazards of excessive alcohol intake. The average alcohol intake should be no more than two drinks a day for men and one drink a day for women (5 oz. of wine, 12 oz. of beer, or 1 and a half oz. of spirits equals one drink).

Caffeine. Tea and Coffee. Tea may have a very positive effect on the heart. Although it contains caffeine, it also is rich in flavonoids and other substances that offer protection against damaging forms of LDL. Green tea is often cited for its health benefits but black tea may also be beneficial. In one study, higher intake of black tea, particularly by women, was associated with a reduced risk for severe coronary artery disease. Tea also contains folic acid, which reduces homocysteine levels, a possible factor in coronary artery disease.

Coffee did not appear to have any affect one way or the other, although drinking coffee increases excretion of calcium, which is important for bones and possibly for heart-health. Studies are finding that unfiltered coffee (Turkish coffee, Scandinavian boiled or French pressed coffee, and espresso) contains an alcohol called cafestol, which can raise cholesterol levels. Filtered coffee does not contain this residue. Of some concern is a study that reports high levels of homocysteine in people who drink many cups of coffee per day (decaf does not raise these levels). Homocysteine is a possible factor in coronary artery disease. On the other hand, coffee, like red wine, contains phenol, which helps prevent oxidation of LDL cholesterol. There is no evidence that drinking coffee increases the risk for heart disease, although tea is the better caffeine choice.

Chocolate. Chocolate contains stearic acid, which may lower LDL. Food containing chocolate, however, also contains sugar and fat, so it is not recommended for prevention.