Home > Medical Reference > Patient Education

Ask Our Experts

Get answers to your specific medical questions from UM Medical Center experts.

Note: This is for informational purposes only. Doctors cannot provide a diagnosis via e-mail.

 

Related Content

Our Doctors

Patient Success Stories

Speciality Services

Podcasts

Heart-healthy diet

Description

An in-depth report on how to build the best diet for your heart's health.


Alternative Names

Diet - heart health


Introduction

Heart-Healthy Goals. The goals of a heart-healthy diet are to eat foods that help obtain or maintain healthy levels of cholesterol and fatty molecules called lipids. You can achieve this by:

Any diet should also help keep blood pressure and weight under control.

General Recommendations

The U.S. Department of Agriculture discarded its nearly 15-year-old food pyramid in early 2005, opting for a new symbol that places more emphasis on portion control, healthy food choices, and regular exercise. The new model, called MyPyramid, is based on revised dietary guidelines which encourage people to eat more fruit, vegetables, whole grains, and fat-free or low-fat dairy products, and to reduce their intake of bad fats, cholesterol, salt, and added sugars.

Although there are many major dietary approaches for protecting health, experts generally agree on the following heart-smart recommendations:

After starting any heart healthy diet, it generally takes an average of 3 to 6 months before any noticeable reduction in cholesterol occurs, although some people have reported better levels in as few as 4 weeks. An intensive program may be necessary to achieve significant improvements in cholesterol levels and to reduce other heart risk factors.

Children

Atherosclerosis, the build-up of plaque in the arteries, begins in childhood. Experts stress the importance of heart healthy dietary guidelines for children and adolescents to help prevent the development of heart disease later in life. Children should eat foods that are low in saturated fat, trans fat, and cholesterol. These foods include:

Cholesterol
Cholesterol is a soft, waxy substance that is present in parts of the body including the nervous system, skin, muscle, liver, intestines, and heart. It is made by the body and obtained from animal products in the diet. Cholesterol is manufactured in the liver and is needed for normal body functions, including the production of hormones, bile acid, and vitamin D. Excessive cholesterol in the blood contributes to atherosclerosis and subsequent heart disease. The risk of developing heart disease or atherosclerosis increases as the level of blood cholesterol increases.

[For more information on heart problems, see In-Depth Report #23 : Cholesterol; Report #3 : Coronary artery disease and angina; Report #14 : High blood pressure; Report #53 : Weight control and diet.]

Fats and Oils

Some fat is essential for normal body function. Fats can have good or bad effects on health, depending on their chemistry. New research suggests that the type of fat is more important than the total amount of fat when it comes to reducing heart disease.

All fats, good or bad, are high in calories compared to proteins and carbohydrates. In order to calculate daily fat intake, multiply the number of fat grams eaten by nine (one fat gram is equal to 9 calories, whether it's oil or fat) and divide by the number of total daily calories desired. One teaspoon of oil, butter, or other fats equals about 5 grams of fat. All fats, no matter what the source, add the same calories. The American Heart Association recommends that fats and oils have less than 2 grams of saturated fat per tablespoon.

Try to replace saturated fats and trans fatty acids with unsaturated fats from plant and fish oils. Omega-3 fatty acids, which are found in fish and plant sources, are a good source of unsaturated fats. Generally, two servings of fish per week provide a healthful amount of omega-3 fatty acids.

The Chemistry of Fats and Cholesterol.

Harmful Fats. Reducing consumption of saturated fats and trans fatty acids is the first essential step in managing cholesterol levels through diet. Experts say the combined amount of trans fat and saturated fat in the diet should not exceed 10 percent of the total calories consumed each day.

Beneficial Fats and Oils. 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.

Researchers are most interested in the smaller fatty-acid building blocks contained in both oils, which may have more specific effects on lipids. Three important fatty acids are the essential fatty acids omega-3, omega-6, and omega-9.

Omega-3 fatty acids are found in fish oil ( docosahexaenoi c and eicosapentaneoic acids) and plants ( alpha-linolenic acid ).

Omega-6 polyunsaturated fatty acids are found in corn, safflower, soybean, and sunflower oil. PUFA oils containing omega-6 fatty acids constitute most of the oils consumed in the US. Some omega-6 fatty acids are important for health. However, high intake of these fats may be associated with weight gain in the abdomen (the so-called apple shape), a risk factor for heart disease. High consumption is also associated with a higher risk for certain cancer and some chronic diseases.

Omega-9 monounsaturated fatty acids are contained in canola and olive oil, which help protect the heart.

Research suggests that a healthy balance of all these fats may be important and that our current Western diet contains an unhealthy ratio of omega-6 to omega-3 fatty acids (10 to 1). Omega-9 fatty acids may also contain chemicals that block harmful factors found in omega-6 fatty acids. Researchers suggest that the most benefits may be found in mixture of all three fatty acids found in both poly- and monounsaturated oils, but in modest amounts that do not add 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.

A number of other fat-replacers are also available. Although studies to date have not shown any significant adverse health effects, their effect on weight control is uncertain, since many of the products containing them may be high in sugar. One study suggested 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.

Note on Dietary Cholesterol

The story on cholesterol found in the diet is not entirely straightforward. The body produces cholesterol naturally or obtains it through meals. Animal-based food products contain cholesterol. High amounts occur in meat, dairy products, egg yolks, and shellfish. (Plant foods, such as fruits, nuts, grains, do not contain cholesterol.) The American Heart Association recommends no more than 300 mg of dietary cholesterol per day for the general population and no more than 200 mg daily for those with high cholesterol.

Carbohydrates

Carbohydrates are either complex (as in starches) or simple (as in fruits and sugars). One gram of carbohydrates equals four calories. The current general recommendation is that carbohydrates should provide between 50 - 60% of the daily caloric intake. Many studies report that people can protect their heart and circulation by eating plenty of fruits and vegetables.

Complex Carbohydrates. Complex carbohydrates found in whole grains and vegetables are preferred over those found in starch-heavy foods, such as pastas, white-flour products, and potatoes. Most complex carbohydrates are high in fiber, which is important for health. Whole grains specifically are extremely important for people with diabetes or at risk for it.

Simple Carbohydrates (Sugar). Experts recommend that no more than 10% of daily calories should come from sugar. (Currently, Americans eat nearly half a pound of sugar a day on average, and sugar intake constitutes 25% of a day's calories.) Sugars are usually one of two types:

High levels of sugar consumption -- whether fructose or sucrose -- have been associated with higher triglycerides and lower levels of HDL cholesterol, the so-called good cholesterol. The high consumption of sugar is most likely one of the factors in the current obesity epidemic. Soda, other sweetened beverages, and fruit juice are major contributors to childhood obesity.

Possible harm from sugar comes from advanced glycation end-products (called AGEs), which are end-products of the chemical reaction between sugar and protein. This reaction occurs most intensively when cooking at high temperatures -- particularly animal fats. (Steaming or cooking food in water does not produce these chemicals. Low, slow cooking also produces fewer AGEs.) AGEs can also be formed by chemical reactions in the body itself. They are now believed to promote factors in the inflammatory response that cause a number of diseases or their complications, including Alzheimer's disease, diabetes, atherosclerosis, cataracts, and osteoporosis.

Fiber-Rich Foods

Fiber is an important component of many complex carbohydrates. It is almost always found only in plants. (One exception is chitosan, a dietary fiber made from shellfish skeletons.) Fiber cannot be digested but passes through the intestines, drawing water with it, and is eliminated as part of feces content. High-fiber diets (up to 55 grams a day) can be very helpful. Different fiber types may have specific benefits:

  • Insoluble fiber (found in wheat bran, whole grains, seeds, nuts, legumes, and fruit and vegetable peels) may help achieve weight loss. Consuming whole grains on a regular basis may lower the risk for heart disease, improve factors involved with diabetes, and lower the risk for type 2 diabetes.(Wheat bran taken as a supplement has not been associated with any benefits. The whole grain may be needed for good health.) High consumption of nuts (such as almonds, macadamia, and walnuts) may be highly heart protective, independent of their fiber content.
  • Soluble fiber (found in dried beans, oat bran, barley, apples, citrus fruits, and potatoes) may help achieve healthy cholesterol levels and possibly reduce blood pressure as well. For example, one study indicated that eating beans four or more times a week reduced the risk for heart disease by 22%. Oat bran has also been highly studied for its benefits on the heart.
  • Soluble fiber supplements, such as those that contain psyllium or glucomannan, may also be beneficial. Psyllium is taken from the husk of a seed grown in India and is very effective for lowering total and LDL cholesterol. It is found in laxatives (Metamucil), breakfast cereals (Bran Buds, Plantaben), and other products. However, some studies suggest that psyllium increases triglyceride levels in postmenopausal women. Sodium levels may also rise. People who increase intake of soluble fiber should also drink more water.

Protein

In general, experts recommend that proteins should provide 12 - 20% of daily calories. One gram of protein contains four calories. Protein is important for strong muscles and bones and may have specific benefits on blood pressure. The best sources of protein are fish, poultry, and soy. Restrict intake of red meat or any meat that is not lean.

Fish. Fish is probably the best source of protein. Evidence suggests that eating moderate amounts of fish (twice a week) may improve triglyceride and HDL levels and help lower the risks for death from heart disease, dangerous heart rhythms, blood pressure, a tendency for blood clots, and the risk for stroke.

The most healthy fish are oily fish, such as salmon, mackerel, or sardines, which are high in omega-3 fatty acids. Three capsules of fish oil (preferably as supplements of DHA-EPA) is about equivalent to eating one serving of fish.

Some studies have reported a higher incidence of heart attack in men who ate fish daily. Such findings may be due to mercury toxicity, which has harmful effects on the heart. High mercury content has been observed in swordfish and shark and, to some extent, in tuna, trout, pike, tilapia, and bass. Fish oil supplements also may have some adverse effects on LDL levels in certain people and glucose control in people with type 2 diabetes. More research is needed to further define the risks and benefits of fish, but at this time most guidelines recommend evidence eating fish two or three times a week.

Soy. Soy is an excellent food. It is rich in both soluble and insoluble fiber, omega-3 fatty acids, and provides all essential proteins. Soy proteins have more vitamins and minerals than meat or dairy proteins. They also contain polyunsaturated fats, which are better than the saturated fat found in meat. The best sources of soy protein are soy products (tofu, soy milk, soybeans). Soy sauce is not a good source. It contains only a trace amount of soy and is very high in sodium.

For many years, soy was promoted as a food that could help lower cholesterol and improve heart disease risk factors. But an important 2006 American Heart Association (AHA) review of studies found that soy protein and isoflavone supplement pills do not really have any effects on cholesterol or heart disease prevention. The AHA still encourages patients to include soy foods as part of an overall heart healthy diet, but does not recommend using isoflavone supplements.

Meat and Poultry. For heart protection, choose lean meat. Saturated fat in meat is the primary danger to the heart. The fat content of meat varies depending on the type and cut. It is best to eat skinless chicken or turkey. However, the leanest cuts of pork (loin and tenderloin), veal, and beef are nearly comparable to chicken in calories and fat as well as their effect on LDL and HDL levels. However, even chicken and lean meat do not improve cholesterol levels and, in terms of heart health, fish is a more desirable choice.

Dairy Products. A 2002 study reported a lower incidence of factors related to type 2 diabetes and heart disease (insulin resistance, high blood pressure, obesity, and unhealthy cholesterol) with a high intake of dairy products. Some researchers suggest the calcium in dairy products may be partially responsible for these benefits. The effects of extra calcium on blood pressure, however, are mixed with some even showing higher pressure. The best dairy choices are low fat or fat free products.

Some Examples of Healthy Foods

Foods

Important Phytochemicals (Plant chemicals) Contained in the Foods

Vitamins and other valuable food components

Possible Benefits

Apples

Flavonoids

Fiber

May protect against certain cancers (lung), heart disease, asthma, and type 2 diabetes.

Avocados

Vitamin E, vitamin B6, folate

May be heart protective

Beans

Flavonoids

Folate, iron, potassium and zinc, fiber

Some experts believe beans are the perfect food.

Berries, All kinds of dark colored (especially blueberries)

Ellagic Acid

Vitamin C, minerals

May protect the aging brain. (Many studies recommend blueberries.)

Broccoli (also kale, Brussels sprouts, cauliflower)

Flavonoids, Isothiocyanates

Vitamin C, folate, fiber, and selenium

Anticancer properties. Protects against heart disease and stroke.

Carrots and other bright yellow vegetables

Lutein, Beta carotene

Vitamin A (converted from carotenoids), vitamin C, fiber

Protect heart, eyes, lungs. (Cooking carrots may increase their benefits.)

Fish (particularly oily fish, such as mackerel, salmon, sardines)

Vitamins B3 and B12, essential fatty acids, selenium

Heart and brain protective.

Garlic

Allium (organosulfurs)

May be slightly protective against heart disease. Possible infection fighter.

Ginger

Zingiberaceae

Cancer fighting properties.

Grains (whole)

Lignans (phytoestrogens)

Vitamin B, selenium (important antioxidant mineral), fiber, folate

May help reduce the ability of cancer cells to invade health tissue.

Grapes and red wine

Flavonoids, resveratrol

Fight heart disease and cancer. May have activity against asthma, and type 2 diabetes.

Nuts (such as almonds, macadamia, and walnuts)

Vitamin E, Vitamin B1, Essential fatty acids, folate, fiber

May lower cholesterol levels, reduce sudden death rates from heart disease, and help prevent stroke and type 2 diabetes.

Onions

Flavonoids, allium (organosulfurs)

May have activity against certain cancers (lung), heart disease, asthma, and type 2 diabetes.

Oranges and orange juice

Monoterpenes

Vitamin C, folate, potassium, fiber

Many health benefits. Increase HDL levels and helps maintain normal blood pressure.

Potatoes (Sweet)

Vitamins A, C, and E

Many health benefits.

Soy:

Four ounces of tofu equals about eight to 13 grams of soy.

A soy burger contains about 18 grams of soy.

Isoflavones (phytoestrogens), flavonoids, phytosterol, phytate, saponins

May have effects similar to estrogen, including maintaining bone and benefiting the heart. May protect against prostate cancer and possibly other cancers. Possible protection against mental decline.

Spinach and other dark green leafy vegetables

Zeaxanthin, Beta carotene

Vitamin C, folate, vitamin A (converted from carotenoids)

Protects heart, lungs and brain.

Tomatoes

Lycopene, flavonoids

Vitamin C, biotin, minerals

Protects heart. Studies suggest reductions in prostate and other cancers. Infection fighters.

Vitamins

Antioxidant Vitamins E, C, and A. Vitamins E, C, and A are most studied for their health effects because they serve as antioxidants. Antioxidants are chemicals that act as scavengers of particles known as oxygen-free radicals (also sometimes called oxidants ). High intake of foods rich in these vitamins (as well as other food chemicals) have been associated with many health benefits, including prevention of heart problems.

Research on the effects of vitamin supplements on heart disease and diabetes, however, has been mixed. Although some research initially observed favorable effects from vitamin E in preventing blood clots and preventing build-up of plaque on blood vessel walls, most studies found no heart protection from either vitamin E or C supplements. A 2005 Journal of the American Medical Association study found that vitamin E supplements can actually increase the risk of heart failure, especially for patients with diabetes or vascular diseases. Results from the long-term Women’s Health Study, also released in 2005, showed that vitamin E supplements do not protect women from attacks or stroke.

Oxygen-Free Radicals and Antioxidants

Antioxidants are chemicals that act as scavengers of particles known as oxygen-free radicals (also sometimes called oxidants ). These chemically active particles are by-products of many of the body's normal chemical processes. Their numbers are increased by environmental assaults, such as smoking, chemicals, toxins, and stress. In higher levels, oxidants can be very harmful:

  • Oxygen-free radicals can damage cell membranes and interact with genetic material, possibly contributing to the development of a number of disorders including diabetes, cancer, heart disease, cataracts, and even the aging process itself.
  • They can also enhance the dangerous properties of low-density lipoprotein (LDL) cholesterol, a major player in the development of coronary artery disease.

Antioxidant vitamins (A, C, and E), beta carotene, and many phytochemicals can neutralize free radicals and have been studies for possible benefits. It is clear that such vitamins are required to prevent deficiency diseases. In addition, foods rich in antioxidants are important disease fighters. To date, however, there is no strong evidence that antioxidant supplements offer any real protection.

Special Warning on High-Dose Antioxidant Supplements. Some studies suggest that excessive use of antioxidant supplements may interfere with other nutrients or convert into pro-oxidants and become harmful. Some of the findings are as follows:

  • One small study found that high doses of antioxidants, including vitamins C and E, interfered with cholesterol-lowering drugs and blunted their effect. This study also supports other evidence that high doses of vitamin C may speed up atherosclerosis. A 2002 randomized study of postmenopausal women, for example, found a higher risk for heart disease in people who took vitamin E and C supplements.
  • Of particular concern are studies that have found an increase in lung cancer and overall mortality rate among smokers who took beta carotene supplements. A 2000 study further reported a higher risk for cancer in male smokers who took multivitamins plus A, C, or E. Even more worrisome, in people with existing cancer, high doses of antioxidant vitamins, such as vitamin C or beta carotene, may actually protect cancer cells (just as they do healthy cells).

B Vitamins (Folic Acid). Deficiencies in the B vitamins folate (known also as folic acid), B6, and B12 have been associated with a higher risk for heart disease in some studies. Such deficiencies produce higher blood levels of homocysteine, an amino acid that has been associated with a higher risk for heart disease, stroke, and heart failure. Researchers have been studying whether vitamin B supplements can reduce homocysteine levels and, consequently, heart disease risks.

Several major 2006 studies indicated that while B vitamin supplements help lower homocysteine levels, they have no effect on heart disease outcomes. The studies, published in the New England Journal of Medicine , examined patients who had either recently had a heart attack or who suffered from diabetes or heart disease. Results showed a similar number of heart attacks and strokes among patients who took folic acid and B6 and B12 vitamins and those who received placebo. And, the vitamins seemed to increase risks for patients who had undergone stenting. Some experts think that homocysteine may be a marker for heart disease rather than a cause of it.

Minerals

Potassium, Magnesium, and Calcium. Some experts believe that sufficient intake of minerals, particularly potassium, magnesium, and calcium, may be even more beneficial than salt restriction for reducing blood pressure.

Salt Restriction

In the past, everyone was advised to consume less than 2,400 mg (about one teaspoon) of sodium (salt) each day. However, in February 2004, a long-awaited report by the Institute of Medicine (IOM) recommended that individuals slash their salt intake in half. The IOM report stressed that no one should consume more than 1,500 mg/day. Because blood pressure tends to rise with age, the Institute also suggested that people over 50 reduce their sodium intake to less than 1,300 mg daily; those over 70 should not eat more than 1,200 mg a day. Reducing sodium may also help protect against heart failure. Unfortunately many people find it very difficult to achieve these goals. Experts disagree on the overall benefits of salt restriction for everyone. Still, the following people should take particular measures to restrict salt:

Simply eliminating table and cooking salt can be beneficial. Salt substitutes, such as Cardia, (containing mixtures of potassium, sodium, and magnesium) are available, but they are expensive. About 75% of the salt in the typical American diet comes from processed or commercial foods, not from food cooked at home, so the benefits of table-salt substitutes are likely to be very modest. Some sodium is essential to protect the heart, but most experts agree that the amount is significantly less than that found in the average American diet. If people cannot significantly reduce the amount of salt in their diets, adding potassium-rich foods might help to restore a healthy balance.

Water and Other Fluids

Water. Many heart risk factors, especially those associated with blood clotting, are increased with dehydration. In one study, drinking five or more glasses of water a day was significantly associated with a lower risk for fatal heart events than drinking two or fewer glasses a day.

Alcohol. A number of studies have found heart protection from moderate alcohol intake (one or two glasses a day). The benefits reported include higher HDL levels, blood clot prevention, and anti-inflammatory properties. Although red wine is most often cited for healthful properties, any type of alcoholic beverage appears to have similar benefit. On the negative side, an estimated 10% of hypertension cases are caused by alcohol abuse. Men with hypertension should limit their intake to an average of no more than one or two drinks a day, and women (especially those at risk for breast cancer) and lighter people should also drink less. Alcohol may raise a man’s risk for atrial fibrillation according to a study in the Archives of Internal Medicine. Pregnant women, people who can't drink moderately, and people with liver disease should not drink at all.

Caffeinated Beverages.


A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process . A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
adam.com