Eating for a Healthy Heart

Healthy heart diet: the basics

While age and genetics play a role, doctors have identified six controllable risk factors for heart disease: high blood pressure, high cholesterol, diabetes, smoking, physical inactivity, and obesity. The first steps in preventing heart disease are to quit smoking and incorporate exercise into your life. The rest of your heart healthy plan can focus on your diet – what you eat, and what you don’t eat.

Coronary heart disease is caused by blockages in the arteries that supply blood to the heart. When the blood supply is obstructed, the heart muscle becomes deprived of oxygen and essential nutrients needed to function properly, which can result in angina (chest pains) or a heart attack. The primary substances responsible for narrowing of the arteries are cholesterol and fatty deposits – making dietary cholesterol and saturated fat the two major dietary culprits that affect your heart health,

In order to protect your heart, certain foods should be drastically reduced or eliminated from your diet, while increasing foods that support cardiovascular health.

Eat More	Eat Less
Healthy Fats (raw nuts, olive oil, fish oils, flax seeds, avocados)	Damaged fats (trans fats from partially hydrogenated foods, deep fried foods); saturated fats (whole-fat dairy; red meat).
Colorful, nutrient-loaded fruits and vegetables	Processed food (foods that come in a package); foods high in sodium
Fiber rich foods (whole grains and legumes)	Refined carbohydrates (white starches).
Fish (especially wild salmon, whitefish, tilapia, catfish, flounder, and mahi mahi)	Red meat
Water	Fruit juices, soda

Cholesterol, diet, and heart disease

Cholesterol is a waxy substance present throughout the body, and is involved in the production of hormones, Vitamin D, and the bile acids used for digestion. Your body gets cholesterol in two ways: by producing the substance organically, and through the food your eat. The body makes enough of the stuff on its own, so most of the cholesterol we eat is excessive. This is why, if you are at risk of heart disease or have high cholesterol levels in your blood, it is vitally important to cut out the “unnecessary” cholesterol from your diet.

Since cholesterol can’t dissolve in the blood, it must be “chauffeured” to and from the cells by carriers called lipoproteins. There are two types of lipoprotein: low-density lipoprotein, or LDL, is known as “bad” cholesterol. High-density lipoprotein, or HDL, is known as “good” cholesterol.

HDL is considered good because high levels of this substance seem to protect against heart disease. According to the American Heart Association, this may be because HDL tends to carry cholesterol away from the arteries and back to the liver, where it's passed from the body, and removes excess cholesterol from arterial plaque, slowing its buildup.

On the flip side, “bad” LDL cholesterol can speed up the buildup of dangerous plaque in the arteries, which can lead to a dangerous medical condition called atherosclerosis. This occurs when too much LDL circulates in the blood, which is why your doctor might encourage you to cut down on the cholesterol you are consuming.

Good fats vs. bad fats in the fight for cardiovascular health

Contrary to what many Americans believe, not all fat is bad. Fats are necessary and vital for good health; the type of fat you consume is what is important. In fact, the American Heart Association has an entire website dedicated to fats and heart health, called Face The Fats, where it explains the importance of replacing bad fats with good fats.

The good fats for heart health are monounsaturated and polyunsaturated, which reduce bad cholesterol levels and provide nutrients that help our cells function properly.  Polyunsaturated fats include the Omega-3 and -6 fatty acids, which also benefit cardiovascular health. Easy sources of these good fats include nuts, seeds, fish, vegetable oils (especially olive oil) and avocados.

The bad fats when it comes to heart disease include saturated, trans fats, and damaged fats. Saturated fat is considered “bad” because it is unnecessary – our bodies produce sufficient amounts on their own, so there’s no need to eat additional saturated fat, which can spike LDL (bad cholesterol) levels. But even a good fat can become bad. Just like leaving meat out in the sun can cause it to spoil, a healthy oil or fat can be rendered unhealthy if it is damaged by light or heat. Examples of fat that has been damaged are partially hydrogenated oils, or anything deep fried.

However, when talking about unhealthy fats, there is one type that is the arch-nemesis of heart health: trans fats. Trans fatty acids spike LDL levels even more than saturated fats, as well as lowering the good HDL levels in your blood. According to the American Heart Association, eating trans fats increases your risk of developing heart disease, stroke, and Type 2 diabetes. Trans fats are found in many processed foods like cookies, crackers, fast food, some margarines, and in anything that contain partially hydrogenated oils, so read labels carefully and avoid deep fried fast foods.

Fish: A great source of heart-healthy fat

Cold water fish like wild salmon, herring, mackerel and sardines are a great sources of omega-3 fat, which has been proven to reduce the risk of heart disease and stroke. The American Heart Association recommends that people eat fish, especially oily fish, at least twice a week, as some studies suggest that this can reduce your risk of heart disease by 23%.

Since much of the fish we consume today has a high mercury content, mercury-free omega-3 fish oil can be taken in supplement form with all the same benefits. Other fish good for heart health that tend to have lower levels of mercury are lake trout, tilapia, flounder, cod and mahi-mahi.

If you are unable to eat seafood, try to consume more soybean products (like tofu), canola oil, walnut and flaxseed, which contain alpha-linolenic acid (LNA).  LNA can turn into omega-3 fatty acid after it is digested.

Carbohydrates and heart disease

Just like with fats, carbohydrates can both beneficial and detrimental to your heart health. Simple, refined carbohydrates like sugar and white flour can create a spike in blood sugar and insulin, which increases the likelihood that calories from these foods will be converted into fat and cholesterol. In addition, refined carbohydrates can lower your “good” HDL cholesterol, and boost triglycerides.

However, complex carbohydrates are one of the building blocks of a heart-healthy diet. Whole grains, fruits, and vegetables take longer to digest, and do not cause the same rapid increase in blood sugar and insulin.

Rather than embarking on a “low-carb” diet, consider the glycemic index  (GI) of your food.  As a basic rule of thumb, foods that contain good fat, fiber and complex carbs will be lower on the glycemic index. High glycemic foods are typically white and processed with very little fat and fiber.

Using the GI, its best to choose low glycemic foods that are slowly digested and do not cause the extreme spikes in blood sugar associated with high-glycemic foods.  High-glycemic foods have also been linked to a higher incidence of heart disease and diabetes, so try to choose low and medium GI foods (a GI of 55 or less ranks as low) as much as possible. An additional tip: if you know you are going to eat a high GI food, combine it with a low GI food for an overall medium GI meal.  For example, combine white rice (high GI) with legumes (low GI).

Glycemic Index: “Good” and “Bad” Carbohydrates
For a complete list of low and high glycemic foods, visit the Glycemic Index website.
High glycemic index (“bad” carbs”)	Low glycemic index (“good” carbs)
white bread (rolls, biscuits, bagels) white potatoes biscuits, waffles & pancakes white rice crackers pretzels potatoes sugary breakfast cereals processed foods crackers refined cereals soft drinks fruit juices refined sugar	whole-grain breads and cereals whole-wheat products brown rice oatmeal whole fruits barley bran legumes (beans, peanuts, peas) bulgur wheat lentils certain fruits (apples, apricots, cherries, grapefruits, peaches, pears, plums, oranges)

The importance of fiber to heart health

Diets high in fiber lower cholesterol levels and reduce the risk of heart disease.  Fiber is classified as either insoluble fiber or soluble fiber depending on whether it dissolves in water.  Soluble fiber is particularly important for lowering cholesterol since it binds with the cholesterol, enabling it to leave the body without getting reabsorbed back into the blood. Insoluble fiber acts like a broom to move food out of the intestines quickly, but does not seem to help lower blood cholesterol. The American Heart Association Eating Plan suggests that you eat foods high in both types of fiber. 

Food sources high in heart-healthy soluble fiber include the following:

• Oatmeal / oat bran
• legumes (chickpeas, northern beans, pinto beans, black, kidney, lima, navy)
• grapefruit, orange, blackberries, pear, figs, apple
• artichokes, brussel sprouts, winter squash, parsnips, carrots
• flax seeds
• psyllium husk

The average American only consumes around 15 grams of dietary fiber per day, falling short of the recommended daily intake of 38 grams for men and 25 grams for women under the age of 50. Recommendations are lower for people over age 50 (30 grams for men, 21 grams for women), but still a good deal higher than the national average consumption.  When increasing fiber intake, do it gradually, a little more each day – eating too much fiber too quickly can cause gas, bloating and cramping.  Try starting by adding a piece of fruit to meals, and using whole grain breads. Some people may need a fiber supplement if dietary changes aren’t sufficient, or if they have certain medical conditions.  Check with your doctor if you need to take fiber supplements.

Other elements of cardiovascular health: calcium, potassium & plant sterols

Calcium

According to Harvard University’s Healthy Eating for a Healthy Heart Diet, research suggests that low calcium levels may contribute to high blood pressure. A lack of calcium may cause your body to retain sodium, which raises blood pressure. 

Consuming calcium-rich foods and beverages (low- or nonfat yogurt, cheese, and milk, as well as nondairy foods such as salmon, broccoli, tofu, and legumes) may help lower your risk of heart disease, while protecting you from other health concerns such as osteoporosis and bone loss.

Potassium

Potassium, a mineral found in fruits and vegetables such as bananas, tomatoes, oranges, and spinach, as well as in plain yogurt and certain types of fish, helps lower blood pressure. It’s important to consult a physician before taking supplements or drastically increasing your potassium consumption (we only need about 4.7 grams a day), as people with certain diseases and conditions can be sensitive to potassium.

Plant sterols

Plant sterols and stanals are natural cholesterol-lowering substances. While they occur naturally in vegetables, fruits and other plant-based foods, they are not in large enough quantities to have a real effect on our bodies. However, they can be chemically modified and added to foods such as “heart healthy’ margarine spreads or granola, and used to lower LDL cholesterol up to 10%.

Diets for preventing hypertension and stroke

The Dietary Approaches to Stop Hypertension, or DASH diet, is a specially designed eating plan to help you lower your blood pressure, which is a major cause of hypertension and stroke. At its core, the DASH diet is rich in fruits, vegetables, low-fat dairy products, and whole grains, and low in saturated fat and cholesterol. While fish, poultry, and nuts are emphasized, red meat, sweets, and sugar-containing beverages are kept to a minimum. This makes for an eating plan low in saturated fat, cholesterol, total fat and sodium, and rich in protein, fiber and healthy nutrients (particularly magnesium, potassium and calcium).

Three major clinical trials have proven this diet’s efficacy, and since DASH consists of an overall healthy eating plan, it is certainly worth a shot if you are at risk for these conditions. To learn more about the DASH diet, see Related Links at the end of this article.

Related links for preventing heart disease and stroke

Heart healthy diet: the basics

Heart Healthy Diet – Eating guidelines to lower your cholesterol and reduce your risk of heart disease. (National Heart, Lung and Blood Institute)

Dr. Dean Ornish Lifestyle Modification – Nutritional and dietary guidelines, including a “reversal” diet for those diagnosed with heart disease and a prevention food pyramid. (Preventative Medicine Research Institute)

 Heart-healthy eating to help prevent cardiovascular disease – Five strategies to kick-start your diet for better cardiovascular health (Mayo Clinic)

Eating for a Healthy Heart - Simple ,colorful tips   (US Health Human Services )

Good fats & bad fats in the fight for cardiovascular health

Face the Fats – Real-life advice for incorporating good fats and reducing bad fats to help reduce heart disease risk. (American Heart Association)

Fats and Cholesterols - The Good, The Bad, and the Healthy Diet – Discusses the new way of looking at fats, with information on specific foods and types of fats as well as their benefits. (Harvard School of Public Health)

Carbohydrates and heart disease

Glycemic Index- the official website of the glycemic index; includes searchable database listing the glycemic index of your favorite foods.

Heart health and fiber

Dietary Fiber: An essential part of a healthy diet – Explains the differences between soluble and insoluble fiber; offers fiber content information for a variety of foods; and includes tips on incorporating more fiber into your diet. (Mayo Clinic)

High-Fiber Diet May Fight High Blood Pressure – Details of a 2005 study on the benefits of a high-fiber diet on blood pressure and heart heath. (WebMD – commercial site)

Other elements of coronary health: calcium, potassium, and plant sterols

Phytochemicals and Cardiovascular Disease – Background and explanation of plant sterols and other phytochemicals and the role they play in heart health. (American Heart Association)

Potassium – Extensive explanation of the mineral Potassium – what it does in the body, where it is found, and its benefits and risks. (University of Maryland Medical Center)

Diets to prevent hypertension and stroke

Your Guide to Lowering High Blood Pressure – Overview of the DASH (Dietary Approaches to Stop Hypertension) program, with six additional links offering specific guidance on portions and fats, recipes, and preparing healthier meals. (National Heart, Lung and Blood Institute)

DASH Eating Plan (PDF) – A detailed user's manual (24 pgs) for reducing high blood pressure through diet. (National Heart, Lung and Blood Institute)

Suzanne Barston, Gina Kemp, M.A., and Mary Toscano contributed to this article. Last modified on: 7/18/08.