It is no secret that abnormal levels of fats and cholesterol in the blood are associated with an increased risk of coronary heart disease. These fats and cholesterol are called blood lipids, and the good news is that there are effective ways to manage them. In fact, dramatic improvements in lipid levels can be achieved through simple lifestyle changes.
The National Institutes of Health National Cholesterol Education Program (NCEP) has developed a set of therapeutic lifestyle changes for reducing the risk of coronary heart disease. These guidelines for change are designed primarily to lower low-density lipoprotein (LDL, or “bad”) cholesterol and to manage other risk factors associated with the metabolic syndrome. This cluster of risk factors is associated with cardiovascular disease and diabetes and includes the following: abdominal obesity, high blood pressure, abnormally low high-density lipoprotein (HDL, or “good”) cholesterol, a high level of triglycerides (the chemical form in which most fat exists in the body), and high blood glucose.
National guidelines have established a goal of LDL cholesterol below 100 milligrams per deciliter (mg/dl) for most people and have recently given physicians the option to lower LDL cholesterol to less than 70 mg/dl in people considered to be at very high risk (such as those with established coronary heart disease and/or diabetes). A fasting triglyceride level of less than 150 mg/dl is considered normal for both men and women. An HDL cholesterol level of at least 40 mg/dl is recommended for men and a level of at least 50 mg/dl is recommended for women.
The first lifestyle change recommended by the NCEP is to reduce your intake of saturated fat and cholesterol. Saturated fat should be less than 7% of your total calories per day, and dietary cholesterol should be less than 200 mg per day.
Saturated fat is found mostly in foods that come from animals: meat, poultry fat, lard, butter, cheese, and other dairy products. It is also found in foods from tropical plants such as coconut oil, palm oil, and cocoa butter. Saturated fat is solid at room temperature. If you can see solid fat in your food — such as the fatty strips in bacon or the fat found under chicken skin — chances are that there is a significant amount of saturated fat present.
It’s easy to eat too much saturated fat. For example, a grilled cheese sandwich made with two pieces of bread, two slices of American cheese, and one pat of butter contains 11 grams (99 calories) of saturated fat. If additional butter is used to cook the sandwich, or if it is served with French fries, the meal has even more saturated fat. So what many people might consider a simple lunch contains more than the recommended daily upper limits for saturated fat intake. (See “Saturated Fat Goals” for more information about saturated fat intake.)
If you do not know your recommended daily calorie intake, ask your physician for a referral to a registered dietitian. A registered dietitian can calculate the number of calories you need to achieve and maintain a healthy weight and can give you personalized suggestions for how to minimize your saturated fat intake — without giving up all of the foods you enjoy.
Dietary cholesterol can also add up quickly. Cholesterol is only found in foods that come from animals, such as meat, poultry, egg yolks, butter, and cheese, and is usually found in the same places as saturated fat. If you reduce your intake of saturated fat to no more than 7% of your total calories, you will probably reduce your dietary cholesterol intake to goal level as well.
Many people wonder if they should avoid foods such as eggs and shellfish altogether, because one serving of them may exceed daily cholesterol recommendations. Although these foods are higher in cholesterol than others, they are lower in saturated fat than other sources of animal protein. That means they can be part of a sensible meal plan if you consume small portions. For example, by choosing one small or medium egg, with 157 or 187 mg of cholesterol, respectively, you can stay within daily upper intake limits. But remember to balance the dietary cholesterol in that egg with the other foods that you eat. For example, don’t use butter to cook the egg (use a nonstick spray instead, or have it boiled or poached instead of fried), and have vegetarian meals for lunch and dinner. Alternatively, you could have just the egg whites and avoid any cholesterol whatsoever.
Trans fat is another type of fat to avoid. Trans fat is generally produced by hydrogenation of vegetable oils, although some is found naturally in animal fats. Hydrogenation increases the shelf life and flavor stability of many processed foods — for instance, shortening, some margarines, and fried foods. Other major sources of trans fat include foods made with partially hydrogenated oils such as certain crackers, cookies, doughnuts, and fast foods. The problem with trans fat is that it can both raise LDL cholesterol and lower HDL cholesterol levels.
As of January 1, 2006, the Food and Drug Administration requires that the amount of trans fat in a serving of food be listed on a separate line under saturated fat in the Nutrition Facts panel. However, foods with less than 0.5 grams of trans fat per serving can claim 0 grams of trans fat on the label. So it’s also important to look for partially hydrogenated oils in the ingredients list. If they’re there, the product contains at least a small amount of trans fat.
Reducing the amount of saturated fat, trans fat, and cholesterol in your diet does not mean that you should follow an extremely low-fat diet. On the contrary, for persons with the metabolic syndrome, lipid disorders, and/or diabetes, total fat should make up 30% to 35% of total calories. In addition, saturated fat and trans fat should be replaced with monounsaturated fat (up to 20% of calories) and polyunsaturated fat (up to 10% of total calories). Evidence suggests that replacing saturated fat with unsaturated fat is more effective in lowering the risk of coronary heart disease than reducing total fat consumption.
The two types of unsaturated fat in the diet — monounsaturated and polyunsaturated — are found in a variety of foods. Monounsaturated fat is found in avocados, almonds, olives, peanuts, and olive, peanut, and canola oils. Polyunsaturated fat can be divided into two groups: omega-6 polyunsaturated fat, which is found mainly in seeds and vegetable oils such as corn and soy oils, and omega-3 polyunsaturated fat, which is found in fish, flaxseeds, and walnuts. Consuming omega-3 fatty acids from fish and plant sources may lower your risk of coronary heart disease.
Replacing saturated fat with monounsaturated or polyunsaturated fat can be as simple as putting avocado on your sandwich instead of cheese, having nuts for a snack instead of chips or baked goods, and using salad dressing made with olive oil or canola oil instead of using a creamy salad dressing.
Going even lower
If reducing your intake of saturated fat, cholesterol, and trans fat does not get you to your LDL goal, you might try two additional strategies.
First, try adding plant stanols or sterols to your diet. These are derived from natural plant components such as soy. They reduce the absorption of cholesterol in the digestive tract, resulting in lower total and LDL cholesterol levels. They can be found in some soft margarine products, orange juice, and select other foods, and also in supplement form. If you choose to use one of the margarine products, be sure to adjust your calorie level to account for the calories contained in the product, and if you use the orange juice, take the grams of carbohydrate into account. Plant stanol or sterol intake of 2–3 grams per day has been found to lower LDL cholesterol by 6% to 15%.
A second strategy is to add more foods high in soluble fiber to your diet. See “Sources of Soluble Fiber” for a list of foods that contain soluble fiber. A total fiber intake of 20–30 grams per day is part of the diet recommended by the NCEP. By increasing their soluble fiber intake by only 5 to 10 grams per day, most people can reduce their LDL cholesterol by about 5%.
Managing your weight and engaging in regular physical activity are also fundamental components of the NCEP-recommended changes. If you are at a healthy weight, work with your physician to prevent weight gain. Develop strategies for weight maintenance, and anticipate high-risk occasions for possible weight gain (for example, times of significant stress). If you are overweight, start with a weight-loss goal of 10% through dietary changes, portion control, and daily physical activity. You should also consider regular visits with your physician to follow up and examine your progress. Any increase in physical activity should take into consideration your current heart health, your age, and your physician’s assessment of your limitations and goals. Once you get the OK to exercise, try 30 minutes of moderate-intensity activity on most, if not all, days of the week — even if you are not overweight.
Triglycerides in the blood come from the foods we eat. Calories that are not immediately used by the body are converted into triglycerides and transported to the fat cells to be stored. Like LDL cholesterol, excess triglycerides in the blood are linked to a higher risk of coronary artery disease.
If triglycerides remain elevated once LDL cholesterol is reduced to your goal, losing weight and engaging in regular physical activity should become your primary focus. Overweight and lack of physical activity are strong contributors to high triglycerides, so working with your health-care provider to start a program of weight loss and daily exercise could lead to an improved triglyceride level.
In addition to reducing your calorie intake and exercising, there are some other changes that can lower your triglyceride level. First, reduce your intake of refined or processed carbohydrates, such as candy, table sugar, white flour, and baked goods made with white flour. These foods can promote an increase in triglycerides. Excessive intake of these foods may also increase blood glucose, and it is very common to see high blood triglycerides when diabetes is not well controlled.
Eat foods rich in monounsaturated and polyunsaturated fats instead of those that contain refined sugar. Substituting fish rich in omega-3 fatty acids (found in fatty fish such as salmon, sardines, and tuna) may also lower triglycerides. Omega-3 fish oil capsules may be therapeutic in some cases, but over-the-counter fish oil supplements have been found to contain varying amounts of fish oil, so only prescription supplements are recommended at this time. Discuss the risks and benefits of taking fish oil with your physician. High doses can cause excessive bleeding in some people.
Even small amounts of alcohol can increase triglycerides. So if high triglycerides are a problem for you, it would be a good idea to cut down on alcohol as much as possible.
HDL cholesterol is called “good” cholesterol because higher levels protect against coronary heart disease by carrying cholesterol away from the arteries and back to the liver where it is disposed of. A low level of HDL cholesterol is associated with an increased risk of coronary heart disease.
When triglyceride levels are elevated, HDL cholesterol levels begin to fall. So when you make changes to improve your triglycerides, this may also lead to an improved HDL cholesterol level. However, low HDL cholesterol may also be present in the absence of high triglycerides. This is called isolated low HDL cholesterol and is attributed to many of the same factors that may promote high triglycerides, including overweight and obesity, physical inactivity, cigarette smoking, very high carbohydrate intake (more than 60% of calories), Type 2 diabetes, and genetic factors.
All the lifestyle changes covered in this article are essential components of HDL cholesterol management. In particular, losing weight or maintaining a healthy weight, being physically active most days of the week, and not smoking can increase your HDL cholesterol. In addition, maintaining a low intake of saturated fat and trans fat, avoiding processed carbohydrates, and consuming an adequate amount of monounsaturated and polyunsaturated fats all promote a healthy level of HDL cholesterol.
Special considerations for diabetes
The combination of high triglycerides and low HDL cholesterol is common among people with diabetes (especially Type 2 diabetes) and is often referred to as diabetic dyslipidemia or atherogenic dyslipidemia. Abnormalities in blood lipids, high blood pressure, high blood glucose, insulin resistance, and other factors also contribute to the increased risk of coronary heart disease among people with diabetes.
Just having diabetes is considered a coronary heart disease “risk equivalent.” This means that the lipid management goals for people with diabetes are the same as for people who have established coronary heart disease. A change in lifestyle should always be part of a plan to lower lipid levels, but doctors may also prescribe lipid-lowering drugs to further reduce the risk — even if lipid goals are met through lifestyle changes alone. To keep track of your lipid levels, annual testing is recommended. And because nutrition can be complex, it is also recommended that people with diabetes meet with a registered dietitian to devise individualized strategies for meeting their dietary goals.
Improving your lipid levels may not be easy and may take time, but significant change is possible. An estimated LDL cholesterol reduction of 8% to 10% can be achieved by cutting intake of saturated fat to less than 7% of calories. An additional reduction of 3% to 5% can be achieved by cutting cholesterol intake to less than 200 mg per day. A 10-pound weight loss could mean as much as a 5% to 8% decrease in LDL cholesterol. The addition of plant sterol and stanol esters to your diet could reduce LDL cholesterol even further, by up to 15%. And consuming more soluble fiber can reduce it up to 5% more. This adds up to a possible 30% reduction in LDL cholesterol through lifestyle changes alone.
These lifestyle modifications may not only improve lipids, but also have a ripple effect: Blood glucose control and blood pressure may also improve as a result. The best way to start is to talk with your doctor. Review your lipid levels with him, set lifestyle change goals, and set a date to follow up and track your progress.