Cholesterol, Other Lipids, and Lipoproteins

Description

An in-depth report on the diagnosis, treatment, and prevention of high cholesterol.

Lifestyle Changes

Although most studies that prove that lowering cholesterol saves lives are done using drug therapy, the absolute mandate for improving cholesterol levels is to first make changes in life style (both diet and exercise). And, even when drugs are used healthy diet and physical activity are critical companions.

As in hypertension, people with unhealthy cholesterol levels do not experience symptoms until dangerous heart disease develops. So, changing their daily patterns is like breaking through a wall. It seems impenetrable at first, but once the patient has broken through, the rewards of these good, new habits are a sense of energy and physical freedom that few will want to relinquish.

Heart Healthy Diets

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

• Choose fiber-rich food (whole grains, legumes, nuts) as the main source of carbohydrates, along with a high intake of fresh fruits and vegetables.
• Avoid saturated fats (found mostly in animal products) and transfatty acids (found in hydrogenated fats and many commercial products and fast foods). Choose unsaturated fats (particularly omega-3 fatty acids found in vegetable and fish oils).
• In selecting proteins, choose soy protein, poultry, and fish over meat.
• Weight control, quitting smoking, and exercise are essential companions of any diet program.

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

Therapeutic Lifestyle Changes (TLC) from the National Cholesterol Education Program. Guidelines in 2001 from the National Cholesterol Education Program include the following for preventing and managing high cholesterol levels in adults:

• Choose five or more servings of fresh fruits and vegetables and six or more servings of whole grains, legumes. Soluble fiber is preferred (from cereal grains, beans, peas, legumes, and many fruits and vegetables).
• Fats can be up to 35% of daily calories, but no more than 7% should be from saturated fat. (People with high triglycerides or low HDL or both may need a higher fat intake.) Choose fats containing unsaturated fatty acids (from vegetables, fish, legumes, and nuts). Choose margarines containing sterols or stanols (e.g., (Benecol, Take Control). Avoid trans fatty acids found in commercial products as much as possible.
• Proteins choices should be limited in general to fat-free and low-fat milk products, fish, legumes, skinless poultry, and lean means.
• Limit cholesterol intake to less than 200 mg per day.

Maintain healthy body weight and a healthy level of physical fitness.

Mediterranean Diet. The Mediterranean diet is rich in heart-healthy fiber and nutrients, including omega-3 fatty acids and antioxidants. The diet recommends the following:

• A relatively high fat intake (about 35% to 45% of daily calories, mostly in monounsaturated and polyunsaturated fats.) The Mediterranean diet is known for its use of olive oil, but the greatest benefits found in a major study of this diet appeared to be derived from the use of canola oil, which is rich in omega-3 fatty acids. Olive oil, in fact, does not contain omega-3 fatty acids. On the other hand, olive oil, may have beneficial effects independent from those on lipids, such as improving insulin and blood glucose levels and reducing blood pressure.
• Daily glass or two of wine.
• The same protein intake as the AHA, although fish is the primary source. (It avoids high-fat dairy and meat products.) In fact, one 2001 study suggested that fish-consumption, not wine, that is the heart-protective ingredient in this diet.
• Lower carbohydrate intake than AHA. Emphasizes not only fresh fruits and vegetables, but also higher amounts of nuts, legumes, beans, and whole grains.
• Foods seasoned with garlic, onions, and herbs.

The Ornish Program and Severely Fat-Restricted Diets. The Ornish program limits saturated fats as much as possible, reduces total fat to 10%, and increases carbohydrates to 75% of calories. It is a very effective but demanding regimen:

• It excludes all oils and animal products except nonfat yogurt, nonfat milk, and egg whites.
• Foods stressed are whole grains, legumes, and fresh fruits and vegetables.
• People in the program exercise 90 minutes at least three times a week.
• Stress reduction techniques are employed.
• People do not smoke nor do they drink more than two ounces of alcohol per day.

Everyone on a low-fat diet should consume a wide variety of foods and take a multivitamin, if appropriate.

The DASH Diet. The DASH diet (Dietary Approaches to Stop Hypertension) is proving to help lower blood pressure after eight weeks. Restricting sodium improves results. The diet appears to have antioxidant effects and may even prove to be a good diet for lowering LDL cholesterol levels -- although the beneficial HDL levels also decline.

This diet is not only rich in important nutrients and fiber but also includes foods that contain far more electrolytes, potassium, calcium, and magnesium, than are found in the average American diet.

A diet that is effective in lowering blood pressure is called Dietary Approaches to Stop Hypertension (DASH).

The dietary recommendations are as follows:

• Avoid saturated fat (although include calcium-rich dairy products that are no- or low-fat).
• When choosing fats, select monounsaturated oils, such as olive or canola oils. (One study reported a reduced need for anti-hypertension medication in people with a high intake of virgin olive oil, but not sunflower oil, a polyunsaturated fat.)
• Choose whole grains over white flour or pasta products.
• Choose fresh fruits and vegetables every day. In one 2002 study people who increased their intake of fruits and vegetables experienced a drop in blood pressure after six months. Many of these foods are rich in potassium, fiber, or both which may help lower blood pressure.
• Include nuts, seeds, or legumes (dried beans or peas) daily.
• Choose modest amounts of protein (preferably fish, poultry, or soy products). Soy in combination with fiber-rich foods or supplements may have specific benefits. Oily fish may also be particularly beneficial. They contain omega-3 fatty acids, which have been associated with heart and nerve protection.

Calorie Restriction. Calorie restriction has been the cornerstone of weight-loss programs. Restricting calories also appears to have beneficial effects on cholesterol levels, including reducing LDL and triglycerides and increasing HDL levels. In fact, in a study of an African community, inhabitants had very-low calorie diets and favorable cholesterol levels in spite of a high intake of saturated fat.

The standard dietary recommendations for losing weight are the following:

• As a rough rule of thumb, one pound of fat equals about 3,500 calories, so one could lose a pound a week by reducing daily caloric intake by about 500 calories a day. Naturally, the more severe the daily calorie restriction, the faster the weight loss.
• To determine the daily calories requirements for specific individuals, multiply the number of pounds of ideal weight by 12 to 15 calories. The number of calories per pound depends on gender, age, and activity levels. For instance, a 50-year-old moderately active woman who wants to maintain a weight of 135 pounds might require only 12 calories per pound (1,620 calories a day). A 25-year-old female athlete who wants to maintain the same weight might require 25 calories per pound 2,025 (calories a day).

Fat intake should be no more than 30% of total calories. Most fats should be in the form of monounsaturated fats (such as olive oil). Saturated fats (found in animal products) should be avoided.

Exercise

Inactivity is one of the four major risk factors for coronary artery disease, on par with smoking, unhealthy cholesterol, and high blood pressure. In fact, studies suggest that people who change their diet in order to control cholesterol are successful in actually lowering their risk for heart disease only when they also follow a regular aerobic exercise program.

The following are some observations on the effects of exercise on coronary artery disease and cholesterol:

• People who maintain an active lifestyle have a 45% lower risk of developing heart disease than do sedentary people. Even moderate exercise reduces the risk of heart attack. One 2001 study of women found that just one hour of walking a week was associated with a lower risk for heart disease. The effects were similar even in women at high risk for developing heart disease.
• People who are on a cholesterol-lowering diet are successful in actually lowering their risk for heart disease only if they also follow a regular aerobic exercise program.
• Some studies suggest that for the greatest heart protection, it is not the duration of a single exercise session that counts but the total daily amount of energy expended. Therefore, the best way to exercise may be in multiple short bouts of intense exercise.
• Burning at least 250 calories a day (the equivalent of about 45 minutes of brisk walking or 25 minutes of jogging) seems to confer the greatest protection against coronary artery disease, most likely because it raises HDL levels-the so-called good cholesterol. (Note, however, that moderate exercise has little effect on HDL, and it may take up to a year of sustained exercise to make any significant difference on HDL levels.)
• Aerobic exercise appears to open up the blood vessels and, in combination with a healthy diet, may improve blood-clotting factors.
• Resistance (weight) training offers a complementary benefit to aerobics by reducing LDL levels (the so-called bad cholesterol).
• Exercises that train and strengthen the chest muscles may prove to be very important for patients with angina.

Quitting Smoking

Cigarette smoking lowers HDL-cholesterol levels and is directly responsible for approximately 20% of all deaths from heart disease. Once a person quits smoking, HDL cholesterol levels rise within weeks or months to levels that are equal to their nonsmoking peers. Passive smoking also reduces HDL levels in people highly exposed to smokers. The importance of breaking this habit cannot be emphasized enough.

Alcohol

A number of studies have found heart protection from moderate intake of alcohol (defined as one or two glasses a day). The benefits reported have been 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. Women -- especially those at risk for breast cancer -- and lighter men should also drink less. Pregnant women, anyone who cannot drink moderately , and people with liver disease should not drink at all.