Health: What Is Cholesterol?‏

Edited by Guy Slowik MD FRCS. Last updated on January 31st 2011

 

Cholesterol is a waxy, fat-like substance that is made in the body by the liver. Cholesterol forms part of every cell in the body and serves many vital functions. Our bodies need cholesterol to:

• Maintain healthy cell walls
• Make hormones (the body's chemical messengers)
• Make vitamin D
• Make bile acids, which aid in fat digestion

Sometimes, however, our bodies make more cholesterol than we really need, and this excess cholesterol circulates in the bloodstream. High levels of cholesterol in the blood can clog blood vessels and increase the risk for heart disease and stroke.

• Our bodies can make too much cholesterol when we eat too much saturated fat - the kind of fat found in animal-based foods such as meat and dairy products.
• In addition to making cholesterol, we also get a small percentage of our body's cholesterol from the foods we eat. Only animal-based foods such as meat, eggs, and dairy products contain cholesterol. Plant foods such as fruits, vegetables, and grains do not contain cholesterol.

The Different Types Of Cholesterol

There are different types of cholesterol - and not all cholesterol is harmful.

• Low-density lipoprotein (or LDL) cholesterol is a bad type of cholesterol that is most likely to clog blood vessels, increasing your risk for heart disease.
• High-density lipoprotein (or HDL) cholesterol is a good type of cholesterol. HDL cholesterol helps clear the LDL cholesterol out of the blood and reduces your risk for heart disease.

Facts About Cholesterol

• More than one-half of American adults have blood cholesterol levels that are too high.
• Lowering your cholesterol level has a double payback: For every one percent you lower your blood cholesterol level, you reduce your risk for heart disease by two percent.
• Even if you already have heart disease, lowering your cholesterol levels will significantly reduce your risk for death and disability.
• As blood cholesterol exceeds 220 ml/dl risk for heart disease increases at a more rapid rate.
• All adults should have their blood cholesterol level measured at least once every five years.
• The liver makes most of the cholesterol in our bodies-only a small percentage comes from food. But the more saturated fat we eat, the more cholesterol our bodies make.
• Most people can bring down their blood cholesterol levels without medication by changing the way they eat and by becoming more active.
• Only animal foods contain cholesterol; plant foods do not contain cholesterol.
• A medium egg contains about 213 milligrams of cholesterol, a three-ounce portion of lean red meat or skinless chicken contains about 90 milligrams of cholesterol, and a three-ounce portion of fish contains about 50 milligrams of cholesterol.

What Causes High Blood Cholesterol?

Edited by Guy Slowik MD FRCS. Last updated on January 31st 2011

Many factors can contribute to high blood cholesterol levels or cholesterol levels that are out of balance. Some of these factors are within your control, and some are not.

To some extent, your genetic make-up determines your cholesterol level.

• Some people inherit a condition called familial hypercholesterolemia, which means that very high cholesterol levels run in the family.
• Some people may simply be more likely than others to react to lifestyle factors(such as lack of exercise or a high-fat diet) that push up cholesterol levels.
• Other people, especially people for whom diabetes runs in the family, inherit high triglyceride levels. Triglycerides are another type of blood fat that can also push up cholesterol levels.

Besides your genetic make-up, many lifestyle factors affect cholesterol levels and cholesterol balance:

• What you eat. Eating too much saturated fat (the kind found in high-fat meats and dairy products) and cholesterol can cause your body to make more cholesterol, raising your blood cholesterol levels. You can lower your cholesterol level by cutting down on animal fat and other fats and eating foods rich in starch and fiber, such as fresh fruits, vegetables, and whole grains.
• How active you are. Regular exercise not only reduces total blood cholesterol, but it lowers the bad kind of cholesterol (LDL cholesterol) while raising the good kind of cholesterol (HDL cholesterol).
• What you weigh. Being overweight contributes to rising blood cholesterol levels. Fortunately, changes to lower cholesterol levels also help you control your weight, a double benefit.
• Your hormones. Women get a natural boost in their HDL cholesterol (the good kind of cholesterol) from their hormones until they reach menopause. After menopause, taking estrogen can help maintain higher HDL cholesterol levels.

What Is The Best Way Lower Blood Cholesterol?

Edited by Guy Slowik MD FRCS. Last updated on January 31st 2011

Making gradual and permanent changes in your diet and lifestyle can help you lower your cholesterol levels. Not only will these changes reduce your risk for developing heart disease, but they will also reduce your risk for other serious conditions such as high blood pressure, cancer, stroke, and diabetes.

The main lifestyle changes to help you lower your cholesterol levels are:

• Reduce fat and cholesterol in your diet.
• Eat more foods rich in carbohydrates and fiber, such as fruits, vegetables, and whole grains.
• Increase your level of physical activity.
• Maintain a healthy body weight.

In addition to lowering cholesterol levels, if you smoke cigarettes or have high blood pressure, quitting smoking or moderating your sodium intake can also significantly reduce risk for heart disease.

How -To Information: Consider taking a systematic approach to lowering cholesterol, one step at a time: 1.        Find your starting point, or think about what needs to be changed. Sometimes this means keeping a diary for a few days to record your normal food intake or patterns of exercise. 2.        Once you have identified your problem, make a commitment to change. 3.        Plan how you will start to make a change. If many changes are required, plan which change you will make first. 4.        Check up on yourself to see how well you are carrying out and keeping up the changes.

Of course, it is unrealistic to expect to make many lifestyle changes all at once. However, as you will see, there is plenty of overlap. For example, regular exercise will help you lower your cholesterol and lose weight, which further lowers your cholesterol.

When making changes, you need to pace yourself. Make adjustments to your way of living in whatever order is easiest and don't rush. Gradual change is more likely to be permanent than many rapid and drastic changes. When you change your diet or exercise routine, don't think of it as going on a temporary diet or exercise program. Instead, think of it as adopting a healthier way of living to continue for life.

Also, don't feel you have to give up any favorite food completely when making dietary changes. If you really enjoy certain high-fat foods:

• Eat them in smaller portions (example, one cookie instead of three).
• Find a version of the food that is lower in fat (example, ice milk instead of ice cream).
• Find a substitute for the food that you like almost as well (example, popcorn instead of peanuts).

All of the above changes are healthy for the entire family. Not only will these changes help you lower your cholesterol level, but they will also help reduce the entire family's risk of developing chronic health disorders such as heart disease, cancer, high blood pressure, and obesity.

Reducing Total Fat

Ounce for ounce, fat contains over twice the calories that protein or carbohydrates do. So even if saturated fat is the type of fat most likely to raise harmful blood cholesterol levels, you should limit intake of all fats. Eating too much fat, no matter what kind, can make you put on excess weight. Eating too much fat can also increase your risk of certain types of cancer, such as breast or colon cancer.

To limit total fat intake:

• Broil, bake, boil, or roast foods rather than fry.
• Use non-stick pans or coat pans with a thin layer of non-stick spray.
• Add less fat to food during both cooking and eating. Some examples include using jam instead of margarine on toast, a non-fat or low-fat salad dressing instead of a high-fat dressing, lemon juice instead of butter on vegetables, or salsa instead of sour cream on baked potatoes.
• Experiment with butter substitutes, spices, and other flavorings as alternative to fat.
• Look for low-fat alternatives to foods, such as a bagel instead of a doughnut, pretzels instead of potato chips, or a round steak instead of a t-bone steak
• Try new fat-free products like yogurt, cookies, or crackers.
• Read labels, which offer excellent information to help you compare fat content of prepared foods.

Reducing Saturated Fat And Cholesterol

To reduce the fat and cholesterol intake in your diet, start with changes that are relatively easy to make. For example, many people find it easy to switch from 2% milk to 1% or skim milk. Once you have adjusted to one change, pick another change to work on.

Here are some simple changes that will help you greatly reduce saturated fat and cholesterol in your diet.

Egg yolks:

• Eat no more than three eggs yolks weekly.
• Eat as many egg whites as you like - they contain no cholesterol.

Meats:

• Buy lean meats such as fish, poultry, veal cutlet, pork tenderloin, or flank steak.
• Trim as much fat off meat as possible.
• Broil, barbecue, or roast meat on a rack rather than fry them. This allows some of the fat to escape during cooking.
• Limit the amount of hamburger you eat, and buy the leanest type available.
• Replace high-fat prepared meats like sausage and luncheon meats with lower-fat meats like lean turkey or chicken.
• Remove the skin from chicken or turkey before you cook or eat it.
• Try to eat fish twice weekly. Fish contains a type of fat called omega-3 fat that may help prevent heart disease.

Dairy products:

• Use margarine instead of butter, choosing a margarine that has a liquid oil rather than a hydrogenated oil listed as the first ingredient.
• Choose a lower-fat milk. If you use whole milk, switch to 2%. If you use 2%, switch to 1% or skim milk. (All types of milks have the same amount of calcium and other vitamins and minerals.)
• Use non-fat or low-fat yogurt.
• Use plain non-fat yogurt instead of sour cream.
• Cut down on the amount of regular cheeses you eat. Look for lower-fat cheese that contains less than 3 grams of fat per ounce.
• Sprinkle a little Parmesan cheese on food to give it a cheesy taste. Parmesan cheese is strong tasting, so a little goes a long way.

Tropical oils and processed oils:

• Check food labels to see what the main type of fat in the food is. Limit foods that list palm oil, coconut oil, or a hydrogenated oil as one of the first type of fats. (Food labels list ingredients in order from greatest to least by weight.)
• Be suspicious of commercial baked goods such as doughnuts, sweet rolls, brownies, and cookies, which are a major source of saturated fat.

Nice To Know: About 60% of the saturated fat in the American diet comes from three food sources: Hamburger Cheese Whole milk Cutting down on these foods, or cutting them out, can go a long ways toward helping you cut down saturated fat and cholesterol.

Increasing Starches And Fiber

Including more starches and fiber in your diet can help you lower your cholesterol level, as well as reduce your risk for obesity, cancer, high blood pressure, and other diseases. Fresh fruits and vegetables, whole grain breads and cereals, and legumes are naturally low in fat, cholesterol-free, and rich in starches and dietary fiber.

A certain type of dietary fiber, called soluble fiber, may help lower cholesterol levels by sweeping cholesterol out of the body before it gets into the bloodstream. Foods rich in soluble fiber include oat bran, dried beans and peas, some fruits, and psyllium seeds (the main ingredient in Metamucil, a fiber supplement).

Fruits, vegetables, whole grains, and nuts and seeds also contain antioxidants, which are substances that help protect body cells from damage. Examples of antioxidants are:

• Vitamin C (in citrus fruits)
• Beta-carotene (in carrots)
• Vitamin E (in vegetable oils)

To damage artery walls, cholesterol must first be chemically changed through a process called oxidation. Antioxidants help prevent cholesterol from being chemically changed and help prevent cholesterol from moving out of the blood and into the lining of the blood vessels.

The U.S. Department of Agriculture's Food Guide Pyramid recommends that you eat the following number of servings of these plant foods daily:

• 6-11 servings of grains (1 serving equals 1 slice of bread, ½ of a bun, ½ cup of pasta or rice)
• 3-5 servings of vegetables (1 serving equals 1 cup of raw leafy vegetables or ½ cup cooked vegetables)
• 2-3 servings of fruits (1 serving equals 1 medium apple, peach or orange; ½ cup of berries; or 3/4 cup juice)

How-To Information: To include more starches and fiber in your diet: Keep a food diary showing the number of servings of fruits, vegetables, and grains you get daily. If the number is low, gradually try to increase servings of the groups lacking by adding fruits, vegetables, or whole grains as side dishes or snacks. Buy breads and cereals that list a whole grain as the first ingredient - they contain more fiber and vitamins and minerals. Whenever possible, choose raw fruits and vegetables rather than processed ones. Steam vegetables until crisp-tender, rather than boiling them until soft. Whenever possible, leave skin on fruits and vegetables. Add lemon juice, butter flavoring, or other seasoning to vegetables rather than fat. Try including several meatless meals weekly. Start with breakfasts, then gradually add two or three lunches or dinners weekly.

Eating Out

Eating out is certainly possible but requires more careful planning for low-fat, low-cholesterol eating. When eating out:

• Choose a restaurant with heart-healthy items marked on the menu.
• Ask how foods are prepared, and don't hesitate to make special requests, such as for the sauce or dressing to be served on the side.
• Avoid foods described as fried, breaded, creamed, or buttered, as well as salads that already have a dressing on them.
• Order fresh fruit or sherbet for dessert. For a special treat, share a rich dessert with several people so you all get a taste but no one overdoes it.
• If you must eat at a fast-food restaurant, order a plain hamburger or a vegetarian pizza with a thick crust and half the cheese. Try to avoid or limit fries, onion rings, chicken nuggets, and other fried foods.

Reading Food Labels

Use food labels to help you identify foods high in fat, saturated fat, and cholesterol. Start by searching the front of the food package for nutrient claims such as "low-fat" or "low-calorie." These terms now have standard definitions and provide dependable information:

• "Fat-free" means less than 0.5 grams of fat per serving.
• "Low-fat" means 3 grams or less per serving.
• "Reduced fat" or "less fat" means at least 25% less per serving than a similar food.
• "Light" means 33% fewer calories or 50% less fat per serving than the reference food.

Next, read the "Nutrition Facts" panel, usually found on the side or back of the food package. The Nutrition Facts panel lists the total calories per serving near the top of the panel. It also lists the calories from fat.

To figure the percentage of calories from fat in an individual food, simply divide fat calories by total calories and multiply by 100. Remember, a low-fat diet means that less than 30% of calories come from fat. If one food provides 50% of calories from fat, you must balance it with other lower-fat foods to stay within the 30% guideline.

The Nutrition Facts panel also lists the grams of total fat, saturated fat, polyunsaturated fat, and monounsaturated fat and the milligrams of cholesterol in a serving of the food. The "% Daily Value" shows what percentage of total recommended intake of fat and cholesterol the food provides, based on a 2,000-calorie diet.

Controlling Your Weight

If you weigh more than you should, losing weight is an important step toward lowering your cholesterol levels. To lose weight, you will need to cut calories and boost your activity level. Fortunately, when you lower your fat and cholesterol intake and eat more starches and fiber, you automatically lower your calorie level.

Cutting your calories involves changing both the type of food you eat and the way you eat. Since fat is a very concentrated source of calories, eating more of the low-fat foods that help you lower your cholesterol levels (such as fruits, vegetables, and whole grains) will also help you cut your calories.

If you tend to eat even when you are not really hungry, you may also need to change the way you eat. To help you cut calories:

• Eat three main meals, including breakfast.
• Plan for low-fat snacks in the morning and afternoon.
• Keep a food diary to help you identify problem areas or situations that trigger overeating.
• Always eat in the same place when you are home, which will help keep you from nibbling frequently.
• Sit down while you eat.
• Keep problem foods out of the house (or at least off the counter and less accessible).
• Find substitutes for favorite foods that are high in calories; for example, angel food cake instead of richer types of cakes, pretzels instead of potato chips, bagels instead of doughnuts.

For most people, permanent weight loss is impossible by reducing calorie intake alone. When you cut calories, some of the weight you lose comes from muscle tissue in addition to fat loss. When you severely cut your calorie intake, your body reacts as though it were being starved, slowing down its metabolism and making it harder to lose weight.

Exercising regularly helps you lose weight in several ways:

• Exercising while cutting calories helps you maintain muscle tissue and burn a higher percentage of body fat.
• Exercising re-sets the body's metabolism, countering the effects of calorie restriction.
• Exercise burns calories.
• Exercise keeps you out of the kitchen and away from food.

Exercising Safely

Most people think they have to really work up a sweat for physical activity to count. Although deliberate forms of exercise such as walking, jogging, or swimming are great, smaller periods of less intense physical activity also help lower cholesterol, control weight, and reduce your risk for heart disease.

Experts now recommend that all adults accumulate at least 30 minutes or more of moderate-intensity physical activity on most, preferably all, days of the week. This doesn't mean, however, that you need to jog or swim 30 minutes a day. You can also benefit from several shorter periods of physical activity throughout the day.

The best activities for your heart are those that use the large muscles of your body, particularly those in your legs, making them demand more oxygen to do their work. Examples of such "aerobic" activities include:

• Walking
• Running
• Rowing
• Bicycling
• Swimming
• Skating
• Cross-country skiing

In addition to these deliberate forms of exercise, try to include more activity throughout your day:

• Park farther from work and walk the extra distance, or better yet, walk to work if possible.
• When shopping, park farther away and walk more between stores.
• Take walking breaks at work.
• Take the stairs instead of the elevator.
• Clean your own house.
• Mow the lawn yourself.
• Choose leisure-time activities that get you moving. Golfing, skiing, bowling, dancing, or playing tennis or basketball can all add to your overall activity level.

Almost everyone can do some form of exercise, but to exercise safely you must start very slowly and build up gradually. You should check with your doctor before beginning a vigorous exercise program if you:

• Are a man over 40 years of age
• Are a woman over 50 years of age
• Have risk factors for heart disease such as high blood chole
  sterol levels, high blood pressure, diabetes, or cigarette smoking
• Have symptoms of heart disease (pain in the chest, neck or shoulder during exercise, shortness or breath, faintness, or dizziness) or known heart disease

Start by finding out how much exercise you are getting now. Look back on the last three days and write down the approximate length of time you spend being physically active. Then gradually increase the minutes you spend being physically active, adding a few minutes each week.

When you are exercising vigorously, check your heart rate periodically by counting your pulse at the neck or wrist. Count your heartbeats for 10 seconds, then multiply by 6 to get the beats per minute.

In the early stages of your exercise routine, try to keep your heart rate within 65% to 70% of your maximum heart rate (your maximum heart rate is 220 minus your age). As you get in better shape, you may be able to let your heart rate climb to 75% of your maximum heart rate.

For example:

• A 60-year-old man has a maximum heart rate of 160 beats per minute (220 minus 60).
• So 65% to 70% of this figure is 104 to 112 beats per minute.
• Thus, this man should count 17 to 18 beats during a 10-second pulse check.

Be sure to include a five-minute warm-up and cool-down period of light stretching before and after exercise to warm up your muscles and avoid injury and stiffness. If you experience any of these warning signs, stop exercising and check with your doctor:

• Lightheadedness or dizziness
• Headache
• Nausea
• Shortness of breath
• Cold sweat
• Pain or pressure in the chest, neck, shoulder, or arms, especially on the left side

How many times a week do you get at least 30 minutes of activity?	one or less	2 to 3	5 or more
How many eggs do you eat weekly?	more than 3	2 to 3	1 or less
How often do you eat red meat (beef, pork, or lamb) weekly?	5 or more	3 to 5	2 or less
What kind of milk do you drink?	whole	low-fat	1% or skim
How often each week do you eat cheese or ice cream that is not low-fat?	5 or more	3 to 4	2 or less
How often do you eat baked goods like doughnuts, pastries, or cookies?	4 to 5	2 to 3	1 or less
Including breakfast, lunch, and dinner, how many meals do you eat weekly that include fruits and vegetables?	5 or less	6 to 13	14 or more

As you can guess, the ideal way of eating is shown in the right-hand column, which represent an aggressive approach to lowering cholesterol. If you have blockages of the arteries, this approach can even shrink these blockages.
After three months of making changes, test yourself again with this same self-assessment. If you have more answers in the right columns, you making changes in the right direction.

Cholesterol intake should be less than 300 milligrams daily.

Frequently Asked Questions

Edited by Guy Slowik MD FRCS. Last updated on January 31st 2011

Q: Does caffeine raise blood cholesterol levels?

A: Caffeine is found in many soft drinks, coffee, tea, and to a lesser extent, chocolate.Caffeine does not raise blood cholesterol levels, and research has yielded conflicting results on whether caffeine increases risk of heart disease. Based on current evidence, a moderate intake of caffeine does not seem to be harmful.

Q: Should a person avoid eating eggs entirely?

A: Health experts advise limiting cholesterol intake to 300 milligrams or less daily. One large whole egg yolk contains about 215 milligrams of cholesterol. The American Heart Association recommends limiting egg yolk consumption to three to four times weekly and focusing on the total diet instead of just one food. The cholesterol in eggs is found in the yolk portion, so you can use as many egg whites as you want. Eggs contain B vitamins, iron and other minerals and are a good source of high-quality protein.

Q: Can fat substitutes help lower blood cholesterol?

A: Many low-fat foods and fat replacers have made reducing fat intake easier. Often, however, these fat substitutes are used in foods such as cookies, chips, or desserts. While lower in fat, such foods often contain the same number of calories as their comparable counterparts. Overeating on low-fat foods can still contributes to obesity, which in turn contributes to high blood cholesterol and other health problems. Further, these foods often lack the vitamins, minerals, fiber, and other healthy substances found in alternative food choices such as fruits, vegetables, and whole grains.

Q: Should a person avoid dairy products to lower cholesterol?

A: Skim milk and low-fat dairy products contain only small amounts of saturated fat and cholesterol and can easily be included in a low-fat, low-cholesterol eating plan. In addition, dairy products are excellent sources of calcium, a mineral that may help prevent the development of osteoporosis, or brittle bones, later in life.

Q: Should people trying to lower their cholesterol level use margarine or butter?

A: Although butter is high in both saturated fat and cholesterol, some margarines may not be much better than butter. Stick margarines that have been hydrogenated, or chemically changed, contain trans-fatty acids, a type of fat that can raise blood cholesterol levels. Choose liquid vegetables oils or soft margarines over stick margarines or butter. The softer a margarine is, the more unsaturated it is. As a general rule, shop for margarine with no more than 2 grams of saturated fat per tablespoon and with liquid vegetable oil listed as the first ingredient.

Q: Can fish oil help lower cholesterol?

A: Although fish oil may lower levels of blood triglycerides (another type of fat) and very-low-density lipoprotein (VLDL) cholesterol, it does not seem to significantly lower the LDL, or bad type of cholesterol. However, fish is a great protein source that is very low in fat and saturated fat. Eating fish two to three times weekly does helps to lower risk for heart disease, possibly by interfering with the ability of blood to clot. The American Heart Association recommends that people eat fish regularly but does not advise taking fish oil supplements.

Q: Should people use oat bran to lower cholesterol levels?

A: Oats and oat bran contain generous amounts of soluble fiber, which helps to lower the bad LDL cholesterol and raise the good HDL cholesterol. However, some oat bran muffins can be high in fat and calories, so read labels carefully. Although oat bran may help lower cholesterol, many other foods, particularly legumes and certain fruits, are also rich in soluble fiber. The body needs both soluble and insoluble fiber to function properly.

Q: How do I know the amounts of fat, cholesterol, and sodium in the foods I eat?

A: Read food labels. The labels on the packaging of the foods you buy will list these amounts, as well as other helpful information such as fiber and vitamin content. The quantities given on food labels are on a "per-serving" basis. The top of the label will define what a "serving" is for that particular food.