CHAPTER
8

Fats and Cholesterol

In This Chapter

• Identifying sources of good and bad fats in foods
• Why is fat essential in your diet?
• How to increase good cholesterol levels
• Do your cholesterol numbers put you at risk?

Fats are essential to a healthy diet but can also be detrimental to your health. Getting the right type and in the correct amounts is important for good health. The body is capable of synthesizing most fats from the foods you eat. However, there are two fats that must be consumed through your diet because your body cannot make them: omega-3 and omega-6 fatty acids.

Fats are involved in many functions, such as the absorption of fat-soluble vitamins, insulating your organs, providing your body with energy, and being a part of your cell membranes. Fat is also a flavor carrier and an energy nutrient, which provides 9 calories per gram.

Although fats are an important part of a healthy diet, eating too much of the wrong types can increase your risk of cardiovascular disease and shorten your lifespan.

The Many Types of Fats

The three main categories of fat are unsaturated, saturated, and trans fat. Unsaturated fatty acids can be either monounsaturated or polyunsaturated. The polyunsaturated group contains fats referred to as omega-3s and omega-6s, which are considered essential fatty acids. Saturated fats and trans fats are solid at room temperature. However, they’re most commonly found in processed foods.

All fats are made up of carbon and hydrogen atoms with an attached alcohol group. These chains of organic fatty acids are hydrophobic, which means they are not soluble in water.

We’re going to take a look at each type of fat, its chemical structure, and where to find it as well as its effect on the body and impact on health.

FOODIE FACTOID

Emulsions are a combination of two liquids that don’t normally mix together, like fat and water. Examples of emulsions in common foods are mayonnaise, milk, cream, vinaigrettes, and Hollandaise sauce.

How Fats Are Broken Down

Fats don’t readily mix with water, so they cluster together as they move through the digestive system. To break down the fat, bile is released from the gallbladder into the digestive tract. The bile salts in the bile emulsify the fat. Emulsification refers to breaking the large fat clusters of molecules into smaller ones. When the fat is in smaller particles, it’s easier for pancreatic lipase, the fat-digesting enzyme, to break it down for digestion. The lipase breaks the fat into free fatty acids and monoglycerides, which are easier for the body to absorb.

Once absorbed, the free fatty acids and monoglycerides are resynthesized into triglycerides inside the epithelial cells of the small intestine. Proteins then coat the triglycerides to form chylomicrons. The protein coating gives the chylomicrons their water-soluble coat and allows them to travel outside of the cell. The chylomicrons leave the epithelial cells and enter the lymphatic capillaries, which allows for their absorption directly into the bloodstream. They circulate in the bloodstream to carry cholesterol and fatty acids to cells throughout the body.

NOTABLE INSIGHT

All fatty acids are not needed immediately for energy use, so the remainder are bound into triglycerides and stored in fat cells. These fat cells have unlimited capacity, and the body is great at storing fat.

Saturated Fat

A saturated fat is a type of fat that is solid at room temperature. “Saturated” refers to its chemical structure being made up of fatty acids heavily laden with hydrogen atoms, which allows for no double bonds between carbon molecules. The hydrogen atoms make the long fatty acid chain more stable because it’s difficult for other molecules to knock off a hydrogen atom and cause oxidation. Oxidation makes the fat go rancid.

Health experts agree that saturated fat should only be consumed in limited amounts, as this type of fat can clog arteries. The Dietary Guidelines for Americans recommend consuming no more than 10 percent of calories from saturated fats. This equates to about 22 grams of fat in a 2,000-calorie diet.

Saturated fats come mainly from animal sources of food that include full-fat dairy products (butter and cheese), lard, the fatty portion on the outside of meats as well as the marbling within, and poultry with skin.

Trans Fats

There are two types of trans fat: artificial (made in a lab) and naturally occurring in nature. The primary focus is on the detrimental effects associated with consumption of artificial trans fat. Naturally occurring trans fats like those found in beef, lamb, and butterfat are insignificant sources and very little research has been performed with these types of trans fats in relation to their impact on health.

Trans fats in nature have what is called a “cis” configuration or bend in the molecule. The chemical structure of an artificial trans fat is in a “trans” configuration, which makes its shape straight. It doesn’t occur in nature. This shape makes the artificial trans fat very stable and strong. To make trans fats in the lab, liquid oil is heated under pressure and exposed to hydrogen gas and a catalyst. This process is called hydrogenation. The oil is now transformed into a solid and can be used many times without spoilage. It also makes processed foods that contain it less likely to spoil and increases their flavor stability. That’s why processed foods contain trans fat. Oil is a very expensive ingredient, and it makes sense why food manufacturers and the restaurant industry would benefit from its use.

In 2002, the National Academy of Sciences recommended that trans fats be eliminated from American diets due to their detrimental effect on health. One study reported that for every 2 percent of trans fat calories in the diet, there was a 23 percent increased risk of cardiovascular disease. Consumption of trans fats has been shown in studies to increase inflammation, insulin resistance, and risk of type 2 diabetes.

Trans fat is often seen in processed foods. However, the Food and Drug Administration (FDA) ruled in June of 2015 that artificial trans fats are to be eliminated from all products over the next 3 years. Food manufacturers can still petition the FDA for certain uses though. The mention of the word “hydrogenated” in the ingredients on the nutrition facts label is usually a sure sign that the food contains trans fat. Food manufacturers are allowed to label food as having 0 grams of trans fat if the food contains less than 0.5 grams of trans fat. For example, some foods will have “partially hydrogenated oil” listed on the food label. Hydrogenation should be a red flag that the product contains trans fats.

FOODIE FACTOID

Food manufacturers strive to find the perfect levels of ingredients, such as fat, in their food products to optimize palatability. This is called a bliss point, and it's how they get consumers to crave and keep purchasing their products.

Trans fats are most commonly found in shortening, margarine, creamers, crackers, cookies, packaged baked goods, deep-fried foods (french fries, doughnuts, and chicken), and snack foods (chips and microwave popcorn).

Monounsaturated Fats

Monounsaturated fats are liquid at room temperature and will solidify when refrigerated. Their chemical structure has one unsaturated bond in the fatty acid, making the molecule more susceptible to oxidation.

Even though monounsaturated fats are considered heart healthy, they’re still fats. The Dietary Guidelines for Americans recommend that Americans consume no more than 10 to 15 percent of their daily calories from monounsaturated fats like olive oil. This is equivalent to 22 to 33 grams per day. One tablespoon of olive oil provides 14 grams of fat.

The health benefits of monounsaturated fats are that they lower LDL (bad) cholesterol levels without adversely affecting your HDL (good) cholesterol levels. Some research has shown that these fats may aid in maintaining blood sugar levels and help improve the function of your blood vessels.

Food sources richest in monounsaturated fats are macadamia nut oil, avocado oil, olive oil, canola oil, macadamia nuts, almonds, cashews, and pecans.

Polyunsaturated Fats

Polyunsaturated fats are essential fatty acids that are necessary for your health. However, your body cannot make them, so you must get them from your food. They’re also considered heart healthy. Their chemical structure contains two or more unsaturated bonds in the fatty acid chain, which makes the molecule more susceptible to oxidation and spoilage.

Polyunsaturated fats are further divided into what’s called omega-3s and omega-6s, which refers to the position of the double bond in the molecule. Omega-3s and omega-6s like those found in olive and safflower oils are essential to your health. The Dietary Guidelines for Americans recommend that Americans consume no more than 10 percent of their calories from polyunsaturated fats.

The ratio of omega-6s to omega-3s in your diet can influence your risk for chronic diseases. A ratio as close to 1:1 as possible is optimal for health. However, in Western diets the ratio tends to be high in most individuals. Today, the average ratio is upwards of 10:1 and can often be as high as 30:1. Excess omega-6s compete with omega-3s, and thus impact their health benefits. A ratio that’s too high can have a negative affect on the body by increasing the risk for cardiovascular disease, cancer, and inflammatory disease.

The health benefits of polyunsaturated fats are that they lower LDL (bad) cholesterol levels. The omega-3s and omega-6s have a variety of specific functions that are beneficial to the body, including maintaining a healthy nervous system and brain function.

Omega-3s

Omega-3s are important for metabolism. These fats are most commonly found in fatty fishes such as salmon, mackerel, tuna, herring, sardines, anchovies, and trout.

Omega-3s benefit the body by reducing triglycerides, controlling irregular heartbeat, slowing plaque buildup, and lowering your blood pressure. Research shows that omega-3s also improve cardiac and vascular hemodynamics, or blood flow.

NOTABLE INSIGHT

Some research has found lower levels of depression in cultures that consume high amounts of omega-3s.

Omega-6s

Omega-6s benefit the body by improving blood sugar control, decreasing risk of diabetes, and lowering blood pressure. However, if they are eaten in excess, they can promote an inflammatory response, prevent cell repair, and eventually lead to disease. Research shows an increased risk of developing inflammatory bowel disease (IBD) with high consumption of omega-6s.

Food sources for omega-6s include safflower oil, walnut oil, sunflower oil, corn oil, and soybean corn oil. You should properly balance your intake of omega-6s with your intake of omega-3s.

Triglycerides

A triglyceride is a type of fat. Its chemical structure is made up of three fatty acids attached to a glycerol molecule. Fats from foods you eat and those made by your body don’t freely circulate in your blood. They’re packaged up into a triglyceride molecule, which typically contains a variety of fatty acids. A triglyceride is the primary storage form of fats in your body. Your body will gather any excess calories from the diet and package them into a triglyceride in order to store it inside your fat cells. An excess consumption of simple carbohydrates like sugary candies or even alcohol can easily increase triglyceride levels. Triglycerides can be released for your body to use as fuel (energy reserves), to insulate body temperature, for shock protection, and to aid the body in the metabolism of carbohydrates and protein.

The American Heart Association (AHA) recommends a triglyceride level of 100mg/dL or less. Check out the following listing to determine where your triglyceride levels rate.

Triglyceride blood levels ranges:

• Normal: Less than 150mg/dL
• Borderline high: 150-199mg/dL
• High: 200-400mg/dL
• Very high: 500mg/dL or above

A high level of triglycerides can harden your arteries and increase the risk of heart disease and stroke, along with obesity and metabolic syndrome. Other conditions that can increase triglyceride levels are uncontrolled type 2 diabetes, hypothyroidism, and liver or kidney disease. Some medications can also increase levels.

FOODIE FACTOID

The suffix -ol is used to denote a derivative representing alcohol. Examples include glycerol, sorbitol, and ethanol.

To help decrease your triglycerides, you can:

• Reduce alcohol intake.
• Manage blood sugars if diabetic.
• Stop smoking.
• Eat fewer fatty foods.

Cholesterol—the Good and the Bad

Cholesterol is so important to your body that it makes all the cholesterol it needs, so technically you would never need to eat any cholesterol-containing foods. Cholesterol is a waxy substance that’s present in all the cells in your body. Chemically, cholesterol is made up of a four-ring carbon structure. This shape reduces permeability of cell membranes and acts as a gatekeeper for certain charged molecules like sodium. Cholesterol also participates in forming bile acids, sex hormones like testosterone, adrenal hormones, and vitamin D.

Your liver manufactures cholesterol and makes about 800 to 1,500mg per day. It also recycles about 50 percent of what it produces, which is reabsorbed within the bowel and carried back into the bloodstream.

When the body makes more than it needs and/or receives too much from the diet, the extra cholesterol often affects the arteries that carry blood from your heart to your body. High levels of circulating cholesterol can damage the epithelial lining of your arteries. LDL cholesterol is especially damaging because it’s sticky and thickens your blood. As high levels of LDL circulate through your vessels, some of the LDL becomes oxidized by free radicals. Oxidized LDL encourages the accumulation of inflammatory cells in the inner lining of an artery, which attracts white blood cells and promotes their bonding to the damaged area. The site then becomes laden with more cholesterol and lipids, which continues to increase the thickness of the buildup we call plaque.

Plaque formation actually begins in the first decade of life. But plaque build-up can eventually occlude an artery, blocking blood flow completely and leading to a heart attack. A piece of plaque can also break off and create an occlusion that can cause a stroke. This hardening of the arteries is called atherosclerosis.

Most people are unaware that they have atherosclerosis until middle age when it causes pain on exertion during exercise or walking. As blood flow is restricted, it results in pain in the legs or chest. Atherosclerosis can affect arteries anywhere in the body. The plaque can burst and cause a blood clot, which can travel throughout the body. Atherosclerosis can cause coronary artery disease (CAD), peripheral artery disease (PAD), cerebrovascular disease, or angina.

Coronary artery disease occurs when the arteries that supply your heart with oxygen, blood, and nutrients become diseased or damaged. The main causes of CAD are plaque buildup and inflammation.

Peripheral artery disease is a condition in which your arteries become narrow and restrict blood flow to your limbs. It’s most often caused by atherosclerosis.

Cerebrovascular disease is a variety of disorders that affect the brain by restricting blood flow or by bleeding. A blood vessel may rupture or become narrow or blocked by a blood clot.

Additionally, plaque can cause angina, which is a reduction in adequate blood flow that can cause pain in the chest, shoulders, neck, arms, jaw, or back. This chest pain or discomfort mimics indigestion. Less severe angina commonly occurs upon exertion, such as walking, and will last about 5 minutes with rest.

WAKE-UP CALL

The National Institutes of Health (NIH) reports that more than 12.5 million Americans suffer from coronary artery disease and each year it causes 500,000 deaths.

To lower cholesterol levels, eat a low-calorie, low-fat diet and exercise 30 minutes per day. Cholesterol is found in animal food sources including meat, poultry, fish, butter, cheese, and eggs.

High-Density Lipoprotein (HDL)

HDL is considered “good” cholesterol. It’s made up of high-density lipoproteins and is a combination of protein, cholesterol, phospholipids, and triglyceride molecules. Protein is found in the greatest percentage at around 50 percent, which is a good thing. HDL’s main function is to transport cholesterol back to the liver through the blood. It also removes cholesterol deposited in the walls of blood vessels. Simply stated, HDL keeps your arteries clean and free from blockages.

An HDL cholesterol level of 60mg/dL or greater is considered good. HDL of 40mg/dL is considered low, and you’re going to want to try to increase your HDL cholesterol to prevent heart disease.

There are some people who genetically have a high level of HDL so they have added protection, but there are ways you can improve your HDL numbers:

• Replace saturated fat with monounsaturated fats
• Lose weight
• Stop smoking
• Exercise 30 to 60 minutes a day

Low-Density Lipoprotein (LDL)

LDL is considered “bad” cholesterol. It’s made up of 50 percent cholesterol, phospholipids, triglycerides, and protein molecules. The function of LDL is to transport cholesterol to the body’s cells for use in hormone synthesis. Too much can lead to a build-up of plaque in the arteries, as previously discussed.

Very low density lipoprotein (VLDL) is produced by the liver and released into the bloodstream to supply tissues with triglycerides, which make up about half of VLDL particles. VLDL numbers are often not mentioned during a cholesterol test because there’s no direct way to measure them. The number is usually derived as a percent of your triglyceride level. You can lower your VLDL by lowering your triglycerides, losing weight, exercising, and limiting your intake of sugary foods and alcohol.

It’s best to keep your intake of high-cholesterol foods at a low or moderate level to help decrease your risk of plaque accumulation. The best way to reduce your LDL cholesterol level is through proper diet and exercise. A good plan is to stop smoking if you do, and to eat foods that are low in fats and high in fiber and omega-3s.

Sometimes diet and exercise aren’t enough to bring down LDL levels and your doctor may need to prescribe a cholesterol-lowering medication to your healthy diet and exercise plan.

WAKE-UP CALL

An estimated 73.5 million American adults have high LDL levels and less than half receive treatment for it.

Total Cholesterol

The term “total cholesterol” or “total blood (serum) cholesterol” refers to the combination of LDL, VLDL, and HDL cholesterol. It’s measured by milligrams of cholesterol per deciliter of blood and is calculated by using the following equation:

HDL + LDL + 20% triglyceride level

A total score of less than 180 mg/dL is considered optimal for your health. When you receive your blood work from your doctor’s office, it’s already calculated for you. The following are the ranges of cholesterol levels:

Optimal: Below 180 mg/dL

Desireable: Below 200 mg/dL

Borderline high: 200 mg/dL – 239 mg/dL

High: Above 240 mg/dL

The higher your cholesterol level is, the greater your risk of heart disease. People with high cholesterol can also develop a medical condition known as xanthoma. It’s important to know your numbers. Most physicians recommend cholesterol testing every 5 years or sooner if your lab results are outside of the normal range or if other risk factors are present.

DEFINITION

Xanthoma is a skin condition in which cholesterol-rich material is deposited under the surface of the skin. This is most commonly associated with medical conditions that increase blood lipids, such as hyperlipidemia, diabetes, and pancreatitis.

Cholesterol Ratio

Health professionals use the cholesterol ratio to predict your risk of heart disease. To determine your ratio, divide your HDL number by your total cholesterol number. An optimal ratio is less than 3.5:1.0. The greater the cholesterol ratio, the higher your risk of heart disease. This is believed to be a better predictor of heart disease than simply using your LDL or total blood cholesterol levels.

This test accounts for your HDL levels. Two people with the same cholesterol level can have different cholesterol ratios. For example, if you take two people who both have a cholesterol level of 160 but have different HDL levels, they won’t have the same ratio. One person has an HDL of 60, so his ratio is 2.7. The other person has an HDL level of 30, so her cholesterol ratio is 5.3. This person would be at an increased risk for developing heart disease.

How to Improve Your Numbers

Changing your diet and lifestyle is the first step toward achieving healthy lipid levels. Research has shown that losing 5 to 10 percent of your total body weight can improve your health. Those who lose weight gradually are more successful at keeping it off and continuing with a healthy lifestyle.

Here are 10 tips to lower your cholesterol and increase your HDL:

1. Aim to lose 5 to 10 percent of your body weight.

2. Work toward a goal of 30 minutes of exercise daily.

3. Decrease or eliminate sources of saturated and trans fats in your diet.

4. Use only healthy fats in your diet.

5. Eat two or more servings of foods rich in omega-3s weekly.

6. Stop smoking.

7. Drink alcohol in moderation.

8. Replace simple carbohydrates with high-fiber foods.

9. Add nuts to your diet.

10. Learn to relax through meditation or yoga.

Discovering Healthy Fats in Foods

Fat is a flavor carrier, but a little will go a long way. If you eat too much fat, as we learned earlier, it will be stored in your body’s cells as energy reserves. However, the problem is we never seem to need those extra reserves. We just keep adding more to the stockpile and thus more body weight, which is detrimental to health. Consequently, it’s important to choose a healthier type of fat to use in your meals that provides all the health benefits with a taste you can enjoy.

Keep in mind that most Americans consume an unbalanced ratio of essential fatty acids. We have too much omega-6s and too few omega-3s in our diets. So it makes sense that great fats to use in your diet would be ones high in omega-3s.

Top Sources of Heart-Healthy Omega-3 Fats in Foods

Healthier fats can be found in fatty fish, fruits, nuts, oils, and whole grains. The following table includes some of the best sources for omega-3 fats.

Top Sources of Omega-3s

FOODIE FACTOID

Consuming approximately two 3-ounce servings of fatty fish each week is recommended for their health benefits. However, it’s important to limit fish that contain high levels of mercury, including king mackerel, swordfish, shark, and tile fish. Seafood with low levels of mercury but high levels of omega-3s include flounder, herring, salmon, oysters, and canned light tuna.

Healthy Fats Recipe

This recipe highlights the use of healthy fats such as monounsaturated-rich olive oil and omega-3–containing walnuts.

Beet Greens Pesto

4 cups beet greens, stems removed and roughly chopped

2 garlic cloves

2 TB. lemon juice

⅓ cup Parmesan cheese, freshly grated

¼ cup walnuts, chopped and toasted

¼ tsp. kosher salt

⅛ tsp. black pepper

5 TB. extra virgin olive oil

1. Bring a pot of salted water to a boil. Place chopped beet greens in boiling water for 2 minutes. Remove from water and place directly into a bowl of ice water. Let greens stand in ice water for 2 minutes. Drain water and squeeze greens to remove excess water.

2. Add beet greens, garlic, lemon juice, Parmesan cheese, walnuts, salt, and pepper to a food processor fitted with a chopping blade. Turn machine on and slowly drizzle in olive oil while the machine is running for 1 minute, or until mixture is completely combined and smooth. Season with additional salt and pepper to taste.

The Least You Need to Know

• Fat is a flavor carrier and provides satiety in your diet. Eating a little bit of healthy fat may help you eat less later in the day.
• Some people overproduce cholesterol, and when exercise and healthy eating can’t lower the numbers, your doctor may prescribe a cholesterol-lowering medication along with a healthy diet and regular exercise.
• Heart-healthy fats can be found in certain types of fish, nuts, and oils, and whole grains.