Question of the Week

January 2, 2008


With the new year upon us, one common New Year's resolution is to "eat better." While it can not only be challenging to make the changes in one's diet, it can also be a challenge to know what changes need to be made.

While "Eat a low fat diet" or "Eat less fat" may seem like straightforward decisions, in this world of food choices, hardly anything is as simple as it sounds. That said, as people understand more about the fats in their diets, labels become less confusing, and healthy choices are easier to make.

"Fats are organic compounds that are made up of carbon, hydrogen, and oxygen. They are a source of energy in foods. Fats belong to a group of substances called lipids, and come in liquid or solid form. All fats are combinations of saturated and unsaturated fatty acids."

While it may seem like a good thing for people to eat "non-fat" versions of the foods they like, some fat is essential.

"Your body needs fat to function properly. Besides being an energy source, fat is a nutrient used in the production of cell membranes, as well as in several hormone-like compounds called eicosanoids. These compounds help regulate blood pressure, heart rate, blood vessel constriction, blood clotting and the nervous system. In addition, dietary fat carries fat-soluble vitamins -- vitamins A, D, E and K -- from your food into your body. Fat also helps maintain healthy hair and skin, protects vital organs, keeps your body insulated, and provides a sense of fullness after meals."

When it comes to fat, "quantity" is only part of the equation; quality is equally, if not more, important.

"'Eat a low-fat, low-cholesterol diet.' Most of us have heard this simple recommendation so often over the past two decades that we can recite it in our sleep. Touted as a way to lose weight and prevent cancer and heart disease, it's no wonder much of the nation - and food producers - hopped on board. Unfortunately, this simple message is now largely out of date. ... What is becoming clearer and clearer is that bad fats, meaning saturated and trans fats, increase the risk for certain diseases while good fats, meaning monounsaturated and polyunsaturated fats, lower the risk. The key is to substitute good fats for bad fats."

Where it gets confusing for many is figuring out which are the good fats, which are the bad fats, and which foods contain each of these.

"Basically, trans fat is made when manufacturers add hydrogen to vegetable oil--a process called hydrogenation. Hydrogenation increases the shelf life and flavor stability of foods containing these fats. Trans fat can be found in vegetable shortenings, some margarines, crackers, cookies, snack foods, and other foods made with or fried in partially hydrogenated oils. Unlike other fats, the majority of trans fat is formed when food manufacturers turn liquid oils into solid fats like shortening and hard margarine. A small amount of trans fat is found naturally, primarily in some animal-based foods. Trans fat, like saturated fat and dietary cholesterol, raises the LDL cholesterol that increases your risk for CHD."

It is recommended that people remove all trans fat from their diets while they keep the saturated fat to a minimum.

"Eating too much saturated fat is one of the major risk factors for heart disease. A diet high in saturated fat causes a soft, waxy substance called cholesterol to build up in the arteries. Too much fat also increases the risk of heart disease because of its high calorie content, which increases the chance of becoming obese (another risk factor for heart disease and some types of cancer). A large intake of polyunsaturated fat may increase the risk for some types of cancer. Reducing daily fat intake is not a guarantee against developing cancer or heart disease, but it does help reduce the risk factors."

While trans fat is predominantly found in processed foods, saturated fat occurs naturally.

"Saturated fat is the main dietary cause of high blood cholesterol. Saturated fat is found mostly in foods from animals and some plants. Foods from animals include beef, beef fat, veal, lamb, pork, lard, poultry fat, butter, cream, milk, cheeses and other dairy products made from whole and 2 percent milk. All of these foods also contain dietary cholesterol. Foods from plants that contain saturated fat include coconut, coconut oil, palm oil and palm kernel oil (often called tropical oils), and cocoa butter."

There are health concerns associated with trans fat and saturated fat, but this does not mean that all fat should be completely avoided.

"[Unsaturated fats] help to lower blood cholesterol if used in place of saturated fats. However, unsaturated fats have a lot of calories, so you still need to limit them. Most (but not all!) liquid vegetable oils are unsaturated."

Good or bad, fat is a high calorie food. While every gram of fat has the same amount of calories, some fats are better than others (when eaten in moderation).

"Polyunsaturated and monounsaturated fats are the two unsaturated fats. They're found mainly in many fish, nuts, seeds and oils from plants. Some examples of foods that contain these fats include salmon, trout, herring, avocados, olives, walnuts and liquid vegetable oils such as soybean, corn, safflower, canola, olive and sunflower. Both polyunsaturated and monounsaturated fats may help lower your blood cholesterol level when you use them in place of saturated and trans fats in your diet. But a moderate intake of all types of fat is best. Keep total fat intake between 25 and 35 percent of calories, with most fats coming from sources of polyunsaturated and monounsaturated fatty acids such as fish, nuts and vegetable oils."

Moderation is key. It may seem logical that "since less fat is good, no fat is better," but this is not the case. People need fat in their diets in order to break down fat-soluble vitamins and have the nutrients their bodies need for proper development and growth.

Additionally, "Omega-3 fatty acids are considered essential fatty acids. They are essential to human health but cannot be manufactured by the body. For this reason, omega-3 fatty acids must be obtained from food. Omega-3 fatty acids can be found in fish, such as salmon, tuna, and halibut, other marine life such as algae and krill, certain plants (including purslane), and nut oils. Also known as polyunsaturated fatty acids (PUFAs), omega-3 fatty acids play a crucial role in brain function as well as normal growth and development."

"Extensive research indicates that omega-3 fatty acids reduce inflammation and help prevent risk factors associated with chronic diseases such as heart disease, cancer, and arthritis. These essential fatty acids are highly concentrated in the brain and appear to be particularly important for cognitive (brain memory and performance) and behavioral function. In fact, infants who do not get enough omega-3 fatty acids from their mothers during pregnancy are at risk for developing vision and nerve problems. Symptoms of omega-3 fatty acid deficiency include extreme tiredness (fatigue), poor memory, dry skin, heart problems, mood swings or depression, and poor circulation."

Questions of the Week: Why is fat important? How can you know what kinds of fat are in the foods you are eating? How can you determine how much fat should be replaced and how much should be removed from your diet? What can you do to reduce the amount of "bad fats" in your diet while replacing those that should be replaced with "good fats"? Does "low fat" mean healthy (or healthier)? How might a "low fat" version be worse than the "real" food?

Please email me with any ideas or suggestions.
Note: Due to increasing amounts of SPAM sent to this account, please include "QOW" in the subject line when sending me email.

I look forward to reading what you have to say.

Health Community Coordinator
Access Excellence @ the National Health Museum

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