The Big FAT Debate: Part 2 (Article from Competition Zone.com)
Last months article (Part 1) reviewed the different types of fat in our diets. This article discusses the benefits and sources of unsaturated and essential fatty acids
There are two types of unsaturated fatty acids that are categorized based on their chemical structure. Mono-unsaturated fatty acids (MUFA) contain one carbon double bond, whereas polyunsaturated fatty acids (PUFA) contain two or more carbon double bonds. The fatty acids may also be referred to as long or short-chain fatty acids, depending on the number of carbons that make up the fatty acid chain. This chemistry plays a role in how your body uses these fatty acids.
Monounsaturated Fatty Acids…The Cholesterol Busters
In the 1980’s the beneficial effects of the “Mediterranean” diet (rich in olive oil) were discovered. Researchers found that the high amounts of MUFA had beneficial effects on blood cholesterol levels, by decreasing “bad” cholesterol levels (LDL cholesterol). Olive and canola oils have the highest amount of MUFA compared to other fat sources. Other potential health benefits include prevention of blood clots and antioxidant properties (cancer fighters).
Polyunsaturated Fatty Acids…The Essentials
There are many different forms of PUFA due to the various lengths and chemical structures. Our bodies can manipulate a fatty acid to suit its needs such as for energy production, cell wall structures and hormone production. However there are some fatty acids it can not produce. These must be obtained from our diet, and are considered essential.
Essential fatty acids come from the omega 3 and omega 6 families, and play a role in our body’s inflammatory response. They come in various forms depending on the number of carbons in their chemical chain structure (i.e. short-chain and long-chain varieties). The “omega” notes the placement of the first double bond from the methyl end of the fatty acid chain.
Omega 6 vs. Omega 3…The Balancing Act
Below is a list of food sources of omega 6 and omega 3 fatty acids. To get enough omega 6 fatty acids through the diet is easy (in some cases too easy). On the other hand, obtaining adequate amounts of omega 3 fatty acids through the diet can be difficult. Good food sources of omega 3 fatty acids are not as common in the North American diet compared to sources of omega 6’s. Although we need certain amounts of both types of fatty acids it is important to have a balance between the two.
In recent years there has been concern that the “Western” diet does not contain enough omega 3 fatty acids to “balance out” the intake of omega 6’s. Omega 6 fatty acids competes with the omega 3s within the body for cell membrane and metabolic pathway positioning (kind of like the beginning of a swim in a triathlon). Omega 6 fatty acids are precursors for inflammatory “messengers” (eicosanoids) in the body. Where as, omega 3 fatty acids are recognized for their beneficial anti-inflammatory effects. If your diet contains high amounts of omega 6 fatty acids and lower amounts of omega 3’s you may be increasing your risk of negative health effects such and increased inflammatory diseases and cardiovascular disease.
Food Sources of Essential Fatty Acids
______________________Omega 6 Fatty Acids__________________________Omega 3 Fatty Acids ___________________________
Short Chain Long Chain Short Chain Long Chain (Linoleic acid) (DGLA and AA)* (Linolenic acid) (EPA, DPA, DHA)* Corn oilEggsFlaxseed (oil)Salmon Sunflower oilDairy products Walnut (oil) Herring Safflower oil Meats Canola oil Mackerel Canola oil Poultry Soybean (oil)Sardines
*DGLA= dihomo-gamma-linolenic acid; AA = arachidonic acid;
EPA = eicosapentaenoic acid; DPA = docosapentaenoic acid;
DHA = docosapentaenoic acid
Potential Benefits for Athletes
The benefits of supplementing the diet with essential fatty acids, primarily in the forms of salmon and flaxseed oils, are being researched for many chronic inflammatory conditions such as asthma, arthritis and inflammatory bowel disease. The effects of a diet high in omega 3 fatty acids can be compared to the effects of anti-inflammatory drugs such as aspirin and ibuprofen. For an athlete, a diet high in omega 3 fatty acids has the potential for enhancing recovery and decreasing muscle inflammation after a hard workout of race.
The best forms of omega 3 fatty acids are the long-chain varies (EPA and DHA). The body most efficiency uses the forms to produce the beneficial eicosanoids and hence a more potent anti-inflammatory response. The best dietary source of these fatty acids are fish oils, salmon being one of the most popular.
By making some small dietary changes you can decrease the amount of omega 6 fatty acids that you eat and increase the amount of omega 3s. The following are some suggestions to try:
1) Change your selections of sandwich fillings from beef or ham to salmon or tuna.
2) When eating-out choose a salmon entrée.
3) Rather than toast with butter or margarine have cereal with ground flaxseed for breakfast. (Grind flaxseed in a clean coffee grinder and store in an airtight container in the fridge.)
4) Rather than a cookie or muffin for mid-day snack make a mix of dried cereal, walnuts and dried fruit.
5) Use soymilk rather than milk to make fruit smoothies.
This article was prepared by Kim Sorenson (Triathlete and Registered Dietitian and Nutritionist). Kim is coached by Coach Joel Filliol at Canada's National Triathlon Training Centre in Victoria BC.
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