Important Fats For The Body This section is compiled by Frank M. Painter, D.C.
Send all comments or additions to: Frankp@chiro.org
From the November 1996 issue of Nutrition Science News
Excess calories, not fat, cause obesity, and essential fatty acids are crucial to maintaining health.
"Save your heart-eat less fat." This is a fallacy believed by many. People follow the simplified formula by eating traditionally low-fat foods such as bread, pasta and cereal. Manufacturers supplement consumer buying trends with low-fat cookies, crackers and treats.
The result?
Statistics show that Americans are fatter than ever and no closer to avoiding heart disease than they were before the no-fat craze. Mainly this is because excess calories, not fat, cause obesity and its slew of health hazards-a detail that got lost somewhere between the lab and the food store. It's also because most consumers are replacing their fats with carbohydrates. Carbohydrates do have less calories than fat, but a constant diet of them can still lead to weight gain. All the extra calories in bread and pasta that aren't used for energy are converted into fat and stored in the body, just like a hamburger would be. Even more problematic is that without the proper safeguards, a low-fat diet may also put people at risk for serious health problems such as cardiovascular disease, stroke and atherosclerosis.
The Role Of Fats
The link between high-calorie foods (including saturated fats) and heart disease is long established. But swearing off all fats isn't the answer. Some fats are good for you, especially the essential fatty acids (EFAs) found in certain plants, seeds, oils and cold-water fish.
Studies have shown that consuming a diet rich in fish oil not only helps to lower blood cholesterol, triglycerides and low-density lipoproteins (LDL, the bad cholesterol), it also raises levels of beneficial high-density lipoproteins (HDL, the good cholesterol). EFAs also help regulate cellular oxygen use, electron transport, energy production, hemoglobin formation, blood pressure, cholesterol transport and immune functions. Unaware of the importance of EFAs, many consumers confuse them with fats that really are bad for their health.
There are three types of fat: saturated, monounsaturated and polyunsaturated. Each is a mixture of different fatty acids, and each plays an important role in the body after it's ingested. The specific amount of each fatty acid and its respective molecular structure determine whether the fat is a solid or liquid.
Saturated fats such as beef fat and hydrogenated oils form solids at room temperature because they are straight molecules. Monounsaturated fats, including olive oil, have one "kink" or bend in their structure and remain liquid (except in the refrigerator). The body can make both saturated and monounsaturated fats, so they are called nonessential.
Polyunsaturated fats are a different story. Even in the refrigerator they remain liquid because of two kinks in their molecular structure. The human body can't manufacture polyunsaturated fats; they must be supplied by dietary sources.
Only two types of polyunsaturated fatty acids are considered essential: omega-6 (called linoleic acid or LA) and omega-3 (called alpha-linolenic acid or LNA). Other important fatty acids that aren't essential are derived from EFAs. Gamma-linolenic acid (GLA) and arachidonic acid (AA) are both made from linoleic acid, while eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are derived from alpha-linolenic acid.
Essential fatty acids are nutritionally important because they're precursors to a group of hormone-like compounds known as prostaglandins, thromboxanes and prostacyclins that help regulate the central nervous system, blood pressure and heart rate. EFAs are also required to make phosphatides, the main structural components of all cell membranes.
Omega-3 and omega-6 fatty acids generally promote the production of PGE3- and PGE1-series prostaglandins that are anti-inflammatory in nature. These forms of prostaglandins help keep blood platelets from sticking together, open up blood vessels and slow down cholesterol production. They may also help prevent cancer cell growth by regulating the rate of cell division.
Arachidonic acid, found mostly in animal foods but also derived from omega-6 fatty acids, produces PGE2-series prostaglandins that are inflammatory in nature-promoting blood clotting, blood vessel restriction and salt retention, which can lead to water retention and high blood pressure. These are valuable functions under survival conditions; however, under chronic stress they become detrimental. A good supply of omega-3 fatty acids counters overproduction of AA in the body and helps strike a healthy balance between the different types of prostaglandins.
Beyond Heart Disease
The list of EFAs' health benefits keeps growing. In addition to lowering the risk of heart disease, EFA supplements have proven beneficial in the treatment of a wide range of conditions including allergies, inflammation, ulcerative colitis and multiple sclerosis.
For example, omega-3 EFA is helpful in treating rheumatoid arthritis, a disease characterized by pain and inflammation. In 1985, after animal studies conducted at Harvard University in Cambridge, Mass., indicated that EFAs help protect the body against attacks by its own immune system (i.e., arthritis), Joel Kremer, M.D., associate professor of medicine at Albany Medical College in New York, conducted a controlled experiment using EFAs. Kremer found that fish oil supplements significantly improved the health of people with rheumatoid arthritis. "Those taking fish oil had only about half the number of tender joints as they had prior to the study," he reported.
Essential fatty acid supplements can also result in gradual weight loss among people who are genetically obese. Although it's unclear how the weight loss occurs, it may be linked to EFAs' ability to "trigger" brown fat, the most metabolically active form of fat, to maintain a high heat-producing rate of metabolism.
Getting The Right Fats
Even diets full of polyunsaturated fats can be unhealthy. Deep-frying damages EFAs, and food-processing methods such as hydrogenation change polyunsaturated fats into more saturated fats. Done to promote shelf-stability, the process also creates detrimental trans fatty acids-thought to both raise cholesterol and crowd out EFAs in the cells. Probably the least expensive way to supplement the diet with a good source of EFAs is to eat more cold-water fish, whole grains, good quality nuts and seeds, dark-green leafy vegetables, and soybeans; cook with good quality vegetable oils; and incorporate small amounts of supplemental oils in meals.
Although supplemental oils vary in their essential fatty acid content, all can exert healthful effects. Store-bought, extracted EFA oils including flaxseed, borage and evening primrose oils are easily oxidized (which results in trans fatty acids), so they should never be heated and are best stored in the refrigerator and consumed by the expiration date. Following is a list of some supplemental oils that are good sources of EFAs:Fish Oil: Cold, saltwater fatty fish such as salmon, herring, cod, mackerel, sardines and tuna are excellent sources of essential fatty acids. When given in supplement form, fish oils rich in the omega-3 fatty acids EPA and DHA have produced changes in blood platelets associated with a reduced risk of heart disease. Omega-3 fatty acids also help reduce the blood's tendency to clot.
DHA: Often called "brain oil," DHA is the latest fish oil to hit the market. This particular fatty acid, derived from cold-water fish such as tuna and salmon, reportedly reduces blood cholesterol without the side effects of blood clot prevention. Researchers also document its ability to inhibit certain cancers and heart disease as well as aid brain function.
Flaxseed (Linum usitatissimum): A rich, deep-golden oil derived from seeds of the fibrous flax plant, flaxseed oil contains both LA and LNA and is one of the richest sources of omega-3 fatty acids. Flaxseed oil is also a good source of lecithin and phosphatides, which aid in the digestion of fats and oils. It's a good vegetarian supplement for people with omega-3 deficiency-related fatty degeneration.
Evening Primrose (Oenothera biennis): Used for healing by North American natives, the evening primrose plant was soon sent back to Europe by the colonists, where it was dubbed the "king's cure-all." It's been shown to significantly reduce the painful symptoms of rheumatoid arthritis and certain autoimmune diseases. Rich in GLA and other omega-6 fatty acids, evening primrose oil has proved effective in reducing the itchiness associated with atopic eczema. It's also used to treat PMS, allergies, depression, colitis and liver degeneration.
Borage (Borago officianalis): Used during the Middle Ages to ensure blood quality, borage oil was later recommended for depression and heart strength. It's derived from borage plant seeds and is high in GLA, an omega-6 fatty acid. It's been used in conjunction with arthritis, allergies, multiple sclerosis, cancer and PMS.
Pumpkin Seed (Cucurbita pepo): Pumpkin seeds produce a dark green oil that has been used throughout history in India, Europe and America to nourish and heal the digestive tract, fight parasites, heal prostate disorders and help prevent dental cavities. It contains slightly more omega-3 fatty acids than omega-6, making it one of the most nutritious oils. Pumpkin seed oil is also recommended for pregnant and lactating women because of its high EFA content.
Wheat Germ: Wheat germ oil contains alpha-linolenic acid (LNA) and is also a good source of a 28-carbon fatty alcohol (octacosanol), which protects heart function and may help nerve regeneration. It's also one of the richest sources of vitamin E and is often used externally for burns, sores and other skin problems.
Conclusion
It is important that your customers and clients don't swear off fats completely, particularly EFAs. As seen above, essential fatty acids are nutritionally important for the numerous roles they play in maintaining healthy body functions. Fortunately, nature has provided an abundance of foods that contain EFAs. Adding them to the diet can provide an initial defense against a whole host of diseases.
This article is compiled from information that appeared in the book Essential Fatty Acids in Health and Disease by Edward Siguel, M.D., Ph.D., (Nutrek Press, 1994) and two articles that ran in Delicious! Magazine: "The Fats That are Good for You," October 1996, vol. 12, number 10, and "A New Generation of Healthy Oils," January 1996, vol. 12, number 1.
BibliographyMurray, M. & Pizzorno, J. Encyclopedia of Natural Medicine. Prima Publishing. Rocklin, CA, 1991.
Braly, J. & Torbert, L. Dr. Braly's Food Allergy and Nutrition Revolution. Keats Publishing: New Canaan, CT, 1992.
Siguel, E. Essential Fatty Acids in Health and Disease. Nutrek Press: Brookline, MA, 1994.
Erasmus, U. Fats That Heal, Fats That Kill. Alive Books: Burnaby, B.C., CANADA, 1993.
Finnegan, J. The Facts About Fats. Celestial Arts: Berkeley, CA, 1993. Barilla, J. The Good Fats And Oils. Keats Publishing: New Canaan, CT, 1996
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