(This is an extract from a document prepared by Alan J Snow.)
Omega 3 Fatty Acids:
Omega 3 is a general description for the highly polyunsaturated fatty acids in fish oils. It refers to the position in the fatty acid chain (three carbons away from the end of the chain). This is the position of the first double bond or pair of missing hydrogens in the polyunsaturated fatty acids in fish oils. Omega 3 fatty acids normally have 15, 17 or 19 carbon atoms.
Fish oils are the richest source of Omega 3 fatty acids. The major Omega 3 fatty acids in fish are:
EPA (eicosapentaenoic acid), and
DHA (docosahexaenoic acid).
Linolenic acid is an omega 3 fatty acid found in small amounts in plants but its fatty acid chain is not as long nor as unsaturated as omega 3 fatty acids from fish oil.
Research has shown that the consumption of fatty fish causes a dramatic reduction in the levels of triglycerides in the blood, even in people with extraordinarily high triglyceride levels. Consumption of fish oil actually restored blood triglycerides to their normal range in people with very high triglyceride levels.
One of the major benefits associated with the consumption of seafood is the presence omega 3 fatty acids. These fatty acids are principally found in seafood and have been shown to play a role in both controlling and treating coronary heart disease, types of asthma, and possibly even cancer.
The body’s immune system is responsible for reactions that we call inflammatory responses. Examples of these responses are:
*coughing and wheezing of asthma attacks,
*red weals of hives,
*sneezing of hay fever,
*pain of arthritis.
These symptoms are caused by the immune system of the body using its forces to combat the invasion by foreign particles.
Prostaglandins are a group of highly reactive compounds made from polyunsaturated fatty acids. The consumption of omega 3’s influence prostaglandin metabolism in specialized cells in the body.
Diseases of the coronary arteries that supply oxygen and nutrients to the heart is the most common heart ailment. Coronary heart disease is characterized by an atheroma, a fatty deposit of cholesterol beneath the inner lining of the artery. The atheroma obstructs the passage of blood thereby, reducing the flow nourishment to the heart muscle. It also sets up conditions for a blood clot in the coronary artery.
There are a number of contributing factors to heart disease.
*a family history of heart disease;
*eating foods which are rich in saturated animal fat and cholesterol;
*hypertension or high blood pressure;
*high cholesterol levels in the blood.
Platelets are small cells in the blood responsible for blood clotting. They have the ability to clump together to form a clot at the site of a wound. They can also stick to the side of blood vessels that have been damaged by arteriosclerosis, a thickening of the arterial wall. When the flow of blood to the heart is restricted by these lipid deposits and platelet clumps, a heart attack can occur. A similar process to the brain is called a stroke.
The consumption of foods rich in Omega 3 fatty acids reduce the incidence of heart disease by:
*lowering the level of triglycerides in the body;
*reducing blood clotting by lowering blood viscosity;
*reducing inflammation in conditions such as rheumatoid arthritis and asthma;
*improving the immune system.
Only animals that are part of the food chain from the sea have these long chain omega-3 fatty acids available for consumption. This is because these substances are made in the first place by phytoplankton — the tiny aquatic plants that serve as food for small fish and produce oxygen for the atmosphere. Fish devouring other fish accumulate fats and the omega-3 fatty acids become concentrated through the food chain.
When we eat seafood rich in omega 3 fatty acids, the omega 3’s become part of the platelet membranes. Once there, they inhibit the growth of blood clotting material in platelets thus having the effect of slowing the formation of blood clots which would prevent the flow of blood to the heart or brain. This has the effect of greatly reducing the risk of having a heart attack or stroke.
Fish Oils: The Essential Nutrients
by Hans R. Larsen, MSc ChE
There are good fats and there are bad fats. Artificially produced trans-fatty acids are bad in any amount and saturated fats from animal products should be kept to a minimum. The best fats or oils rather, since they are liquid at room temperature, are those that contain the essential fatty acids so named because without them we die. Essential fatty acids are polyunsaturated and grouped into two families, the omega 6 EFAs and the omega 3 EFAs.
Seemingly minor differences in their molecular structure make the two EFA families act very differently in the body. While the metabolic products of omega-6 acids promote inflammation, blood clotting, and tumor growth, the omega 3 acids act entirely opposite. Although we do need both omega 3s and omega 6s it is becoming increasingly clear that an excess of omega 6 fatty acids can have dire consequences. Many scientists believe that a major reason for the high incidence of heart disease, hypertension, diabetes, obesity, premature aging, and some forms of cancer is the profound imbalance between our intake of omega 6 and omega 3 fatty acids. Our ancestors evolved on a diet with a ratio of omega 6 to omega 3 of about 1:1. A massive change in dietary habits over the last few centuries has changed this ratio to something closer to 20:1 and this spells trouble.
Sources and requirements
The main sources of omega 6 fatty acids are vegetable oils such as corn oil and soy oil that contain a high proportion of linoleic acid. Omega 3 acids are found in flaxseed oil, walnut oil, and marine plankton and fatty fish. The main component of flaxseed and walnut oils is alpha-linolenic acid while the predominant fatty acids found in fatty fish and fish oils are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The most beneficial and active of these fatty acids are EPA and DHA. Alpha linolenic acid can be converted to EPA and DHA in the body, but the conversion is quite inefficient especially in older people.
Scientists were first alerted to the many benefits of EPA and DHA in the early 1970s when Danish physicians observed that Greenland Eskimos had an exceptionally low incidence of heart disease and arthritis despite the fact that they consumed a high-fat diet. Intensive research soon discovered that two of the fats (oils) they consumed in large quantities, EPA and DHA, were actually highly beneficial. More recent research has established that fish oils (EPA and DHA) play a crucial role in the prevention of atherosclerosis, heart attack, depression, and cancer. Clinical trials have shown that fish oil supplementation is effective in the treatment of many disorders including rheumatoid arthritis, diabetes, ulcerative colitis, and Raynaud’s disease.
Recognizing the unique benefits of EPA and DHA and the serious consequences of a deficiency the US National Institutes of Health recently published Recommended Daily Intakes of fatty acids. They recommend a total daily intake of 650 mg of EPA and DHA, 2.22 g/day of alpha-linolenic acid and 4.44 g/day of linoleic acid. Saturated fat intake should not exceed 8 per cent of total calorie intake or about 18 g/day.
Good for the brain and children too. The human brain is one of the largest “consumers” of DHA. A normal adult human brain contains more than 20 grams of DHA. Low DHA levels have been linked to low brain serotonin levels which again are connected to an increased tendency to depression, suicide, and violence. A high intake of fish has been linked to a significant decrease in age-related memory loss and cognitive function impairment and a lower risk of developing Alzheimer’s disease. A recent study found that Alzheimer’s patients given an omega 3 rich supplement experienced a significant improvement in their quality of life.
Several studies have established a clear association between low levels of omega 3 fatty acids and depression. Other studies have shown that countries with a high level of fish consumption have fewer cases of depression. Researchers at Harvard Medical School have successfully used fish oil supplementation to treat bipolar disorder (manic-depressive illness) and British researchers report encouraging results in the treatment of schizophrenia.
An adequate intake of DHA and EPA is particularly important during pregnancy and lactation. During this time the mother must supply all the baby’s needs for DHA and EPA because it is unable to synthesize these essential fatty acids itself. DHA makes up 15 to 20% of the cerebral cortex and 30 to 60% of the retina so it is absolutely necessary for normal development of the fetus and baby. There is some evidence that an insufficient intake of omega 3 fatty acids may increase the risk of premature birth and an abnormally low birth weight. There is also emerging evidence that low levels of omega 3 acids are associated with hyperactivity in children.
The constant drain on a mother’s DHA reserves can easily lead to a deficiency and some researchers believe that preeclampsia (pregnancy-related high blood pressure) and postpartum depression could be linked to a DHA deficiency. Experts recommend that women get at least 500-600 mg of DHA every day during pregnancy and lactation. The easiest way to ensure this intake is to take a good fish oil supplement daily.
Researchers at the University of Sydney have found that children who regularly eat fresh, oily fish have a four times lower risk of developing asthma than do children who rarely eat such fish. They speculate that EPA present in the fish may prevent the development of asthma or reduce its severity by reducing airway inflammation and responsiveness. Researchers at the University of Wyoming have found that supplementation with 3.3 grams/day of fish oil markedly reduces breathing difficulties and other symptoms in asthma patients. Other research has found fish oil to be beneficial in the treatment of other lung diseases such as cystic fibrosis and emphysema.
The heart’s best friend
An enormous amount of medical literature testifies to the fact that fish oils prevent and may help to ameliorate or reverse atherosclerosis, angina, heart attack, congestive heart failure, arrhythmias, stroke, and peripheral vascular disease. Fish oils help maintain the elasticity of artery walls, prevent blood clotting, reduce blood pressure and stabilize heart rhythm.
Danish researchers have concluded that fish oil supplementation may help prevent arrhythmias and sudden cardiac death in healthy men. An Italian study of 11,000 heart attack survivors found that patients supplementing with fish oils markedly reduced their risk of another heart attack, a stroke or death. A group of German researchers found that fish oil supplementation for 2 years caused regression of atherosclerotic deposits and American medical researchers report that men who consume fish once or more every week have a 50% lower risk of dying from a sudden cardiac event than do men who eat fish less than once a month.
Greek researchers report that fish oil supplementation (10 grams/day) reduces the number of attacks by 41% in men suffering from angina. Norwegian medical doctors have found that fish oil supplementation reduces the severity of a heart attack and Indian researchers report that supplementation started immediately after a heart attack reduces future complications. Bypass surgery and angioplasty patients reportedly also benefit from fish oils and clinical trials have shown that fish oils are safe for heart disease patients. The evidence is indeed overwhelming. An adequate daily intake (about 1 gram) of EPA and DHA is essential to maintain a healthy heart. Fish oils are especially important for diabetics who have an increased risk of heart disease.
Researchers at the University of Cincinnati have found that supplementing with as little as 2 grams/day of fish oil (410 mg of EPA plus 285 mg of DHA) can lower diastolic pressure by 4.4 mm Hg and systolic pressure by 6.5 mm Hg in people with elevated blood pressure. Enough to avoid taking drugs in cases of borderline hypertension. Several other clinical trials have confirmed that fish oils are indeed effective in lowering high blood pressure and that they may work even better if combined with a program of salt restriction.
Reduces pain and helps prevent cancer
Fish oils are particularly effective in reducing inflammation and can be of great benefit to people suffering from rheumatoid arthritis or ulcerative colitis. Daily supplementation with as little as 2.7 grams of EPA and 1.8 grams of DHA can markedly reduce the number of tender joints and increase the time before fatigue sets in. Some studies have also noted a decrease in morning stiffness and at least two clinical trials concluded that arthritis patients who took fish oils could eliminate or sharply reduce their use of NSAIDs and other arthritis drugs.
Patients with ulcerative colitis have abnormally low blood levels of EPA. Clinical trials have shown that supplementation with fish oil (2.7 grams of EPA and 1.8 grams of DHA daily) can reduce the severity of the condition by more than 50% and enable many patients to discontinue anti-inflammatory medication and steroids.
There is now also considerable evidence that fish oil consumption can delay or reduce tumor development in breast cancer. Studies have also shown that a high blood level of omega 3 fatty acids combined with a low level of omega 6 acids reduces the risk of developing breast cancer. Daily supplementation with as little as 2.5 grams of fish oils has been found effective in preventing the progression from benign polyps to colon cancer and Korean researchers recently reported that prostate cancer patients have low blood levels of omega 3 fatty acids. Greek researchers report that fish oil supplementation improves survival and quality of life in terminally ill cancer patients.
Safe and easily available
It is estimated that 85% or more of people in the Western world are deficient in omega 3 fatty acids and most get far too much of the omega 6 fatty acids. Vegetarian diets, for example, tend to be very high in omega 6.
The recommended daily intake of EPA plus DHA is about 650 mg rising to 1000 mg/day during pregnancy and lactation. Clinical trials have used anywhere from 1 g/day to 10 g/day, but little additional benefit has been observed at levels above 5 g/day of EPA and DHA combined. The benefits of therapeutic supplementation may become evident in a few weeks when blood parameters (triglycerides, fibrinogen) are involved, but may take 3 months or longer to materialize in degenerative diseases like atherosclerosis and rheumatoid arthritis.
The processing and packaging of the fish oil are crucial in determining its quality. Low quality oils may be quite unstable and contain significant amounts of mercury, pesticides, and undesirable oxidation products. High quality oils are stabilized with adequate amounts of vitamin E and are packaged in individual foil pouches or other packaging impervious to light and oxygen. Some very recent research carried out at the University of Minnesota found that emulsified fish oils are much better absorbed than the straight oils in gelatin capsules.
Cod liver oils and fish oils are not the same. Cod liver oil is extracted from cod liver and is an excellent source of vitamins A and D. Fish oils are extracted from the tissues (flesh) of fatty fish like salmon and herring and are good sources of EPA and DHA. Fish oils contain very little vitamin A and D, but cod liver oil does contain EPA and DHA. However, you would probably exceed the recommended daily intake of vitamins A and D if you were to try to obtain therapeutic amounts of EPA and DHA from cod liver oil.
Supplementing with fish oils has been found to be entirely safe even for periods as long as 7 years and no significant adverse effects have been reported in hundreds of clinical trials using as much as 18 grams/day of fish oils. Fish oil supplementation does, however, lower blood concentrations of vitamin E so it is a good idea to take extra vitamin E when adding fish oils to your diet. A clinical trial carried out by the US Department of Agriculture found that taking 200 mg/day of synthetic vitamin E (equivalent to about 100 IU of natural alpha-tocopherol) is sufficient to completely counteract this effect of fish oil supplementation.
Omega 3 Essential Fatty Acids and Your Health
(excerpt of an article by Ms. Jane E. Brody – New York Times’ Personal Health Columnist and writer of health issues)
Omega 3 fatty acids may have a role in preventing cardiovascular disease. For fish to maintain fluidity in cold water, their fats have to remain liquid, and liquid fats (really oils) are polyunsaturated. But fish oils, rich in omega 3 fatty acids, are chemically different from the polyunsaturated oils in plants like corn and soybeans, and it is that difference that has given fish “star billing”.
The two omega 3s in fish are eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA. They are considered essential fatty acids, although they can be formed in the body from another omega 3, alpha linolenic acid, or ALA. ALA is found in plants like flaxseed, spinach, mustard greens, soybeans, canola oil, wheat germ and walnuts, as well as in marine animals that eat plants containing ALA.
The conversion rate is poor; however, and you will have to consume large amounts of ALA (from plant sources) to obtain a meaningful amount of EPA and DHA. Eating fish and fish products is far more efficient.
“DHA is a natural ingredient in breast milk, and it is critical to the normal development of the brain and retina. It has recently been approved as an additive to infant formula. In addition, the omega 3 acids perform many biochemical functions that can benefit the heart and blood vessels. Omega 3 fatty acids can inhibit the synthesis of substances that promote inflammation, reduce the tendency of the blood to form clots, stabilize the electrical activity of the heart, lower triglyceride levels, reduce blood pressure moderately and improve the functioning of artery linings. Other suggested benefits include an anti-inflammatory effect that can help people with autoimmune diseases such as rheumatoid arthritis, psoriasis and ulcerative colitis.”
Cancer Experts Applaud FDA for Action on Omega 3 Fatty Acids Too Much Omega-6, Not Enough Omega-3 Imbalance Linked to Increased Cancer Risk
WASHINGTON, May 26 — The American Institute for Cancer Research (AICR) today applauded the decision by the Food and Drug Administration (FDA) to permit nutrient content claims for foods rich in specific omega-3 fatty acids. Recent research suggests a link between omega 3’s and reduced risk of some cancers.
At a time when about a third of all cancer cases are related to nutrition, physical activity and other lifestyle factors, AICR urged FDA to take this step so that the public will be better informed about those foods that are rich in the essential omega-3 fatty acids. Of special importance for AICR is to help consumers identify foods high in DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), two omega-3 fatty acids that have been associated with lower cancer risk.
Cancer experts said today that even though many Americans have cut back on fat, the relative amount of two specific kinds of fat in the typical diet remains “out of whack” — and unhealthy. AICR researchers expressed concern that American diets are overloaded with omega-6 fats and deficient in omega-3 fats, a state of affairs that has been linked to increased cancer risk.
Omega-6 fats are found in vegetable oils such as corn, safflower, sunflower and soybean oil. They are often used in processed snacks, baked products and commercial salad dressings.
Omega-3 fats are found mostly in fatty fish like salmon, sardines, trout and herring. Smaller amounts are found in canola oil, flaxseed, green leafy vegetables and walnuts. Omega-3 fats have displayed a range of anti-cancer activities in the laboratory and have been repeatedly associated with lower cancer risk in population studies.
Different Ratios = Different Risk
The ratio of omega-6s to omega-3s in the current American diet has been measured as high as 15:1,” said Melanie Polk, RD, Director of Nutrition Education at AICR. To put that figure in perspective, consider that according to the World Health Organization, in countries consuming a traditional plant-based diet, the ratio of omega-6s to omega-3s is closer to 4:1, or even 2:1.
The ratio of “omega” fats in a given diet has been linked to heart disease for years, but new research suggests that it seems to have a direct effect on cancer risk, Polk said. Studies that have compared the diets and disease rates of large populations show that when the “omega” fats are in better balance, the risk for breast cancer, prostate cancer and colon cancer is lower. The risk for heart disease and inflammatory conditions such as arthritis is also lower.
But only recently have researchers uncovered a “smoking gun” that could explain how and why different ratios coincide with such striking differences in cancer risk.
Laboratory Reveals Possible “Smoking Gun”
The key seems to be that both omega-6 fats and omega-3 fats are metabolized (processed) similarly by the body. Because their molecular structures are so similar, they compete for many of the same enzymes.
Once paired with an enzyme, however, omega-3s and omega-6s behave very differently. The molecules that arise when omega-3 fatty acids get metabolized provide a range of potential anti-cancer benefits. They show the ability to reduce the production of other, cancer-promoting enzymes, increase the rate at which cancer cells die, and help keep cancer cells from forming the new blood vessels needed for them to grow.
In fact, research funded by AICR has shown that adding omega-3 fatty acids to the diet of mice can actually reduce the occurrence of tumors and slow tumor growth. Dr. W. Elaine Hardman, Ph.D., a researcher at the Pennington Biomedical Research Center of Louisiana State University, has received several AICR grants to study the cancer-fighting potential of omega-3 fatty acids.
Her previous AICR-funded research has demonstrated that omega-3s also have a potential role in helping chemotherapy drugs work more effectively and in reducing side effects from cancer treatment. This July, Dr. Hardman will chair a panel devoted to the role of fat in the cancer process at the Annual AICR/WCRF International Research Conference on Food, Nutrition and Cancer taking place in Washington.
Another recently funded AICR grantee is investigating still another possible protective mechanism. Researchers Robert Chapkin, Ph.D. and Joanne Lupton, Ph.D. of Texas A & M University are investigating how a particular omega-3 fatty acid (docosahexaenoic acid, or DHA) interferes with a specific protein that is critical for tumor formation in the colon.
When omega-6 fatty acids pair with an enzyme, on the other hand, the resulting molecules can actually promote inflammation, spur cells to multiply, and decrease cancer cell death.
Omega-6 fats do have a place in healthy diets,” said Polk. The problem right now is that 15:1 ratio. When the amount of omega-6 fat we consume is so hugely out of proportion with the amount of omega-3s in our diet, we effectively cut ourselves off from the protective benefits that omega-3s provide.
Essential Fatty Acids Supplementation
The following are excerpts from The BARF Diet by Dr. Ian Billinghurst.
“There are two types of of polyunsaturated fatty acids that may need to be added to BARF (Biologically Appropriate Raw Foods). Our pets are unable to make either type. One type is referred to as the Omega 6 essential fatty acids (EFA’s) and the other is referred to as the Omega 3 EFA’s. Both types of EFA’s must be supplied either in the basic diet, or as a supplement. Any lack, or imbalance in, the EFA’s will result in disease.
Unfortunately, modern foods commonly lack either one of both types of EFA’s, or they may contain an excess of one type with a deficiency of the other. The most common imbalance is an excess of Omega 6’s. This commonly produces skin problems, but can also result in a whole range of other inflammatory conditions. The net result is that EFA supplementation of some type is often required, even when feeding a BARF diet.
Fatty acid supplements for dogs may contain either active or inactive EFA’s. Inactive EFA’s are unable to carry out their vital role without first being converted by your dog to the active form. This conversion can only be carried out by enzymes, which your dog may or may not produce. If your dog does not produce these enzymes for any reason, these inactive essential fatty acids are unable to carry out many of their vital functions. This will lead to ill health.
Supplements which contain the activated Omega 6 EFA’s for dogs include Evening Primrose oil, Borage oil and Black Currant oil.
Supplements which contain inactive Omega 6 EFA’s include vegetable oils such as safflower oil, sunflower oil and corn oil.
Supplements which contain the activated Omega 3 EFA’s include cod liver oil and fish body oils such as Salmon oil.
Supplements which contain the inactive Omega 3 EFA’s include flaxseed oil and hemp seed oil.
Healthy young dogs may be fed supplements containing inactive essential fatty acids because the enzyme system necessary to activate them are usually fully functional. In other words, supplements containing inactive essential fatty acids will probably work fine in young dogs, but may not work so well in older dogs.
Older dogs and unhealthy dogs and dogs that may have eaten diets high in heat-damaged fats (trans fatty acids, etc.), or dogs that have lost (through inheritance), the ability to convert inactivated essential fatty acids to the activated form, should be supplied with activate essential fatty acids.
Cats can only use activated essential fatty acids and these must be derived from animals, not from plants. All raw meats, but most particularly red meats and eggs, supply cats with all the activated Omega 6 essential fatty acids they need. Cod liver oils and fish body oils are used to supply cats with supplementary Omega 3’s, if required.”
Containing excessive levels of the Omega 6 EFA’s is one of the most common problems seen with modern foods. Pets consuming excessive Omega 6 EFA’s will suffer conditions of excessive inflammation (as seen in many degenerative diseases), vaso-constriction (constriction of blood vessels causing high blood pressure), broncho-constriction (constriction of airways causing airway disease) and platelet stickiness (producing a tendency to clot which can lead to strokes and heart attacks).
These excessive levels of Omega 6 contribute enormously to the production of problems such as arthritis, heart, kidney and lung disease, through to cancer and on to inflammatory skin disease. This situation can be counteracted (in part) by the addition of Omega 3 EFA’s to the diet.
A diet that lacks sufficient Omega 3’s is arguably THE NUMBER ONE fatty acid associated problem caused by modern processed pet foods. This lack of Omega 3’s allows the Omega 6’s (if they are present in sufficient quantities) to produce the whole range of problems caused by an excess of Omega 6’s. In addition, the lack of Omega 3’s can be a potent cause of infertility in our breeding stock together with growth problems in young pups and kittens, and most importantly, problems with the development of the nervous system. This can result in early deterioration of vision and hearing, learning difficulties in puppies and kittens and behavioral problems in our pets that can continue throughout life.
An excess of Omega 3’s in the diet is usually caused by an over-supplementation of something like flaxseed oil. The problems likely to be seen will be mostly problems involving a deficiency of Omega 6’s. Skin problems will commonly occur first.
Oral Fatty Acids
from the book The Arthritis Solutions for Dogs by Dr. Shawn Messonier, DVM
Fats in the form of fatty acids have recently become a popular supplement among most veterinarians, not just those interested in holistic care. We are, in fact, just beginning to see that fatty acids may be valuable in a variety of conditions. Fatty acids were first purported to work in some pets with allergic dermatitis, and are in fact an essential part of the pet’s diet. They are also prescribed for pets with dry flaky skin and dull coats. Recently, they have been advocated in pets with kidney disease, elevated cholesterol, and arthritis.
When discussing fatty acids, we’re not just talking about adding some vegetable oil to the pet’s diet to get a nice, shiny coat. The fatty acids of most concern are the Omega 3 and Omega 6 fatty acids. Omega 9 fatty acids have no known use in treating pets. Omega 3 fatty acids — eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) — are derived from fish oils of coldwater fish such as salmon and trout, and flax seed. Omega 6 fatty acids — linoleic acid (LA) and gamma-linolenic acid (GLA) — are derived from the oils of seeds such as primrose, black currant, and borage. Often fatty acids are added to the diet with other supplements to attain and additive effect. This is especially common in arthritic dogs, as fatty acid supplements by themselves usually fail to relieve pain and lameness.
NOTE: Flaxseed oil is a popular source of alpha-linolenic acid (LNA), an omega 3 fatty acid that is ultimately converted to EPA and DHA. However, many species of pets and some people cannot convert LNA to these other more active non-inflammatory omega 3 fatty acids. In one study (Hobbs and Bucco, 1999), flaxseed oil was ineffective in reducing symptoms or raising levels of EPA and DHA. Therefore, because supplementation with EPA and DHA is important, flaxseed oil is not recommended as a fatty acid supplement for pets.
A Closer Look
Cell membranes in the joint contain phospholipids. When the membrane is injured, an enzyme acts on the phospholipids in the cell membranes to produce fatty acids including arachidonic acid (an omega 6 fatty acid) and eicosapentaenoic acid (an omega 3 fatty acid). Further metabolism of the arachidonic acid and eicosapentaenoic acid by additional enzymes (the lipooxygenase and cyclooxygenase pathways) produce chemicals called eicosanoids. The eicosanoids produced by metabolism of arachidonic acid are pro-inflammatory and cause inflammation, suppress the immune system, and cause platelets to aggregate and clot. Many disorders are due to overproduction of the eicosanoids responsible for producing inflammation, including arthritis. The eicosanoids produced by metabolism of eicosapentaenoic acid are non-inflammatory, not immunosuppressive, and help inhibit platelets from clotting.
In general, the products of omega 3 (specifically, EPA) and one omega 6 fatty acid (DGLA) are less inflammatory than the products of arachidonic acid (another omega 6 fatty acid). By changing dietary fatty acid consumption, the eicosanoid production changes right at the cellular level, decreasing inflammation within the body.