Essential Fatty Acids (EFAs) are probably the most important and least understood of all fats.
The major building block
of fats
The essential fatty acids Linoleic acid
(Omega 6) and Alpha Linolenic acid
(Omega 3), found only in
polyunsaturated fats, are the major building blocks of fats. They are
categorized as essential
because they cannot be manufactured by the body. As integral cellular
components, actions of these two EFAs include:
Maintenance
of cell membrane fluidity and stability
(also important for proper
cell division and genetic expression).
Development and function of brain and nerve tissue.
Oxygen transfer and energy production.
Immune functions.
Conversion
into compounds involved in all body functions
including local hormones
governing inflammatory responses.
Consensus agrees that the American population does not consume enough of the "good" fats. A report from the Surgeon General on Nutrition and Health declares that deficiencies, excesses or imbalances in fats are involved in 70% or more of all U.S. deaths. High on the list are death from Cardio Vascular Disease (heart disease, stroke and atherosclerosis), cancer, diabetes, and lung disease
The guidelines for "good" fat consumption need to define the differences between polyunsaturated fats. They must include recommendations on how to maintain a beneficial balance between the various "good" fats.
Linoleic acid (LA) of the omega-6 family is found in most plant oils (corn, safflower, canola, sunflower) and in nuts, seeds, and soybeans.
Alpha-Linolenic acid (ALA) of the omega3 family is found only in oils from cold-water marine animals (mackerel, sardines, anchovies, cod liver oil, salmon) and in flax oil. Though canola oil and soybeans have a minimal amount.
Omega 3 vs. Omega 6
The composition of cellular membrane lipids determines the type of prostaglandins (hormones that govern cellular responses, immune functions and hormone synthesis) produced during an inflammatory response and are directly influenced by the type of fats in the diet.
For example, anti-inflammatory prostaglandins dilate blood vessels, reduce clotting, lower LDL, and raise HDL cholesterol levels. Pro-inflammatory prostaglandins do the reverse.
The actions of both omega-6 and omega-3 prostaglandins are necessary to maintain balance and homeostasis during an inflammatory response. However, Omega 6 converts primarily to arachidonic acid which is already abundant in the American diet due to meat consumption. Whereas Omega 3 converts to biologically active eicosapentanoic acid (EPA) and docosahexanoic acid (DHA).
For optimum health and disease prevention, the balance should consist of
one to four times more omega-6 fatty acids than omega-3 fatty acids.
Because modern diets are already high in omega 6 due to meat consumption,
the recommended ratio in a supplement is 1:1.
Most pharmacological anti-inflammatory and analgesic therapy such as aspirin and ibuprofen work by inhibiting prostaglandin production. Unlike pharmacological therapies, Omega-3 fatty acids modify enzyme activity but do not disturb the metabolic pathway.
Arachidonic acid is the major fatty acid released in response to injury. By increasing the availability of EPA through fatty acid supplementation and food choices, competitive inhibition limits the release of pro-inflammatory prostaglandins in response to injury.
Prostaglandins are not only involved in inflammatory response, but also in:
fat metabolism
energy production
blood pressure regulation
growth and tissue repair
Fish Oil supplementation providing EPA/DHA
has great potential for management of
inflammatory and chronic diseases,
as well as insurance for healthy pregnancy
and childhood growth and development.
EFAs in fish oil are important for membrane flexibility and synaptic cell signaling. Studies support the use of fish oil supplements for diseases and inflammatory disorders such as:
rheumatoid arthritis, lupus, and Crohn's disease
arrhythmias, coronary heart disease and stroke
hypertension
breast, prostate, and colon cancer
atopic dermatitis
diabetes
as well as:
regulation of triglycerides, cholesterol levels, and prevention of atherosclerosis
human growth and development
mood disorders, depression, and dementia
The commercial refinement of fats and oils has meant lower availability of EFAs in the diet, conversion of EFAs into toxic compounds and blockage of proper EFA metabolism.
Dietary deficiencies and disease conditions can block or slow down EFA metabolism:
Excess dietary cholesterol, saturated and monounsaturated fats (85-93% of all fats in Western diets)
Processed oils and trans fats
Alcohol and sugar consumption
Diabetic and pre-diabetic conditions
Aging
Comparing Signs of EFA Deficiency
|
(Omega-6) |
(Omega-3) |
|
Eczema-like skin eruptions |
High blood pressure |
|
Loss of hair |
High triglycerides |
|
Liver or kidney degeneration |
Learning impairment |
|
Behavioral disturbances |
Poor motor coordination |
|
Excessive sweating with thirst |
Tingling in arms and legs |
|
Susceptibility to infections |
Behavioral changes |
|
Poor wound healing |
Immune dysfunction |
|
Sterility (males) / miscarriage |
Sticky platelets |
|
Growth retardation |
Dry skin or edema |
|
Heart / circulatory problems |
Mental deterioration |
Adapted from Erasmus U
EPA and DHA, found in fish oils and converted in the body from Omega 3 fatty acids, also have distinctive roles in the body. EPA benefits the cardiovascular system and inflammatory conditions by:
Decreasing triglycerides, increasing HDLs (good cholesterol)
Suppressing AA for anti-inflammatory effect
Decreasing triglycerides, increasing HDLs (good cholesterol)
Preventing arrhythmias/ stabilizing heart rhythm
Producing anti-thrombotic effects.
DHA plays a critical role during pregnancy and infant development, old age, for mental conditions and peroxisomal disorders by:
Maintaining membrane fluty and function, regulating cellular receptor
Facilitating normal growth and cognitive development
Participating in development, composition and function of the central nervous system
Research
shows EPA or DHA supplementation to be beneficial
for the following diseases and conditions:
CARDIOVASCULAR DISEASE
Consumption of Omega-3 fatty acids is inversely associated with incidence of Cardiovascular Disease. Relatively low doses have been shown to reduce risk of secondary coronary events.
Omega-3 fatty acids:
Inhibit coagulation
Promote vasodilatation
Reduce inflammation
Modify plasma lipid and lipoprotein
Non-fasting plasma triglyceride concentrations are a strong independent predictor of future myocardial infarction (MI). Omega-3s reduce plasma triglyceride concentrations depending upon the specific dose.
ATHEROSCLEROSIS
Experimental, epidemiological, and interventional studies all suggest fish oils produce beneficial effects on thrombosis and atherosclerosis reducing procoagulant activities of monocytes.
Autopsies performed by medical doctors revealed that the degree of atherosclerosis present in coronary arteries was inversely proportional to the amount of DHA in adipose (fatty) tissue'
In JAMA (2001) highlighted a study evaluating 79,839 women (ages 34 to 59 years) who were followed over a 14-year period:
Women in the highest quintile for fish and omega-3 EFA intake reduced risk for stroke by 0.72, and for thrombotic infarction by 0.67
No relationship was found between fish or omega-3 fatty acid consumption and risk of hemorrhagic stroke.
ASTHMA
With the appearance of the class of asthma medications, the leukotriene receptor antagonist, it is easy to see how omega-3 fatty acids may work to relieve asthma symptoms. By displacing arachidonic acid, therefore preventing production of inflammatory leukotrienes, they may work as leukotriene inhibitors. In the NHANES I study, fish consumption was associated with approximately 80 ml increase in FEV for both smokers and nonsmokers" In a recent study, children (mean age of 10 years) with asthma receiving EPA/DHA supplementation for 10 months were compared with controls. In the supplemented group only:
Asthma symptom scores were reduced
Response to acetylcholine increased"
CANCER
EPA and DHA show inhibitory effects on tumor growth:
EPA inhibits cell division in some human cancer cell lines
DHA inhibits growth of cultured metastatic melanoma cells
In undernourished patients with breast, lung, liver, GI and pancreatic malignancies, omega3 fatty acids exhibited imunomodulating effects:
· Increasing ratio of T helper cells to T suppressor cells
· Restoring tumor necrosis factor production
Survival was prolonged in both well-nourished and undernourished patients.
The Lancet (2001) reported that in a prospective 30 year study of 6272 Swedish men, those who ate no fish had a 2- to 3-fold higher frequency of prostate cancer than those who ate moderate or high amounts!'
BRAIN
Deficiencies in EPA, DHA, total omega-3 fatty acids, and lower omega-3/omega-6 ratio are found in patients with Alzheimer's diseases, other dementias, and in cognitive impairment associated with aging. Low serum DHA is a significant risk factor for development of Alzheimer's disease and has been linked to depression.
Replacement of fatty acids from plasma to brain occurs at the rate of 2-8% per day for DHA, and 3-5% per day for AA. It is suggested that altering plasma fatty acid concentrations can
• regulate brain fatty acid content
• help treat diseases involving fatty acid imbalance
Researchers at Purdue University report that ADHD may be linked to insufficient intake of ALA, EPA, and DHA, or to reduced ability to metabolize EPA and DHA from precursors. They conclude supplementation to be a useful treatment for ADHD.''
Fish oils promote good mood. People with bi-polar disorder, a condition of depression with manic periods, felt more emotionally stable after taking fish oils!"
RHEUMATOID ARTHRITIS
Omega-3 fatty acids suppress production of both TNF alpha (which causes breakdown of certain body tissues) and IL-1 B by monocytes in patients with rheumatoid arthritis. Supplementation with 2.2 g EPA and 1.4 g DHA per day produced >90% inhibition of pro-inflammatory cytokine production!
AUTOIMMUNE CONDITIONS
Diets rich in omega-3 fatty acids are associated with suppression of cell-mediated immune responses. Studies show that omega-3 fatty acids inhibit the antigen-presenting cell expression on monocytes.
PREGNANCY AND HUMAN DEVELOPMENT
DHA is essential for fetal brain and cognitive development due to rapid growth of lipid-rich membranes.
Lipids comprise 50-60% of structural brain matter
70% of energy during fetal development is devoted to brain development
Formula fed term infants who died of unexplained causes had lower brain DHA levels
Studies show preferential uptake of the preformed fatty acid (DHA) over those biosynthesized from precursors (ALA) for neural cell membranes.
DHA is even more critical for pre-term infants since they receive less DHA in utero putting them at nutritional and developmental disadvantage.
EPA and DHA may have protective effects against Type 1 diabetes. In a comparison of 1,156 diabetic and normal controls, the offspring of mothers who took EPA/DHA and vitamin D rich cod liver oil during pregnancy had a lower risk for development of diabetes (odds ratio of 0.30)?
FISH OR FLAXSEED? WHEN THE SOURCE MAKES A DIFFERENCE
For maximum benefit, specific criteria should be satisfied when determining which Omega-3 fatty acid to favor for supplementation. Several factors may influence choice.
Degree of Need:
Only up to 15% of ALA is converted to EPA and 5% to DHA at best. This means that for most people, and especially in those with other health issues, supplementation with flaxseed oil may not produce desired benefits. In addition it is critical to note that trans fats completely inhibit conversion to EPA. Therefore, supplying preformed EPA and DHA from fish oil is preferred.
Targeting specific health concerns:
The biological effects of preformed EPA and DHA are much stronger than ALA on parameters related to specific health concerns.
On a gram for gram basis, fish oils are the optimal means of enhancing EPA and DHA in the body.
The following factors will inhibit conversion of ALA to EPA and DHA:
Saturated, trans fats, and LA inhibit up to 40%
Alcohol
Cofactor nutrient deficiencies: Vitamins B3, B6, C, or minerals zinc and magnesium
Health conditions such as diabetes
Some prescription drugs
Certain ethnicities
RECOMMENDATIONS FOR ADDING OMEGA-3 FATTY ACIDS TO THE DIET
It is important to note that EPA and DHA are complementary EFAs found together in nature. Recent research finds that EPA and DHA must be supplied together to produce results.
Research in the American Journal of Health-System Pharmacy suggests the following daily fish oil intake as a preventative measure:
2 to 4 g of fish oil capsules per day
Additional advice includes:
Take 200 IU Vitamin E daily when supplementing with fish oils.
Keep fish oils away from heat and light.
Protect from oxygen exposure
For More information about Essential Fatty Acids, visit these links:
Arctic Omega | ProDHA | Fish Oil | DHA Junior | Omega for Pets
† Statements made have not been evaluated by the Food and Drug
Administration.
These statements are not intended to diagnose, prevent, treat, or
cure any disease.
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