Researchers today realize that not all fats are created equal. Anyone who does supermarket shopping is likely to know there are four major categories of fats listed on the labels of the foods we eat: cholesterol, saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids. Of the the three fatty acid categories, only one - the saturated fats found in animal and dairy products - have been implicated in raising LDL, or bad cholesterol. Most foods contain a combination of three fatty acids.
Fatty acids are classified as saturated, monounsaturated and polyunsaturated. Saturated fatty acids are mainly found in animal foods such as meats, eggs and daily products. They are also abundant in tropical oils such as coconut, palm, and palm kernel and vegetable shortening. Unsaturated fatty acids fall into two categories: monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). Monounsaturated fatty acids are synthesized within the human body.
Linoleic (omega-6 fat) and alpha-linolenic (omega-3 fat) acids are called essential fatty acids (EFA) because the human body cannot synthesize them and must obtain them from food. They used to be referred to as vitamin F.
The long-chain omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaneoic acid (DHA) are formed from alpha-linolenic acid. They are found in fish, especially cold-water fish, such as salmon, mackerel, herring, and halibat and are gaining tremendous recognition among the scientists because of their beneficial effects related to their protection against heart diseases, diabetes, arthritis, rheumatoid arthritis and immune system disorders. Supplementation of omega-3 fatty acid in the form of fish oil can lower the levels of blood triglycerides by 50 percent. DHA has also been recognized as a very important nutrient for the brain and eyes.
Essential fatty acids (EFA) play a number of vital roles in the body. One key role is that they are converted into hormonelike substances called "eicosanoids" which influence blood pressure, boost or repress your immune system, increase or decrease your tolerance of pain, make you more or less prone to allergies and inflammation. Eicosanoids produced from omega-6 FA can have the opposite effect from eicosanoids produced from omega-3 FA. If you diet is high in omega-6 oils, your body produces more proinflammatory eicosanoids increasing your risk of asthma, arthritis, psoriasis, colitis and other inflammatory diseases.
Sources of Omega-3 Fatty Acid
The best source of omega-3 fatty acid is high oil fish. The main producers of omega-3 FA in the marine food is algae, such as blue-green alga Aphanizomenon flos-aquae, a naturally occurring alga growing in Upper Klamath Lake, Oregon. It is currently harvested and sold as a high protein nutritional source. Fish consume these organisns and become a composite mixture of the essential fatty acids (EFA). Most Western population are consuming far less omega-3 fatty acid than required. The daily intake of omega-3 FA in the "average American diet" is 150-200 mg, which is a far cry from 400-1200 mg a day as recommended by some nutrition experts!
Polyunsaturated Fatty Acid Deficiency
Deficiencies or imbalances of EFA can occur in malnutrition, certain genetic disorders, and as a consequence of some drug therapies. Deficiency symptoms include scaly skin, below normal growth rate, excess water loss through the skin, kidney malfunction, fatty liver, and reduced life span. Both EPA and DHA are necessary for infant development. During pregnancy, the developing fetus obtains DHA from maternal blood and concentrates it in the placenta, thus maternal blood levels are critical for the availability of DHA and EPA for the fetus. After birth, the infant receives omega-3 FA, including EPA and DHA, from maternal milk. In women who consume no fish, levels of EPA and DHA are 30 to 50 percent those observed in women who eat fish regularly.
Omega-3 fatty acids are essential for the normal development of the unborn baby's brain, especially during the final three months of the gestation when the size if its brain increases threefold. If the mother fails to get enough of these nutrients in her diet, the fetus will pirate what she has stored in her tissues, including brain. Lab tests show that new mothers have half the normal blood levels of omega-3 FA. Women who breast-feed their babies have even lower levels of DHA because they continue to supplement the baby's need for omega-3 FA. The fact that these nutrients are essential for fetal development is reason enough for women to ensure they get adequate supply.
Omega-3 Fatty Acid and ADHD
One of the consequences of growing up deficient in omega-3 FA may be attention deficit hyperactivity disorder, or ADHA. Five out of every 100 schoolchildren are diagnosed with ADHD, making it the most common childhood behavioral problem. Symptoms include hyperactivity, difficulty in concentrating and planning. Researchers found that boys with ADHD have significantly lower levels of both EPA and DHA than those without the disorder. The boys with the most abnormal behavior have the lowest levels of DHA. In particular, they are more likely to be hyperactive, anxious, and bothered by sleep disorders, including difficulty going to sleep and getting up in the morning.
Omega-3 Fatty Acid and Heart Diseases
Omega-3 fatty acid family have been extensively studied for their effect upon cardio-vascular disease (CVD disease). Recent studies suggest that omega-3 FA in the form of fish oil can prevent CVD by lowering blood triacylglycerols levels. Omega-3 FA has also been proved to be beneficial in the treatment of attention deficit hyperactivity disorder, fibromialgia, high blood pressure (hypertension), epilepsy, skin diseases, depression, rheumatism, arthritis, Crohn's disease and other inflammatory disorders.
Omega-6 to Omega-3 Ratio
Your body functions best when your diet contains a balanced ratio of EFA, yet the typical Western diet contains approxomately 14 to 20 times more omega-6 FA than omega-3 FA. This imbalance is linked to the following health conditions: heart diseases, stroke, cancer, obesitys, insulin resistance, diabetes, arthritis, asthma, lupus, depression, schizophrenia, attention deficit hyperactivity disorder, and postpartum depression. The balanced ratio, which is estimated to be less than 4:1, can make you less vulnerable to inflammatory and autoimmune diseases.
What created the imbalance of omega-6 to omega-3 ratio in modern diets?
- Eating grains increases the intake of omega-6 FA.
- Eating meat produced by animals fed an artificial diet of grains results in meat and eggs that have more omega-6 and less omega-3 FA than the meat from wild game.
- Eating large quantities of omega-6 vegetable oils, further upsetting the omega-6 to omega-3 balance.
- The campaign to lower cholesterol has led to an excessive consumption of omega-6 oils.
- The widespread fear of fat has further stripped omega-3 FA from the avarage Western diet.
The most important source of omega-3 from vegetable sources are olive oil, falxseed oil, canola oil and walnut oil. These oils are low in saturated fat and have a low ratio of omega-6 to omega-3 FA. Olive oil is also rich in antioxidants and a substance called "squalene" that reduces the blood clot formation and lowers cholesterol. Most importantly, eating olive oil increases the amount of omega-3 FA taken up by the cells, whereas eating omega-6 oils, such as corn oil and safflower oil decreases the amount.
Why Is It So Important To Maintain the Balanced Omega-6 To Omega-3 Ratio?
- Omega-6 oils, as well as low-fat, high-carbohydrate diet, can lower your LDL, or bad cholesterol, but at the same time they can also lower your heart-protective HDL cholesterol. The HDL cholesterol clears your arteries by taking cholesterol to the liver for processing and excretion into the bile. Instead of eating low-fat or now-fat food, you should concentrate on eating more healthy fat. Recent studies have shown that people who consume a seemingly "healthy diet" containing fruits and vegetables rich in the very nutrients known to protect against colon cancer - fiber, calcium adn antioxidants, have six times the rate of this deadly disease compared to those who have three times more omega-3 fatty acids in their blood (primarily from the high amount of fish in their diet) and considerably less amount of omega-6 fatty acid. More than two hundred studies have shown that eating oils high in omega-6 acids speed the growth of tumors and make them more aggressive.
Essential Fatty Acids and Immune System
Every year people spend millions of dollars on vitamins, herbs and hormones to boost their immune system. Some researchers and scientists maintain that many health disorders, including skin allergies, asthma, diabetes, rheumatoid arthritis, lupus, Crohn's disease, Parkinson's disease and Alzheimer's disease are triggered by hyperactive and confused immune system, and not just "weak" immune system. Since essential fatty acids acts like hormones, they suggest that the balance of EFA will "teach" the immune system when to attack, what to attack and when to stay put. Dozens of studies in recent years have shown that omega-3 supllements can alleviate symptoms of arthritis, including morning stiffness, fatigue, pain, and the numbre of inflamed joints.
A Word of Caution
The source of some omega-3 fatty acids may be a health concern. Many larger predatory fish contain toxins absorbed from pollution. Swordfish, shark, and tilefish (golden bass or golden snapper), for instance, which are high in omega-3 fatty acids, may also contain high levels of mercury. King mackerel, a lesser source of omega-3s, may also have high mercury levels. Grouper, red snapper, and fresh or frozen tuna may have more moderate amounts of mercury. Other larger fish, such as tuna and salmon, may contain other compounds such as dioxin and polychlorinated biphenyls or PCBs, although fresh or frozen salmon usually has low mercury levels and large amounts of omega-3 fatty acids. Some studies have shown that farm-raised fish may carry more toxins than fish caught in the wild. Unfortunately, there is no way for a consumer to know what might be present in any particular fish, although some fish are inclined to have higher levels of contamination than others.
Most refined fish oil supplements have little or none of these contaminants.