For us important omega−3 fatty acids include α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). What differentiates omega 3 fatty acids from other unsaturated fatty acids is basically the length of chain of carbon atoms. EPA has chain of 20 carbon atoms, while DHA has chain of 22 carbon atoms. ALA is bit shorter with 18 carbon atoms.
Mammals including human are not capable to synthesize long chain omega-3 acids. But omega 3 fatty acids are essential for normal functioning of human body. Plant oils like flaxseed oil, soybean oil, canola oil, walnuts and algal oil are some sources of omega 3 fatty acids. Even fish cannot synthesize omega 3 acids. But then why are we discussing about health benefits of omega 3 fatty acids from fish oil? Fish actually accumulate omega 3 fatty acids by consuming micro algae. Hence predator fish top of the food chain, like sharks, swordfish, tuna have high omega 3 fatty acids.
Omega 3 fatty acids have been known to be beneficial for health since 1930. However it was only in 1990 that its uses have been drastically popularized. In 1970, studies on Greenland Inuit people and Japanese people showed that they consumed large amount of fats from sea food and displayed no heart related diseases, which was later found supportive evidence to omega 3 fatty acids in sea food. In 2004, US FDA gave qualified health claim status to EPA and DHA omega 3 fatty acids.
Not every fish have abundant omega 3 fatty acids. Fish with good source of fish oil are salmon, mackerel, rainbow trout, lake trout, halibut, herring, sea bass, sardines, swordfish, oysters, albacore tuna, blue fin tuna, yellow fin tuna, turbot, pilchards, anchovies and other sources of oily fish. Commonly used fish for obtaining fish oil are tuna, herring, trout and salomon. Quality and purity of fish oil depends on the type of fish.
What are Health benefits of Fish Oil?
As we have already discussed, health benefits of fish oil can be attributed to presence of Omega 3 fatty acids DHA and EPA present in fish oil. Research have shown that ratio of omega 6 to omega 3 fatty acids is important criteria. Elevated ratio has been major risk factor for various cancers, thrombotic diseases, allergy, hyperactivity. Japan Society for Lipid Nutrition recommends ratio less than 4 for healthy adults and ratio less than 2 for prevention of chornic diseases. World health organization recommends ratio of 3 to 4. Studies have shown that in US ratio is around 10, which stresses on need for intake of omega 3 fatty acids in form of supplements like fish oil and others.
Health benefits of fish oil include prevention and treatment of heart related diseases, reducing high cholesterol, anxiety and depression, treatment of low immunity, cancer, diabeties, eye disorders, arthritis, ulcers and others.
Heart Health and prevention of heart related disorders: A research study published in Journal of American College of Cardiology, covering thousands of patients, have provided sufficient evidence that omega 3 fatty acids from fish or fish oil may not only prevent cardiovascular diseases but also reduce cardiac events with existing heart diseases. Study has suggested for consumption of omega 3 fatty acids. Daily dietary intake of fish oil can reduce risk of atherosclerosis, arrhythmias, heart attack, cardiac death and even health failure. Omega 3 fatty acids – EPA and DHA help improving heart’s electrical activity, vascular tone, blood pressure, among other benefits. Though most studies have found health benefits of fish oil over heart diseases, there are group of researchers who have been questioning health benefits of fish oil for heart health. Read “Fish oil questioned as treatment for heart disease” – Harvard medical School. Still it is only because of health benefits of fiish oil and omega 3 fatty acids that various countries including organizations like World Health Organization have made formal population based recommendations for omega 3 fatty acids and fish oil. According to American Heart Association (AHA), fish oil and Omega-3 fatty acids have been shown in epidemiological and clinical trials to reduce the incidence of cardio vascular diseases.
Fish oil helps in reduction of blood pressure in people suffering from hypertension. Omega 3 fatty acids in fish oil help in expanding blood vessels and thereby reduce blood pressure. High triglycerides and high cholesterol are associated with heart disease and diabetes. Fish oil is found to be effective in reducing triglyceride cholesterol levels. Lovaza fish oil is found very effective in treating high triglycerides.
Depression: It may appear absurd, but there is strong correlation between daily fish consumption and depression. Scientists have noticed that countries with the highest fish consumption had the lowest rates of depression. Imbalance in omega 3 and omega 6 fatty acids have shown high correlation with depression. These fatty acids have been associated with reducing inflammation. Some studies have suggested that omega-3 fatty acids can help smooth out the mood swings of bipolar disorder. It is because of omega 3 fatty acids, fish oil is good for relieving depression, anxiety, sadness, restlessness, mental fatigue, stress, decreased sexual desire, suicidal tendencies and other nervous disorders
Diabetes: American Diabetes Association (ADA) recommends consumption of fish oil regularly for improving health in diabetes. Researchers at the University of California have identified the molecular mechanism that makes omega-3 fatty acids so effective in reducing chronic inflammation and insulin resistance. This has led to considering fish oil as dietary remedy on diabetes. Another studies done in Australia have shown that increasing intake of fish oil and omega 3 fatty acids reduce resistance to insulin in body. This caused a decrease in insulin level in blood as lower levels were now enough, which then caused the body to burn the glucose deposits already present. So the sugar levels in the blood were lowered without using any medication.
Inflammatory bowel disease (IBD): Fish oil and omega-3 fatty acids because of their anti inflammatory properties have been found beneficial in treatment for inflammatory bowel disease and in particular Crohn’s disease. Research is still ongoing to determine extent of anti inflammatory properties of fish oil on inflammatory bowel disease and other chronic inflammatory conditions.
Weight Loss: Fish oil doesn’t directly decrease weight but aids in process which reduces weight. Fish oil helps in positively influencing metabolism and regular intake of fish oil reduces obesity. One study shows that fish oil improves efficacy of weight loss exercise. It is believed that fish oil help activate enzymes responsible for burning fat and coupled with exercise and increased oxygen intake increases metabolic rate.
Gum Disease: Fish oil due to its anti inflammatory properties is found effective on treatment and prevention of periodentitis, an inflammatory disease separating gum tissue from teeth.
Immunity: Fish oil is believed to enhance body immune system and helps in prevent common diseases.
AIDS: Though not conclusive but some promising research has been going in the area of benefits of fish oil in treatment of AIDS.
Rheumatoid Arthritis: It is found consuming fish oil reduces pain and stiffness in rheumatoid arthritis.
Pregnancy: Fish oil is found very useful for pregnant women. DHA helps in development of the child eyes and brain. It helps in avoiding premature births, low weight at birth, and miscarriage. It makes sense for eating fish or taking fish oil supplements during pregnancy for development of child. However fish oil obtained from fish liver which are rich in Vitamin A or retinol should not be consumed during pregnancy.
Other disorders where fish oil has been found particularly useful are Attention deficit hyperactivity disorder (ADHD), dysmenorrheal or menstrual pain, Raynaud’s syndrome, osteoporosis or weak bones, atherosclerosis or hardening of arteries, psychotic illness and some kidney problems.
Fish oil also along with omega 3 fatty acids also contains Vitamin A and D which is helpful in strengthening of bones and prevention of eye disease and skin diseases. There has been insufficient evidence on fish oil and its health benefits on Allergies, Alzheimers’s disease, Atrial fibrillation, dry eye syndrome, Cataract and cancer. However health benefits of Fish oil cannot be underestimated.