Fish oil and its supplements

a) Fish oil is oil derived from the tissues of oily fish. Fish oils contain the Omega-3 fatty acids eicosapetaenoic acid (EPA), and docosahexaenoic acid (DHA), precursors of certain eicosanoids that are known to reduce inflammation throughout the body, and are thought to have many health benefits.

Fish do not actually produce Omega-3 fatty acids, but instead accumulate them by consuming either mictoalgae or prey fish that have accumulated Omega-3 fatty acids, together with a high quantity of antioxidants as iodide and selenium, from microalgae, where these antioxidants are able to protect the fragile polyunsaturated lipids from peroxidation. Fatty predatory fish like sharks, swordfish, tilefish, and albacore tuna may be high in Omega-3 fatty acids, but due to their position at the top of the food chain, these species can also accumulate toxic substances through biomagnification. For this reason, the U.S. Food and Drug Administration recommends limiting consumption of certain (predatory) fish species (e. g. albacore tuna, shark, king mackerel, tilefish and swordfish) due to high levels of toxic contaminants such as mercury, dioxin, PCBs and chlordane. Fish oil is used as a component in aquaculture feed. More than 50 percent of the world's fish oil used in aquaculture feed is fed to farmed salmon.

The Omega-3 fatty acids in fish oil are thought to be beneficial in preventing heart disease. Fish oil and Omega-3 fatty acids have been studied in a wide variety of other conditions, such as clinical depression, anxiety, cancer, and macular degeneration, although benefit in these conditions remains to be proven.

Many people have turned to fish oil supplements to get adequate Omega-3 fatty acids. Fish oil supplements have sometimes come under scrutiny in recent years. In early 2006, government agencies such as the Food Standards Agency in the UK and the Food Safety Authority of Ireland reported PCB levels that exceeded the strict new European maximum limits in several fish oil brands, which required temporary withdrawal of these brands. To address the growing concern over contaminated fish oil supplements, the International Fish Oil Standards program, a voluntary review process, was created at University of Guelph.

Patented production purification processes do however exist in order to remove pollutants and dioxins from fish oil to levels far below the EU limits. This is called stripping technology.

Most of the fish oils used for Omega purposes are originating from Peru, Chile and Morocco because the Omega-3 levels in the fish caught in these areas are higher (around 30 %) than in Scandinavian and other fish oils (around 20 %). Fish oils are being used in the Omega-3 industry to produce nutraceuticals and pharmaceuticals. However, the largest off-takers of the Omega-3 fish oils are still the feeding buyers with the big fish feed companies such as Ewos, Skretting and Biomar in the lead.

b) Benefits. Some experts believe that taking fish oil (in any form) can help regulate cholesterol in the body, because fish oil has high levels of Omega-3 fatty acids. Besides cholesterol regulation, benefits include anti-inflammatory properties and positive effects on body composition. However, the preferred source of Omega-3 should be from the fish's body, not the liver. The liver and liver products (such as cod liver oil) of fish and many animals (such as seals and whales) contain Omega-3, but also the active form of vitamin A. At high levels, this form of the vitamin can be dangerous. Early explorers to the land of the Inuit were given raw liver by the natives, which contained a toxic overdose of vitamin A for the white explorers; however, the same amount was harmless to the Inuit, who had no other source of vitamin A except animal livers.

Studies were conducted on prisoners in England where the inmates were fed seafood which contains Omega-3 fatty acids. The higher consumption of these fatty acids led to a drop in the assault rates. Another Finnish study found that prisoners who were convicted of violence had lower levels of Omega-3 fatty acids than prisoners convicted of nonviolent offenses. It was suggested that these kinds of fatty acids are responsible for the neuronal growth of the frontal cortex of the brain which, it is further alleged, is the seat of personal behavior.

Recent studies have suggested that fish oil may affect depression, and importantly, suicide risk. One such study took blood samples of 100 suicide-attempt patients and compared the blood samples to those of controls and found that levels of eicosapentaenoic acid were significantly lower in the washed red blood cells of the suicide-attempt patients.

A study examining whether Omega-3 exerts neuroprotective action in Parkinson's disease found that it did, using an experimental model, exhibit a protective effect (much like it did for Alzheimer's disease as well). The scientists exposed mice to either a control or a high Omega-3 diet from two to twelve months of age and then treated them with a neurotoxin commonly used as an experimental model for Parkinson's. The scientists found that high doses of Omega-3 given to the experimental group completely prevented the neurotoxin-induced decrease of dopamine that ordinarily occurs. Since Parkinson's is a disease caused by disruption of the dopamine system, this protective effect exhibited could show promise for future research in the prevention of Parkinson's disease.

The American Heart Association recommends the consumption of 1 g of fish oil daily, preferably by eating fish, for patients with coronary heart disease.

Exercise 2. Using the information from the text write an essay about fish oil as one of the important by-products used for human consumption.

Exercise 3. Make a report about any by-product manufactured at the local fish processing enterprises (not more than 180 words).