Healthy Eating - 'Understand the health benefits of eating Island Seafares fresh seafood'

Health Benefits of Eating Fish

It is important to include fish and shellfish within an healthy diet. Seafood provides protein, fats and oils, vitamins and minerals and fish is a unique source of the Omega 3 fatty acid. In terms of nutritional value to the human body; fish can be classified into different groups, with each group providing a slightly different nutritional value than the next.

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White Fish

Demersal fish feed in deep water or on the seabed. Examples of such fish are cod, haddock, plaice, whiting, sole, coley and monkfish. Their meat tends to be white and relatively low in fats. Nutritionally, the demersal group provide mainly protein. Demersal fish in general do not have a lot of lipid in their flesh, generally lipid stores are found in the liver. The high levels of lipid found in the liver of the Gadidae family (including cod, coley and haddock) is exploited to produce cod liver oil, a rich source of the Omega 3 long chain polyunsaturates as well as vitamins A and D.

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Oil Rich Fish

Pelagic fish feed near the surface and have higher levels of lipid in their flesh giving them a non-white colour, they are often referred to as 'fatty', 'oily' or 'oil-rich' fish.. Examples of pelagic species are sprats, pilchard, tuna, herring and mackerel. Nutritionally trout and salmon are very similar to pelagic fish. Levels of protein in pelagic fish are similar to those in demersal fish.

The major proteins in fish are actin and myosin, which combine in muscle to form actomyosin. The amino acid composition of fish protein is such that it can provide the sole source of protein for humans. The actual amino acid pattern is comparable to that of other proteins of high biological value, such as beef, egg or milk protein.

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Shellfish

The term "Shellfish" is often used to describe a very broad range of aquatic organisms. All living organisms are classified / identified using the same methods. They are grouped according to their biological appearance and structure and genetic make up. The table below shows how some of the most economically important "shellfish" are identified using these classification methods.

The nutrient content of shellfish is much more variable than in fish and true comparison is difficult since analytical data is not available on all species in the same state. Generally, protein levels are a little lower and lipid levels a little higher than in demersal fish. Shrimp and crab are notable for a relatively high amount of lipid (2.5-5.5g/100g) and oysters and scallops for a significant amount of carbohydrate (2.7-3.4g/100g). There is no doubt that the crustaceans as a group contain quite high levels of cholesterol. Prawns in particular contain about 195mg of cholesterol per 100g of meat. In the context of a recommended maximum cholesterol intake of 300-600mg per day, this is significant, though it is still less than the cholesterol contained in an egg. At one stage it was thought that molluscs also contained high levels of cholesterol however this was caused by an analytical error. What was identified as cholesterol is now known to include other plant derived sterols or phytosterols. Cholesterol levels in molluscs range from 40-60mg in mussels, scallops and oysters up to 150-200mg in cuttlefish and squid. The phytosterols, though not yet widely studied are considered to be beneficial in the diet since they interfere with the absorption of cholesterol.

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Vitamins Provided by Fish

Fish and shellfish are best known as sources of the fat soluble vitamins A and D, though they can also provide significant amounts of some B vitamins. Seafoods generally provide little or no vitamin C. The B vitamins are represented to varying extents, with the supply of thiamine, riboflavin and pyridoxine being the most significant nutritionally. 100g portions of most seafoods will supply 10% or more of the adult Reference Nutrient Intake (RNI) for these nutrients. Seafoods are especially rich in vitamin B12, supplying 100% or more of the adult RNI in a 100g portion.

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Minerals Provided by Fish

Seafoods are better known nutritionally for the dietary minerals they supply than for vitamins. This is because minerals such as iodine and selenium, which are supplied by seafoods are not readily available at the same levels in many other non-marine foods. In general the balance between sodium and potassium is favourable in fish. In shellfish there is more sodium so the ratio is not so favourable. Calcium levels are low in most seafoods, though sprats, sardines and oysters are exceptions. Iron levels are also generally low, however iron is easily absorbed from white fish, and is therefore a useful dietary source. The level of iron in molluscs is similar to that of red meat. Zinc is also especially rich in molluscs, particularly oysters. Seafood is the richest source of iodine in the normal diet and one or two seafood meals per week will supply 100-200mcg per day, enough to meet the adult RNI of 140mcg.

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Omega 3 Fatty Acids

Fish also contains the right type of fats, known as Omega 3 fatty acids, which are polyunsaturated fats that have a range of health benefits. In the human diet, omega 3 is a preferred substitute for Omega 6 fatty acids, the fats commonly found in other red meat and plants. The right balance between Omega 3 and Omega 6 acids also seems to be a factor in our getting the most health benefits.

The human body has evolved to run best on a mixture of Omega 3 and Omega 6 type polyunsaturates. While it can survive in the short term without either, long term optimal health requires that both be present in the diet. A growing body of evidence indicates that Omega 3 molecules help maintain cardiovascular health because they play a role in regulating blood clotting and vessel constriction. They may reduce tissue inflammation and alleviate the symptoms of rheumatoid arthritis. Other maladies in which Omega 3 may play a beneficial role include depression and irritable bowel syndrome. Various studies have shown that fairly small amounts of Omega 3 can make a big difference to heart risks. Current thinking is that around 400mg a day is enough to reduce risk quite substantially. You can get it by eating oil-rich fish or by simply taking one or more concentrated fish oil capsules a day. Eating oil-rich fish once or twice a week will make a good contribution towards supplying the right amount of Omega 3 you need to improve general health. Omega 3 fatty acids are found in high concentrations in finfish and shellfish that eat plankton and smaller fish with Omega 3 in their tissues. Good sources are bluefish, striped bass, smelt, shark tuna, salmon, mackerel, oysters, mussels, shrimp and squid.

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Signs of Good Quality Fish

Fish is very easy and quick to cook. At Island Seafare all our products are readily prepared for you so that you do not have to worry about how to prepare our products for cooking. We have also produced a recipe book which is available upon request, all recipes are also available on the website. If you have any queries regarding the cooking of your fish do not hesitate to contact us by phone or e.mail and our in house chef will be pleased to pass on his knowledge.

Island Seafare is a company dedicated to quality and we take great pride in the products we produce. At first people were sceptical of receiving seafood by mail order, but we have proved that with our chilled packaging delivered to your door by noon next day the quality in no way suffers. We have also taken into account the higher summer temperatures and to ensure our produce reaches you in the best condition possible we have improved the insulation of our packaging and included extra gel packs to combat the summer temperatures.

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What to Look for when Buying Fish

Whole Fish

• Clear bright eyes, not sunken
• Bright red gills
• Scales should not be missing
• Skin is moist and feels slightly slippery
• Skin is shiny with bright natural colouring
• Tail is stiff and the flesh feels firm
• Fish has a sea fresh smell

Fillets

• Neat, trim fillets with firm flesh
• Closely packed together
• White fish should have a white translucent colour

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Smoked Fish

• Glossy appearance
• Firm flesh, not sticky
• Pleasant, smoky smell

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Shellfish

• Shells not cracked or broken
• Shells of oysters and mussels are tightly shut
• Lobsters, crabs and prawns have good colour and be heavy for their size
• Lobsters and crabs have all their limbs

Fish has a shelf life of 10 to 12 days. At Island Seafare we recommend that upon receipt of our products they are kept for a maximum of 5 days in the refrigerator (between 0 and 5 degrees C). Fresh fish should be covered with cling film and stored in the bottom of a refrigerator, it should be eaten as soon as possible. Ready to eat cooked fish such as our hot smoked mackerel, smoked salmon, kippers, prawns, dressed crab and lobster, should be stored on shelves above raw foods to avoid cross contamination. Smoked fish should be well wrapped up and kept separate from other fish to prevent the smell and dye penetrating other foods. Our products are ideal for home freezing in our vacuum packaging. Fish should not be stored at temperatures lower than -18 degrees C. In should be thawed overnight in a refrigerator. Defrosting fish in water is not recommended as the taste and texture are easily spoiled and valuable water soluble nutrients are lost. We recommend that our white fish and smoked fish be frozen for up to three months, our cooked fish and oil rich fish be frozen for up to two months and shellfish is only to be kept in the freezer for up to one month.

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