Later On

A blog written for those whose interests more or less match mine.

Eat oily fish to preserve eyesight

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From the Wikipedia article:

Oily fish, oil-rich fish, or pelagic fish are those fish which have oils throughout the fillet and in the belly cavity around the gut, rather than only in the liver like white fish. Oily fish fillets may contain up to 30 percent oil, although this figure varies both within and between species. Oily fish generally swim in the pelagic zones of the oceans and are usually cold water fish (while white fish are warm water fish)[1].

Oily fish are a good source of Vitamins A and D as well as being rich in omega 3 fatty acids (white fish also contain the same nutrients but at a much lower level[2]). For this reason the consumption of oily fish can be more beneficial to humans than white fish, particularly concerning cardiovascular diseases[3], but oily fish are known to carry higher levels of contaminants than white fish[4]. Amongst other benefits, studies suggest that the omega 3 fatty acids in oily fish may help sufferers of depression, reduce the likelihood of heart disease and improve inflammatory conditions such as arthritis.

Specifically:

Oily / fatty fish      White (non-oily) fish
Salmon
Trout
Mackerel
Herring
Sardines
Pilchards
Kipper
Eel
Whitebait/Smelts
Tuna (fresh only)
Anchovies
Swordfish
Bloater
Cacha
Carp
Hilsa
Jack fish
Katla
Orange roughy
Pangas
Sprats
Cod
Haddock
Plaice
Coley
Whiting
Lemon sole
Skate
Halibut
Rock Salmon/Dogfish
Ayr
Catfish
Dover sole
Flounder
Flying fish
Hake
Hoki
John Dory
Kalabasu
Ling
Monkfish
Parrot fish
Pollack
Pomfret
Red and grey mullet
Red fish
Red Snapper
Rohu
Sea bass
Sea bream
Shark
Tilapia
Turbot
Tinned tuna
Marlin

And here’s why to eat them:

Eating oily fish once a week may reduce age-related macular degeneration (AMD) which is the major cause of blindness and poor vision in adults in western countries and the third cause of global blindness, according to a study published today in the American Journal of Clinical Nutrition. There are two types of AMD, wet and dry. Of the two, wet AMD is the main cause of vision loss. A team of researchers across seven European countries and co-ordinated by the London School of Hygiene & Tropical Medicine sought to investigate the association between fish intake and omega 3 fatty acids with wet AMD, comparing people with wet AMD with controls. Participants were interviewed about their dietary habits including how much fish they ate and what type. Information on the main omega 3 fatty acids (docosahexaenoicacid (DHA) and eicosapentaenoic acid (EPA) was obtained by linking dietary data with food composition tables.

The findings show that people who habitually consume oily fish at least once a week compared with less than once a week are 50% less likely to have wet AMD. There was no benefit from consumption of non oily white fish. There was a strong inverse association between levels of DHA and EPA and wet AMD. People in the top 25% of DHA and EPA levels (300 mg per day and above) were 70% less likely to have wet AMD.

Astrid Fletcher, Professor of Epidemiology at the London School of Hygiene & Tropical Medicine, who led the study, commented: “This is the first study in Europeans to show a beneficial association on wet AMD from the consumption of oily fish and is consistent with results from studies in the USA and Australia. Two 3oz servings a week of oily fish, such as salmon, tuna or mackerel, provides about 500 mg of DHA and EPA per day”.

The research team is not, however, recommending omega 3 supplements as the study did not investigate whether supplements would have the same benefit as dietary sources.

Source: London School of Hygiene & Tropical Medicine

Written by Leisureguy

8 August 2008 at 10:13 am

Posted in Daily life, Food, Health, Science

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