The many benefits of fish oil

Charles Sammut of New York (June 14) recalls the 1950s when schoolchildren in Malta and Gozo were regularly given cod liver oil (along with milk and vitamin C-supplemented orange juice). This was standard schoolchildren's nutritional practice throughout the British Empire, and I'm sure Mr Sammut also remembers the schools' Empire Day sports event at the former Empire Stadium in Gzira.

Mr Sammut correctly quotes some scientific claims that the Omega-3 essential fatty acids in fish oil may enhance children's brain function. There are also scientific claims that fish oil may help children with attention deficit hyperactivity disorder, and that fish (or fish oil supplements) in pregnant women's diet may improve the offspring's intelligence. The latter might be the reason for the claimed slightly higher average IQ of Japanese children compared to those of northern Europe and north America. It is likely that commercial baby food will eventually be supplemented with these marine fatty acids, although eggs do contain one of these fatty acids.  

One word of caution about cod liver oil; it contains high levels of vitamin A derived from fish liver, and too much vitamin A is not recommended for ladies planning pregnancy because it may cause foetal abnormalities. Pure fish oil (not cod liver oil), made from fish flesh, and not from fish liver, is the supplement to go for. It is more expensive than cod liver oil, but hasn't got the vitamin A problem, and is purified from contaminants (possibly mercury) that cod liver oil may contain.

Fish oil is also linked to adult health, and is thought to influence the blood clotting, immune, inflammatory and nervous systems. We now know that fish oil thins the blood, like aspirin, and has anti-arrhythmic action on heart muscle, which explains why fish-eating populations, like Eskimos and Japanese, have little cardiovascular disease (the main cause of morbidity and mortality in the West), and one reason why the Japanese maintain the highest population longevity. Fish oil has also been linked to benefits in arthritis, asthma, inflammatory bowel diseases, eczema, psoriasis, lupus, depression, schizophrenia, diabetes, high blood pressure and cancer prevention. This may sound too good to be true, but fish oil is thought to beneficially influence the action of very important hormones (eicosanoids-prostaglandins and leucotrienes) found in all our cell membranes, and is why some of the newer anti-inflammatory painkillers have been causing serious complications (heart attacks and strokes); these drugs may negatively influence the action of these crucial but poorly understood hormones, and some of them have already been withdrawn.

As with all supplementation, the natural food is preferable, and eating oily cold-water fish (e.g., salmon and mackerel; Mediterranean warm-water fish has little oil) several times a week is thought to be more beneficial than fish oil capsules. However, many people don't like eating fish (isn't cheap either), and pure high-concentrate fish oil capsules are the next best thing. Taken with food (and not on empty stomach), they should not cause any fishy after-taste. They are usually available in 500 and 1,000mg doses. Small 500mg "one-a-day" capsules are a marketing ploy; people in generally good health need 2,000 to 3,000mg daily; people with specific diseases, e.g., arthritis may need far higher doses. A lot of fish oil may raise your LDL cholesterol levels; this might be corrected by adding vitamin B3 (niacinamide/niacin) and garlic concentrate tablets (if you are not already on a cholesterol-lowering drug).