In the UK, government guidelines suggest that we eat 2 portions of oily fish a week. The reason for this is being that oily fish contain large amounts of the essential omega-3 fatty acids.
These omega-3 fatty acids are hard to find in modern diets, and fish is arguably the best food source. 1 portion of salmon will give you 1.5 grams of omega-3 fatty acids, in a combination of ALA, EPA and DHA, which is perfect. You can of course get omega-3s from nuts and seeds, but these are a poorer of these fats source then fish.
In reality, the studies (such as the GISSI and JELIS studies) which the government used as a guide for their guidelines showed that we need at least twice that amount of omega-3 fatty acids.
The recommendations have been reduced because large oily fish such as cod and salmon often have high levels of toxins in their oil such as methyl mercury and dioxins. These toxins attack the nervous system, and foetuses are particularly susceptible to damage (so pregnant women should be careful). 2 portions of these fish will result in a ‘safe’ amount of these toxins consumed whilst still providing some omega-3 fatty acids.
Safer sources of omega-3
Not all oily fish are high in toxins. In fact mackerel (which is extremely high in omega-3s) contains virtually no amount of these toxins. Mackerel is low in the food chain, and as these toxins bio-accumulate, smaller fish are virtual toxin free, meaning you can eat lots of them, and get plenty of omega-3
The government guidelines form omega-3 consumption doesn’t mention nuts and seeds, and although they are a poorer source of omega-3 fatty acids, they don’t contain any of the toxins that large fish do, which makes them a safe way to increase the amount of omega-3 you consume.
Alternatives to eating fish
Fish and nuts are both expensive, and not to everyones taste, but their nutritional value is too good to eliminate from you diet. These foods are the only major sources of omega-3 fatty acids, and if you want to be healthy, you do kinda need these fats in your diet. If you don’t want to eat these foods you can look into a good quality fish oil product, which is a simple way to get these fats into your diet.
Government guidelines for how much fish you should eat are a little over simplified. The guidelines should recommend eating more smaller oily fish and limit larger oily fish to 2 portions a week. The recommendations should also include other sources like nuts and seeds.