So just what does this diet recommendation do for you, and how much should you be eating?
Why oily fish?
Fish are packed with vitamins and minerals, but oily fish in particular, boast the all-important long-chain omega-3 fatty acids, DHA, EPA and DPA. Recent research has linked DHA with an astonishing 40 per cent reduction in the risk of heart disease, while DPA lowers the risk of dying from a stroke, and EPA has been linked to a lower risk of heart attacks.
According to the British Heart Foundation, a study by Professor Ed Rainger of the University of Birmingham revealed that omega-3s "naturally dampen inflammation", which could be one reason why the risk of heart disease is lowered, as too much inflammation can lead to hardened or narrowed arteries.
Last year, US research suggested that omega-3 fish oil reduced the risk of men dying from prostate cancer by up to 40 per cent, while a further study conducted recently found that adults over 65 with high blood levels of omega-3s lived on average 2.2 years longer than those who avoided oily fish.
Furthermore, such seafood is a good source of nutrients like vitamins A and D, which help to keep our bones healthy, our skin flawless, and aid the body in fighting infection.
How much and what?
The National Institute for Clinical Excellence (NICE) recommends adults eat at least two portions of oily fish a week, but there are certain limitations depending on your sex and whether you are pregnant.
For example, men and boys can happily wolf down up to four portions a week, while girls or women who are either pregnant or may become pregnant in the future, or breastfeeding should limit themselves to two helpings, as pollutants found in the fish may negatively impact baby's development in the future. For women over childbearing age or those who have no intention of starting a family, up to four portions is fine.
There are also plenty of options to choose from so there's no need to stick to salmon. Anchovies, herring, mackerel, pilchards, sardines, whitebait, and even trout and carp are the fish to buy if you are to benefit from the healthy omega-3s, while tuna is also a source, though only the fresh variety, as the canned variety contains reduced levels of fatty acids.
Getting your fatty acid fix is more tricky if you are vegetarian, but omega-3s are found in some seeds, notably flax and rapeseed oil, while some swear by fish oil supplements.
Opinion is divided on just how effective omega-3 supplements really are, but if you begin taking them and feel a benefit, then carry on. Just be sure to check the label and look for a breakdown of the ingredients, and the all-important DHA and EPA to get the best from your supplement.