It’s not often that when I advise a client to take a supplement that they ask if it’s still made, yet this does sometimes happen when I suggest cod liver oil, simply because it’s been around so long, its rather fallen out of fashion, often overlooked in favour of omega 3.
Whilst fish oils and cod liver oil seem as if they are one and the same, there is a slight difference. Cod liver oil, as the name implies, is extracted from the livers of codfish, whilst omega-3 fish oils are usually derived from the tissue of oily fish such as sardines, mackerel and anchovies. Whilst they both offer omega-3 fatty acids, they differ significantly in what else they contain.
One of the main benefits of cod liver oil is its high content of omega-3 fatty acids—primarily EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). These too are found in omega 3 oils and have a wide range of benefits including contributing to normal brain function and vision but can help maintain triglyceride levels in the blood, assist in maintaining normal blood pressure and normal heart function.
But cod liver oil is a good source of both vitamins A and D. Vitamin A is crucial for maintaining normal healthy vision, immune function, skin and mucous membrane health. It is found in dairy, eggs, oily fish and liver, and so you may already be getting a good amount from your diet.
Vitamin D contributes normal calcium levels as well as the normal absorption and utilisation of calcium and phosphorous. Vitamin D can also help maintain normal muscle function as well as teeth and the immune system.
Omega 3 fats will have been purified to ensure that they deliver the good concentrations of both DHA and EPA, but the process removes other nutrients. This allows for targeted supplementation as if you are looking for the benefits of fish oil alone, then omega 3 is an option.
If you wanted the addition of vitamins A and D, then cod liver oil may suit you better. But there is a caveat, in as much as vitamin A intake should be modest and having more than 1.5mg from all sources is not advisable, especially for women post menopause, but also for older people in general.
Vitamin A may already be in other supplements you are taking, such as a multi, in which case you should seek the advice of a nutrition professional before taking supplements that contain more.
This subtle yet important difference between cod liver oil and omega 3 underlines the fact that supplements have a role and are not inert and should be taken after consulting a nutrition professional. If you are taking any medication for raised blood pressure then do get professional advice before taking cod liver oil or omega 3 supplements.