Cod liver oil offers a number of health benefits because it contains a number of important nutrients. These benefits include, but are not limited to improving cardiovascular health, improving immunity, and preventing some cancers.
Cod liver oil is high in a number of naturally occurring nutrients that are not abundant in a modern diet. These are the omega-3 fatty acids EPA and DHA, and the fat-soluble vitamins A and D. It is these nutrients that the health benefits of cod liver oil can be attributed to.
Omega-3 fatty acids
The omega-3 fatty acids found in cod liver oil are EPA and DHA. These omega-3 fatty acids are common in oily fish/ seafood but are not found in significant quantities in other foods. Although omega-3 fatty acids help support a range of health functions, they are particularly important in protecting the cardiovascular system.
The benefits of omega-3 fatty acids on the cardiovascular system have been demonstrated in numerous studies. One large study in Japan found that EPA supplementation reduced the risk of a major coronary event (heart attack or similar) by 19%.
Another study in Italy with 11,324 patients showed that supplementation with omega-3 fatty acids was clinically important and statistically significant in reducing death from cardiovascular disease.
With cod liver oil containing a variety of omega-3 fatty acids and vitamins, a well-demonstrated benefit from cod liver oil is the protection of the cardiovascular system.
Vitamin D is an extremely beneficial nutrient, and there is evidence that large amounts of the population are not consuming enough vitamin D.
The primary benefit of vitamin D is its influence on the immune system. Vitamin D is involved in a variety of roles in the immune system from modulating the cells that fight infections, to reducing the oxidative stress on the body from infections. Having sufficient vitamin D levels means that the body can reduce the severity/ duration of many infectious diseases. Vitamin D’s ability to support the immune system was particularly important during the Covid-19 pandemic, as vitamin D levels we associated with the severity of symptoms from catching Covid-19. This led the National Health Service in the UK to offer free vitamin D supplements to those most at risk from coronavirus.
Vitamin D also plays an important role in bone density. It improves calcium absorption in the digestive system and calcium reabsorption in bones. This means it can help protect against osteoporosis and rickets.
There is some evidence that vitamin D can protect against some cancers, although research is inconsistent. As vitamin D is important in so many functions in the body, a deficiency in vitamin D may lead to other health problems, which then lead to an increased risk of developing cancer.
Vitamin A plays an important role in a variety of biological functions. There is evidence that it can help prevent some cancers and reduce the severity of some ailments. Due to its broad functions in the body, the health benefits of vitamin A is that it supports overall health.
Vitamin A is found in a variety of foods. Typical diets are not deficient in vitamin A, and although raw cod liver oil is not very high in vitamin A, some cod liver oil has extra vitamin A added. In some circumstances, for example, taking a multivitamin with high levels of vitamin A, a high vitamin A cod liver oil, and/ or a vitamin A-rich diet (such as one containing liver), there is a risk of vitamin A toxicity.
Vitamin A toxicity from cod liver oil alone is extremely unlikely, but it is important not to take too many supplements that contain vitamin A.
Other nutrients in cod liver oil
Although the above nutrients are the most important and abundant nutrients, cod liver oil does contain other nutrients. Raw cod liver oil contains some vitamin K and various other omega-3 fatty acids beyond EHA and DHA. Some also have vitamin E added to them. However, due to the various processing methods available to produce cod liver oil these nutrients are not guaranteed.
Other benefits of cod liver oil
The primary benefits of cod liver oil are improved immunity, protection of the cardiovascular system, and stronger bones. These are arguably the most important, and the most researched. However, there are other benefits. Cod liver oil might improve joint health, skin health, recovery from physical exercise, and even improve your mood. Evidence on these benefits isn’t clear. However the key nutrients in cod liver oil are involved in so many important functions in the body, it is a reasonable assumption that it offers benefits throughout the body, even if they are indirect.