The health benefits of fish oil are numerous, including boosting our heart health, protecting our brain from dementia, and easing the symptoms of rheumatoid arthritis.
What are the health benefits of omega-3 fats?
Does eating fish have the same benefits as supplements? Why or why not?
The use of omega-3 fatty acids is an example of a polyunsaturated fatty acid. Our diet can't contain these essential foods because we can't make them in our bodies.
In our diet, we are consuming three main types of omega-3 fats.
The structure of our cells is preserved by Omega 3s, which are crucial for maintaining our heart, lungs, blood vessels, and immune system function.
The initial studies suggesting omega-3 fats may have health benefits came from observational studies on people eating fish, not from fish oil.
Are the EPA and DHA supplements absorbed into our body in the same way as fish?
In a study, the levels of EPA and DHA in your body rose a similar way when you consumed equal amounts of them from either fish or fish oil.
This assumes it is just the omega-3 fats that provide health benefits. There are other components of fish, such as protein, vitamins A and D, iodine, and selenium, which could be wholly or jointly responsible for the health benefits.
The absence of specific nutrients that would otherwise have been utilized in other meats, such as saturated fats and salt, may have contributed to the benefits seen.
What are the benefits of eating omega-3 fats? The evidence for heart disease, arthritis and dementia is still debated.
A meta-analysis has shown that fish oil supplementation probably makes little or no difference for cardiovascular disease.
A meta-analysis found that every 20 grams a day of fish consumed decreases the risk of coronary heart disease by 4 percent.
The National Heart Foundation recommends eating fish that are rich in omega-3 fats for optimal heart health, based on the scientific evidence. In terms of their omega-3 content, fish differ in their taste and usually the fishier they taste the more omega-3 fats they have - such as tuna, salmon, deep sea perch, trevally, mackerel and snook.
The institute says fish oil can be helpful for people with heart failure or high triglycerides, a fat that circulates in the blood that increases the risk of heart disease and stroke. But it does not recommend the use of fish oil for reducing the risk of cardiovascular diseases.
For rheumatoid arthritis, studies have shown that fish oil supplements can enhance the severity and progress of the disease.
Eating fish also improves the health of the environment, but with the high level of EPA and DHA needed, it's difficult and expensive to consume such a lot from fish alone.
The evidence supports Arthritis Australia recommends about 2.7 grams of EPA and DHA a day to reduce joint inflammation. Most supplements contain about 300-400mg of omega-3 fats.
If you take EPA and DHA in every day, you may need nine to 14 capsules a day. This is about 130g -140g of grilled salmon or mackerel, or 350g of canned tuna in brine.
A positive correlation between increased DHA intake and a lower risk of Alzheimer's disease, a type of dementia, has been observed in epidemiological studies.
Animal studies have shown that DHA can alter the markers used to assess brain function. However, this has not been shown in humans yet.
The systemic review of multiple studies in humans has revealed different results for omega-3 fats from supplements.
In two studies, where Omega-3 fats were given as supplements for people with dementia, there was no improvement. However, given a condition associated with increased risk of dementia, there was a improvement in those with mild cognitive impairment.
A meta-analysis suggested higher intake of fish was associated with a reduced risk of Alzheimer's, but this relationship was not observed with total dietary intake of omega-3 fats. The evidence demonstrates that there may be other protective benefits derived from eating fish.
In line with the evidence, the Alzheimer's Society recommends eating fish over taking fish oil supplements.
The more people stick to a plant-based diet with fish and minimal intakes of extremely processed foods, the better their health will be.
The evidence suggests that fish oil is beneficial for rheumatoid arthritis, particularly if people find it difficult to eat large amounts of fish.
To reduce the risk of heart disease and dementia, it's important to obtain your omega-3 fats from your diet. While plant foods contain ALA, this will not be as efficient as increasing your EPA and DHA levels in your body by eating seafood.
As a product that sits on the shelf, check the use-by-date of the fish oil and make sure you won't be able to consume it all by then. The chemical structure of EPA and DHA is prone to degradation, which affects its nutritional value. Store it in a refrigerator, away from light, in a cold environment.
There are some irritating side effects of fish oil, such as fishy burps, but generally, there are minimal serious side effects. However, it's important to discuss taking fish oil with all your treatment doctors, particularly if you're on other medication.
Evangeline Mantzoris, a Professor of Nutrition and Food Sciences at the University of South Australia, is a Program Director of Nutrition and Food Sciences, an accredited practising dietitian. The conversation premiered this piece on tv programme The Conversation.