/newsdrum-in/media/member_avatars/9Rj3p38eDEeibqzKtTLR.jpg "Are fish oil supplements as healthy as people think? Is it better to eat fish?")
Fish oil, which contains omega-3 fatty acids, is believed to have many health benefits, including improving heart health, protecting our brain from dementia and reducing arthritis symptoms.
But what exactly are omega-3 fatty acids and what is the evidence for their health benefits?
If it's good for us, does eating fish provide the same benefits as supplements?
What are omega-3 fatty acids?
Omega-3 fatty acids are a type of polyunsaturated fatty acid. It is important to consume them in our diet because we cannot create them in our bodies.
There are three main types of omega-3 fatty acids that are important in our diet:
Alpha-linolenic acid (ALA) is found in plant foods such as green leafy vegetables, nuts, flaxseeds, and chia seeds.
Eicosapentaenoic acid (EPA) is found in shellfish, eggs (more free than diseased eggs) and breast milk.
Docosahexaenoic acid (DHA) is only found in seafood, eggs (again higher in free range eggs) and breast milk.
Omega-3s are essential for the structure of our cells and contribute to the functioning of the heart, lungs, blood vessels and immune system.
Eat fish or take supplements
The first studies showing that omega-3 fatty acids may have health benefits came from observational studies of people who ate fish, not fish oil.
So, are the "active ingredients" in nutritional supplements - EPA and DHA - absorbed by our bodies like fish?
An intervention study (one group was given fish and the other a fish oil supplement) found that the levels of EPA and DHA in your body increase similarly when you consume the same amount of fish or fish oil.
However, this assumes that only omega-3 fatty acids provide health benefits. There are other components of fish, such as protein, vitamins A and D, iodine and selenium, that may be responsible for the overall or combined health benefits.
The observed health benefits may also be due to the lack of certain nutrients, such as saturated fat and salt, that can be consumed from other types of meat (red meat and processed meat).
What are the benefits of omega 3 fatty acids? Is the source important?
Let's look at the evidence for heart disease, arthritis and dementia.
My heart disease
For cardiovascular disease (heart attack and stroke), meta-analyses, which provide the highest quality evidence, show little or no benefit from fish oil supplementation.
Another study found that for every 20 grams of fish consumed per day, the risk of coronary heart disease was reduced by 4%.
The National Heart Foundation, based on scientific evidence, recommends eating fish rich in omega-3 fatty acids for better heart health. Fish have varying levels of omega-3, and the thicker the flavor, the more omega-3 fatty acids they tend to contain, such as tuna, salmon, sea bass, flounder, mackerel and snook.
The foundation says fish oil may benefit people with heart failure or high levels of triglycerides, a type of fat circulating in the blood that increases the risk of heart disease and stroke. However, it recommends against using fish oil to reduce the risk of cardiovascular disease (heart attack and stroke).
Read more: Omega-3 supplements do not protect against heart disease - new review
arthritis
For rheumatoid arthritis, studies show that fish oil supplements provide benefits in reducing the severity and progression of the disease.
Eating fish also causes these improvements, but because of the high levels of EPA and DHA needed, it is often difficult and expensive to eat only these amounts of fish.
Arthritis Australia recommends an evidence-based intake of approximately 2.7 grams of EPA and DHA per day to reduce joint inflammation. Most supplements contain about 300 to 400 mg of omega-3 fatty acids.
So, depending on the amount of EPA and DHA per capsule, you need between nine and 14 capsules per day (or five or seven fish oil concentrates). This is equivalent to 130-140g of grilled salmon or mackerel or 350g of tinned tuna in brine (about four small cans).
dementia
Epidemiological studies show a positive relationship between increasing DHA intake (from the diet) and reducing the risk of Alzheimer's disease, a type of dementia.
Animal studies show that DHA can alter markers used to assess brain function (such as the accumulation of amyloid, a protein thought to be linked to dementia, and damage to the tau protein that helps stabilize nerve cells in the brain). However, this has not been seen in humans.
A systematic review of several human studies showed mixed results for omega-3 fatty acids from supplements.
In two studies that gave people with dementia omega-3 fatty acid supplements, no improvement was seen. But when it was given to people with mild cognitive impairment, a condition associated with a higher risk of developing dementia, improvement was seen.
Another meta-analysis (a review of studies) showed that higher fish consumption was associated with a lower risk of developing Alzheimer's disease, but this association was not seen with total dietary intake of omega-3 fatty acids. This suggests that eating fish may have other protective benefits. .
Based on the available evidence, the Alzheimer's Association recommends eating fish over fish oil supplements.
Read more: Some foods you can eat to reduce the risk of Alzheimer's disease?
So what's the point?
The more people eat a healthy, plant-based diet with less fish and ultra-processed foods, the better their health will be.
Evidence now suggests that fish oil is beneficial for rheumatoid arthritis, especially if sufferers have difficulty eating large amounts of fish.
For dementia and heart disease, it is best to try to eliminate omega-3 fatty acids from the diet. Although plant foods contain ALA, they are not as effective as increasing EPA and DHA levels in the body by consuming seafood.
As with any product on store shelves, check the use-by date on fish oil and make sure you can use it all by then. It renders the chemical structure of EPA and DHA capable of degradation, thus affecting their nutritional value. Store in a cool place, preferably in the refrigerator, away from light.
Fish oil can cause some annoying side effects, such as fish burps, but generally there are few serious side effects. However, it is important to discuss the use of fish oil with all of your doctors, especially if you are taking other medications.
Read more: Can supplements or diet reduce arthritis symptoms? Here's what the evidence says