What Are the Benefits of Fish Oil?

by | Dietary Supplement, Nutrition

Let’s get straight to the facts: fish oil is one of the most thoroughly researched supplements . It's been proven to have a positive effect on overall human health, physical and mental performance. In a world where 99% of the supplements are bunk that really says something.

The bad news is… you’re probably wasting your hard-earned cash on a product that does nothing at best. It may even be harmful.

This article doesn’t have the goal to scare you or start a new fear-mongering trend. Omega-3 fatty acids, the main ingredient of fish oil, are an important component of any healthy diet.

But in order to make an educated decision what’s the best way to include them in our diet, we need to understand what Omega-3s are in the first place.

What is Omega-3?

Liquid Fish Oil - Omega 3

Simply put, Omega-3 fatty acids are a type of polyunsaturated fats. That’s important and you’ll see why in the next sections. For now, let’s discuss the difference between each group of fats.

There are 4 main types of fats:

  • Saturated fats (SFA): usually solid at room temperature, mostly found in meat and animal products
  • Trans fats (TFA): solid at room temperature, don’t occur often in nature, mostly man-made. Found in junk food
  • Monounsaturated fat (MUFA): usually in liquid form, most vegetable oils
  • Polyunsaturated fats (PUFA): also in liquid form, found in fatty fish, some nuts, and seeds

Note: we’ve discussed fats in detail in our article “How to Eat Healthy: Distinguishing Between Good and Bad Foods

Olive Oil and Olives

What you may have noticed is some fats are solid, some are liquid. That’s because of their molecular structure, in particular, the number and configuration of carbon atoms connected by double covalent bonds.

You don’t need the details, it’s important to understand that some molecules line up neatly and stay together. Others, because of their structure, have a hard time lining up properly.

You can imagine filling up a box with even-sized cubes. If you move the box around, the cubes won’t shift much. But if you fill the same box with similar-sized marbles and you start moving it, the balls will start moving around.

That’s why some fats are solid – their structure is more rigid and they stay solid. Unsaturated fats are far more likely to be in liquid form since their molecules move around way more.

Key takeaways: Omega-3 fatty acids are a type of polyunsaturated fat and they are usually in liquid form.

Polyunsaturated Fats: Omega-3 vs Omega-6

There’s another type of polyunsaturated fatty acid (PUFA) you may have heard of, Omega-6.

The difference between the two types is how far away is the double bond from the methyl carbon. In the case of Omega-3 (ω-3) it’s three carbons away, and in Omega-6 (ω-6) it’s six carbons away.

In simple words: the difference is where exactly a certain bond occurs in the structure of the PUFA.

Both fats are essential, meaning humans can’t produce them and they need to be obtained from the diet.

PUFA content in our diet has a considerable influence on adipose tissue (fat reserves) and plasma triglycerides composition. However, we won’t focus on this too much. Though it does have health implications and it’s important you consume enough PUFAs.

The ratio between both essential fats has an even greater influence on phospholipid composition than the total PUFA consumed [1]. Phospholipids are a type of lipids (fat) that is one of the main components of all cell membranes.

What Happens When You Don’t Consume Enough Omega-3?

DNA Image

Omega-3 fatty acids help maintain a “healthy” cell membrane. Cells are the main structural element of the body. Different organs are made up of different types of cells, but pretty much all those cells, regardless of the type and function, have cell membranes.

As we already mentioned, the cell membrane consists of mostly phospholipids (fats). One of its roles is to let certain elements (for example enzymes) in or out of the cell. A rigid cell membrane will make it hard for anything to pass through it.

А more permeable membrane will help the cell be more efficient. So if it needs to send a chemical messenger to another cell it can easily do it. This also affects important processes like DNA translation.

Imagine a heavy door that is really hard to open. The type that is super heavy and requires effort to open. Let's now say you need to carry things through that door multiple times a day. Imagine the struggle to keep the door open as you carry things in and out. 

It’s the same with your body. One inefficient cell is not a problem. But when a whole bunch of them don’t work properly for a long period of time, you start having problems. In time, this can lead to other issues that can evolve into a serious medical condition.

Omega-3 fats, due to their structure, help maintain a permeable cell membrane which helps the cell be more efficient. That helps your organs, and your body as a whole, function at an optimum level. This minimizes the risks of a particular system breakdown (disease).

Key takeaways: not consuming enough Omega-3 can negatively impact the cell membrane. This can negatively impact its functionality. That, in turn, can make whole organs and systems not function optimally.

How Important Is the ω-3 vs ω-6 Ratio?

health and omega-3 intake

When ω-3 content is less than 10% (1:9 ratio) of total PUFA that has a negative effect on membrane composition and that has significant health implications. However, when the ratio is more balanced that effect almost disappears.

An imbalance between Omega-3 and Omega-6 is associated with a number of diseases like:

  • hypertension
  • chronic inflammation
  • insulin resistance [2]
  • depression [3]
  • abdominal obesity
  • type II diabetes [4]
  • cardiovascular disease

Most of those medical conditions result from an overall unhealthy lifestyle, genetic predispositions, and a multitude of different factors. Consuming enough ω-3 can help reduce your the risk, but is far from the be-all and end-all solution. An overall healthy diet and sufficient physical activity are key components for maintaining a healthy body.

Note that Omega-6 have pro-inflammatory properties, while Omega-3 anti-inflammatory. Not consuming enough ω-3, coupled with excessive consumption of ω-6, can lead to chronic inflammation.

This can increase your risk of different types of cancers, atherosclerosis, and neurodegenerative diseases like Alzheimer's disease [5].

How Does the Typical Western Diet Influence Omega-3 Intake?

unhealthy fats vs healthy fats

The average ratio between ω-3 and ω-6 is the western word is around 1:15 [6]. As we’ve discussed before, that’s lower than the recommended minimum. In an ideal scenario, the ratio should be closer to 1:1.

Overall PUFA deficiency is unlikely since Omega-6 is abundant in a lot of vegetable oils, nuts, cereals, and meat.

Omega-3 is mostly found in fatty fish and some nuts, like walnuts for example. These are foods that are not as popular or widely consumed as Omega-6 rich products. This creates a bit of a problem.

Both PUFAs are metabolized by similar enzymes. An imbalanced ratio can affect how much of the less-consumed fat is metabolized. What you consume more will have priority over the other type.  A Omega-6 rich diet will result in poor Omega-3 absorption.

It’s important to stress on the fact that the ratio between both essential fatty acids is far less important than consuming enough Omega-3 in the first place.

Key takeaways: Not consuming enough Omega-3 is a problem on its own, but if you also over-consume Omega-6, that has an even greater negative impact.

Note: excess Omega-3 consumption, while rare in practice, can also lead to health problems [7]

Benefits of Fish Oil

It should already be clear why consuming enough Omega-3 is vital for good health. Whether it’s coming from food or a supplemented such as cod liver oil it doesn’t matter that much.

Major benefits include:

  • Improved cardiovascular health
  • Reduced inflammation
  • Healthier joints may help reduce joint pain as well
  • Improved cognitive performance
  • Lower risk of depression
  • Improved insulin sensitivity

Note that some of the points above are a bit vague. That’s because the body is a complex system, and essential fats are just one component out of many that affect your health and well-being. Healthy individuals following good diet and workout plans won’t notice a huge difference when they start taking a fish oil supplement.

That being said, compared to other fats, and practically 99% of supplements on the market, fish oil has a notable impact on many vital systems. The effect is especially pronounced in people who have poor diet habits.

Anabolic Properties

For people training heavy and regularly, omega-3 supplements are a great addition to the supplement stack. Here are some the major benefits of sufficient intake:

  • can help muscle repair by reducing chronic inflammation [8]
  • can lower muscle damage and soreness [9]
  • can increase testosterone production [10]
  • can reduce cortisol levels [11]

Since PUFAs have a notable effect on adipose (fat) tissue, fish oil consumption can also aid fat loss.

Key takeaways: if you can’t obtain enough omega-3 through your diet, taking a fish oil supplement is a no-brainer. Fish oil supplementation helps you improve your overall health, recover better (thus train harder), and build more muscle.

Fish Oil Dose: How Much Should You Take?

fish oil pills

The recommended Omega-3 dose is around 2,000 to 3,000 mg a day. You can even go a bit higher. More is not better, since this type of fat is very bioactive, taking too much can pose serious health hazards. If you consume a lot of fatty fish, then you may skip supplementation on some days.

It’s important to note that the recommendation is about the actual amount of Omega-3, not the total product serving size. For example, 1 g (1,000 mg) of fish oil product may contain only 300 mg of ω-3. Pay close attention to the label and amounts listed.

Also, there are different types of Omega-3 fatty acids. Not all of them are equally beneficial for your health.

How to Choose Between EPA, DHA, and ALA?

dry chia seeds and flax

There are several different ω-3 fatty acids. Some like DPA and SDA are not very popular. While, others like EPA, DHA, and ALA, are often given the spotlight.

Ultimately, you should mostly care about EPA and DHA content. ALA (alpha-linolenic acid) found in flaxseed, chia, and walnuts, have significantly fewer reactive sites as it’s the shortest-chained member of the Omega-3 family [12].

ALA can be converted to EPA and DHA. But that conversion is around 4-5%, and some people from Scandinavian ancestry may even lack the enzyme needed for the conversion.

This doesn’t mean the other ω-3s are not beneficial, but they act as synergists to EPA and DHA, and shouldn’t be the prime ingredient in a quality product.

To calculate the total amount of Omega-3 you should only look at the EPA and DHA content. If that is not listed, don’t even bother with the product.

Key takeaways: the recommended daily dose of Omega-3 is 2,000 to 3,000 mg of combined EPA and DHA. That may be the equivalent to 2-3 teaspoons of liquid fish oil, or up to a dozen pills.

How to Choose an Omega-3 Supplement?

fish oil supplements

You may have realized that swallowing several large pills a day could be a challenge. But that’s far from a real concern. Here’s a what you really need to consider when purchasing a supplement:

  • EPA and DHA content: as we’ve already hinted, most plant products like flaxseed oil are not a good source Omega-3. Almost all plant-based supplements contain mostly ALA. While they’re good for your health, you’ll get the most benefit if choose product with higher amounts of EPA and DHA. There are good vegan alternatives which we’ll discuss in another section.


  • Level of processing and fatty acid profile: apart from EPA and DHA, natural fish oil contains other cofactors, vitamins, and minerals. If the EPA/DHA content is more than 30% (300mg per 1,000mg product) that means the oil has been heavily processed and valuable nutrients have been lost. Thus the end product is less potent.


  • How the product was stored and transported: omega-3 fatty tend to oxidize easily when exposed to oxygen. Direct sunlight tends to degrade the quality of the product as well. You can’t know for sure how the product was handled, but as a general rule of thumb:
    • check the expiration date, always buy fresh
    • buy smaller packages, so you can consume the oil before it oxidizes
    • make sure the container is dark enough, so sun exposure is limited
    • if you notice the product was exposed to direct sunlight on the aisle, you’d be better off getting one from the back.  
    • If you suspect the product was exposed to heat or high temperatures, that’s a red flag
    • once you purchase a (fresh) supplement you like, keep it in a cold and dark place (e.g. in the fridge) and try to consume it within a month of opening.

But there’s more. The way the fish was processed matters a lot more than how and where the final product was stored. And that first part of the production matters a whole lot more.

Are You Wasting Your Money on Bunk Products?

piggy bank money

Most fish oil products come from fish caught and processed in Central America or South Africa… and not the Arctic Ocean as most brands will have you believe.

Fish may be kept in a huge container for up to a few days before it’s finally processed and the oil extracted. During that time it is exposed to high temperatures and oxygen. It often turns rancid.

Researchers tested different products in New Zealand [13], South Africa [14], and the United States [15]. Oxidation levels ranged from 50 to over 80%. This is not surprising since most oil is coming from the same production facilities. It’s also likely most of the final product is not shipped under ideal conditions. Heat can further degrade its quality.

When the oil oxidizes new byproducts are created and they may give off fishy taste and smell.

Rancid fish oil is not that well researched, but we do know that oxidation can decrease the amount of EPA and DHA. So the numbers seen on the label are probably not accurate. Rancid fish oil is probably not perfectly safe for human consumption either.

Unfortunately, you have no idea of knowing how the fish was processed. You could spend some time researching a product, calling the customer support line, and trying to figure out where the fish is coming from, where it’s kept, and how it’s transported.

Another simple test is to open a fish oil capsule and taste it. If it smells and tastes like rancid fish, that’s a sure sign to stay away from that product. This is why liquid oils are usually a better option. It’s harder to mask the bad odor and smell.

Fishy burps after consumption shouldn’t happen as well. You don’t have nasty fish burps after eating fresh sushi, the same applies to fresh fish oil.

But this method is not perfect either. Signs of rancidity can be minimized by including different additives to the product that change the taste and remove bad odors.

Key takeaways: most fish oil products are not processed under ideal conditions and are a pure waste of money at best. You can use the taste and smell test to determine if the product is fresh.

But it’s a good idea you do some research before you commit to any brand. Avoid sun and heat exposure. Make sure you pay attention to where the product was stored in the pharmacy or store.

Fish Oil Supplements vs Real Food?

salmon roll sushi

Let’s go over the pros and cons of each.

Fish Oil Supplements:
  • Pros:
    • Convenient
    • Require no preparation
    • Travel-friendly (though it depends on how you store it)
    • Require no special storage requirements as long as you have a fridge
    • Can easily be incorporated into your daily routine and help consistency
    • Most good supplements have no taste and odor and can be added to smoothies and shakes


  • Cons
    • Most brands are a waste of money and potentially unsafe for consumption
    • Quality products are almost always very expensive (and for a reason)
    • You need to do some good research before committing to a brand
    • Even products from a trusted brand can degrade if not stored properly
    • Need to be stored in a cold and dark place
Getting your Omega-3 dose from food:
  • Pros
    • There are a number of foods high in ω-3 that make it very easy to hit your daily target
    • Most foods high in Omega-3 are also jam-packed with other nutrients
    • Price-wise, eating fatty fish is probably the cheapest option out there
    • If you’re buying fish you can easily tell how fresh it is
    • Frozen fish is a very convenient option
    • You can cook tasty meals
  • Cons
    • Not convenient
    • Frying, canning, and when high temperatures are used Omega-3 content can decrease significantly
    • Eating a lot of fish frequently is not a good idea, you may overdose on certain nutrients, and that may lead to negative health impacts
    • Food prepping could take a lot of time, storing can also be an issue
    • If you decide to eat out price can be an issue (e.g. sushi)
    • Most Omega-3 foods can be very caloric and not suitable for a weight loss phase

Ultimately, it comes down to personal preference. You can opt for a combined approach where you occasionally supplement cod liver oil to your diet. And also include Omega-3 foods a few times a week.

Not getting 2,000 or 3,000 mg of Omega-3 every single day is not a huge issue. Provided you have some Omega-3 foods or supplements at least a few days a week. The recommendation is for optimum results, not a minimum. You can get away with far, far less.

Foods High in Omega-3

Fatty fish is your best bet: salmon, anchovy, mackerel, tuna, herring, and sardine.

As we discussed most plant-sources contain mostly ALA: walnuts, chia, flaxseed, hemp seeds, etc. These are very healthy foods, but our vegan and vegetarian friends may want to consider algae. According to research that’s probably the best Omega-3 source in the context of a plant-based diet [16]

Key takeaways: there are plenty of good food options high in Omega-3. However, you may want to include a fish oil supplement as well. It’s very convenient and helps hit your daily target much easier.

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Resources and References

[1] Fatty acid composition of membrane bilayers: Importance of diet polyunsaturated fat balance

[2] Quality of dietary fatty acids, insulin sensitivity and type 2 diabetes

[3] Dietary omega-3 fatty acids and psychiatry: Mood, behaviour, stress, depression, dementia and aging

[4] n-3 long-chain polyunsaturated fatty acids in type 2 diabetes: A review

[5] Inflammation Bares a Dark Side

[6] The importance of the ratio of omega-6/omega-3 essential fatty acids.

[7] Excess Omega-3 Fatty Acid Consumption by Mothers during Pregnancy and Lactation Caused Shorter Life Span and Abnormal ABRs in Old Adult Offspring

[8] Influence of combined resistance training and healthy diet on muscle mass in healthy elderly women: a randomized controlled trial

[9] Effects of Short-Term Docosahexaenoic Acid Supplementation on Markers of Inflammation after Eccentric Strength Exercise in Women

[10] Do Fat Supplements Increase Physical Performance?

[11] Effects of supplemental fish oil on resting metabolic rate, body composition, and salivary cortisol in healthy adults

[12] EPA, DHA, ALA: How to Decipher the Omega-3 Alphabet Soup

[13] Fish oil supplements in New Zealand are highly oxidised and do not meet label content of n-3 PUFA

[14] Analysis of the omega-3 fatty acid content of South African fish oil supplements: a follow-up study.

[15] Oxidation levels of North American over-the-counter n-3 (omega-3) supplements and the influence of supplement formulation and delivery form on evaluating oxidative safety/

[16] Bioavailability and potential uses of vegetarian sources of omega-3 fatty acids: a review of the literature.

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