Omega-3: What is it and why do we need it?

Many of us have taken steps to improve our health and fitness. For instance, by boosting our immune system, or increasing our activity levels. However, one of the most important things we can do to stay fit and strong is to eat a healthy, balanced diet – one that contains plenty of vitamins, minerals, and essential fatty acids.

Omega-3 fatty acids are among the most important nutrients our body needs, but many of us aren’t sure exactly what they are, or why they’re so essential for maintaining optimal health. So what are some of the benefits of omega-3 fatty acids, and how can we ensure we’re getting enough?

1. What are omega-3s?

Omega-3s are a type of essential fatty acid. They play a crucial role in our body and have several important health benefits. Because our bodies can’t produce omega-3 fatty acids by themselves, we need to get them from our diet. There are three different types of omega-3 fatty acids – these are:

  • ALA (alpha-linolenic acid). ALA can’t be made in the body, but they have vital functions and are necessary to make other omega-3 fats. ALA is mostly found in plant-based food sources, like vegetable oils, rapeseed and flaxseed, nuts including walnuts, pecans and hazelnuts, and green leafy vegetables like brussels sprouts, kale and broccoli.

  • EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). EPA and DHA are fats that can be made using the ALA in our bodies – however, because this process happens slowly, the best way we can ensure we’re getting enough EPA and DHA is to eat foods containing high amounts of these fats. DHA and EPA are mainly found in oily fish and algae like kelp and seaweed.

2. Why are omega-3 fatty acids important?

So now we know what omega-3 fatty acids are, let’s delve into why exactly they’re so important. Few nutrients have been studied as intensely as omega-3s, and because of the amount of scientific data that’s available to us, it’s evident that omega-3s provide a wealth of health benefits for both our bodies and brains. Some of the most powerful benefits are:

Omega-3s can prevent and treat depression and anxiety

Depression and anxiety are two of the most common mental disorders, and studies show that people who consume omega-3s on a regular basis are less likely to be depressed. Plus, other studies suggest that when people suffering from depression or anxiety begin taking omega-3 supplements, their symptoms often improve. Of ALA, EPA and DHA, EPA seems to be most effective at fighting anxiety and depression; one clinical study found that it was just as effective at fighting depression as prescribed antidepressant drugs.

Omega-3s can enhance eye health

DHA is a crucial component of our eye’s retina, and when we don’t get enough DHA it may lead to problems with our vision. Getting enough omega-3 is also associated with a significantly lowered risk of macular degeneration, which is one of the most common causes of eye damage and blindness around the world.

Omega-3s reduce the risk factors for heart disease

Heart disease is the world’s leading cause of death, and while it’s important to note that there’s no solid evidence to suggest that omega-3s can prevent heart attacks or strokes, they are linked to many powerful benefits for heart health, and are believed to help reduce the risk factors for heart disease. Studies have shown that omega-3s can reduce blood pressure levels, raise “good” HDL cholesterol levels, prevent the formation of blood clots, and help prevent plaque from forming in your arteries. For more information, you might like to have a read of our articles 11 healthy heart tips and 5 tips to help lower cholesterol.

Omega-3s can help fight inflammation

Inflammation is part of our body’s natural response to infection, but chronic inflammation is a major contributor to countless illnesses, including heart disease and cancer. Omega-3s have been shown to reduce the production of substances that are associated with inflammation, and multiple studies show a link between higher omega-3 intake and reduced inflammation.

Omega-3s can help fight autoimmune diseases

When you have an autoimmune disease, your immune system believes healthy cells are harmful and begins attacking them. Studies show that omega-3s can help fight some of these diseases, particularly in early life – e.g. getting enough omega-3s as an infant is associated with a reduced risk of type 1 diabetes, autoimmune diabetes and multiple sclerosis. Omega-3s have also been shown to be effective in treating lupus, rheumatoid arthritis, Crohn’s disease and psoriasis.

Omega-3s can improve psychiatric disorders

Having low omega-3 levels has been linked to psychiatric disorders, and studies suggest that taking omega-3 supplements may reduce the occurrence of both mood swings and relapses of schizophrenia and bipolar disorder. Other studies suggest that taking omega-3 supplements may reduce violent behaviour.

Omega-3s can protect the brain against age-related decline

A decline in cognitive function is an unfortunate but often unavoidable consequence of ageing. However, omega-3s are associated with a healthy brain, and several studies link having higher levels of omega-3s with decreased cognitive decline. While more research is needed to draw definitive conclusions between omega-3s and brain health, multiple studies suggest that taking omega-3 supplements may lower the risk of Alzheimer’s disease, and even after onset, reduce the symptoms of early Alzheimer’s disease.

To find out more about brain health, you may want to have a read of our new article, How to exercise your way to better brain health.

Omega-3s may help prevent cancer

After heart attacks and stroke, cancer is one of the leading causes of death around the world, and studies suggest that omega-3s may reduce the risk of getting certain types of cancer. Some studies show that people who have high levels of omega-3s have up to a 55% lower chance of getting colon cancer; other studies suggest that high levels of omega-3 are linked with a lower risk of both prostate cancer and breast cancer.

Omega-3s may boost bone health

Osteoporosis and arthritis are two skeletal disorders that become increasingly common as we get older. Several studies show that omega-3s can boost bone strength by increasing the amount of calcium that’s present in our bones, which can lower the risk of osteoporosis. Plus, omega-3s may also be effective at treating arthritis: patients suffering from arthritis have reported reduced pain and improved grip strength after taking omega-3 supplements.

To find out more about how to boost your bone health, you may want to read our article, 9 ways to improve bone health.

Omega-3s can reduce liver fat

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the West. However, studies show that people suffering with NAFLD have been able to reduce both liver fat and inflammation by taking omega-3 supplements.

3. How can you get enough omega-3 fatty acids?

So we know that omega-3 fatty acids provide a wealth of health benefits – but how can we be sure we’re getting enough? Most health organisations recommend that healthy adults should consume around 500 mg of omega-3s per day – and because omega-3s are found in several different food sources, it’s often possible to get enough simply from eating a healthy, balanced diet.

So what are some of the best dietary sources of omega-3s?

Oily fish

Because they contain EPA and DHA, oily fish is the best source of omega-3 fatty acids. The fish and seafood that contains the highest amount of omega-3s include:

  • Salmon (4,123 mg per serving)
  • Mackerel (4,107 mg per serving)
  • Cod liver oil (2,682 mg per serving)
  • Sardines (2,205 mg per serving)
  • Caviar (1,086 mg per serving)
  • Anchovies (951 mg per serving)
  • Herring (946 mg per serving)
  • Oysters (370 mg per serving)

However, it’s important to note that some oily fish contain amounts of chemical and metals that can be harmful, so it’s advised that you shouldn’t have any more than four portions of oily fish per week; in addition, swordfish and marlin can contain high levels of mercury, so you shouldn’t eat more than one portion of these per week.

If you’d like to include more oily fish in your diet and need some inspiration, you might want to check out these oily fish recipes from BBC Good Food or The Guardian.


Flax seeds, pumpkin seeds, chia seeds and hemp seeds all contain omega-3s, although flax seeds and chia seeds contain especially high levels.

Flax seeds are often ground, milled or used to make oil – and flax seed oil is often used as a plant-based omega-3 supplement. Flax seeds contain around 2,350 mg omega-3s per tablespoon, so adding a spoonful to your cereal or porridge can be an easy way to up your omega-3 intake.

Chia seeds are also very high in omega-3s, containing around 5,060 mg per serving. You can sprinkle chia seeds over cereal, soups or salads, but one of the most popular ways to eat them is to make a delicious chia seed pudding.


Nuts including walnuts, pecans and hazelnuts all contain high amounts of omega-3s. Walnuts in particular are very nutritious and contain around 2,570 mg omega-3s per serving (around 28 grams, or 14 walnut halves).

Soya beans

Soya beans are another good source of plant-based omega-3s, containing around 1,241 mg per serving. You can eat soya beans in their whole-food form (edamame beans), or you might choose to eat soya-based products, like tofu, tempeh, soya milk, soya protein or miso. For some healthy and tasty tofu recipes, check out Jamie Oliver’s suggestions, or head over to BBC Good Food.

Additional foods

While the foods above have some of the highest concentrations of omega-3s, other omega-3 containing foods that you could incorporate into your diet include brussel sprouts, spinach, avocado, seaweed, vegetable oils (like flax seed, canola, mustard and walnut), and fortified foods such as orange juice, eggs and yoghurt.

4. Should I take an omega-3 supplement?

Because food contains an abundance of important health-boosting nutrients, it’s always best to get your omega-3s from foods rather than supplements where possible.

While omega-3s can be found in plant-based food sources like nuts, seeds, green leafy vegetables and soya beans, these only contain ALA fatty acids. ALA fatty acids are inferior to EPA and DHA, which are found in oily fish and algae like seaweed and kelp. Our bodies can convert ALA into EPA and DHA, but this process can be slow, so if you don’t eat much oily fish or large amounts of plant-based omega-3 sources, then you could consider having a chat with your GP or health practitioner about a supplement.

The most common way to supplement omega-3 is by taking a fish oil capsule. According to Heart UK, you should choose fish oil over fish liver oil, which contains less omega-3 and higher levels of other fats. Fish liver oils also often contain too much vitamin A – which, if consumed in high amounts, can build up in the body and cause harm. The recommended dosage of omega-3 is 500 mg per day – although your GP or health practitioner will be able to advise you on what the correct amount to take is, based on your individual circumstances.

You can buy omega-3 fish oil supplements from Amazon, Holland & Barrett, or your local supermarket. If you’re vegan, vegetarian or you don’t eat fish, you can buy algae-based omega-3 supplements containing EPA and DHA. According to research, it’s best to take omega-3 supplements with a meal that contains healthy fat, as this increases the body’s absorption of omega-3s.

Final thoughts…

Omega-3 fatty acids are essential for optimal health. They can fight inflammation and heart disease, improve eye health, help maintain a healthy brain, and improve the symptoms of certain mental health conditions. Getting your omega-3s from whole food sources is always best, and because omega-3s are found in a variety of foods, from oily fish to nuts and seeds, it’s possible to get enough if you eat a healthy, balanced diet. However, if you don’t believe you’re getting enough omega-3 and are considering taking a supplement, you should always seek advice from your GP or health practitioner first.

Do you take omega-3 supplements, or have you taken steps to include more omega-3 fatty acids in your diet? We’d love to hear about your experiences. Leave us a comment below or join the conversation over on the Rest Less community.

Links with an * by them are affiliate links which help Rest Less stay free to use as they can result in a payment or benefit to us. You can read more on how we make money here.

Discover Readly – the magazine and newspaper app

Enjoy quality reading from over 5,000 titles with Readly – accessible anytime, anywhere.

Get inspiration for your next walk with Country Walking, practice self-care with Planet Mindful, read your favourites or discover something new! Try 2 months free with your exclusive Rest Less offer today.

Get 2 months free


Loading comments...

    Leave a reply

    Thanks, your comment has been saved. We will review it shortly, check back soon.

    Sorry, there was a problem saving your comment. Please refresh and try again.

    Get the latest ideas, advice and inspiration

    No spam. Just useful and interesting stuff, straight to your inbox. Covering jobs, finance, learning, volunteering, lifestyle and more.

    By providing us your email address you agree to receive emails and communications from us and acknowledge that your personal data will be used in accordance with our Privacy Policy and Terms and Conditions. You can unsubscribe at any time by following the link in our emails.

    Enjoying Rest Less? Help us reach more people like you

    Leave us a rating Want to tell us something?