Omega-3: Benefits, side effects and sources

Omega-3 is an essential fatty acid crucial to living an active, fulfilling lifestyle. Not only does it support numerous cell functions, but specific types of omega-3 impact heart health and inflammation. Keep reading to learn about the health benefits of omega-3 and how much you should be consuming.

What is omega-3?

Omega-3 is a polyunsaturated fatty acid essential for human health thanks to its influence on cell function, heart health, inflammation and more. In fact, it’s called an essential fatty acid because the body needs it to function correctly. However, your body cannot produce omega-3 naturally, instead relying on foods such as oily fish, vegetable oils, and nuts. To reap the benefits of omega-3, it’s important to eat several portions of these foods per week.^[1]

Most people assume all omega-3 is the same, but as we’ll discover shortly, various foods contain slightly different versions of the fatty acid. Moreover, the three main types of omega-3 (ALA, DHA, and EPA) affect the body differently, meaning some versions may be more suitable than others, depending on your lifestyle.

ALA (alpha-linolenic acid)

Found primarily in plant foods (kale, spinach, walnuts and hemp), ALA is one of the most common types of omega-3. However, it may not be as effective at encouraging wellness compared to DHA and EPA.

Alpha-linolenic acid is essentially a precursor to the other types of omega-3, meaning it has to be converted inside the body. Typically, this interaction wouldn’t be a problem, but with ALA, the conversion rate is incredibly low (roughly 1–10%). Any unconverted ALA is then stored and used as energy, the same as regular fats.

That’s not to say this version of omega-3 is entirely useless. ALA is still beneficial for providing energy, and if you’re consuming leafy greens and nuts, you’ll benefit from the rest of the vitamins and minerals they contain.

DHA (docosahexaenoic acid)

DHA and EPA mostly come from seafood (often called marine omega-3s), with the highest concentration of docosahexaenoic acid found in herring, salmon, and shrimp. If you regularly consume these oily fish, research suggests that it could help blood vessel function, inflammation, and heart rate.

DHA is also vital for babies and young children, as the compound contributes to brain, skin and eye development. Unfortunately, a DHA deficit during childhood can lead to learning disabilities, while adults may be at greater risk of developing Alzheimer’s disease.^[2]

EPA (eicosapentaenoic acid)

EPA usually works alongside DHA to help modulate the production of eicosanoids, important signalling molecules involved in inflammation. This interaction is significant for non-communicable diseases, given the role chronic inflammation plays in their onset.

If you’re concerned about your EPA intake, most omega-3 supplements contain an abundance, making them ideal for filling gaps in nutrition. Moreover, increased omega-3 intake can also help balance the influx of omega-6 present in most western diets. While both types of fatty acid are useful for well-being, too much omega-6 can increase the risk of chronic disease.^[3]

Benefits of omega-3

We’ve alluded to several possible health benefits, so now it’s time to take a closer look at the omega-3 research and the wealth of supporting studies.

Omega-3 and eye health

Most of the interest in eye health stems from DHA. Not only is it a structural component of the retina, but getting enough DHA could reduce the risk of age-related macular degeneration (AMD), a disease that causes blindness and blurred vision.

A 2014 study from the University Paris Est Créteil examined 290 patients to investigate the importance of sufficient EPA and DHA levels. After testing long-term biomarkers, they found that poor intake of both was “strongly associated with neovascular AMD”.^[4]

Omega-3 and inflammation

Metabolic diseases (heart disease, diabetes and kidney disease) have become a significant concern in western countries. However, a review focusing on the link between omega-3 fatty acids and metabolic disease points to a potential reduction in inflammation thanks to how these acids affect lipid signalling molecules.^[5]

The research explains that oxylipins (fatty acids resulting from the conversation of DHA and EPA) help stimulate the immune system. Moreover, increased levels of oxylipins can help repair cell signalling, leading to better regulation of our inflammatory response. While several steps are involved, the evidence suggests that increasing DHA and EPA consumption could lead to better treatment and prevention of inflammatory diseases.

Omega-3 and brain health

Healthy brain development is vital to well-being, especially during childhood and adolescence. Unfortunately, many maternal and infant diets lack omega-3 fatty acid DHA, which can quickly lead to visual and neurocognitive deficits.^[6]

A review published by American researchers found that “cell culture, animal model, and human clinical trials provide compelling support for choline and DHA in maternal and infant nutrition”. They add that optimal nutrition during pregnancy “requires a multi-faceted approach”, with proper screening of choline and DHA crucial to improving prenatal care.

Sources of omega-3

Given the extensive influence of omega-3 and its role in human health, you’re probably wondering how you can maximise your intake. Thankfully, there are dozens of foods to choose from, with several fish and plants containing over 1000mg of omega-3 per serving.

As a general rule, at least two 100g portions of fish (preferably oily) a week should provide all the DHA and EPA your body needs. However, to give you a better idea of which foods to focus on, we’ve split our recommended sources of omega-3 into fish and plant-based.

Animal-based sources of omega-3 (per 100g):

• Salmon: 3,123mg
• Herring: 946mg
• Mackerel: 4,107mg

Plant-based sources of omega-3 (per 100g):

• Hemp seeds: 2,600mg
• Flax seeds: 2,350mg
• Walnuts: 2,570mg

The foods highlighted above are merely a selection, so don’t worry if they aren’t your favourites. You can always try omega-3 supplements (containing DHA & EPA) to bolster your diet.

Omega-3 deficiency

We’ve highlighted the impact of getting enough omega-3, but what happens when levels begin to dip? Because omega-3 is an essential fatty acid (meaning the body relies on external sources), its role in the immune, cardiovascular and endocrine systems is crucial to thinking and feeling your best. A deficiency can quickly lead to severe symptoms, including:

• Dry skin and skin irritation
• Mood disorders (depression & anxiety)
• Dry eyes
• Joint stiffness and physical discomfort
• Dry, brittle hair

Although an omega-3 deficiency is rare in healthy adults, ensuring a balanced diet with at least two portions of the foods we highlighted earlier is the best way to prevent symptoms. This is especially important for at-risk groups such as those on low-fat diets and vegans.

Dosing omega-3

Dosing omega-3 is very straightforward, with the advice simply to include at least two portions of oily fish (roughly 100 grams each) per week in your diet.

Of course, meeting this threshold is even easier if you take cod liver oil tablets, supplements rich in omega-3. In fact, omega-3 supplements are one of the most commonly consumed nutritional aids, helping bump up your intake of DHA and EPA, the most effective forms of omega-3.

Omega-3 side effects

Even substances as influential as omega-3 can have unwanted side effects. However, we should point out that side effects from omega-3 are rare and usually the result of an underlying condition (like an allergy). Still, it’s entirely possible to have too much of a good thing, and excess doses of omega-3 may cause the following:

• Fishy breath
• Upset stomach/ nausea
• Diarrhoea
• Bleeding gums

The last side effect, bleeding gums, is crucial for anyone taking blood thinning medication. Under these circumstances, it’s best to consult your doctor or physician for case-specific advice. However, for most people, sticking with the recommended dosages and consuming whole food sources of omega-3 should reduce the risk of unwanted side effects.

Omega-3: Is it good for you?

Omega-3 fatty acids have a broad but significant influence on well-being in children and adults. And, with many health-related governing bodies encouraging regular intake of omega-3 (specifically DHA and EPA), it’s safe to say the substance is a good choice for most people.

The main watch-out with omega-3 is not trying to overdo it, sticking to the modest recommendation of at least two portions of oily fish per week. Of course, if this isn’t feasible, daily supplements can help keep your wellness journey on track.

Why not add omega-3 to your daily routine with a complete selection of wellness supplements from Cibdol? Or, to learn more about cell function and our inflammatory response, head to our Education section for everything you need to know.