From improving cardiovascular health to boosting immunity, the reported benefits of omega-3 have seen fish oil become one of the most sought-after dietary supplements. But are there really tangible health gains to be made from upping your daily intake of omega-3?
Omega-3 is an umbrella term used to describe a group of unsaturated fatty acids with a specific double bond in their chemical structure, such as eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and alpha-linolenic acid (ALA).
“They are known as ‘essential fatty acids’ as our bodies cannot create them, and we can only get them through our diet,” says Dr. Claire Thomas, medical doctor and clinical content lead at Evergreen Life. “Other than dietary supplements, there are some great sources of omega-3 found in other foodstuffs. Unsurprisingly, oily fish such as mackerel, salmon and herring are full of omega-3. Walnuts, soya beans, and chia and flax seeds are also great meat-free options.”
Scientists have been studying the potential benefits of omega-3 for years. According to the Nutrients journal, these nutrients have been shown to be the key factor in reducing inflammation levels, a major risk factor for multiple chronic diseases. In fact, omega-3 could be crucial to our cardiovascular, nervous, and immune systems.
“Some studies indicate its anti-inflammatory properties may also have benefits for conditions such as rheumatoid arthritis and other inflammatory and degenerative joint conditions and inflammatory bowel diseases” says Thomas.
Here, we take a deep dive into the science of essential fatty acids to give you a better understanding of how these nutrients can impact our mind and body.
1. It supports cardiovascular health
One of the most widely researched benefits of omega-3 applies to our cardiovascular system, with most studies suggesting that it has a highly protective effect on our heart. According to a major Cochrane systematic review, these fatty acids may significantly reduce the risk of dying from coronary heart disease and cardiac events, while ALA may also help prevent arrhythmia.
Omega-3 can boost our cardiovascular health in several ways. “They are fundamental in making hormones that regulate blood clotting, the contraction and relaxation of artery walls, and inflammation,” says Abbas Kanani, pharmacist at Chemist Click. “This can be beneficial for cardiovascular disease as they work to reduce plaque in the heart's arteries.
Omega-3 fatty acids may also improve the functioning of the endothelium — a thin membrane that lines the inside of the heart and blood vessels. As described in the Atherosclerosis journal, that is because they may help control how much fluid is carried with the blood, and how blood vessels dilate and constrict.
Studies done on overweight patients with metabolic syndrome have also shown that omega-3 may help balance blood lipids, particularly by reducing levels of the ‘bad’ LDL cholesterol.
However, it needs to be pointed out that quite a significant number of studies throughout the years did not show any significant links between omega-3 and heart health. Scientists suggest that these differences may have been linked to the doses used in tests.
2. It may boost immunity
Recently, scientists have discovered another potential benefit of omega-3 — a healthier immune system. Studies have shown that these fatty acids may affect the composition of our gut microbes, which in turn may have a positive impact on our gut health. Since our digestive system is the first line of defense against harmful microbes, omega-3 may have an indirect, yet wide-ranging, effect on our whole immune system.
These fatty acids have also been shown to stimulate the production of antibodies and regulate the functioning of white blood cells, as described in the International Journal of Molecular Sciences.
3. It keeps your brain healthy
Omega-3s may be essential for the proper functioning of our central nervous system, and the brain in particular. In fact, they have been shown to prevent or slow the progression of neurodegenerative diseases such as Parkinson's and Alzheimer's disease, as reported in the International Journal of Molecular Sciences.
There are several reasons why these fatty acids may benefit our nervous system. According to an article in Frontiers in Aging Neuroscience, these compounds are found in abundance in the brain cell membranes, and they may affect how neurons communicate with each other. And according to another review in the Nutrients journal, DHA is one of the key components of healthy brain and eye development. This particular fatty acid may also play a significant role in mental health throughout early childhood. Evidence suggests that low intake of omega-3 may increase the risk of developing Attention Deficit Hyperactivity Disorder (ADHD), autism, bipolar disorder, and depression.
“Studies indicate that those who regularly consume omega-3 are less likely to experience depression,” adds Thomas. “While studies that point towards EPA helping with more severe neuropsychiatric disorders are relatively recent, they do seem to indicate that the link is there.”
4. It contributes to eye health
Since omega-3 is a significant structural component of the retina, it plays an important role in eye health. The role of retina is to capture the light that enters your eye and translate it into the images you see. Without these crucial fatty acids, you may experience problems with your eyesight.
“Omega-3 optimizes the variability of photoreceptor membranes, retinal thickness, function and provides a protective role,” says Kanani. “Healthy levels of DHA also protect against damage from bright light exposure and oxidative stress.”
Scientists from The American Journal of Clinical Nutrition suggest that these fatty acids may even protect against neovascular eye diseases, such as diabetic retinopathy and age-related macular degeneration. Both of these conditions may lead to blindness, and they both lack treatment options that would be free of adverse side effects.
5. It may improve your skin health
One of the lesser known benefits of omega-3, and EPA in particular, is that it may contribute to healthier skin.
“A healthy intake of EPA can help to not only keep skin moisturized, but also reduces the risk and effects of acne,” says Thomas. Indeed, as described in a study from the Clinics in Dermatology journal, omega-3 may help improve the skin hydration and balance out its oil production, as well as reduce the risk of premature aging. In fact, these fatty acids may be the key to effective management of inflammatory skin diseases.
As reported in the International Journal of Molecular Sciences, combined omega-3 and omega-6 supplementation appears to be effective at treating the symptoms of atopic dermatitis, psoriasis, and acne.
6. It keeps your bones healthy
Some of the benefits of omega-3 may relate to bone health. A review in the British Journal of Nutrition reported that a significant number of studies suggest these fatty acids may help improve bone mineral density and several bone turnover markers. According to a meta-analysis published in the Climacteric journal, omega-3 may particularly affect the levels of osteocalcin in postmenopausal women. Osteocalcin is a protein hormone involved in maintaining and regenerating bone tissue, and postmenopausal women are at particularly high risk of developing osteoporosis.
It is worth mentioning though that a significant number of studies produced rather conflicting results. However, scientists have recently found that different sources of omega-3 may have a different effect on bone remodeling processes. For example, a flaxseed oil may be better at improving bone structure, while fish oil may promote higher bone mineral density.
“Anti-inflammatory properties found in omega-3 can help with lowering pain intensity to many of your body's joints, with studies showing that it can significantly improve joint pain in people with rheumatoid arthritis,” adds Kanani. “They also form the support for prostaglandins, which regulate our immune system and fight joint inflammation.”
7. It may affect sleep
A growing body of evidence suggests that omega-3 may play a role in sleep regulation. According to an article in the American Journal of Clinical Nutrition, individuals with higher regular intakes of these fatty acids appear to need less sleep.
What’s more, omega-3 fatty acids may help improve sleep in infants. This may be because they help organize and mature their sleep-wake routine, while having no effects on total sleep duration or efficiency.
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Anna Gora is a health writer at Live Science, having previously worked across Coach, Fit&Well, T3, TechRadar and Tom's Guide. She is a certified personal trainer, nutritionist and health coach with nearly 10 years of professional experience. Anna holds a Bachelor's degree in Nutrition from the Warsaw University of Life Sciences, a Master’s degree in Nutrition, Physical Activity & Public Health from the University of Bristol, as well as various health coaching certificates. She is passionate about empowering people to live a healthy lifestyle and promoting the benefits of a plant-based diet.