We take a deep dive into what omega-3s are, health benefits of omega-3s and food sources to help you meet your needs. 
Fish Oil Bursting From a Whole Fresh Mackerel.
Credit: Getty Images / Shana Novak

If you try to keep up with nutrition news, you've likely heard some of the buzz about omega-3 fatty acids. They can help with brain health, skin health, heart health and might even help you lead a longer life. On the flip side, not getting enough can lead to some negative outcomes like high blood pressure, joint pain, heightened depression symptoms and more. But what exactly are omega-3s and why do we need them? Here we dive into the science about omega-3s plus the best food sources to help you meet your needs. 

What Are Omega-3s?

To understand omega-3s, we need to zoom out on dietary fats in general. There are two main types of fat: saturated and unsaturated fats. Unsaturated fats are found in foods like oils, nuts, seeds, fatty fish and avocados, and are touted as the healthier option of the two. Within the unsaturated fats category, there are several types of fats that are defined based on their size and shape. For example, monounsaturated fats have a different molecular shape than polyunsaturated fats. 

There are two major classes of polyunsaturated fats: omega-3 fatty acids and omega-6 fatty acids, whose main difference is the size of their molecules. Within the omega-3 group, there are three major kinds: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). ALA is found in plant sources like oils, flaxseed, soybeans and chia seeds. EPA and DHA are found in animal sources like fish, fish oils and krill oils, because EPA and DHA are synthesized by microalgae

Health Benefits of Omega-3s 

More and more research is coming out about the benefits of including more omega-3-rich foods in your eating pattern. Here are some of the main health benefits associated with omega-3s. 

Promotes Heart Health 

There are decades of research on how omega-3s can help you protect your heart and prevent cardiovascular disease, and there are a few main reasons why. Having an adequate intake of omega-3s has been shown to lower triglyceride levels, lower LDL cholesterol levels and support an overall healthier heart. Research has found that omega-3s have anti-aggregatory effects that help promote healthy artery function, blood flow and blood pressure. 

Not only can omega-3s improve heart health, but also they can help reduce risk of heart disease and even heart attacks. One study published in 2019 found that participants taking an omega-3 supplement had a 28% reduced risk of heart attack, including a 77% reduced risk among black participants and a 40% reduced risk among those who ate at least 1.5 servings of fish per week. 

Reduces Inflammation 

Inflammation can lead to a slew of undesirable health problems, like forgetfulness, joint pain, weight gain, digestive distress and more. But diet and lifestyle can help quell inflammation and its symptoms. Research suggests that omega-3s provide anti-inflammatory effects to tissues throughout our body. One potential reason for this is that omega-3s compete with more inflammatory molecules to be digested, and break down into antioxidants and inflammation-fighting particles. Other research has suggested that maintaining a 1-to-1 ratio of omega-3s to omega-6s helped reduce bodily inflammation by 38% over a 3-month period, but more research is needed to clarify an optimal ratio for overall health.   

Improves Cognitive Function 

One important role of omega-3s is that their antioxidants can help protect cell membranes, including those around our brain cells. Research has shown that this might play an important role in the development and integrity of neurons, and might even help prevent Alzheimer's disease and its complications. Other studies have shown that omega-3s provide an anti-inflammatory effect to the blood vessels in the brain, which might help prevent and mitigate cognitive decline. Several studies show that a higher blood level of omega-3s is consistently associated with lower risk of dementia and lower overall cognitive decline.  

Protects Eye Health 

Omega-3s play an important role in eye health, and are routinely recommended by optometrists to help quell symptoms of dry eye disease. Research has found that people with higher blood levels of omega-3s were significantly protected from age-related macular degeneration as well. However, some studies have found that omega-3 supplementation did not significantly influence one's risk of developing AMD. More research is needed to clarify the relationship between eye health and omega-3s, and food sources that contain additional vitamins and other nutrients might provide more benefit than supplements. 

Improves Mental Health 

While many people's relationship with their mental health is complicated, there are several diet and lifestyle factors that can play a role in conditions like anxiety, depression and more. There is a trend of recent research that suggests omega-3s might help with certain mental illnesses, including depression. One meta-analysis found a 17% lower risk of depression for those with the highest fish intake versus those with the lowest fish intake. Another recent review of studies found that omega-3s might present a small-to-modest benefit for symptoms of major depressive disorder, but more research is needed to help clarify the relationship. 

Omega-6 to Omega-3 Ratio for Health 

Some research suggests that there are health benefits to maintaining a low omega-6 to omega-3 ratio, particularly related to inflammation, heart health and mood. Most of us get plenty of omega-6s, as they are commonly found in plant oils like canola oil, but we may not be getting a comparable amount of omega-3s. Some research has found that a typical Western diet has an omega-6 to omega-3 ratio of 20-to-1, whereas a ratio of 2-to-1 or 1-to-1 is the most health-promoting. While an optimal ratio is not strictly defined in research, most evidence points to a benefit from increasing omega-3 intake. 

Food Sources of Omega-3s 

The recommended daily allowance of omega 3s is 1.6 grams for men and 1.1 grams for women, and 1.4 grams daily for pregnant women. Here are some of the most potent food sources of omega-3s to help you get enough (plus the percent of the RDA for women over 14 years of age): 

  • Flaxseed oil: 7.3g per 1 Tbsp. (664% RDA)
  • Chia seeds: 5g per 1 oz. (455% RDA) 
  • Walnuts: 2.6g per 1 oz. (236 % RDA)
  • Canola oil: 1.3g per 1 Tbsp. (118% RDA)
  • Salmon: 1.2g per 3 oz. (109% RDA) 
  • Herring: 0.9g per 3 oz. (82% RDA) 
  • Soybean oil: 0.9g per 1 Tbsp. (82% RDA)
  • Sardines: 0.7g per 3 oz. (64% RDA)
  • Mackerel: 0.6g per 3 oz. (55% RDA) 
  • Edamame: 0.3g per ½ cup (27% RDA) 

Bottom Line 

Omega-3s are important for a variety of reasons, from our brain health and heart health to our skin health and several things in between. These nutritious unsaturated fats can be found in a variety of foods, including plant oils, nuts, seeds and fish. For more, check out these sneaky signs that you might be deficient in omega-3s