Understanding Omega-3 Fatty Acids: Benefits and Sources

As a registered dietitian, I often get questions from patients about omega-3 sources, their potential benefits, and whether to take a supplement such as a fish oil. This article will help address these common questions.

What Are the Types of Omega-3s?

Omega-3 fatty acids are polyunsaturated fats, meaning they have more than one double bond in their chemical structure. Omega-3s are essential fats not produced by the body, meaning we must obtain them through food or supplements. A deficiency in essential fatty acids can cause rough, scaly skin and dermatitis. They can be categorized into three main types:

1. ALA (Alpha-Linolenic Acid): ALA is the most common type of omega-3 in the typical Western diet and is found primarily in plant-based sources like flaxseeds, chia seeds, walnuts, and canola oil. ALA is also found in small amounts in the fat of some grass-fed animals. ALA is converted into EPA and DHA in the body, but the conversion process is inefficient and not enough to support your body’s needs.
2. EPA (Eicosapentaenoic Acid): Predominantly found in fatty fish such as salmon, mackerel, and sardines, EPA is particularly beneficial for reducing inflammation in the body. EPA has also been linked to improved heart health and may help lower the risk of cardiovascular diseases.
3. DHA (Docosahexaenoic Acid): Like EPA, DHA is found in fatty fish and is a key component of brain tissue. DHA is essential for cognitive health and may aid in preventing age-related cognitive decline. It also supports eye health and is crucial during pregnancy for fetal brain development.

What Are the Health Benefits of Omega-3s?

Omega-3 fatty acids have been extensively researched for their health benefits. Some key areas where omega-3s have shown positive effects include:

• Heart health: Omega-3 fatty acids are well-known for their ability to reduce the risk of heart disease. They help lower triglyceride levels, reduce blood pressure, and reduce the risk of arrhythmias (irregular heartbeats). Omega-3s also contribute to reducing inflammation in the arteries, thus improving overall cardiovascular health.
• Brain function: DHA, in particular, is a major structural component of the brain and eyes. Studies suggest that adequate levels of omega-3s may improve memory, support learning, and even lower the risk of Alzheimer’s disease and dementia. Omega-3s also play a role in mental health, with research linking them to a reduced risk of depression and anxiety.
• Reduced inflammation: Chronic inflammation is linked to many diseases, including arthritis and other autoimmune disorders. Omega-3 fatty acids have potent anti-inflammatory effects, which can help alleviate symptoms of conditions such as rheumatoid arthritis and inflammatory bowel disease.
• Eye health: DHA is found in high concentrations in the retina, making it essential for maintaining good vision. Regular intake of omega-3s may help protect against dry eye disease and age-related macular degeneration (AMD), a leading cause of vision loss.

It should be noted there is much less research on the health benefits of ALA compared to EPA and DHA.

How Can I Incorporate Omega-3s into My Diet?

Including omega-3s in your diet is relatively easy with a few dietary changes. The best approach is to incorporate a variety of plant-based ALAs as well as marine-based EPA and DHA.

• Fatty fish: Fish like salmon, mackerel, sardines, and herring are rich in both EPA and DHA. Aim to include 8-12 ounces of fatty fish per week in your diet for optimal heart and brain health.
• Flaxseeds and chia seeds: For those who prefer plant-based sources, flaxseeds and chia seeds are excellent choices. These seeds are rich in ALA and can easily be added to smoothies, oatmeal, or made into chia pudding.
• Walnuts: Another plant-based source of ALA, walnuts are a great snack option or can be sprinkled over salads, yogurt, or incorporated into recipes.
• Soy-based foods: Soybeans, tofu, and edamame also contain ALA. These can be included in a variety of meals to boost your omega-3 intake.

When Should I Consider an Omega-3 Supplement?

The American Heart Association (AHA) recommends 1000 mg daily of EPA and DHA combined which can come from food or supplements but AHA does not recommend supplement for people with a low cardiovascular risk. With a doctor’s supervision, higher therapeutic dosages of 2000-4000 mg daily may be recommended for lowering triglycerides. Before starting omega-3 supplements, it’s important to consult with your doctor as they can interact with medications, particularly blood thinners like warfarin (Coumadin) or apixaban (Eliquis).

When choosing supplements, it's important to select those that are third-party tested to ensure they are free of contaminants. For people who do not eat fish, whether due to a fish allergy or a vegan lifestyle, algal oil supplements are an alternative source of DHA.

Large clinical trials have not shown that omega-3 supplements provide the same cardiovascular protection that eating fatty fish weekly provides, so in the end, food sources of EPA and DHA should be prioritized first, supplements second.