What vegetable is high in omega-3? Exploring the Best Plant-Based Sources

October 8, 2025 •

4 min read

While most people associate omega-3 fatty acids with fatty fish, a 2010 study from the EPIC-Norfolk cohort found that vegans may have significantly more long-chain omega-3 fats in their blood than fish-eaters. This surprising fact leads many to question: what vegetable is high in omega-3? The truth is that while some vegetables contain small amounts of the essential fatty acid ALA, the most potent plant-based sources are actually seeds, nuts, and certain oils.

Quick Summary

This article details the top plant-based sources of omega-3 fatty acids, highlighting vegetables like edamame and brussels sprouts, as well as superior sources such as flaxseeds, chia seeds, and walnuts. It also explains the ALA conversion process and practical ways to integrate these foods into your daily meals.

Key Points

ALA vs. EPA/DHA: Most vegetables provide ALA, a precursor omega-3, which the body must convert inefficiently into the active forms EPA and DHA. Algae and seaweed are the exceptions, containing EPA and DHA directly.
Edamame and Brussels Sprouts: These are some of the most notable vegetables containing omega-3 (ALA), contributing smaller but valuable amounts to a balanced diet.
Chia Seeds and Flaxseeds: These seeds are the most concentrated plant-based source of ALA, offering several grams per serving and significantly higher quantities than standard vegetables.
Walnuts and Hemp Seeds: Excellent additions to a plant-based diet, these nuts and seeds are rich in ALA and other beneficial nutrients like fiber and minerals.
Algal Oil: Derived from algae, this is the only reliable vegan source for EPA and DHA, making it a key option for supplementing active omega-3s.
Focus on Variety: A diverse diet including a mix of leafy greens, vegetables like edamame, and concentrated sources such as seeds and nuts is the best approach to meeting plant-based omega-3 needs.
Supplementation Consideration: Due to the low conversion rate of ALA to EPA/DHA, some individuals, especially those with increased needs, may benefit from algal oil supplements.

Understanding Omega-3s: Beyond the Fish

Omega-3 fatty acids are a family of polyunsaturated fats essential for human health, playing critical roles in brain function, heart health, and reducing inflammation. The three main types are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). While EPA and DHA are most famously found in fatty fish, ALA is the primary omega-3 found in plants. The human body can convert ALA into EPA and DHA, but this conversion process is often inefficient, so it's vital to consume enough ALA-rich foods to meet your needs.

Top Vegetables with Alpha-Linolenic Acid (ALA)

While vegetables generally offer lower omega-3 content compared to seeds and nuts, some provide a respectable contribution, especially for those on a plant-based diet.

Edamame: These immature soybeans are a great option, providing protein, fiber, and omega-3s. A half-cup serving of frozen edamame contains approximately 0.28 grams of ALA. They are also one of the few plant sources that offer some omega-6 fatty acids in a relatively balanced ratio.
Brussels Sprouts: These cruciferous vegetables are another source of ALA. Cooking them can increase their omega-3 content. A half-cup serving can contain around 135 milligrams of ALA.
Green Leafy Vegetables: Greens like spinach and kale contribute minor amounts of ALA to your diet. Incorporating them regularly in large salads or cooked dishes can add up, but they are not a primary source.
Seaweed and Algae: These marine plants are unique because they can contain both EPA and DHA, making them a crucial source for strict vegans and vegetarians seeking these specific types of omega-3s. This is because fish get their omega-3s from eating microalgae. Algal oil is a popular supplement derived from this source.

Beyond Vegetables: The Plant-Based Omega-3 Powerhouses

To significantly increase your plant-based omega-3 intake, it's necessary to look beyond traditional vegetables to seeds, nuts, and specific oils. These sources contain much higher concentrations of ALA.

Flaxseeds (Ground): A tablespoon of ground flaxseed is one of the most concentrated plant-based sources of ALA, providing about 2.4 grams. It's crucial to consume flaxseeds ground, as the oil inside the whole seeds is not easily absorbed.
Chia Seeds: An ounce of chia seeds packs around 5 grams of ALA, making it an excellent option. They can be added to smoothies, oatmeal, or used to make pudding.
Hemp Seeds (Hemp Hearts): Three tablespoons of hemp seeds contain approximately 2.6 grams of ALA, along with a beneficial ratio of omega-6 to omega-3 fatty acids. They are also a great source of magnesium, iron, and zinc.
Walnuts: These nuts offer a significant amount of ALA, with one ounce containing about 2.5 grams. Walnuts are also associated with improved cognitive function.
Perilla Oil: Extracted from the seeds of the perilla plant, this oil has one of the highest concentrations of ALA among all plant oils, typically ranging from 54–64%.

Practical Ways to Incorporate Plant-Based Omega-3s

Getting enough plant-based omega-3s is simple with a few dietary changes. Here are some actionable tips:

For breakfast: Add ground flaxseeds or chia seeds to your oatmeal, yogurt, or morning smoothie. A sprinkle of walnuts can also add texture and flavor.
For lunch: Toss a handful of edamame or walnuts into your salads. Use a dressing made with canola oil or perilla oil for an extra boost.
For dinner: Include Brussels sprouts in your roasted vegetable mix or steam some edamame as a side dish. Stir-fries and curries can also feature edamame or tofu.
For snacks: Enjoy a handful of walnuts or a small bowl of steamed and lightly salted edamame. Chia seed pudding is another satisfying and nutrient-dense snack option.

Comparison of Plant-Based Omega-3 Sources


Source	Serving Size	Omega-3 (ALA) Content	Notes
Chia Seeds	1 oz (28g)	~5 grams	Versatile, high fiber, and absorbs liquids to form a gel.
Ground Flaxseeds	1 tbsp (7g)	~1.6 grams	Must be ground for absorption; excellent source of fiber.
Flaxseed Oil	1 tbsp (14g)	~7.2 grams	Concentrated ALA, lacks fiber from the seed.
Walnuts	1 oz (28g)	~2.5 grams	A great snack with brain health benefits.
Hemp Seeds	3 tbsp (30g)	~2.6 grams	Good omega-6 to omega-3 ratio, excellent source of minerals.
Edamame (shelled, frozen)	1/2 cup	~0.28 grams	Also a good source of protein and fiber.
Brussels Sprouts	1/2 cup (cooked)	~0.135 grams	Omega-3 content increases with cooking.
Perilla Oil	1 tbsp	~9 grams	One of the highest ALA concentrations in plant oils; best used uncooked.

Conclusion

For those seeking plant-based sources of this essential fat, understanding what vegetable is high in omega-3 involves looking at the wider plant kingdom. While leafy greens and specific vegetables like edamame and brussels sprouts offer smaller amounts of ALA, seeds like chia and flax, as well as nuts like walnuts, are the true superstars of plant-based omega-3s. For EPA and DHA, algae is the only reliable plant-based source. Including a variety of these foods in your diet, and considering an algal oil supplement, is the most effective way to ensure adequate omega-3 intake for overall health and well-being. A balanced, whole-foods diet rich in these sources can provide all the benefits of omega-3s without needing to rely on marine-based options.

A note on bioavailability

One of the main takeaways from the science on plant-based omega-3 is that while our bodies can convert ALA into the longer-chain fatty acids EPA and DHA, the conversion rate is often low. For optimal health, particularly for brain and eye function where DHA is critical, it is important to incorporate concentrated plant-based sources like seeds and nuts daily. For individuals with increased needs, such as pregnant women or those with specific health conditions, an algal-derived DHA and EPA supplement is often recommended by health professionals.

Outbound Link: Learn more about Omega-3 Fatty Acids from the National Institutes of Health

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Frequently Asked Questions

While it's not a true vegetable, edamame (young soybeans) is one of the highest contenders among plant-based foods often prepared like a vegetable, with about 0.28 grams of ALA per half-cup. Brussels sprouts also contain a notable amount of ALA.

While vegetables contribute to your overall omega-3 intake, it is difficult to get sufficient amounts from vegetables alone. It is more effective to include a variety of seeds (chia, flax), nuts (walnuts), and algae for adequate intake.

Plant-based sources contain alpha-linolenic acid (ALA), while fish provide the more readily usable EPA and DHA. The body's conversion of ALA to EPA and DHA is inefficient, so direct sources of EPA/DHA like algal oil are more potent.

Yes, seeds like chia and flax are significantly more concentrated sources of omega-3 (ALA) than most vegetables. A tablespoon of ground flaxseed, for example, provides far more ALA than a cup of leafy greens.

Yes, seaweed and other forms of algae are particularly important for vegans and vegetarians because they are some of the few plant-based sources that contain both EPA and DHA, the active forms of omega-3.

It depends on your dietary choices and health needs. While a diverse plant-based diet can provide enough ALA, an algal oil supplement containing EPA and DHA might be recommended to ensure optimal levels, especially for pregnant women or those with specific health concerns.

Cooking can sometimes change the nutritional profile. For example, some studies show that cooked Brussels sprouts may have a higher ALA content than raw ones. However, it's generally best to consume a mix of raw and cooked vegetables to get a wide range of nutrients.