The simplest way to raise your omega-3 intake through food is to eat fatty fish such as salmon, trout, herring, mackerel or sardines about twice a week, and to add plant sources like ground flaxseed, chia, walnuts, hemp seeds and canola oil most days. Fish provides the EPA and DHA forms directly; plants provide ALA, which your body converts to EPA and DHA only in small amounts. A short shopping list and a few go-to meals make this easy.
The three main omega-3s
- EPA and DHA are found mainly in fish and seafood, especially cold-water fatty fish.
- ALA is found in plant foods: flax and chia seeds, walnuts, and oils such as canola, soybean and flax.
The Harvard T.H. Chan School of Public Health explains that ALA is essential because the body can’t make it, and that the body can convert some ALA into EPA and DHA, but not very efficiently. That’s why EPA and DHA are best obtained directly from food (Harvard T.H. Chan School of Public Health).
For people who eat fish, a mix of both is ideal. If you don’t eat fish, plant sources still matter; see the note on plant-based eating below.
Why food first?
Harvard’s Nutrition Source notes that research strongly supports eating fatty fish weekly for heart health, while many large clinical trials have not shown that omega-3 supplements provide the same protection. Fish also brings protein, vitamin D, selenium and other nutrients a capsule doesn’t.
Food is also easier to keep up over time when it tastes good and fits your routine, which is what the rest of this article is about.
How much fish, and which kinds?
The NHS recommends at least two portions of fish a week, including one of oily fish, with a portion around 140 grams cooked. It lists salmon, trout, sardines, herring, mackerel, pilchards and sprats as oily fish (NHS). Harvard similarly suggests fish or seafood one to two times a week, with an emphasis on fattier fish.
Choose lower-mercury options
Health Canada lists anchovy, capelin, char, hake, herring, Atlantic mackerel, mullet, pollock, salmon, smelt, rainbow trout and lake whitefish, along with shrimp, clams, mussels and oysters, as fish and seafood that are higher in omega-3s and low in mercury. Fresh or frozen tuna, shark, swordfish, marlin, orange roughy and escolar should be eaten less often (Health Canada).
If you are pregnant, may become pregnant or are breastfeeding, Health Canada has specific limits, including for canned albacore (white) tuna. Canned light tuna is lower in mercury. Check the Health Canada page or ask your healthcare provider.
Plant sources to use every day
- Ground flaxseed: stir into oatmeal, yogurt, smoothies or muffin batter. Whole flaxseeds often pass through undigested, so grind them or buy ground.
- Chia seeds: make chia pudding or sprinkle on cereal.
- Walnuts: a small handful as a snack, or chopped on salads and oatmeal.
- Hemp seeds: sprinkle on bowls, salads and toast.
- Canola or soybean oil: use for cooking and homemade dressings.
- Edamame and tofu: add to stir-fries and grain bowls.
Smart swaps
| Instead of | Try |
|---|---|
| Peanut butter on toast every day | Walnut butter some days, or peanut butter with a sprinkle of hemp seeds |
| Croutons on salad | Toasted walnuts or pumpkin and hemp seeds |
| Plain oatmeal | Oatmeal with 1 tbsp ground flax and berries |
| Deli meat sandwich | Canned salmon or sardine sandwich with lemon and herbs |
| Bottled dressing | Canola or flax oil whisked with vinegar, mustard and herbs |
A week of omega-3 menus
This sample week includes two oily fish meals and a daily plant source. Mix and match.
- Monday: Overnight oats with ground flax and walnuts. Dinner: baked salmon with potatoes and green beans.
- Tuesday: Leftover salmon flaked into a whole-grain wrap with greens for lunch.
- Wednesday: Chia pudding made with milk or soy beverage, topped with fruit. Dinner: tofu and edamame stir-fry with canola oil.
- Thursday: Salad with chickpeas, hemp seeds and a canola-vinegar dressing.
- Friday: Dinner: salmon cakes made with canned salmon, egg, oats and herbs, with a big salad.
- Saturday: Sushi-style bowl: rice, cucumber, avocado, nori strips and canned salmon or smoked trout.
- Sunday: Lettuce wraps with trout or sardines, shredded carrot and a lemon-yogurt sauce. Snack: energy balls with oats, ground flax, chia and date paste.
Shopping list
Fish and seafood
- Salmon (fresh, frozen or canned with bones)
- Rainbow trout or Arctic char
- Canned sardines, herring or mackerel
- Canned light tuna
- Frozen shrimp or mussels
Plant foods
- Ground flaxseed (store in the fridge or freezer)
- Chia seeds and hemp seeds
- Walnuts
- Edamame and firm tofu
- Canola oil
- Nori or other seaweed snacks
Helpful extras
- Lemons, fresh herbs and Dijon mustard for quick fish flavour
- Whole-grain wraps, rice and oats as bases
- Plain yogurt for sauces
What about supplements?
Supplements have a place for some people, but they aren’t a substitute for an overall healthy diet. Harvard notes that the American Heart Association did not find enough evidence to recommend omega-3 supplements for preventing heart disease in the general population, though they may be reasonable for some people with existing heart disease after talking with a doctor. If you’re considering one, discuss it with your healthcare provider, particularly if you take blood thinners or other medications.
If you don’t eat fish
Include an ALA source every day: ground flax, chia, hemp seeds, walnuts or canola oil. Because conversion to EPA and DHA is limited, talk with a registered dietitian about whether an algae-based supplement makes sense for you, especially during pregnancy.
For more ideas, see budget proteins, including canned fish, and five-minute balanced meals.
When to check with a professional
Talk with your doctor or pharmacist before starting omega-3 supplements if you take blood-thinning medication, have a bleeding disorder, have a fish or shellfish allergy, or are pregnant or breastfeeding. A registered dietitian can help plan intake for vegetarian or vegan diets.
Quick FAQ
Does canned fish count?
Yes. Canned salmon, sardines, herring and mackerel are convenient, affordable sources of omega-3s. Canned salmon and sardines with soft bones add calcium as well. Rinse or choose lower-sodium versions if you’re watching salt.
Does cooking destroy omega-3s?
Gentle methods such as baking, poaching, steaming and pan-cooking work well for fish. Deep-frying adds a lot of extra fat, so save it for occasional meals. For flax oil, use it cold in dressings and drizzles rather than for high-heat cooking.
Key takeaways
- Aim for fish twice a week, with at least one oily fish such as salmon, trout, herring, mackerel or sardines.
- Choose lower-mercury fish and limit fresh or frozen tuna, shark, swordfish and marlin.
- Add a daily plant source: ground flax, chia, hemp, walnuts or canola oil.
- Canned salmon and sardines are budget-friendly and quick.
- Food first; ask a professional before adding supplements.