DHA sources: fish and algal products differ from ALA-rich foods

Look for DHA specifically

DHA is one long-chain omega-3 fatty acid. Fatty fish provide it, while flaxseed, walnuts and several plant oils mainly provide ALA. The body can convert some ALA to longer-chain omega-3s, but conversion is limited; grams of ALA should not be counted as the same grams of dietary DHA. [1]

Food values depend on species and preparation

The NIH ODS food table lists DHA of 1.24 g for 3 ounces cooked farmed Atlantic salmon,0.94 g for cooked Atlantic herring and 0.17 g for drained light tuna canned in water. These are selected reference entries, not a guarantee for every fish meal or a complete best-to-worst health ranking. [1]

Read algal and fish-oil labels by amount

Algal oil can supply DHA, and some formulations also contain EPA. Fish-oil amounts likewise vary. Imagine a label states 1,000 mg total oil but only 200 mg DHA: the DHA contribution is 200 mg, not 1,000 mg. Compare the serving sizes and declared DHA rather than inferring it from total oil weight. [1]

Hypothetical example — apply the distinction to the stated scenario
Hypothetical label	DHA accounting
1,000 mg oil containing 200 mg DHA	200 mg DHA
Two such servings	400 mg DHA
ALA amount only	Does not declare a direct DHA amount

DHA sources: fish and algal products differ from ALA-rich foods — original article outline diagram — Original editorial diagram of this article’s sections; no product photograph or clinical finding is depicted.

Sources for this article

Omega-3 Fatty Acids - Health Professional Fact Sheet
Source consulted: 2026-09-20. This is a reference resource, not a claim that we conducted the studies or tested a product.