Flax seeds & other seeds provide ALA but not EPA & DHA. You need all 3. The body has some ability to convert ALA to EPA & DHA, but at extremely low rates (part

Flax seeds & other seeds provide ALA but not EPA & DHA. You need all 3. The body has some ability to convert ALA to EPA & DHA, but at extremely low rates (particularly for DHA) - it's not a consideration in practice. So no, eating seeds will not fulfill your body's requirements.