Scientific evidence confirms that flax seeds (rich in alpha-linolenic acid) and fish oil (rich in EPA and DHA) differ significantly in their metabolic conversion and overall omega-3 bioavailability in the body.
The retrieved papers consistently support the claim that plant-based omega-3s (ALA from sources like flax or perilla) and marine-derived omega-3s (EPA and DHA from fish oil) have different metabolic fates and efficiencies. ALA must undergo inefficient enzymatic conversion to EPA and DHA, and direct supplementation with EPA/DHA is far more effective at raising tissue omega-3 levels and conferring specific health benefits.