Some nuts are rich in omega-3 fatty acid in the form of alpha-linolenic acid (LNA) which represents approximately 8% by weight of English walnuts. You are correct in stating that the Sacha Inchi oil is rich in omega-3 fatty acid. This omega-3 is LNA and not DHA/EPA. This legume as you likely know has traditionally been consumed by the Indians of Peru. The seed contains approximately 35-60% as oil with approximately 50% of the oil being represented by LNA.
The omega-3 fatty acid in the form of the plant-based LNA does appear to exhibit beneficial effects based on some population studies when consumed in higher quantities-particularly in particular those with very low intakes of DHA/EPA from fish sources. With respect to the five major population studies that have been published to date, three of these have shown a tendency for a lower risk of mortality from cardiovascular disease in those consuming higher intakes (2.5-3g per day ) of LNA omega-3 as compared to those consuming much lower amounts (approx. 1.4 g/day). LNA omega-3 does not exhibit the same effects as DHA/EPA omega-3 (derived from fish) for number of risk factors (for cardiovascular disease). For example, DHA/EPA omega-3 fatty acid does exhibit a consistent blood triglyceride-lowering effect when consumed at levels ranging from 1- 4 g/day whereas the corresponding amounts of LNA do not provide such an effect. The existing overall science suggests that consuming DHA/EPA omega-3 fatty acid in addition to some LNA omega-3 from plant sources is a reasonable strategy for overall health and the prevention/management of cardiovascular disease along with various other strategies from medical, nutritional, lifestyle, and other perspectives. The Sacha Inchi seed oil, while lacking in DHA/EPA, is a substantial source of LNA.