That's part of my question. ALA is supposed to not convert to DHA easily.
But these results seem to say at higher concentrations ALA lowers risk of EOD. Which tends to refute the belief that only DHA/EPA lower chronic inflammation or that EOD is not just a story about inflammation.
I cannot read the whole article, but the abstract says nothing about ALA.
The abstract only partitions the omega-3 acids in DHA and non-DHA.
While non-DHA includes ALA, without any concrete evidence that ALA has some direct role, it is more likely that the correlation seen with non-DHA refers not to ALA, but to the other long-chain omega-3 fatty acids besides DHA.
Humans can elongate ALA into useful long-chain acids, but the efficiency of this is typically lower in males than in females and lower in old people than in young people. Usually pregnant women have the best conversion efficiency.
Unless you monitor your blood composition, you cannot know if eating ALA (e.g. flax seeds or oil, or walnuts) can be sufficient for you. If you are an older male, it is very likely that eating ALA cannot be enough for avoiding deficiency.