« Optimal » for fish oil is probably an impossible goal; the ideal dose will change based on:
- Your history of fish intake and supplementation
- Dietary omega-6 intake from all sources
- Excluding plants, your dietary intake of arachidonic acid (omega-6 from meat products)
- Dietary intake of phytonutrients that influence omega fatty acid metabolism (ie. rosmarinic acid or fucoxanthin)
- Activity level
- Intake of antioxidants to assess lipid turnover
And I can confidently say that all the above are not only difficult to measure, but even then they aren’t perfect indicators of your ‘optimal’ level. It truly leads to a « fuck this shit » conclusion. There’s a reason why most educated persons just hedge their bets and say « eat some fish or supplement fish oil kinda maybe evenly with your omega 6? »
The 1:1 ratio thing (animal sources of omega-3 and animal sources of omega-6) is a vague goal but it works pretty well, no better measurement seems to be on the horizon so we’re sticking with it still.
1:1 is just some vague target. We know that some populations work well at 1:4, and some also at 3:1.
Most of all, we know that if you tell people to aim for 1:1 they still won’t get it because they can’t micromanage their diet that well, but at least it gets them close.