[Candace]

Since ALA is good regarding prostate cancer when it comes from "good" foods (e.g. walnuts, canola, flax, vegetables, olive oil) and bad when it comes from red meat, it might not have any effect of its own. Here are a few meta-analyses. 1 2 They say that if you ignore the Health Professionals’ Follow-up Study, where the main source of ALA was red meat, then there's no problem with ALA.

ALA also enhances the effects of EPA and DHA for cardiovascular health. 1 2

Here is a paper with equations to predict the effect of your diet on your tissue levels of the long chain polyunsaturated fatty acids. It's basically a zero-sum game between three competitors: omega-6; the omega-3 DHA; and the omega-3s EPA and DPA. The Keep It Managed software says some constants were changed in 2002, so 0.008 should be 0.005 (HI3), 0.5 should be 0.7 (HC6), and 8.75 should be 3.0 (HC3).

So here are the LC-PUFA predictions for me supplementing various amounts of fats:

9 g flax oil: 64% n-6, 23% EPA+DPA, and 13% DHA.
500 mg EPA/DHA: 61% n-6, 12% EPA+DPA, and 27% DHA.
500 mg EPA/DHA + 1 g flax oil: 60% n-6, 15% EPA+DPA, and 25% DHA.
1000 mg EPA/DHA: 51% n-6, 18% EPA+DPA, and 31% DHA.
2400 mg EPA/DHA: 35% n-6, 31% n-3, and 34% DHA.

I think 500 mg EPA/DHA + 1 g flax oil gives me the best profile if you don't take lignan aromatase inhibition into consideration. It's close to what they used in the Alpha Omega Trial in the papers above so it works in practice as well as in theory. It is the cheapest method that yields n-6 ≤ 60%, EPA+DPA ≥ 13%, and DHA ≥ 22%. (These are the highest levels of omega-3 that I can justify with data, but I don't think we know the exact optimum yet.) I would switch to 1000 mg EPA/DHA if I wanted to maximize aromatase activity.