@einhippo:

Flax is good, but be aware that males do not convert this omega-3 source to long chain EPA and DHA in large amounts like women do. There is a genetic difference in the genders for this task because women must nourish the developing fetus to birth.
This requires huge amounts of DHA for that developing brain.

When adults get low in omega-3s males should take some of their supplements as fish or krill oil. One cannot assume a male will make enough DHA and EPA for their needs from flax sources alone.

Flax is a good source for skin issues in both genders. Dry flaking skin, thick callouses on the feet, etc, will respond nicely to Omega-3 (alpha linolenic acid) provided by flax, walnuts, and a few other veggie sources. Flax also helps with acne. We used it for our son, back when, and it was very successful.