I use ground flaxseeds. I used to eat it everyday - no difference in acne. It does have alot of fibre - helps keep you "regular" if you know what i mean  I stopped having it so often though because i heard that flax is a phytoestrogen which could have hormonal effects in some people. I still eat it a bit but I'm trying chia meal at the moment because it doesn't have those phytoestrogenic properties yet still alot of omega 3 and fibre.

I saw wonderful effect from flaxseed on my nails - with no effect whatsoever on acne....