G.B.
My husband has extremely high triglycerides too. We did everything we could to lower them and nothing worked except medication. With the medication they went down no matter what he ate or did. So we went back to a more normal style of eating and didn't worry so much about the diet and stress over it.
If he is enjoying his lifestyle then it is just one of those things and the doc is the only one that can help him change his levels.