Yes, I would aim for an amount based on our evolutionary intake, or an intake similar to that of healthy cultures that we've studied such as the Kitavans.

Polyunsaturated fats, including omega 3, are highly oxidizable oils. You need to keep the total percentage of calories from polyunsaturated fats low in your diet. For modern Americans, that means severely restricting omega-6. For people on the Paleo diet and supplementing with a lot of fish oil, often that means taking in less omega-3.

Keep in mind that hunter gatherer populations don't supplement with fish oil. They have fresh fish if they are near the water, but there are also plenty of those populations which get by well on just a little bit of DHA from grass fed land mammals. There are certainly reasons to look at getting your omega 3 intake from fresh fish over oils contained in jars for several months--one of the main reasons being that omega 3 is highly reactive and you could be eating rancid or abnormal amounts of oxidized fat when you consume oils that were derived from a fish over a year ago.

A lot of the long term literature on fish oil isn't that impressive.

I think a good goal is to arrange one's diet so that the supplementation of omega-3s is unnecessary. This can be achieved via the consumption of grass-fed ruminants and fatty fish.

Check out PaNu on this topic and you'll get more than what you're seeking, information-wise.

http://www.paleonu.com/panu-weblog/2010/3/18/sat-fat-or-pufa-which-one-do-you-fear.html

http://www.paleonu.com/get-started/

Basically, ALL PUFAs will oxidize, including Omega 3s. You'll be better off if you investigate the possibility of reducing your Omega 6 intake in order to lessen the need for too many Omega 3s, which should be taken in proportion to Omega 6s.

Roughly how much omega-3 a day is too much if one is not supplementing with pills/oils? I typically get between 2-5g of o3 a day. My sources are fish (I am paleo-pescetarian), berries and vegetables. I consciously try to get as much omega-3 as possible and keep my o6 as low as possible.

From the American Heart Association page "Patients taking more than 3 grams of omega-3 fatty acids from capsules should do so only under a physician’s care. High intakes could cause excessive bleeding in some people. "

Though my understanding of this topic is limited, I seem to remember several studies suggesting extremely high omega-3 intake results not only in blood-thinning and bleeding, but also immune system depression. Specifically, one study found suppression of natural killer T-cells and natural killer cells (the implication being theoretical increase in rates of cancerous tumors and susceptibility to viral infection).

Moderation in all things, I suppose. I've yet to really be convinced of any supplement that's not better obtained from the fresh, whole food.

First of all, an omega 3 vs omega 6 ratio of 1:1 is very hard to maintain. 1:3 omega 3 vs omega 6 ratio is more realistic. Can we consume too much of omega 3? Of course. Even though omega 3 fat is a healthy fat it is still fat. And too much of fat is not recommended because fat has a lot of calories. 1 gram of fat has 9 calories. So 50 grams of fat that contains omega 3 means 450 extra kcal per day. That's a half hour of intense running. See this article on how much omega 3 per day is advised for a healthy individual. In short, try to eat as much food that contains omega 3 as you can. That would be different kinds of fish or nuts and don't worry about consuming it too much. Rather be worried about consuming too much of omega 6 and omega 6 fat. Hope this helps. Regards, Tom

Actually the study that refers to suppression of T Cells doesn't nessecarily mean that is a bad thing. Remicade and other agreessive treatments for Ulcerative Colitis are administered for this very reason, to reduce the activity of T Cells. I'm not familiar with the study that you have referenced, since it's not listed, but if it was in a specific population of people suffering from auto immune conditions, then its possible that suppression of T Cell activity would be a good thing. Just my thoughts.