How much oily fish per week is too much?

[Sasha]

A while back, I switched to the Paleo diet and, being stuck for easy-to-prepare food, started having a piece of smoked mackerel for breakfast and for supper every day. I did that for a couple of months and then it occurred to me that maybe that wasn't the idea. Googling around, there seems to be a lot of focus on minimum amounts - that is, you should have at least one piece per week - but things get a bit woolly when it comes to maximum amounts and yet there is a sense that a maximum limit exists.

For example:

http://www.ifbb.org.uk/how-much-oily-fish-should-i-eat-

Suggests a minimum of one and a maximum of four.

Is there any rational basis to this? I know there are mercury issues with some fish, but not, apparently, mackerel. And oily fish have lots of omega 3 fats, which are good for the immune system.

There's no limit on the amount of meat or white fish you can eat: why a limit on (mercury-free) oily fish?

 

[adreno]

Because too much omega-3 isn't "good for the immune system". I usually see two servings per week recommended.

 

[Thinktank]

Most fish, especially predator-types like salmon etc. are all contaminated and not only with mercury, there are other toxins in those fish that might affect your health even more! Mackerel is a better choice than salmon but still not ideal. Even wild-caught Alaskan salmon is not so safe to eat anymore due to salmon farms which are located along the natural migration path of wild samon fish and spread disease.
If you want to eat oily fish then i guess the small ones like sardines are a much better choice.
If you're eating it only for the omega's then why not use a DHA/EPA (krill oil) supplement or high quality COD liver oil

 

[Sasha]

Most fish, especially predator-types like salmon etc. are all contaminated and not only with mercury, there are other toxins in those fish that might affect your health even more! Mackerel is a better choice than salmon but still not ideal. Even wild-caught Alaskan salmon is not so safe to eat anymore due to salmon farms which are located along the natural migration path of wild samon fish and spread disease.
If you want to eat oily fish then i guess the small ones like sardines are a much better choice.
If you're eating it only for the omega's then why not use a DHA/EPA (krill oil) supplement or high quality COD liver oil

I'm eating it partly because I need food - there's not much that's ready to eat but not extensively processed with artificial ingredients - but if it's beneficial that's an added bonus.

Why are small ones better?

I assume the Inuit eat loads of oily fish but maybe I'm wrong.

 

[adreno]

Why are small ones better?

Because the big fish eat the smaller fish, and so they accumulate mercury. You want to eat from the bottom of the food chain, not the top. Sharks are probably the worst, tuna is very bad as well.

I think salmon is probably ok in smaller portions, but it would be safer to stick to smaller fish.

 

[IreneF]

It's a toss-up. Since many bioaccumulating substances are fat-soluble, you get them in your fatty fish, and in the fatty parts of the fish. But those are the type of fish you want to eat.

I buy yellowfin instead of regular tuna because it's supposed to be lower in mercury. I think sardines are good, plus the little bones have lots of calcium.

Article on healthy fish:
http://healthyeating.sfgate.com/top-10-healthy-fish-eat-2796.html
http://www.eatingwell.com/blogs/health_blog/6_of_the_healthiest_fish_to_eat_and_6_to_avoid

Personally, I don't like the taste of farmed fish, but fresh wild-caught fish has gotten too expensive.

 

[xks201]

I know several people that have eaten fish daily and don't have high mercury levels. Most of it is fear mongering. Seriously.

 

[optimist]

I eat loads of salmon. I've heared it is not too healthy because of the way they are farmed, but I have to eat something.

@adreno How much is too much Omega-3?

 

[Thinktank]

I know several people that have eaten fish daily and don't have high mercury levels. Most of it is fear mongering. Seriously.

Broscience, keep that to yourself.

 

[Tunguska]

Problem with seafood is that dioxins and PCBs accumulate especially in marine animal fats. So the oilier the more likely contaminated. Even sardines were found to be quite high in them (more than larger but leaner fish!) though it depends where they're caught and on brand - you have no way of knowing. I don't have all the references on hand, but last read this report which gives an idea: http://www.efsa.europa.eu/en/press/news/120718.htm

Clams and scallops are usually very low in PCBs and dioxins since they have almost no fats. They may have other metals though.

Mercury in lowest-mercury fish (salmon, sardines, etc.) probably isn't a concern unless you already have a mercury problem. http://chriskresser.com/5-reasons-why-concerns-about-mercury-in-fish-are-misguided

From personal experience I found that 3g omega-3 per day is the max I can tolerate (more leads to bad headaches, heart racing) and various sources I vaguely remember also set the max intake at 3g/day. Probably a bad idea to do 3g/day long-term, possible links to cancer and whatnot (also read Ray Peat, who urges zero omega-3s). But at times doing 3g/day from salmon and sardines has been useful, for head trauma especially.