Tuna?!?!?!?!

[YoungMuscle]

I have heard that you should try to limit your consumption of tuna to 2 or 3 times weekly. Is this true? I love to eat it and need help losing about another five pounds, so the more of it I can eat the better. So, any help on this would be appreciated!

[Trans_Isomer]

Ive read about the sea having all sorts of contaminants in it. Ive never really followed up on it to see how true this really is, but ive read that females who are pregnant should avoid any seafood because pregnant woman who eat seafood give birth to low birth weight babies. They say the mercury content in tuna and other fish are high, because it stores in them, then you eat them and get too much of it.
Now I wouldnt stop eating seafood or anything, but at the same time im not eating fish everyday.

[Ibanez]

I am like you, love my Tuna, and heard that too much may not be all that good due to contaminents. I was told that finding 'wild' tuna/salmon was better for you than the 'farmed' variety... It will cost more, but have less 'crap' pumped in there....

Now who knows, maybe this lab finding was sponsored by John West or some sea based tuna company...lol, but it does make sense. Anyone else have some concrete evidence to offer??

[wedgylx]

with tuna, you're only worrying about mercury. We pollute the water and mercury is absorbed into the micro-organisms of the sea. Little fish eat those microorganisms and in turn become loaded with mercury.

then larger fish eat the smaller fish and, in turn, become loaded with mercury

then a big fish like a tuna eats that fish and becomes loaded with mercury...

then we eat the tuna, and well you see where I'm going with this

[Ibanez]

Thanks for making that more clear Wedgy.... :)

[dinoiii]

I like your explaination wedg.

I would like to add that it is actually methylated mercury that causes problems not the non-methylated. It is kind of like methylating a prohormone for lack of better comparison. The bacteria wedg brings up actually do the methylation turning mercury into methyl mercury.

In a common-sensical explaination,it is a general rule that the larger the predator fish, the higher potential exposure you will have to methylated mercry - this is why in fact you should watch out for the essential "farm-bread / hormonally enhanced" varieties.

The mechanism of action for the science guys can be summed as follows: Methyl mercury binds tightly to the proteins in fish tissue, including muscle. Cooking does not appreciably reduce the methyl mercury content of the fish.

Nearly all fish contain trace amounts of methyl mercury, some more than others. In areas where there is industrial mercury pollution, the levels in the fish can be quite elevated. In general, however, methyl mercury levels for most fish range from less than 0.01 ppm to 0.5 ppm. It's only in a few species of fish that methyl mercury levels reach the FDA limit for human consumption of 1 ppm. This most frequently occurs in some large predator fish, such as shark and swordfish. Certain species of very large tuna, typically sold as fresh steaks or sushi, can have levels over 1 ppm. (Canned tuna, composed of smaller species of tuna such as skipjack and albacore, has much lower levels of methyl mercury, averaging only about 0.17 ppm.) The average concentration of methyl mercury for commercially important species (mostly marine in origin) is less than 0.3 ppm.

Eating commercially available fish should not be a problem. The 1 ppm limit FDA had set for commercial fish is considerably lower than levels of methyl mercury in fish that have caused illness.

While I am unfamiliar with the fetal studies you mention wedg except one done at the University of Rochester, my initial teaching facility, I can only give decent comment on it. FDA and the National Institute of Environmental Health Sciences are supporting a study by the University of Rochester to gather conclusive data on the effects of long-term exposure to low levels of methyl mercury in the fetus and infant. The study is being conducted in the Seychelles Islands, off the coast of East Africa in the Indian Ocean.

Fish is the major source of protein for people in the Seychelles Islands,. Begun about 10 years ago, the study focuses on the approximately 700 pregnancies that occur on the islands each year. Preliminary results do not support significant problems like those seen in adults with overexposure (i.e. - paresthesias, etc...). That is really all I can comment on here doing any justice.

[ghostwheel]

Oh no, now he is dissin' sushi!

One thing about fresh deep sea caught local fish here in Hawaii, there is no mercury pollution around here like the mainland fish.

"Lucky you live Hawaii"