Tuna...

[NewJuice]

Trying to get real lean I find myself eating plenty of tuna mabey 2 much... I opt for the 2.5 portion pouches, the major draw back is the 280mg of sodium per portion. Im also concerned about the mercury... Im eating about 5 to 7 portions per day. I also eat salmon every other day or so. My question whats the maxium amount I should eat. I know the sodium is high just wondering how low I should be shooting for? Is the mercury something I really need to worry about or is that for the non chemically enhanced...lol???

[Sliceruk]

I was gonna say mate i am eating Tuna on my cutting diet but no where near 5-7 A DAY!!!

I am no expert on this but that seems bloody high!!!

[NewJuice]

I know it sounds high but its only 2 or 3 pouches a day. I grab it because its easy, Just want to make sure Im not harming myself.

[DeBaie]

Chicken breast?

[JC2007]

I know it sounds high but its only 2 or 3 pouches a day. I grab it because its easy, Just want to make sure Im not harming myself.

Fine just make sure it's not albacore. This topic has been covered a few times already, search or scroll down a bit or to the previous page. I know there was a thread on it a week or two ago that you may be interested in checking out.

[Prada]

^^^^Right, avoid albacore. I try to keep it under 5 servings per week

[beenie]

As for the salt, you COULD buy sodium free. As for the mercury, I guess you take you chances. As for me, I have more important thing to worry about than something that hell field mice in 50 yeear. Rather be thinkikng about my next workout, or perhaps getting laid.

Trying to get real lean I find myself eating plenty of tuna mabey 2 much... I opt for the 2.5 portion pouches, the major draw back is the 280mg of sodium per portion. Im also concerned about the mercury... Im eating about 5 to 7 portions per day. I also eat salmon every other day or so. My question whats the maxium amount I should eat. I know the sodium is high just wondering how low I should be shooting for? Is the mercury something I really need to worry about or is that for the non chemically enhanced...lol???

[NewJuice]

Thanks guys...

[StairRoyd]

I need to search on why not albacore! I just bought some tuna and of course it was albacore...

[Mr.Akeym]

I need to search on why not albacore! I just bought some tuna and of course it was albacore...

Right I need to know this as well. I have at least 50 cans of albacore.

[brikks]

Albacore has about 3 times the mercury levels of light tuna.

I believe there is albacore, white tuna, light tuna and i haven't seen yellowfin in a can yet.

Of those 4 light tuna has the lowest amount of mercury

http://www.cfsan.fda.gov/~frf/sea-mehg.html

But 7 servings a day is extreme bud.

I'm not sure what the max amount of mercury per week/month is recommended, but this little calculator might come in handy.

http://www.gotmercury.org/

cheers

[goalkeeper]

i suggest you dont eat it at my desk anymore

[smokeyd]

o a little mercury is good for you, dont be scared

[Perforator]

I read somewhere the experts recommend no more than two 6oz cans a week. Like the others said Albacore has the highest content of mercury.

[audis4]

please, don't worry about mercury or sodium....just eat it and drink a lot of water.
I eat at least 6 cans/tuna/day

[HowIdo]

I think the concern over Mercury (which is actually the consumption of Methylmercury which is what Mercury is in water) is taken way to far.

Most of the guidelines are set for mothers who are pregnant ( Because it is absorbed by the placenta) and there has not been any specific neurologic or autoimmune diseases linked to the consumption of Methylmercury.

Im not saying eathing Mercury is good by any means but im just saying there is still a lot of debate over the levels of Methylmercury that can be toxic.

Oh and just for an interesting fact Mercury has a half life of 50 days in human blood.

[m8intl]

Long, but good. All you ever wanted to know

The Naked Truth: Mercury & Tuna
by Mike Roussell

Heavy Metal

Before we dive into the debate, a little background on mercury is necessary. Mercury, like zinc, iron, and lead, is a heavy metal. But unlike zinc and iron, lead and mercury have no useful function in the human body and can adversely affect the brain and kidneys.


Where Does It Go?

Once in the body, mercury has a half-life of around three days in the bloodstream and a 90-day half-life in other tissues (e.g. brain, kidneys, etc). When you ingest mercury (via your daily can of tuna), it gets readily absorbed by the small intestine and shipped to the liver where it forms a complex with glutathione. From there, the mercury has two fates — bile or blood. It can get incorporated in bile and excreted back into the intestines where it can be either reabsorbed or excreted in your feces.

The other fate for the mecury-glutatione complex is the bloodstream. Once in the bloodstream, mercury readily travels to the kidneys or the brain. In the kidneys it can get filtered and excreted in the urine or stored. The kidneys contain a protein called metallothionein that binds mercury and stores it in a nontoxic form.

As long as the dosage of mercury doesn't overwhelm the system, the kidneys will do a good job of synthesizing metallothionein and binding mercury as needed. If it finds its way to the brain, it gets transferred across the blood-brain barrier and stored. The storage option is the one that leads to mercury toxicity, causing damage to the brain or kidneys.



Mercury Messes with your Mind

Can excess tuna ingestion drive you crazy? Well, neurological problems and "symptoms of madness" are classic signs of methylmercury toxicity. The brain is pretty picky about what it lets across the blood-brain barrier, but mercury has found a loophole to get through and drive you nuts (literally).

Methylmercury can bind to cysteine, and to the brain this methylmercury-cysteine looks like methionine (essentially methylated cysteine). So methylmercury sneaks across the blood-brain barrier disguised as an amino acid.

Luckily, the transport of this methylmercury-cysteine complex is inhibited by methionine, phenylalanine, leucine, and other large neutral amino acids (Clarkson, 1990). Having this transport inhibited by certain amino acids could possibly mean that a high protein diet (and the protein found in tuna fish) will help prevent the transport of methylmercury into the brain.


Let's Talk Tuna

Now that we've laid the foundation for understanding mercury and methylmercury, let's look at its relationship to tuna and tuna consumption. Fortunately for us, canned tuna fish has less mercury than tuna steaks, and chunk light canned tuna has less mercury than chunk white canned tuna. This works out well for the financially conscious because at around 50 cents a can, chunk light is the cheapest form of tuna around.


Unfortunately, there's a lot of contradictory information floating around about tuna consumption. In their report, "Toxicological Profile for Mercury," the CDC states the following:

"No consumption advice is necessary for the top ten seafood species that make up about 80% of the seafood sold in the United States: canned tuna, shrimp, pollock, salmon, cod, catfish, clams, flatfish, crabs, and scallops. The methylmercury in these species is generally less than 0.2 ppm, and few people eat more than the suggested weekly limit of fish (2.2 pounds)."

(Note: 2.2 pounds of fish is almost six cans of tuna.)

Later on in the report, the CDC states that a person can chronically (for about 365 days) ingest .0003mg/kg of mercury per day with "no observed adverse effect." For a 200-pound man this would be a little over one can of chunk light tuna each day.

But the Environmental Working Group has a Tuna Calculator where you enter your weight and they tell you (according to the FDA) how many cans of tuna you can eat each week. Their calculations state that a 200-pound man can eat three cans of chunk light tuna per week. That's three to five cans less that the CDC says you can eat.

There's one more study that's important for answering the mercury/tuna question. Sherlock et al. (1984) found that after a year of consuming fish containing mercury, the subjects' bodies reached a steady state (mercury saturation). Chronic exposure of mercury after that point didn't lead to any great accumulation of mercury.

This study suggests that chronic ingestion of fish containing mercury won't lead to an overabundance of mercury in the body. The body has a fixed capacity for mercury storage that's typically maxed-out after one year (anything after that will just get excreted). This is supported by two other studies that have shown that the urinary excretion of mercury can be increased by up to 53% during chronic mercury exposure (Cherian et al. 1978; Hursh et al. 1976).

In the end, I think we should side with the CDC. Their report on mercury was over 650 pages and quite impressive. The FDA has spent a lot of time monitoring the levels of mercury in foods but they've failed (in my opinion) to look at the data and research on the effects of chronic consumption of fish containing mercury. After you read the book Food Politics by Marion Nestle, you won't be too quick to trust the FDA (or the USDA for that matter).


Preventing Mercury Toxicity — Playing It Safe

Even with the science in our favor, I think it's important to look at some ways that we can help our bodies deal with chronic consumption of mercury. Despite what countless ads would like you to believe, EDTA (ethylene diamine tetraacetic acid) isn't a very good chelator of mercury (mercury is about the only heavy metal EDTA won't chelate) and thus won't do much for the excess mercury in your system.


EDTA supplements: don't buy them if excess mercury is your concern!

Selenium has been shown in various animal models to prevent the toxic effects of methylmercury (Ganther et al., 1972; Iwata et al., 1973) and even increase the inorganic-to-methyl mercury ratio in tissues (Komsta-Szumska & Miller, 1984; Brzeznicka & Chmielnicka, 1985). But unfortunately, selenium has also been shown to increase the methylmercury concentration in the brain, which is just about the worst thing it could do (Magos & Webb, 1977; Brzeznicka & Chmielnicka 1985).

Since methylmercury binds and potentially depletes glutathione stores in the liver, it would be a good idea for heavy tuna eaters to supplement with N-acetylcystine (a glutathione precursor) to insure that the liver maintains optimal antioxidant ability. Dr. Ryan Smith recommends 1500mg a day. This is a good recommendation and should be followed by heavy tuna eaters.


1500mg a day of NAC might be a good idea for those who eat a ton of tuna.

As stated at the beginning of the article, the kidneys can do a good job of removing toxic mercury from the body and storing it in a safer form. The key isn't to overwhelm your system. Don't decide one day that you're going to add tuna to your diet and start eating a couple of cans a day. Increase you tuna intake over the course of several weeks so that your kidneys can adjust and produce metallonthionein accordingly.


Take Home Messages

In summary:

• The science shows that there's no reason bodybuilders should cut tuna out of their diets due to the current mercury scare.

• One can of chunk lite a day is a reasonable and safe intake for a 200-pound man without risking any health problems.

• If you want to eat more tuna now, make sure to increase your consumption over the course of several weeks so your kidneys can adjust.

• Adding 1.5 grams of NAC to your diet is a good idea if you eat a lot of tuna. This will help keep your glutathione stores full and your liver healthy.

In short, don't worry too much about tuna consumption. If you are worried, play it safe and adopt the recommendations above.