Eating Tuna Daily, bad for me?

I looked this up a few years ago becuase I was eating tuna daily. The FDA recommendation at that time was not to eat more than 8oz per week! Like others have said, it's the mercury concern. Tuna has esspecially high levels of mercury.

I was wondering the same thing. I don't eat a bunch now, but have a whole case of tuna to go through. BUMP... to peruse later.

The thing about mercury is that 1. it bioaccumulates and 2. it does not degrade in your system.
Thus, tuna, being a higher order consumer, accumulates very high amounts of mercury in comparison to other organisms. This is especially true of being a marine organism. When you eat tuna, you're consuming all the mercury it did from all the lower order animals it consumed and they lower order animals they consumed etc. That's how mercury bioaccumulates.
Also, once in your body, it will never be removed as most other elements are removed. It has bioaccumulated in you and will remain until.. well, the end.
Why is this a problem? Mercury has been linked to many health problems. Most notably, mercury is linked to birth defects and deformities. If you are planning on having children some day, I would suggest discontinuing your habit of eating tuna on a regular basis, as your mercury toxin levels would be transferred to your child.

You mentioned that you are a picky eater, but I suggest trying out different fish. Essentially, the lower the order, as in the lower in the food chain, an organism is, the less mercury it has ingested, the less mercury it can transfer to your body upon consumption.

I hope this has helped a bit, or at least made sense. Good luck!

No, it does EVENTUALLY leave your system, it just takes a very VERY long time.

This is talking about inorganic mercury (not elemental, as in- not from a metallic form of mercury), if you want to read the full thing, here it is: http://www.atsdr.cdc.gov/phs/phs.asp?id=112&tid=24#bookmark04


From CDC:

Once inorganic mercury enters the body and gets into the bloodstream, it moves to many different tissues. Inorganic mercury leaves your body in the urine or feces over a period of several weeks or months. A small amount of the inorganic mercury can be changed in your body to metallic mercury and leave in the breath as a mercury vapor. Inorganic mercury accumulates mostly in the kidneys and does not enter the brain as easily as metallic mercury. Inorganic mercury compounds also do not move as easily from the blood of a pregnant woman to her developing child. In a nursing woman, some of the inorganic mercury in her body will pass into her breast milk.

Methylmercury is the form of mercury most easily absorbed through the gastrointestinal tract (about 95% absorbed). After you eat fish or other foods that are contaminated with methylmercury, the methylmercury enters your bloodstream easily and goes rapidly to other parts of your body. Only small amounts of methylmercury enter the bloodstream directly through the skin, but other forms of organic mercury (in particular dimethylmercury) can rapidly enter the body through the skin. Organic mercury compounds may evaporate slowly at room temperature and may enter your body easily if you breathe in the vapors. Once organic mercury is in the bloodstream, it moves easily to most tissues and readily enters the brain. Methylmercury that is in the blood of a pregnant woman will easily move into the blood of the developing child and then into the child's brain and other tissues. Like metallic mercury, methylmercury can be changed by your body to inorganic mercury. When this happens in the brain, the mercury can remain there for a long time. When methylmercury does leave your body after you have been exposed, it leaves slowly over a period of several months, mostly as inorganic mercury in the feces. As with inorganic mercury, some of the methylmercury in a nursing woman's body will pass into her breast milk.

How can mercury affect my health?

The nervous system is very sensitive to mercury. In poisoning incidents that occurred in other countries, some people who ate fish contaminated with large amounts of methylmercury or seed grains treated with methylmercury or other organic mercury compounds developed permanent damage to the brain and kidneys. Permanent damage to the brain has also been shown to occur from exposure to sufficiently high levels of metallic mercury. Whether exposure to inorganic mercury results in brain or nerve damage is not as certain, since it does not easily pass from the blood into the brain.

Metallic mercury vapors or organic mercury may affect many different areas of the brain and their associated functions, resulting in a variety of symptoms. These include personality changes (irritability, shyness, nervousness), tremors, changes in vision (constriction (or narrowing) of the visual field), deafness, muscle incoordination, loss of sensation, and difficulties with memory.

Different forms of mercury have different effects on the nervous system, because they do not all move through the body in the same way. When metallic mercury vapors are inhaled, they readily enter the bloodstream and are carried throughout the body and can move into the brain. Breathing in or swallowing large amounts of methylmercury also results in some of the mercury moving into the brain and affecting the nervous system. Inorganic mercury salts, such as mercuric chloride, do not enter the brain as readily as methylmercury or metallic mercury vapor.

The kidneys are also sensitive to the effects of mercury, because mercury accumulates in the kidneys and causes higher exposures to these tissues, and thus more damage. All forms of mercury can cause kidney damage if large enough amounts enter the body. If the damage caused by the mercury is not too great, the kidneys are likely to recover once the body clears itself of the contamination.

If you're worried, try canned salmon or sardines. I don't notice that much of a difference when I make salmon salad as opposed to tuna salad. Sardines are a bit fishier tasting than canned tuna but they are a small fish so you don't have to worry about the mercury problem and I think they would do well as a replacement. Maybe not texture wise, I don't know, I haven't tried it.

I eat too much tuna fish. It's just so quick and easy to mix up a can of tuna and dump it over some lettuce and tomatoes. I really need to quit being lazy and start making chicken salad more often. I think it tastes so much better anyway and I always make a big pot of soup from the carcass which is nice with it getting colder.

Next week is covered because that's exactly what I do with our leftover turkey but I'm definitely going to add a chicken to the weekly grocery list and cut back on all the tuna.

The big risk is from albacore. Choose "light" tuna and AVOID "white" or albacore, but either way, you might want to eat less if you plan on having children (and especially nursing). Try the little pouches of salmon too - they are low risk and yummy.

And fight against coal-burning power plants, which is where most of this mercury comes from!

Before people start protesting random coal burning power plants ...

The US EPA has required scrubbers to remove, among other things, mercury from coal power plant (and other significant sources of mercury) emissions since 2011. The primary source of mercury pollution, as opposed to naturally occurring mercury, is from coal power plants in countries that do not take similar measures.

ETA: this doesn't mean the situation is likely to improve - those other countries are burning a lot more coal than the US, too. I try to avoid eating tuna more than 2x per week. I eat light tuna from the packet because I like it better. Did not realize albacore was a bigger problem - glad I don't prefer it.

The only thing I'd add to the post is that tinned tuna tends to be rendered from smaller fish, so mercury levels are lower in them than they are in slabs of mature albacore tuna that you might eat if having a tuna steak or sushi at a restaurant.

I work on hazardous waste cleanup sites and regularly have my blood tested for mercury (among other things) as part of my job health and safety program. I eat 3-5 cans of tuna a week in addition to potential exposure from my job and my mercury levels are not elevated AT ALL.

So you eat maybe121-200% of the EPA recommended weekly limit for someone your size. Given that the EPA limits are probably somewhat conservative it's not altogether surprising that you're levels are not problematic. That does not negate the fact that it is something people in general would be better off considering, especially if they are of the petite female variety.

Isn't all deep water fish have Mercy now? everything ends up being bad for you. If you want change it up with canned turkey or salmon or something not canned.