Why I tell my patients to not eat fish!

Because of the rise of mercury in our waters, consumption of fish may be harmful due to their levels of mercury. 

In many geographical areas, GUESS WHO is the largest polluters of our waters? You guessed it – the dentists. That is why, since last July, general dentists in Connecticut are required by law to have special mercury traps to help keep mercury out of the wastewater. I have had such a trap for over 15 years!

Can you guess the biggest group of mercury polluters that are NOT being talked about? Anyone who has mercury in their mouth becomes a source of mercury in our wastewater. Every time a person urinates or defecates, mercury is being passed into our wastewater. Because it seems legislators worry more about fish than our children, educating them about this source of mercury may get these fillings banned.

Mercury goes out into the waste stream or falls from the sky into our waters and accumulates in the food that fish feed upon. The smaller fish eat the plankton and algae and then these fish are eaten by bigger fish and the bigger fish are eaten by even bigger fish, etc. At each step more and more mercury is accumulating in the fish. It has gotten to the point where the U.S. government has issued warnings about mercury problems in people because of eating fish. It is estimated by the government that one in six children being born are at risk of developmental problems due to mercury.

Because most of the patients coming to me are so toxic, with mercury being among the toxins, I tell them to not eat any fish. They do not need any additional mercury exposure.

When they are less toxic and feeling well, at that point if they want to have some fish once in a while, they will probably tolerate it.

There has been a lot of “talk” about fish and mercury in the news lately. Unfortunately, I do not see “talk” about mercury fillings. According to the World Health Organization a person’s primary source of mercury is from mercury fillings, not from food or the environment.

For those of you who are not sick or who are now less toxic and want to eat some fish, which ones are better than others? 

Below are some figures to help you in your decision making.

Fish AND Mercury Concentration in parts per million (ppm)

  • Orange Roughy .58
  • Red Snapper .60
  • Tile Fish 1.45
  • Atlantic Haddock .17
  • Tuna (canned chunk light) .123
  • Lobster (Northern U.S.) .31
  • Trout .42
  • Albacore (canned) .358
  • Flounder/Sole .04


The Environmental Protection Agency (EPA) considers .1 ug/kg per day as a safe level of mercury exposure. To give you an idea what this means in real numbers I am going to give an example.

If you weigh 120 lbs. and eat 5 ounces of each of the following fish in a week (remember many recommended you eat 3 servings of fish per week as part of a healthy diet) the percentage shown will be the percentage of the EPA limit, the limit being 100%.

Albacore (canned) + Atlantic Cod + Sole = 210%

You can see how easy it is to go over the limit. Remember these limits are guesses. For instance, the Government’s amount of allowable exposure to lead keeps going down. And what about a small child? This is why the government has warned pregnant women and women of childbearing age who may become pregnant not to eat certain fish high in mercury (shark, swordfish, king mackerel, and tilefish). Also, the Government recommends that nursing mothers and young children avoid these fish. However, by the example I gave, these at-risk groups must be very conscious of all fish and how much they are consuming. Included in my grouping, for example, is sole which has only .04 ppm of mercury.

You can see why I recommend my patients not to eat any fish during treatment.

What about Salmon?

Salmon is very popular and in fact is fairly low in mercury, ranging from undetectable amounts to .18 ppm.

However, there are some problems with certain salmon.

Farm raised salmon vs. wild salmon

We hear about farm raised salmon and it brings to mind salmon being raised in a pristine environment with control over what they are eating. Sounds like this would be the ideal salmon.

However, an article in the January ’04 journal Science bursts that bubble. In this analysis of farm raised vs wild salmon, it was found that in most cases, consuming more than one serving of farmed salmon per month could pose unacceptable cancer risks with respect to the EPA standards. Farmed salmon had up to 10 times higher levels of PCB’s and dioxins than wild salmon.

Also, a few other facts I found out about farm raised salmon – they are often fed antibiotics which can contribute to our antibiotic resistance and often chemicals are added to their food to color their flesh pink to look like wild salmon.

If a patient insists that they want to eat some fish the only one I would recommend is wild salmon, in small amounts.

Hopefully, a point in time will come where we can ingest fish without worrying about mercury or toxic chemical levels. Until then, be careful.

© 2004, Mark A. Breiner, DDS

The information presented is for educational purposes only. Please consult a qualified dentist or health practitioner for diagnosis and treatment.

If you would like to calculate your own mercury exposure from fish go to Got Mercury?

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