How much fish is safe to eat?
Joint recommendations for fish consumption from the EPA and FDA as of 2004 are as follows:
- Eat up to 12 ounces (2 average meals) a week of a variety of commonly eaten fish and shellfish found consistently low in mercury, including shrimp, canned light tuna, salmon, pollock, and catfish
- Limit albacore tuna to 6 oz. per week
- Do not eat shark, swordfish, king mackerel, or tilefish because they contain high levels of mercury
From his research, Dr. Nicholas Ralston believes that since selenium provides our bodies with protective properties against mercury, eating one of the 16 types of ocean fish which has more selenium than mercury is perfectly safe. Previous EPA and FDA guidelines for consuming fish only take into account risk factors of mercury, but not the protective factors of selenium, eating more than the current recommendations is not only advisable, but safe. There should be no reason to limit our consumption.
Dr. James MacGregor, OBGYN, USC Keck School of Medicine says that ocean fish are an ideal nutrient package for nursing and pregnant mothers, to supply critical building blocks for health and development to babies. Susan Carlson, Nutrition Scientist, University of Kansas Medical Center believes any pregnant woman in the U.S. who chooses not to consume regular servings of fish in her diet is taking a risk for the safe development of the unborn infant, as well as possible issues for her own health.
Pregnant mothers and children should eat 2-3 servings of oily fish weekly, and up to about 12 ounces per week of low-mercury containing fish who have a comparable amount of selenium. As long as expectant mothers avoid the following 4 fish whose mercury levels exceed selenium content: swordfish, shark, tilefish, and king makerel, they should be safe eating a variety of seafood.
Some fish have more selenium than mercury, and some contain more level amounts of both. Seafood should be obtained from a fisherman who uses sustainable practices and catches fish wild, from the ocean (not farm-raised). According to Robert Disney, anything you catch on the line is safe to eat. Bigger fish are less safe not only due to the fact that they store more of the heavy metals in their fat tissues, but also due to the lower levels of selenium found in these fish.
For more information on which fish contain adequate amounts of selenium, visit the Western Pacific Regional Fishery Management Council Western web site.
For more information on mercury versus selenium levels in certain types of fish, see the table in the following section How selenium content in fish counteracts mercury.
How selenium content in fish counteracts mercury
Scientists have repeatedly observed how the mineral selenium binds to mercury and acts as a natural chelator of this toxic metal. The selenium found in many types of fish consumed in the U.S. exceeds mercury content of the fish, and actually protects us against mercury toxicity. The nutritional benefits of eating fish far outweigh existing potential risks.
Dr. Nicholas Ralston frequently refers to a study done with animals as long ago as 1967 where feeding them what was considered a toxic amount of mercury that could kill them could be prevented by also administering a similar amount of selenium.
A study performed at Cornell University reveals that adding selenium to the diets of quail “gave complete protection” from significant amounts of mercury. The fact that selenium provides this type of benefit to birds is a testimonial to the important role of minerals in the health of other species besides human beings.
Because most fish are one of the best and most natural sources of selenium and can counteract the mercury absorbed in our bodies, it makes sense to rely on this food source for nutrition and for natural detoxification to keep our bodies healthy.
This table is taken from the document “Selenium and Mercury, Fishing for Answers” from the Energy and Environmental Research Center and shows mercury versus selenium levels in certain types of fish.
For more details about mercury versus selenium content in ocean fish, visit the Energy and Environmental Research Center web site.
What about fish from freshwater sources?
Selenium is not present in all freshwater fish. It is particular to geography and mineral amounts found in the area where the fish live. There is also a vast difference in evaluating fish based on mercury content alone and assessing the mercury versus selenium content. Again, most freshwater fish found to contain more mercury than selenium are those which are the larger species, and using the selenium-mercury assessment would eliminate most fish caught in rivers, streams, and lakes.
To be certain you are getting something safe, research the type of fish to determine the mercury to selenium levels for each type. Check with local fish advisories about those species which contain the most mercury.
Other nutritional benefits of fish
Overall, our population is greatly deficient in Omega 3 essential fatty acids because our modern diets have too many Omega 6s from the widespread presence of industrially produced vegetable oils such as safflower, sunflower, corn, soybean, and canola oils commonly found in processed foods in the Standard American Diet. In addition to selenium and other minerals, fish are also an important source of the long-chain omega-3 fatty acids DHA and EPA.
Some mainstream medical sources assume that consuming plants as a source of omega 3 fats to obtain fatty acids such as ALA are converted to to longer chain DHA and EPA. However, this is not a good way to make these fatty acids since the conversion is poor. Fish are a superior source of these nutrients for this reason, as compared to flax seed oil, as one example.
DHA is essential to brain development, and it cannot be manufactured by our bodies, so it must be obtained in diet. This Omega 3 is found in trace amounts in plants such as flaxseed, but long-chain fatty acids are only found in shellfish and fish.
Dark and oily fish are the richest sources of Omega 3 essential fatty acids. According to Joseph Hibbeln, Nutritional Neuroscientist, National Institutes of Health, Vitamin D and calcium, and a good variety of tuna and salmon, sardines, whitefish, shellfish and shrimp, can be eaten safely 2-3 times weekly.
In areas where more fish are eaten including the Mediterranean, Japan, the shoreline of Asian, and northern Europe, populations have less diabetes, stroke, depression, and cardiovascular disease, according to Dr. James McGregor, M.D., OBGYN from USC Keck School of Medicine.
From ALSPAC (Avon Longitudinal Study of Parents and Children, a large ongoing study in Britain which began in 1991):
“Mothers who consume less fish during pregnancy have children with significantly lower IQs and impaired ability to focus (ref 1). Similarly, another study revealed that children of mothers who ate more than three portions of seafood a week during pregnancy had better neurological function than children whose mothers ate little or no seafood (ref 2). Seafood is a major source of omega-3 fatty acids - essential for neural development - yet expectant mothers are often advised to limit their consumption, as seafood can contain trace amounts of contaminants.
Another study using information from ALSPAC found that persistent depression during pregnancy can increase the chance of a child suffering developmental delay (ref 3). While it was well known that postnatal depression can affect child development, little research into so-called antenatal depression had been carried out. In a different study, depression in fathers was found to be associated with adverse emotional and behavioural outcomes in children aged 3.5 years, and an increased risk of conduct problems in boys (ref 4).”
Chemical impact of mercury on the environment
Robert Disney points out that for thousands upon thousands of years, the earth has experienced seismic and volcanic activity, and scientists know volcanoes are one of the most plentiful and natural sources of mercury on earth. When a volcano erupts, the material goes into the atmosphere, water, land, and sea .
Mercury is also found in man-made substances as well: pharmaceuticals, switches, thermometers, power plants, factories, and many chemical applications including vaccines, fluorescent lights, and food additives like high-fructose corn syrup.
Today there are more chemicals than ever before in history in our environment. From the USEPA, more than 80,000 “chemical substances” are currently in legal use. From Jennifer Taggart’s Smart Mama’s Green Guide: “less than 10 percent have been reviewed for toxic effects.”
According to Environmental Health Perspectives, the high cost and lengthy times required for animal testing in which to determine the toxicity of any given chemical makes it impractical for testing tens of thousands of chemicals. Thus, there is an enormous inventory of chemicals in use which have not currently been tested.
The earth will always be able to rebound from chemical and environmental damage, but our species will suffer due to the amount of poisons we’ve introduced, says Environmental Scientist, Robert Disney. Thus, it is of particular importance that we find safer alternatives to the myriad chemicals we are using. That includes everything we use everyday such as safer soaps, cleaners, detergents, solvents, and many other products.
Because of the undeniably important role minerals such as selenium play in human health, it makes sense to consume the most natural foods containing these minerals. Mercury has been found to have a neuro-toxic effect leading to health issues. In laboratory studies, selenium treatments were shown to be nearly identical, whether mercury administration was discontinued or not. As we read about in selenium protection and therapy studies, observable consequences of methylmercury exposure are eliminated, despite high methylmercury exposures occurring in five-fold excess of selenium. In other words, just 1 selenium molecule would attach itself to 5 mercury molecules and remove it from the body.
Robert Disney believes a good example of how chemicals affect us is the marked increase in infertility in women trying to conceive. Now, just to be able to conceive, more and more women have to take medications and the result is that an increasing number of them have multiple children at once. Is this natural? Science makes definitive statements about health, and yet, time and time again, science also comes out with revisions to those statements. At one point, science told us that eggs were harmful because they were too high in cholesterol. Just a few years ago, that changed and suddenly, eggs were safe to eat again .
The government provides health advisories about consuming fish due to the mercury content. Some people aren’t confident enough to make decisions about their health unless it is validated by the government or larger health authority in some way. We only feel good about following what the “experts” say, and have been made to believe that they are the ones who should tell us what to do .
The protective properties of real, traditional foods
It is very easy to become overly concerned about the content of mercury in everything around us. Robert Disney believes this worry has caused us to avoid nutritious foods such as fish. People all over the world have consumed fish for millennia, and it has helped to ensure the survival of our species. We may have more mercury now than we did many years ago, but avoiding fish just to avoid more mercury doesn’t make sense when you consider all the nutritional benefits of fish, and how vital it is to our health. The bottom line is that we still have to eat to live.
This wisdom that has been handed down through time has enabled us to preserve knowledge of health and healing for thousands of years. In modern times we have become complacent of these teachings and instead give credence to scientific “proof” as being superior to this long-standing knowledge. And yet, it is these great bodies of traditional knowledge which have brought generation after generation of people along. If you wait long enough for science to prove that something is good for you, you will likely starve to death. Anything corrupted by politics and corporate interest will not give us the truth about what’s nutritionally beneficial unless they stand to gain something from it. [23, 24]
We need nutritional elements available in healthy foods like fish to maintain health. We should not stop eating fish because of mercury, which we have consumed since the dawn of time. Traditional foods have protective properties, and will give you greater health benefit than any other substances on earth. The choice is yours: will you risk the small chance of dying of mercury poisoning because you eat fish, or will you starve to death? It makes the most sense to eat the healthiest food you can while you are alive.
By removing chemicals from your environment, you can reduce your toxic load. At the same time, get more exercise and fresh air, sunshine, eat real food like fish, meats and animal products from healthy animals and birds on pasture, and view your health holistically. None of us will live forever. While you are here, do the things you know are right to make your health as good as it can be. 
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- Robert Disney, Environmental Scientist, personal interview, February, 2012.
Robert Disney, Environmental Scientist, Mercury in the environment/Emerging waste water contaminants, live presentation, Weston A. Price Wise Traditions Conference, November, 2010.