‘Eat fish! It is an excellent source of protein, it’s great for heart health and is high in much needed Omega 3 oils’.
How many times have you heard this? Many people begin eating fish regularly at the insistence of healthcare professionals. Fish certainly has wonderful health benefits but it can often harbor a secret that should make you think twice about your fish consumption.
If you consciously consume fish regularly for a healthy diet, you might wonder why you’re suddenly being advised against this. Unfortunately, pregnant women are often bombarded with information that can be overwhelming, especially when battling pregnancy sickness and fatigue.
Keep reading to find out everything you need to know about mercury in fish and what steps you need to take to protect yourself and your baby when eating fish.
Should we worry about mercury in fish?
If you enjoy eating fish, you probably want to know whether you need to worry about the mercury in fish. The reason for caution is that fish is often high in mercury in the form of methyl-mercury. It is a contaminant found at varying levels in fish species, due to factors such as type, size, location, habitat, diet and age.
A friend of mine once spent time in Hong Kong and told me that common Hong Kong folklore said there was so much mercury in Hong Kong harbor that the fish took their own temperature. It gave us a laugh but there is truth behind the humour.
How does mercury get into the fish in the first place?
Mercury occurs naturally in the ocean sediment but can also occur as contamination, as a result of human activities. Microorganisms transform mercury into methyl mercury and it bioaccumulates in aquatic organisms. That means when a larger fish eats a smaller fish, the level of methyl mercury accumulates in its system.
When it eats another smaller fish, it accumulates even more methyl mercury and this vicious cycle continues. This is why the larger the fish the more levels of methyl mercury it would have it its system.
Fish not only accumulate mercury from consuming smaller fish. All fish absorb methyl mercury from the water that passes through their gills. The longer the fish lives, the more methyl mercury it will bioaccumulate. Fish that are not predatory and short lived will not contain as much methyl mercury as their predatory and long living relatives, so these are the fish we want to include in our diet.
Why should we be concerned about mercury in fish?
Just as the methyl mercury bioaccumulates in fish, it also bioaccumulates in human beings. Our biological systems are not adequately designed to cope with this type of contaminant, so it bioaccumulates in our bodies. As it bioaccumulates, it needs to be stored somewhere, and it is stored in our fat tissue, brain and bones. It contributes to what I call the toxic load on our bodies, which increases daily and contributes to the general loss of vitality that affects the general population.
Over time, our bodies can remove the methyl mercury. However, it is difficult for the body to remove the methyl mercury when it is faced with more methyl mercury entering the body faster than it can remove it. Our bodies were never designed to cope with the toxic load it is presented with every day in our current environment. The toxicity our bodies cannot remove today will be stored with the idea that perhaps tomorrow it will be able to deal with it; however, that tomorrow never comes. That’s why looking at simple, everyday detox solutions to help your body is so important. My contact details are listed below if you want more information on this topic.
What happens if you eat too much mercury while pregnant?
The primary concern with methyl mercury is related to its potential effect on the nervous system and especially the developing fetus. Raised mercury levels in the mother can be passed through the placenta to the developing baby.
The fetus appears to be most sensitive to the effects of mercury during the third and fourth months of pregnancy. The effects on the brain and nervous system might not be noticed until developmental milestones – such as walking and talking – are delayed. Memory, language and attention span might also be affected.
Which fish are high in mercury?
Certain types of fish contain higher levels of mercury than others. Orange Roughie, shark, ling and swordfish all contain high levels of mercury. Tilefish from the Gulf of Mexico have also been found to contain high levels of mercury. Experts advise pregnant women and young children to avoid or limit these types of fish.
Fish lowest in mercury
If you wish to consume fish with low levels of mercury, you should choose from the most commonly eaten fish, including;
- Anchovies,
- Salmon,
- Atlantic Mackerel,
- Plaice,
- Sardines,
- Scallops
- Haddock.
Other safe options include clams, catfish, trout, whiting, sole, pollock, shad, crawfish, tilapia, mullet and flounder.
Should we limit the amount of fish we eat?
The answer to this question is ‘definitely’. This is especially important for pregnant women and those wanting to conceive within the next six months.
Avoid the following fish that are known to contain mercury:
- Shark (flake in the fish and chip shops)
- Ray
- Swordfish
- Barramundi
- Gemfish
- Orange Roughie
- Ling
- Southern Bluefin Tuna.
Limit other fish, such as tuna steaks, to one portion per week or two 140g cans of tuna per week (smaller tuna contain less mercury). Salmon, including canned salmon, can be consumed more frequently.
How to remove mercury from fish
Although scientists have begun to explore ways of removing mercury from fish, there is currently no way you can do this safely from home. It is much safer to cut high-mercury fish from your diet altogether during pregnancy. Perhaps, one day in the future, scientists will find a way of safely reducing the mercury in large fish; this is not yet possible.
Breastfeeding, infants and children
The official line is that mercury levels in mother’s milk are not high enough to pose a risk. As you will read in the final paragraph, I have my personal concerns regarding this statement. I prefer the cautionary approach and recommend adhering to the same guidelines for pregnancy.
Infants and children should avoid the high mercury fish. Their developing systems can do without the burden of having to detox or store methyl-mercury.
My personal opinion on mercury in fish
This is where I stick my neck out and tell you what I actually believe. I might not have real scientific evidence for my beliefs but an absence of scientific evidence doesn’t mean that all is OK; it just means there is an absence of scientific evidence.
As I mentioned before, I question methyl-mercury levels in breast milk. I don’t care much for the line that the levels are not high enough to be at risk. I want to give babies the best chance and any way we can reduce their toxic load gets a big thumbs up from me. Keep to the pregnancy option if you need to eat fish.
On the side of extreme caution, I have friends in the natural health field who remove all seafood from the diet of women who want to conceive or are pregnant. Instead, they get their omega-3 from flaxseed oil instead of fish consumption.
I do not think that canned tuna is all that safe for women who want to conceive, especially those who are pregnant. Who really knows what sort of tuna is in the can to start with?
I do not believe methyl-mercury affects only fish; it is in all seafood. Perhaps we all need to think a little more about what we eat when it comes to fish and shellfish.
On a different yet related subject, I also query the health benefits of salmon, as freshwater fish might contain more mercury than saltwater fish.
Farmed fish also concern me as I don’t believe they are fed a diet in keeping with what they should be eating naturally. It seems to me a bit like battery hens versus free-range chickens.
In conclusion
Let’s not go overboard in the other direction and give up seafood forever. If we help our bodies every day, we can lower the toxic load, the methyl-mercury can be removed and it will not bio-accumulate.
We cannot stop eating, drinking and breathing. Not eating what we enjoy is not fun. Just become more aware of what you put into your body and explore the possibilities that can help your body reduce its toxic load. Please pay attention to your potential mercury exposure and take steps to minimize it.
For those who want to conceive, or those who are pregnant, breastfeeding and feeding infants and children, keep to the guidelines and avoid predatory and long-living fish, as indicated above.
For the rest of the population, be aware of how much seafood you consume and implement some detox solutions to help the body cope with the methyl-mercury.
