There is always something to watch out for. Chicken – contains antibiotics. Vegetables – pesticides. Grains and beans – lectins. Fish? Heavy metals! Mercury, Cadmium, Lead are the most common but there is much more to it. Dioxins, antibiotics and harmful PCBs raise concern too, especially in farmed fish. It can be pretty overwhelming what type of fish to choose to get your omega 3s but at the same time how to avoid all these toxic compounds?
Here is a brief summary which fish spices are safest to eat, which should be avoided, how these toxic compounds affect your body and how you can detox from heavy metals.
First, how much fish should you have per week?
The answer is one to two times if its low contaminated fish. Why not more? As basically every fish is contaminated to a greater or lesser extent.
If fish is contaminated, why should you eat it?
Well, you don’t have to 🙂 There are certain benefits though. Apart from great source of protein and B vitamins, certain fish and seafood contain other beneficial nutrients. Haddock and Cod are rich in iodine. Salmon and mackerel are high in omega 3s. Oysters are one of the highest source of zinc but they can be also contaminated with norovirus. So it’s a bit like weighting benefits with side effects. How much of good thing I can get from it, how much harm it can cause and how I can balance potential negative side effects?
What foods can you use for heavy metal detox?
If you decide to eat fish, a good thing to consider is to consume certain foods/nutrients that help with detox of heavy metals found in fish. The best are chlorella and cilantro. Garlic, spirulina and barley grass are good for heavy metal detox too.
How to choose fish that is safe and least contaminated?
The general rule is the smaller fish, the less likely to contain high levels of heavy metals. There is much more factors to consider of course but if you are getting too confused with spices, country of origin, farmed vs wild-caught, then choose smaller rather bigger fish and preferably not farmed or use the list below. Also, don’t be misled by sustainability certifications on the label as it doesn’t mean that fish is free from heavy metals or antibiotics .Sustainability is one thing but fish contamination with mercury and PCBs is another thing
A. What is the safest fish to eat?
These are the safest to consume with no major variability with mercury contamination between samples.
- Shrimps, scallop, clam, squid, oyster.
In general, better to avoid seafood and fish imported from Asia (one of the most polluted waters). Farmed fish should be avoided too. If you decide to buy farmed fish, try to choose organic because non-organic/not certified fish can contain high levels of antibiotics and be contaminated with other toxic compounds like dioxins and PBCs. PCBs are a class of industrial chemicals that are used in the manufacturing of a wide variety of consumer products
B. Other fish that are still safe choice but more questionable
The below fish spices are more questionable because of larger variability of Mercury levels between samples however still fairly safe choice.
- Freshwater Trout (best) or organic farmed Trout – avoid Sea Trout or non-organic farmed Trout.
- Wild caught Alaska/Pacific Salmon yes but definitely not Atlantic or non-organic farmed Salmon
- N. Atlantic Mackerel yes but not S. Atlantic Mackerel, Spanish Mackerel or King Mackerel (worst choice)
C. Moderately contaminated fish
- Black Seabass
D. Highly contaminated fish
- Halibut. Pacific halibut could be better option
- Atlantic Cod. Better choice would be Pacific Cod.
- Sablefish/Black cod
- Sea trout
- Skipjack/Light tuna
- Farmed tilapia
E. The most contaminated fish that you should never eat
- Bluefin/Bigeye/Ahi tuna (worst), slightly better Albacore and Yellowfin tuna however still highly contaminated
- King mackerel and Spanish Mackerel
- Orange roughly
- Chilean sea bass
How much Mercury is safe to have?
It’s a heavy metal and its toxic so the less the better. However, daily acceptable level of mercury consumption recommended by National Research Council is 0.1mcg per kilogram of body weight. For a 60kg person it would be around 6mcg. To put that into perspective, 3 ounces (85 grams) of Big eye tuna contain nearly 60 mcg of Mercury, Albacore and Yellowfin tuna 30mcg and Skipjack tuna 12 mcg.
How heavy metals affect your body?
- MERCURY -It’s the most prevalent and its known to cause damage mostly to nervous system and brain. Apart from that, it binds to glutathione causing impaired liver detoxification capacity. Mercury exposure can also contribute to autoimmune processes, candida overgrowth, fertility problems, depression and anxiety.
- CADMIUM – It’s a significant lung and gastrointestinal irritant. It causes damage to our body through generation of free radicals that can damage our cells and DNA. Cadmium exposure decreases levels of neurotransmitters like serotonin (our happy hormone).
- LEAD – Similar like cadmium, it induces a cellular damage by the formation of free radicals. As long as we can neutralise free radicals with antioxidants, we can’t do much about calcium mimicking effect of lead. Within our bones, lead can be incorporated into the mineral in place of calcium. Lead exposure is also known to induce gene mutations.
FOUR things you should remember
- Always choose smaller fish.
- Wild caught/freshwater fish are generally better than farmed
- If fish or seafood is farmed, make sure they are organic.
- All fish are contaminated to lesser or greater degree. If you eat fish, get chlorella or cilantro to help your body detox from heavy metals 🙂
If you are interested how you can optimise your omega 3:6 ratio check out this post here