Throughout our history, humans have been putting things into our mouths and involuntarily ingesting microorganisms and bacteria. Some are bad for us, but some of the billions of microbes present in our guts are vital to our health. The World Health Organization defines probiotics as “live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.” There are about 1,000 species of bacteria from four taxonomic groups living in our gut, and, although the population is highly dynamic, it is critical in developing and shaping the gut immune system, and it’s vital for us to keep
We hear this all the time: “Eating fish is good for you! It’s good for your heart, it’s good for your mood, it’s good for your joints! Fish and fish oil supplements are great for overall health!”
Yes, it is true that there is a wealth of research to show that the omega-3 fatty acids found in oily fish such as anchovies, sardines and salmon are necessary for optimal health. However, anyone that has dug a bit deeper will tell you that this is not the end of the story. In today’s toxic environment, there is also an undesirable effect associated with fish consumption. Eating more fish leads to increased blood levels of methylmercury and other heavy metals, along with increased polychlorinated biphenol (PCB) and dioxin exposure. Research has clearly defined this dietary link. This is concerning because these toxins have been linked with neurological dysfunction and increased risks of certain types of cancers.
As an alternative, perhaps we should avoid fish altogether and focus on fish oil supplementation. This way we still get the omega-3 health benefits but without the contamination. Herein lies the next problem: how pure and free of toxins are many fish oil supplements? A 2013 study examining 13 separate over-the-counter fish oil supplements found PCB levels in all products. What makes this even worse is that all 13 of these products were designed for children’s consumption.
So what do we do? Where do we go from here? There’s no simple solution but there are certainly steps we can take in the right direction:
• Limit fish intake to one to two servings per week maximum and increase your plant-based sources of omega-3 fatty acids (for example flax seeds and walnuts)
• If you do eat fish, try to avoid farmed and larger fish (such as tuna, swordfish, mackerel and pike)
• When supplementing with fish oil, be sure to spend the extra money on a higher quality brand. Contact the company and ask to see a certificate of analysis report showing that their product is free of toxins
• If you are supplementing with fish oil for its anti-inflammatory effects, consider other nutrients such Eicosatetraenoic acid (ETA) and its precursor Stearidonic acid (SDA), both found in green-lipped mussels. These omega-3 fatty acids have been shown to be more powerful anti-inflammatory agents, and at much lower doses, than Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA), the common omega-3 fatty acids found in fish oil products
• If you are concerned about heavy metal exposure, speak with a qualified physician that can perform objective lab tests to determine your current toxin burden. If necessary, consider nutrients (such as R-lipoic acid) as a safe and gentle method of chelating heavy metals such as mercury from the body.
Above all, do not over-analyze this information with the goal of finding a perfect solution. Just do the best you can. Everything in moderation is a good place to start!
Karouna-Renier NK, Ranga Rao K, Lanza JJ, Rivers SD, Wilson PA, Hodges DK, Levine KE, Ross GT. Mercury levels and fish consumption practices in women of child-bearing age in the Florida Panhandle. Environ Res. 2008;108(3):320-6. Epub 2008 Sep 23.
G.J. Myers, P.W. Davidson, J.J. Strain. Nutrient and methyl mercury exposure from consuming fish. J Nutr, 137(12):2805-2808, 2007.
A.L. Yaktine, M.C. Nesheim, & C.A. James. Nutrient and contaminant tradeoffs: exchanging meat, poultry, or seafood for dietary protein. Nutr Rev, 66(3):113-122, 2008.
Oken E, Choi AL, Karagas MR et al. Which Fish Should I Eat? Perspectives Influencing Fish Consumption Choices Environ Health Perspect. 2012; 120(6): 790–798. Published online 2012 February 22
Ashley JT, Ward JS, Anderson CS et al. Children’s daily exposure to polychlorinated biphenyls from dietary supplements containing fish oils. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2013;30(3):506-14.