Edible Marine Seaweeds: Part 4

Seaweeds can bioaccumulate heavy metals and other toxins if they grow in polluted areas and this has to be taken into consideration if they are to be used as a source of food. There have been reports of excessively high iodine intakes in some populations that consume large quantities of seaweed, such as those in parts of Japan, but this is rare and is balanced by the good nutrition that seaweeds can provide. As always everything in the diet should be in balance and this is an important consideration for all food sources including seaweed. Arsenic has been identified as a heavy metal that can readily accumulate in seaweeds and this can have negative effects because it can displace other minerals from their binding sites on transporters and enzymes, and this may have detrimental effects on metabolism. Cadmium, aluminium, manganese, chromium and nickel may also bioaccumulate in seaweed and these too can be problematic depending on the form present, the amount consumed and the concentration within the tissues.  

Eat Well, Stay Healthy, Protect Yourself


Kumar, M. S. and Sharma, S. A. 2021. Toxicological effects of marine seaweeds: A cautious insight for human consumption. Critical reviews in food science and nutrition. 61(3): 500-521

About Robert Barrington

Robert Barrington is a writer, nutritionist, lecturer and philosopher.
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