Marine foods and toxicity
A vast array of marine-derived nutrients has exhibited significant health benefits ranging from cardioprotective and anti-inflammatory effects to improvements in cognitive function. As sources of the omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), oils from fish and algae are well known for their substantiated heart and mental health benefits. Numerous marine compounds have also been identified for their bioactive antioxidant qualities, most notably the carotenoids and phenolic compounds found in crustaceans, seaweed, and a variety of compounds isolated from microalgae and fish protein hydrolysates. In addition, various polysaccharides, including fucoidans derived from algae and chitin derived from crustacean shells, have demonstrated both antiviral and antitumor activity in mammals. Consumption of health promoting marine-derived foods has been recommended and encouraged for all persons, but they are particularly beneficial for pregnant women and young children due to their positive effects on prenatal and postnatal neural development.
Marine toxins are chemicals and bacteria that can contaminate certain types of seafood. Eating the seafood may result in food poisoning. The seafood may look, smell, and taste normal. There are five common types of marine toxins, and they all cause different symptoms. Food poisoning through marine toxins is rare. Marine toxin poisoning occurs most often in the summer.
Increased consumption of fish and shellfish has, however, recently prompted concerns by the FDA for communication of the safety of these foodstuffs, particularly for consumption during pregnancy and childhood, and the agency is currently considering updates to its nearly 20-year old recommendations for manufacturers and consumers. Though shark, tilefish, swordfish, king mackerel, and canned tuna are fishes traditionally associated with the threat of high levels of mercury, other species of fresh and salt water fish and seafood may also contain levels far in excess of the recommended limit for safe mercury ingestion. This limit, originally calculated by the EPA in 1999, was updated by the World Health Organization in 2003 to 1.6 µg/kg body weight/week, but as fish consumption becomes more prevalent in an increasingly populated world, this figure is currently being reconsidered. Ironically, since mercury is neuro-, nephro-, and immunotoxic, any potential health benefits of marine-derived foods could be negated by exposure to this toxic substance, as reported most markedly in children.
