Why bigger may not better when it comes to certain fish

Florida Fish and Wildlife

Fish certainly offers a bounty of benefits – an arsenal of health promoting  and disease-fighting compounds right through the life cycle. But, according to a recent report published in the American Journal of Tropical Medicine and Hygiene, there are some you definitely want to avoid: large reef or tropical fish.

These fish contain a toxin called ciguatera can leave you feeling ill for months. The study points out  that ciguatera is the most commonly reported marine food-borne illness worldwide and the incidence is higher than previously thought.  Ciguatera is originally found in algae in warm waters.  Small fish eat this algae and contain minor (insignificant) amounts of the toxin. But as bigger fish eat the smaller ones, the amount of ciguatera climbs and in large fish, the consequences can be very distressing.

Cooking does not affect ciguatera levels. This poisoning can not only cause gastrointestinal symptoms  (nausea, vomiting and diarrhea)  but also neurological ones such as tingling fingers or toes or finding that cold things feel hot and hot things feel cold.  Some victims also suffer cardiovascular symptoms such as arrhythmias.

With ciguatera poisoning, you can only treat the symptoms (antihistamines, cool showers etc.) until they disappear but some may last for days or months.  A treatment of a sugar alcohol, mannitol, may help with some of the symptoms –  if administered early enough – but it is not a cure.

It used to be that ciguatera poisoning was a concern only if you were travelling to areas such as South Florida, the Caribbean or Hawaii  but with the  availability of  these fish in northern markets,  awareness is key. The best way to avoid ciguatera is to not eat large reef fish such as barracuda, , grouper, different varieties of  snapper  (not yellowtail snapper) and  king mackerel.

Go for smaller fish and  when eating whole fish,  avoid eating the head, roe and liver  as the ciguatera toxin is most concentrated in these parts.  If you’re buying fish fillets such as snapper and cannot tell how large the fish may have been, skip it.