From: mannj@southern.co.nz (Jay Mann)
Newsgroups: sci.bio.food-science
Subject: Re: tuna
Date: 18 Feb 1997 20:00:49 GMT

Phipps (beowoof@slip.net) wrote:
: jtmiii wrote:
: > Is there a substance (toxic additive or some such) which is often found in
: > small quantities in American canned tuna? If so, are there studies on the
: > effects of this substance on humans?
: Have you considered histamine? It is possible to have small amounts 
: below FDA tolerance, to which susceptible individuals might be 
: sensitive, and experience some allergic reactions.

The symptoms are called scombroid poisoning, and are supposed to be 
typical histamine responses.  (Like so-called Chinese restaurant 
syndrome).  Reportedly both sombroid poisoning and CRS are controlled by 
anti-histamines.

Tuna, albacore, and swordfish are, if I remember correctly, all possible 
causes of scombroid poisoning.  These fish may have different 
metabolisms, since they seem to function as effective hunters in very 
cold waters.   They are said to have internal bacteria capable of 
converting endogenous precursors to histamine if the flesh is not 
processed carefully.  In at least one report, a women developed scombroid 
poisoning just by letting frozen tuna steaks thaw in the fridge for a day 
or so.

Jay D Mann  <mannj@southern.co.nz>
Christchurch, New Zealand