552 U. S. BUREAD' or FISHERIES 



sential difference between the iodine content of fresh and canned 

 sahnon. One hundred and fifty- two different samples of fresh and 

 canned salmon were analyzed for iodine content. 



The results of this mvestigation, summarized briefly, are that 

 salmon has an iodine content from twenty to fifty times that of fruit, 

 vegetables, and milk, and that all canned salmon is a valuable source 

 of iodine. 



A variation in iodine content between species is indicated, the 

 average of all analyses giving red salmon an iodine content of 0.405 

 milligrams per kilo (moist basis); chinook or king, 0.364; coho or 

 medimn red, 0.206; pink or humpback, 0.264 milligrams per kilo. 

 The average iodine content of all species of salmon in all districts is 

 0.290 milligrams per kilo. 



The iodine content apparently varies with the species and within 

 the species, according to the district where the salmon is caught. 

 It is also interesting to note that different parts of the same salmon 

 varv^ in iodine content, the parts of the flesh richest in fat apparently 

 having the most iodine. The roe has been found to have a particu- 

 larly high iodine content, as much as 1.113 milligrams per kilo. 



Attention has already been called to the observations of W. D. 

 Keith on the freedom from goiter of a group of Indians in a particu- 

 larly goitrous district, and his suggestion that this was possibly due 

 to the fact that their diet included a large amount of salmon. This 

 salmon, caught in a spawning condition, is far inferior to the article 

 of commerce, taken at its prime. 



In regard to this, Jarvis, Clough, and Clark, in an article published 

 in the Journal of the American Medical Association, say: 



Salmon has at least equal grounds for consideration with milk products, fruits 

 and leafy vegetables — the materials used in these experiments and found of value 

 in the prophylaxis of goiter. Our results indicate a much higher iodine content 

 in salmon than Fellenberg found in milk products, eggs, leafy vegetables, or 

 fruits. A considerable part of the iodine in fruits is contained in such inedible 

 portions as the rind and seeds. Canned salmon consists only of the edible por- 

 tion, in which all the iodine may be utilized. 



It appears that the systematic use of sea foods which are rich in iodine would 

 be of considerable benefit in the treatment of simi)le goiter or for its prevention 

 in goitrous regions. Canned salmon, on account of its cheapness and availabil- 

 ity, is particularly suitable and should be included in the diet for patients. 



An estimate of the amount of salmon necessary in a diet for the 

 prevention of goiter has also been made. The general average 

 iodine content for all species in all districts may be given as 0.300 

 milligrams per kilo, or 300 parts per billion. The daily iodine require- 

 ment of the thyroid has been stated at approximately 0.01 milli- 

 grams. This amount of iodine is contained in 33 grams of salmon, if 

 300 parts per billion is taken as the average. An average sized 

 portion of salmon or other sea food eaten three or four times a week 

 should go far in helping to prevent goiter, 



