SOME ILLUSIONS ABOUT OYSTERS.

Auckland Star, Volume LX, Issue 46, 23 February 1929, Page 9

SOME ILLUSIONS ABOUT OYSTERS.

TYPHOID DANGER NOT VERY GREAT. NUTRITIVE VALUE NOT HIGH. In writing of oysters, in the first place, it is necessary to destroy certain illusions (says Sir W. Arbuthnot Lane, Bt., ill the "Daily Mail"). Contrary to the generally accepted opinion, the nutritive value of oysters is not extraordinarily high. Analysis shows that about seveneighths of the total weight of an oyster consists of water, which may not even be clean water if the oyster bed is situated in the vicinity of sewage effluent. In most cases, however, precautions are taken to avoid the danger of such contamination and outbreaks of typhoid fever due to eating oysters are now comparatively rare.

Careful experiments have shown that typhoid bacilli, which can be picked up from sewage by oysters and held in an active condition for several days, can be washed out by steady currents of salt water, such as are found in properly planned oyster beds.

Of the remaining one-eighth part of solid matter, roughly one-half, or onesixteenth of the original weight of. the oyster, consists of nitrogenous substances. Part of these are proteins or flesh-forming material, part are degradation products of the proteins, compounds of lower nutritive value. As a source of protein, however, oysters are surpassed by other kinds of fish, notably herrings, eels, cod and haddock, as well as, of "course, by most meats and dairy products.

After making these rather derogatory remarks, it is only fair to consider the other side of the case.

While the actual food value of oysters is not high, the constituents which are present are readily digested, provided that the usual custom be adopted and the ovsters eaten raw, and no alcohol be taken. It has been found that the stomach can entirely dispose of a reasonable amount of oysters in less than two hours, or little more than half the time taken to deal with an average meal. This rapid digestibility is due to the fact that the carbohydrate in oysters is present in the relatively simple form of glycogen, the same compound as is, found in the human lher and muscles. Not for Diabetics. In cases of dyspepsia, where the digestion of starch presents a difficulty, glycogen (obtained either from oysters or other shellfish, or from liver or from yeast) may be a very valuable food constituent. About one-thirtieth of the total weight of an oyster consists of glycogen. It may be advisable to add a word of warning in regard to the use of oysters by diabetic patients. While fish foods in general contain practically no carbohydrate, and are therefore acceptable articles of diet,' oysters, by reason of their glycogen, must only be taken by diabetics with caution, under the direction of the medical adviser. Since oysters are eaten raw, they contain the salts which are so often removed from other food in the processes of cooking. The vitamin content of oysters, so far as i 3 known, is of little importance. Scientific investigation broadlv confirms the generally accepted new that the chief value of oysters lies in their palatability and ready .digestibility.