It is of prime importance that fruit be allowed to get as ripe as possible, so that much sugar will be formed in it. In no case should unripe fruit be eaten, because it contains more acids and cellulose than the ripe fruit and has a prejudicial effect upon the digestive processes. When fruit is plucked before it is ripe, it may subsequently ripen when kept in storage, but its taste will always remain inferior and it will be more difficult to digest. In gathering fruit it must be handled carefully, for when the skin is damaged a path is opened for the penetration of many minute living organisms and the consequent occurrence of decomposition. Fruit of this kind should not be eaten, and in any case fruit should always, if at all possible, be washed or cleaned, so that the bacteria which are often present in large numbers on fruit that has been standing in the streets, or in the dust and dirt elsewhere, may not be swallowed along with the fruit when it is eaten. Sartori found harmful bacteria upon fruit which had previously been twice washed. Owing to the quantity of acid contained in some fruits it would be well to wash out the mouth after having eaten much of them; some alkaline mouthwash is best used for this purpose, having also a protective action for the teeth. When one is taking acid fruits, foods containing much starch, such as cakes, floury foods, bananas, etc., should not be eaten at the same time, since acids prevent the sweetening action of the saliva upon the starches, and have an unfavorable influence upon their digestion. Bananas belong rather with the dried fruits, such as figs, raisins, etc., than with the berries. The seeds of fruits should never be swallowed. While the tiny seeds of strawberries or figs can hardly be considered injurious, it is quite different with cherry pits or plum stones. Even they might perhaps not bring on appendicitis, but occasionally large numbers of cherry stones have caused death. I know of the case of a little girl whose young life was cut short in this way. The entire intestine was found choked up with masses of cherry stones.
A plum stone may also sometimes cause great injury. It gives rise to accumulations of calcareous matter around the stone, forming concretions of great hardness which are found at operation and when cut open disclose the fruit stone in the middle. During life these stones give rise to intestinal colic occurring at intervals and causing very severe pain. Such obstructions may remain for a long time, even many years, in certain localities in the intestinesin a sinus or pouchwithout being expelled. The use of fruit in the raw state is suitable only for healthy stomachs and intestines ; other-wise fruit should first be cooked. With a healthy stomach it is better to eat fruit with the skin, as in this way more salts and ethereal principles are absorbed.
It is very healthful to eat fruit, and in the winter, when it is difficult to obtain any other fresh fruits, apples and oranges will always do good service. Many fruits, such as pineapples, bananas, and peaches, and other fruits that grow in climates like ours, come from countries such as Australia, the Cape Colony, or South America, where there is summer weather while we are enduring the rigors of winter. When using fruits we may always expect a better action of the bowels, for most fruits produce this effect, either through the cellulose contained in them or sometimes because of the small seeds which excite the intestines to action, or possibly owing to the sugar or acids contained in the fruit. The acid content also alkalinizes, the blood, since the acid compounds of the salts are converted into carbonates of the alkali metals during the process of combustion.
Gout is thereby favorably influenced, as it is also by the increased activity of the urinary system. The formation of uric acid concretions in the kidneys and bladder is prevented. Owing to this alkalinizing property of fruit its use is indicated in cases where a diet rich in meat and leguminous vegetables is indulged in and acid urine is formed, as, in fact, whenever acids are formed in the body, particularly in severe cases of diabetes. In such instances the fruit-sugar may also have a beneficial action, as it tends to antagonize the formation of ace-tone. In light cases of diabetes it should be remembered that almost the half of the sugar content of fruit consists of fruit-sugar, which is often much better assimilated than other kinds of sugar. In my last work on diabetes I particularly advised the use of fruit by diabetics. Owing to the properties mentioned the eating of fruit is also often o,f great use in arteriosclerosis, as the fruit juices counteract the abnormal viscidity of the blood. We have already referred to the fact that some skin diseases are much improved by the use of certain kinds of fruit.
We consider it advisable for every one to eat some fruit daily. In the spring, when the cherries ripen, they should be eaten every day as long as the season lasts ; then there are the various kinds of berries ; later, apricots, plums, pears, and peaches, and in the autumn grapes, which can, with a little care, be kept nearly until Christmas time by hanging the bunches up carefully in a storage room,. Hothouse grapes may then come into use; they are available until February or even later, and in June there will again be a fresh crop. Apples are to be had pretty much the whole year round, and oranges as well, except in the autumn.
While referring to the numerous and great advantages of fruit as an article of diet, I must not forget to mention its possible disadvantages. Certain stomachs, particularly those inclined to overacidity, cannot tolerate fruit; but in the cooked form almost anyone can take it without any ill effects. Some fruits, e.g., the strawberry, may in certain persons give rise to skin eruptions. In cases where the urine is alkaline the use of fruit is contraindicated, particularly such varieties as contain much acid; and certain fruits, such as figs, plums, gooseberries, etc., which contain quite an amount of oxalic acid (figs contain, in 100 grams, o.1 gram of oxalic acid), should not be indulged in by persons having oxaluria. Where there is much flatulence, fresh fruits should not be eaten; stewed fruits, such as plums, etc., would be much better.
In view of the very great influence of fruit upon the health of the population in general, it would be desirable that the duties collected on fruits be abolished. The importation of fruit, which is not increasing in this country (Austria), is so slight that the budget is not materially increased by the duties collected, and the improvement in the health of the people would save the country many large expenditures which far exceed the revenue from the duties imposed on fruits.