As soon as you bite into a sweet fruit the stomach goes into sodium bicarbonate production to fill up the salivary glands with alkaline buffers to buffer the fruit sugars. To continue this practice will cause depletion of alkaline buffers, over-stress the stomach with hydrochloric acid and compromise the alkaline pH of the small intestines leading to serious illness.
A raw foodist or fruitarian can get away with this practice for awhile but sooner or later will pay a high price in their health for their over-indulgence of acidic sweet fruit.
I have found that anyone who is eating sweet fruit daily will have anemic-yeasty blood as seen in the phase contrast micrograph above.
My recommendation: eat sweet fruit sparingly and only in the season thereof. The best scenario is to eliminated all sweet fruit, especially if you are dealing with a serious illness.
Here are the fruit which should only be eaten in the season thereof and in moderation. If one is dealing with a serious symptomology these high sugar fruit should be completely avoided. Here is the list of acidic fruit to avoid: apples, oranges, bananas, berries, pineapple, mango, Thai coconut, honey dew, watermelon, cherries, grapes, kiwi, dates, and dried fruit. The fruit which can be eaten freely are cucumbers, lemon, lime, avocado, peppers, cantaloupe and grapefruit.
source :articles of health