This question has become more interesting than I thought after doing a quick google search. Generally fruit is already considered as a plural, e.g. "have some fruit" "that's alot of fruit", never "have some fruits", or "that's alot of fruits". Fruits is used when you allude to the existence of more than one kind of fruit, e.g. "Fruits of the field", "Banana, apples and other fruits", or as a verb "the apple tree fruits this time of year". However, there are many that argue that fruits can be used as the plural. Im not sure if this depends on your location or whether some people are just confused, but I would stick with fruit for conventions sake :)
In standard English, "fruits" refers to a collection of several different kinds of fruit (and is very uncommon, usually used only to disambiguate), whereas "fruit" refers to a single item of fruit OR a quantity of fruit as a sort of mass volume. If I go to a fruit stand and buy a peach, a pear and a bunch of grapes, and someone asks me what I'm eating, I will say "I'm eating fruit" because I would consider it a sort of singular collective mass of fruit-product. If I were French I would say "I'm eating fruits" because I would consider the pieces as individuals. The other way to use "fruits" in English is to refer to a result, as in "the fruits of her labour".
Lydia etc. I tell you why, it's simple, we the "He" guys wether things, animals, or humans are just better and if it is not necessary, we won't let anyone know that a few "she" infiltrated the group and may devalue it. All the "she" upthere, consider yourself lucky we're covering for youz! "MCP"always right !