In the 16th and 17th centuries, many Europeans believed tomatoes were poisonous, because of the plant's relationship to nightshade and tobacco. This misapprehension has been banished, and tomatoes are now eaten freely in Europe as well as the rest of the world. In the past it has also periodically been been believed to be an aphrodisiac?; today, its consumption is believed to benefit the heart.
Botanically a fruit, the tomato is generally thought of--and used--as a vegetable?: it's more likely to be part of a sauce or a salad than eaten whole as a snack, let alone as part of a dessert.
Used extensively in Italian cuisine, the tomato has an acidic property that is used to bring out other flavors.