One source suggests that, in the year 2005, there were 1.8 million acres of land worldwide cultivating berries, with 6.3 million tons produced.:4   In certain regions, berrypicking can be a large part of the economy, and it is becoming increasingly common for western European countries such as Sweden and Finland to import cheap labor from Thailand or Bulgaria to do the berry picking. This practice has come under scrutiny in the past years because of the low wages and poor living standard for the "berry-pickers", as well as the lack of worker safety. Once ripened, berries are typically of a contrasting color to their background (often of green leaves), making them visible and attractive to frugivorous animals and birds. This assists the wide dispersal of the plants' seeds. Berry colors are due to natural plant pigments, such as anthocyanins, together with other flavonoids localized mainly in berry skins, seeds and leaves. Although berry pigments have antioxidant properties "in vitro", there is insufficient physiological evidence established to date that berry pigments have actual antioxidant or any other functions within the human body. Consequently, it is not permitted to claim that foods containing polyphenols have antioxidant health value on product labels in the United States or Europe. Berries are commonly used in pies or tarts, such as blueberry pie, blackberry pie, and strawberry pie. Berries are often used in baking, such as blueberry muffins, blackberry muffins, berry cobblers, berry crisps, berry cakes, berry buckles, berry crumb cakes, berry tea cakes, and berry cookies. Berries are commonly incorporated whole into the batter for baking, and care is often taken so as to not burst the berries. Frozen or dried berries may be preferable for some baked berry products. Fresh berries are also often incorporated into baked berry desserts, sometimes with cream, either as a filling to the dessert or as a topping. Berries are often added to water and/or juiced, as in cranberry juice, which accounts for 95% of cranberry crop usage, blueberry juice, raspberry juice, goji berry juice, acai juice, aronia berry juice, and strawberry juice. Wine is the principal fermented beverage made from berries (grapes). Fruit wines are commonly made out of other berries. In most cases, sugars must be added to the berry juices in the process of Chaptalization to increase the alcohol content of the wine.