White wine is more acidic than red wine, and drinking it frequently may erode enamel, according to researchers at Johannes Gutenberg University (Germany). Riesling wines are the worst in this regard, as they are the most acidic.
To minimise the effect, they recommend eating cheese at the same time (contains calcium, which counteracts the acid's attack). Conversely, eating strawberries at the same time, makes matters worse, as strawberries are also slightly acidic. It is also worth waiting at least half an hour before brushing teeth afterwards, as it gives time for the enamel to recover before it is brushed away.
(BBC Online) | For further info...