(Oct. 3, 2006) -- Down a cocktail made with diet soda and you may end up with a supersize buzz, Australian researchers found. Vodka in their test drinks zoomed into subjects' bloodstreams faster (21 minutes versus 36) and boosted blood alcohol higher (0.05% versus 0.03%) when mixed with diet instead of sugar-sweetened soda. Without sugar to slow it down, alcohol takes the fast train from your stomach to your head.