Is it ok to drink 7up while breastfeeding?

I've been craving soda for SO long but I've been really afraid of making my 6 month old have a sore tummy. Since 7up has no caffeine is it ok to drink? How much would you say is ok per day? I've heard things about high fructose corn syrup being transferred to breast milk and that being bad for babies development? How often do you momma's drink soda per day?