Lemonade is not safe to drink while on an acid reflux diet, according to WebMD. It is one of the foods that interferes with the function of the esophageal sphincter muscle, which helps keep stomach acid from getting into the esophagus.
People with acid reflux or gastroesophageal reflux disease should avoid lemons, as well, states WebMD. Orange, grapefruit and cranberry juice may also make symptoms worse.
Fruits that are usually safe on an acid reflux diet include bananas, honeydew, cantaloupe and watermelon, states Health. However, eating these fruits can increase reflux in a very small percentage of sufferers, so they should steer clear of these foods.