Are there any drawbacks to oral bergamot ingestion?

There has been one case report of negative side effects from bergamot oil ingested orally. Muscle cramps, muscle twitches, and reduced visual acuity were reported in a man who drank up to 4 liters (about a gallon) of Earl Grey tea, a bergamot-infused tea, each day. His symptoms resolved when he switched to black tea and stayed away as long as he kept his Earl Grey consumption under a liter a day.^[1]