Excessive consumption of cola or honey can cause unusual fainting.

Researchers in a new study has said that drinking excessive amount of cola and eating honey made from the pollen of Rhododendrons can cause unusual syncope (fainting) and symptoms of arrhythmia.

The researchers told the EHRA EUROPACE 2013 meeting in Athens about an unusual case of what is called “mad honey poisoning” in two patients they had treated as well as the case of a woman with developed potentially life threatening arrhythmias caused by excessive consumption of cola drinks.

The father and son from Turkey developed heart-related symptoms after eating honey from the Black Sea region. Both father and son were admitted to the Izmir emergency department at the same time with symptoms of vomiting and dizziness. Heart traces known as ECGs revealed they had potentially dangerous heart rhythm disturbances.

Mad honey poisoning occurs when people consume honey contaminated with grayanotoxin, a chemical contained in nectar from the species rhododendron ponticum and luteum. Grayanotoxin interferes with chemical messages in the body - in this case, the heart.
Although very rare, Dr Ugur Turk, who treated them, said wide distribution of honey around the world meant that physicians anywhere could potentially be faced with honey poisoning .

He said anyone buying honey from Turkey - and particularly the Black Sea area where bees feed on rhododendrons - might want to first consume a small amount and leave it a few days before eating any more to check strange side effects.

Researchers at the meeting also reported how excessive consumption of cola drinks resulted into unusual life threatening fainting and symptoms of irregular heartbeat, also known as arrhythmia in a 31- year-old woman.

When they took a medical history, the clinicians discovered that since the age of 15, the patient had exclusively replaced water with cola drinks.

A search revealed six other case studies where excessive cola consumption could be related to adverse medical conditions including damaged skeletal muscle tissue, arrhythmias, and even one death related to Torsades de pointes - a form of ventricular tachycardia that can degenerate into ventricular fibrillation.

There are more common causes of arrhythmia, such as stress, caffeine, tobacco, alcohol and certain medications, including some diet pills and cough and cold medicines. Not all arrhythmias are dangerous but if you think you have one, you should get it checked by a doctor. Symptoms include palpitations or awareness of your heartbeat, tiredness, dizziness and fainting.

Professor Andreas Goette, the EHRA Scientific Programme Committee chairperson, said: “The study underlines the importance of clinicians taking detailed medical histories of patients with unexplained arrhythmias and  questions about their dietary intakes.”