A 31-year old woman's heart problems and fainting might have had something to do with the fact that she drank only soda for about half her life, according to a report of her case.
The woman, who lives in Monaco, a small country near southern France, was brought to a hospital after she fainted. A blood test showed she had severely low potassium levels. And a test of her heart's electrical activity revealed she had a condition called long QT syndrome, which can cause erratic heart beats.
The woman did not have a family history of heart or hormone problems. But she told her doctors that, since the age of 15, she had not drunk any water — soda (specifically cola) was the only liquid she consumed. She drank about 2 liters (2 quarts) of cola daily, she said.
After abstaining from soda for just one week, the woman's potassium levels and heart electrical activity returned to normal.
Drinking too much cola may cause excess water to enter the bowels, which in turn leads to diarrhea, and loss of potassium, the researchers said. High amounts of caffeine can also increase urine production and decrease potassium reabsorption, the researchers said. Potassium plays a role in helping a person's heartbeat, and low levels of potassium may cause heart rhythm problems.
After searching for other similar cases, the researchers found six reports of excessive cola consumption that were thought to be related to adverse medical problems, including heart rhythm problems.
"One of the take-home messages is that cardiologists need to be aware of the connection between cola consumption and potassium loss, and should ask patients found to have QT prolongation about beverage habits," said study researcher Dr. Naima Zarqane, of Princess Grace Hospital Centre in Monaco.
Future studies should examine whether those who drink cola excessively have lower potassium levels than people who don't drink cola, the researchers said.
Excessive soda consumption can also lead to weight gain, which is a risk factor for heart disease, the researchers said.
The case report was presented this week at the European Heart Rhythm Association meeting in Athens, Greece. It has not been published in a peer-reviewed journal.