Doctors issued the warning after noticing an increase in the number of patients suffering from muscle problems, according to the June issue of IJCP, the International Journal of Clinical Practice.
“We are consuming more soft drinks than ever before and a number of health issues have already been identified including tooth problems, bone demineralisation and the development of metabolic syndrome and diabetes” says Dr Moses Elisaf from the Department of Internal Medicine at the University of Ioannina, Greece.
“Evidence is increasing to suggest that excessive cola consumption can also lead to hypokalaemia, in which the blood potassium levels fall, causing an adverse effect on vital muscle functions,” the expert added.
A research review carried out by Dr Elisaf and his colleagues has shown that symptoms can range from mild weakness to profound paralysis. Luckily all the patients studied made a rapid and full recovery after they stopped drinking cola and took oral or intravenous potassium.
The case studies looked at patients whose consumption ranged from two to nine litres of cola a day.
They included two pregnant women who were admitted with low potassium levels.
The first, a 21 year-old woman, was consuming up to three litres of cola a day and complained of fatigue, appetite loss and persistent vomiting. An electrocardiagram also revealed she had a heart blockage, while blood tests showed she had low potassium levels.
The second also had low potassium levels and was suffering from increasing muscular weakness. It turned out she had been drinking up to seven litres of cola a day for the last 10 months.
It appears that hypokalaemia can be caused by excessive consumption of three of the most common ingredients in cola drinks – glucose, fructose and caffeine.
“The individual role of each of these ingredients in the pathophysiology of cola-induced hypokalaemia has not been determined and may vary in different patients,” says Dr Elisaf.
“However in most of the cases we looked at for our review, caffeine intoxication was thought to play the most important role. This has been borne out by case studies that focus on other products that contain high levels of caffeine but no glucose or fructose.
“Despite this, caffeine free cola products can also cause hypokalaemia because the fructose they contain can cause diarrhoea,” the expert added.