LONDON - Excessive cola consumption causes muscular weakness, fatigue and loss of appetite, a latest research has revealed.

‘Evidence shows excessive cola consumption can also lead to hypokalaemia, in which the blood potassium levels fall, causing an adverse effect on vital muscle functions,’ said Moses Elisaf, professor of internal medicine at University of Ioannina, Greece, who led the study.

‘We are consuming more soft drinks than ever before and a number of health issues have already been identified including tooth problems… development of metabolic syndrome and diabetes,’ Elisaf added

It appears that hypokalaemia can be caused by excessive consumption of three of the most common ingredients in cola drinks - glucose, fructose and caffeine.

A research review carried out by Elisaf and 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.

In a commentary on the paper, Clifford Packer from the Louis Stokes Cleveland V.A. Medical Centre in Ohio, relates the strange case of the ostrich farmer who returned from the Australian outback with muscle weakness.

He had been drinking four litres of cola a day for the last three years and drank up to 10 litres a day when he was in the outback, causing a rapid reduction in his potassium levels.

In 2007 the worldwide annual consumption of soft drinks reached 552 billion litres, the equivalent of just under 83 litres per person per year, and this is projected to increase to 95 litres per person per year by 2012, said a release of the University of Ioannina.

However the figure has already reached an average of 212 litres per person per year in the US.

These findings will appear in the June issue of the International Journal of Clinical Practice.