London - The world is addicted to Coca-Cola. Each day, 1.6 billion cans and bottles of the drink are gulped down, making it the world’s most recognised brand.

But ever since it was first concocted in 1886, the makers of Coca-Cola have been secretive about what goes into their drink. American pharmacist and Coke founder Asa Chandler was so concerned that the recipe could fall into the wrong hands that he reportedly never wrote it down.

That secrecy lives on today. Coca-Cola insists only two people alive know the formula; that they never travel on the same plane in case it crashes; and that the list of ingredients is locked in a bank vault.

But the company found its formula under less welcome scrutiny recently. For it has emerged that Coca-Cola in the US has reduced levels of one of its ingredients following fears that it could cause cancer.

The company has also pledged to reduce its levels in Coke sold in the rest of the world, although it hasn’t given a timescale.

The chemical – 4-methylimidazole (4-MI) – helps to give the drink its colour, but is listed by Californian health officials as a potential carcinogen.

Pepsi, meanwhile, has reduced the quantity of 4-MI in its American formula, but has refused to change it elsewhere.

Coca-Cola and Pepsi have insisted that all of their beverages are completely safe, with Coca-Cola claiming it made the change in the US only in response to a “scientifically unfounded” food law in California.

Changes to the recipes have raised the inevitable question: just how safe are the ingredients that go into every can of cola?


Cola’s colour comes in part from4-MI that forms in the production of caramel food colouring.

After studies showed that long-term exposure to the chemical causes lung cancer in rats, California health officials ruled that products with more than 29mcg must carry a health warning.

And when cans were found to contain nearly 140mcg, all cola companies across the US were forced to cut levels.

Food campaigners say that daily consumption of 4-MI at 30mcg would cause cancer in one in 100 000 people over their lifetimes.

The US Food and Drug Administration (FDA) says that someone would need to drink more than 1 000 cans of cola every day to reach the levels that caused cancer in lab rats.


A can of cola contains 40mg of caffeine, a stimulant that works on the central nervous system. It can trigger a dramatic, short-lived increase in blood pressure and increases the heart rate.

But there is little evidence that it causes long-term high blood pressure, or that it is bad for healthy hearts. Many regular coffee or cola drinkers simply develop a tolerance to the stimulant.

Caffeine can also stop the body from absorbing iron from food – so people with a big cola habit may be at greater risk of iron deficiency.


Doctors are in no doubt – the biggest danger from cola comes from sugar. Too much leads to obesity. It also increases the risk of type 2 diabetes, causes heart disease and increases the risk of stroke.

The over-consumption of sugar has been linked to depression, poor memory formation and learning disorders in animal experiments. And it rots teeth.

Each can of cola contains eight teaspoons of sugar.


Phosphoric acid is a clear, odourless chemical that gives cola its tangy flavour and helps cut through the sickly sweetness of all that sugar. It is also an effective rust remover – the reason that a glass of Coke can restore the lustre to coins and old metal.

But it can also disrupt our bodies.

Research at the US National Institutes of Health in Maryland found that drinking two or more colas a day doubled the risk of kidney stones – and the phosphoric acid in it was blamed.

Another US study found that women who regularly drink cola – three or more times a day – had a 4 percent lower bone mineral density in their hips than women who didn’t drink cola. Again, phosphoric acid is thought to be the cause.


Citric acid gives lemons, oranges and grapefruit their kick and cola its bite, helping to make the drink nearly as corrosive as battery acid when it comes to teeth. Prolonged exposure to cola and other fizzy drinks strips tooth enamel causing pain, ugly smiles and – in extreme cases – turning teeth to stumps.

A study in the journal General Dentistry found that cola is 10 times as corrosive as fruit juices in the first three minutes of drinking.

The researchers took slices of freshly extracted teeth and immersed them in 20 soft drinks. Teeth dunked for 48 hours in cola and lemonade lost more than 5 percent of their weight.

A study in the British Dental Journal found that just one can of fizzy drink a day increased the risk of tooth erosion, while four cans increased the erosion risk by 252 percent. – Daily Mail