I love ice cream and wish I could eat nothing else. Except, thinking about it, I wouldn’t. The problem, you see, is that I’m lactose intolerant. After convincing two of my best friends that they, too, are lactose intolerant, I thought I ought to turn this rather unfortunate situation into something productive by writing a scientific article about it.

Lactose intolerance is the inability to digest milk sugar due to lack of the enzyme lactase in the digestive system (usually small intestine). In most mammals the production of lactase stops after weaning, which is why you shouldn’t feed milk to a hedgehog. On consumption of excessive lactose, some of it is not broken down and absorbed. The unabsorbed lactose passes to the colon, where gut bacteria happily start to ferment it. The products of fermentation are short fatty acid chains and large volumes of carbon dioxide (CO2), methane (CH4) and hydrogen gas (H2). These gases give rise to the symptoms of lactose intolerance – abdominal pain, bloating, flatulence, borborygmus (stomach rumbling) and in more severe cases diarrhoea and vomiting.

So how do you know you are lactose intolerant? The most straightforward method is probably the so called 'home self-test', which consists of an overnight fasting followed by ingestion of a large glass of milk. The  procedures that follow for diagnosis should be obvious...

If you find yourself lactose intolerant, do not despair, you are evading the many dangers of milk. The leading cause of death in the Western world is cardiovascular disease, a condition which is worsened by the high cholesterol content of milk. Some studies have also shown a correlation between dairy calcium intake and prostate cancer (6 glasses of milk per day resulted in a significant increase in cancer incidence). Moreover, the milk research community has for some time been debating the possibility of a link between autistic symptoms and consumption of milk, a debate which was recently brought back into the spotlight by a Danish family that wrote a book about how they diminished the symptoms of their autistic son by removing milk from his diet. And if I still haven’t convinced you how evil milk is, then what about the link observed by some studies between milk drinking and acne?

However, if you don’t want to switch to soy milk due to the high phytoestrogen content (which is another story), or because you don’t like the flavour, you might still be able to acquire some milk tolerance. There have been suggestions that regular ingestion of small quantities of lactose may reduce the symptoms by 'training' the bacteria in your large intestine to break down lactose more efficiently without producing as much gas. It’s not quite clear how you’d convince the bacteria to produce less gas rather than carry on with fermentation as before. Nevertheless, this finally gives us (lucky lactose intolerant individuals) a reason to eat ice cream! Let’s celebrate this over a glass of chocolate milk (apparently better tolerated than plain milk according to The Dairy Council)!

Gengshi Chen is a second year NatSci at Selwyn who is currently in negotiations with her gut bacteria.