In part two of my cancer myth-busting series, I’ve searched the Internet for yet more claims of kitchen cancer sources - this time in your drinks. I aim to sort the fact from the fiction in the often sensationalist world of health journalism, to bring you up-to-date and accurate information about what you’re drinking.
“Diet soft drinks cause cancer!”
‘Diet’ soft drinks often contain aspartame, a low-calorie sweetener that is up to 200 times as sweet as sugar. There has been a lot of controversy surrounding this sweetener, which has been added to food/drink products for over 20 years. Many sources claim that when aspartame is broken down in the body, known carcinogens formaldehyde and DKP are formed, which can cause brain tumours and other ill effects.
The main way we ingest formaldehyde is through the air, and most living things also produce small amounts in normal metabolism. In fact, amounts of the compound produced by soft drinks are so low, it is thought that one can of diet cola will result in the production of less formaldehyde than most fruits or – more surprisingly – a single jelly bean sweet. Therefore, it can be concluded that the average person probably doesn’t ingest enough aspartame to produce a particularly worrying amount of formaldehyde.
DKP – or diketopiperizine – is also a known human carcinogen, and has been linked to brain cancers, leukaemia and lymphoma in rats. This study recommended that the daily-recommended limit of aspartame be halved from 40mg/kg body weight to 20mg/kg. However, multiple reviews and studies conducted by the FDA and the EFSA (European Food Safety Authority) have concluded that there is no increased risk of tumours associated with aspartame when consumed at recommended levels.
It is thought that these rumours of the ‘dangers’ of aspartame may have stemmed from a poor scientific study in 1996, which proposed a link between aspartame and brain tumours, and has since been dismissed.
The only people who need be particularly concerned with aspartame intake are those with phenylketonuria (PKU), as aspartame is a source of phenylalanine – which PKU sufferers cannot sufficiently break down.
“Alcohol causes cancer!”
The recommended daily amount of alcohol in the UK is 2-3 units for women and 3-4 units for men, and people who regularly exceed that amount are putting themselves at risk. As well as heart and liver conditions and obesity, seven types of cancers have been linked to excessive alcohol consumption – including liver, bowel, breast and mouth cancers. The connection between alcohol and other cancers, such as bladder, stomach and lung cancers, is still being investigated. In fact, alcohol is cited as the second biggest cause of cancer in the modern world, behind smoking.
Unfortunately for a lot of students, this claim is entirely true. Alcohol is estimated to cause around 4% of cancers in the UK, and it is likely to be a contributing factor to many more. It is known that drinking to excess damages the liver, causing cirrhosis, or the formation of scar tissue. This is a precursor to cancer, and with 11 British citizens dying every day from liver cancer, it is vital that people learn their alcoholic limits.
In addition to liver cirrhosis, alcohol is thought to contribute to tumour growth in other ways. The production of acetaldehyde (related to our old friend, formaldehyde) in our body during the breakdown of alcohol is thought to cause DNA damage, and prevent repairs – meaning an increase in tumour-causing mutations. An increase in hormone production, for example insulin and oestrogen, is also seen in alcohol drinkers. An increase in oestrogen has been linked to the growth of breast tumours in women.
Even more worryingly, it has been suggested that it isn’t just excessive alcohol intake that can damage health. The 2014 World Cancer Report concluded that there really is no such thing as ‘responsible drinking’ where cancer is concerned. Released by the World Health Organisation (WHO) International Agency for Research on Cancer (IARC), a summary of 222 studies suggested that oesophageal and breast cancer is more prevalent in even minimal drinkers. However, risk does increase with alcohol consumption.
In most cancers, the type of alcohol does not seem to have an effect on prevalence of cancer – meaning beers, wines and spirits all pose the same risk. However, in oesophageal cancers hard liquor tends to carry the most risk, as the small protective hairs (cilia) on the surface of the oesophagus are damaged by the high ethanol content.
If the above statistics worry you and you think you may need to change your habits – there is some good news. Decreasing your alcohol intake has been shown to produce quick results, meaning your risk of developing associated cancers will decrease rapidly after you control your drinking. Stopping smoking and eating fruit and vegetables has also been proven to prevent cancers.
To repeat my earlier conclusion: moderation is key to your health. Anything in too high a quantity can be harmful – even water – so it makes sense to regulate what you’re putting into your body. While individually the food and drink discussed in this series may pose small risks, excessive consumption of red meat, canned products, sugar, diet soft drinks and/or alcohol together may present an unnecessary health hazard, and so a balanced diet is recommended for a healthier, longer life.