It’s official: alcohol is carcinogenic. So why doesn’t New Zealand follow other nations in doing more to reduce its harms?
Global health authorities have known for decades that alcohol increases the risk of cancer. This was reinforced by the World Cancer Research Fund warning earlier this year that women should drink no alcohol to reduce the risk of breast cancer.
New Zealand Ministry of Health guidelines for safe drinking are far higher than the six glasses a year that pose minimal risk for breast cancer. The guidelines say men should have no more than 15 standard drinks a week and women 10.
It is unfortunate the alcohol industry appears to have played a part in influencing the Ministry of Health guidelines and potentially other government policies on alcohol.
Other nations including Australia, the United Kingdom and Canada have set lower safe-drinking guidelines in response to recent research on the links between alcohol and cancer. Canada has a safe limit of two drinks a week.
New Zealand’s safe-drinking guidelines clearly need to be reviewed. South Korea requires cancer warning labels on alcohol and these will be introduced in Ireland next year. That has prompted New Zealand winemaker Villa Maria to include cancer warnings on its exports to Ireland – a good sign it is taking a responsible approach to the relationship between alcohol and cancer.
New Zealand should be requiring labels on all alcoholic beverages to make everyone aware alcohol is carcinogenic. For many years, studies have consistently and strongly linked alcohol with cancers of the breast, mouth, throat, voice box, oesophagus, liver, stomach, colon and rectum.
The scientific consensus is unequivocal: alcohol is classified as a group 1 carcinogen for which there is sufficient evidence of its cancer-causing effects in humans. This places alcohol in the same category as such carcinogens as asbestos, tobacco, UV light, processed meats, air pollution and certain viruses.
Our bodies convert alcohol into a known carcinogen, acetaldehyde, and alcohol causes inflammation, which is a precursor for cancer.
The links between breast cancer and alcohol are particularly strong, with about 8% of breast cancers in women attributable to drinking. The more alcohol drunk the higher the risk, and postmenopausal hormone changes make women especially vulnerable.
Women have an 11% chance of getting breast cancer in their lifetime. Alcohol raises the lifetime risk to about 12% and perhaps 15% for heavier drinking. Compared with her non-drinking peers, the postmenopausal woman who downs two bottles of wine a week is at much greater breast-cancer risk.
Even in small amounts, alcohol damages cells, raises oestrogen levels, causes weight gain and inflammation and produces DNA-damaging toxins, all of which lift breast cancer risk. Unfortunately for many wine-lovers, one glass of wine with dinner is probably one too many if you want to do everything possible to dodge cancer. Zero alcohol is the safest level for cancer prevention. Cancer risk factors such as ageing and genetics can’t be changed, but research suggests a healthy lifestyle can cut cancer rates by a third.
I’m not a teetotaller – I even helped Heineken develop a genetic taste-testing kit – but I am cutting back on alcohol based on the growing information about the cancer risk.
It’s time to take the tools developed for fighting smoking harms – including public-awareness campaigns, prominent cancer warning labels on drinks and fewer liquor outlets – into the battle against alcohol’s toll. A sober-friendly society would certainly be one with less cancer.
Professor Andrew Shelling is a director of the Centre for Cancer Research/Te Aka Mātauranga Matepukupuku at the University of Auckland.
