When it comes to drinking, less is really more. By Dawn Chen
Photo: Cathy Yeulet / www.123rf.com
To drink or not to drink? That is the question, but the answer isn’t always easy to swallow. It’s no surprise that heavy alcohol consumption is damaging, but growing evidence shows that sticking to safe levels isn’t totally risk-free either. “The link between alcohol and cancer is related to the volume of alcohol consumed. As such, the lower the volume the better,” says Dr Tan Yu Meng, consultant surgeon, Mount Elizabeth Hospital. “Abstinence is the best. And for people who do not drink, there is no benefit to starting.”
According to the World Health Organization, alcohol is listed as a Group 1 Carcinogen, putting it in the same high-risk category as cigarette smoke and the hepatitis virus. What’s more worrying is that new scientific evidence also links regular drinking to an increased risk of developing seven different types of cancer – mouth, throat, airway, oesophagus, liver, breast and colorectal cancers.
So, how exactly does alcohol harm your body, and why does it increase your risk of getting cancer? Dr Tan explains below:
Alcohol and its by-products as a direct carcinogen
Consuming alcohol induces the production of reactive oxygen species (ROS), a by-product that directly damages your DNA and cells. This then triggers a repair process that leads to an increased likelihood of DNA changes and mutations, which ups your odds of cancer.
As the alcohol is ingested, it is broken down by bacteria. One of the by-products of this process is a toxic chemical called acetaldehyde. This chemical also damages DNA and prevents repair, increasing the risks of colorectal cancer.
The by-products of alcohol are also broken down in the liver. This leads to a condition called liver cirrhosis where the liver undergoes inflammation and repairs itself by scarring. During this process (where the liver tries to repair itself), mistakes in the repairing occur and can also lead to cancerous changes.
Alcohol affects the uptake of important nutrients
Alcohol is known to impair the body’s ability to absorb and break down a variety of nutrients and vitamins. For example, folate and vitamin B are important vitamins which the body requires to produce healthy cells and repair DNA. It is common to find low levels of such vitamins in the blood of moderate and heavy drinkers. Other important vitamins that may be affected include Vitamin A, vitamin C, vitamin E and carotenoids.
Alcohol affects blood hormone levels
Alcohol increases the level of hormones – such as oestrogen – in the blood. These hormones act as messengers in our body to regulate cell division. Increased levels of oestrogen can increase the risk of breast cancer in women.
Alcohol and cigarette smoking
The risk of cancer in patients who drink and smoke appears to have a multiplying effect – both carcinogens appear to work in synergy to cause damage. Alcohol makes it easier for the cancer-causing chemicals of tobacco smoke to be absorbed (especially in the mouth, throat and oesophagus) to cause damage. Frequently smoking and drinking puts you at the highest risk of developing cancer.
Alcohol and weight gain
Alcohol is highly calorific and may contribute to weight gain. Being obese and overweight is known to increase the risk of many cancer types, and this may also indirectly lead to cancer.