Most people know that indulging in too many alcoholic drinks is bad for the liver. But did you know that regular drinking is also linked with the risk of developing seven types of cancer?
A study published in scientific journal Addiction found the link in July last year and sparked concern in those who enjoy having a tipple.
AsiaOne speaks with Dr Tan Yu Meng, consultant surgeon at Mount Elizabeth Hospital to learn more about alcohol-related cancer.
1. What is the recommended alcohol limit for an adult man/woman?
The recommended limit for alcohol drinking varies depending on the country.
Singapore's Health Promotion Board recommends no more than two standard drinks for men and one standard drink for women per day.
A standard drink is a can of beer (330ml), a glass of wine (175ml), or a nip of spirit (35ml). A person should also not drink alcohol for at least one to two days every week.
However, this is a liberal recommendation.
In Jan 2016, the UK's department of health recommended 14 units per week of alcohol for men and women, which is roughly equivalent to one standard drink daily.
The alcohol limit should be similar and get more stringent as a person gets older.
2. What are some of the signs/symptoms that a person should reduce or stop drinking?
This question doesn't really pertain to cancer but rather to addiction to alcohol or alcoholism.
The signs of the various cancers are wide-ranging so it is not possible to list them.
The effects of alcoholism are both social and physical.
Common physical symptoms include insomnia, depression, gastrointestinal disturbances, non-proportional weight gain or weight loss, fatigue, and sexual impotence.
3. Are people with certain drinking habits such as regular drinking, binge-drinking more at risk of developing cancer?
There is now strong scientific evidence that drinking alcohol regularly is linked with the development of seven types of common cancer.
Alcoholic drinks are listed as a Group 1 Carcinogen by the World Health Organisation International Agency for Research on Cancer (IARC) - and carry the highest cancer risk along with cigarette smoke and the hepatitis virus.
They can cause some of the top 10 cancers in Singapore which include cancers of the mouth, throat, airway, oesophagus, liver, breast, and bowels.
4. Does higher alcohol content in drinks such as hard liquor, wine, or beer increase a person's chance of developing cancer?
The link between alcohol and cancer is related to the actual volume of ethanol consumed and not the type of alcohol.
All types of alcohol will increase a person's risk of developing cancer.
The alcoholic drinks of choice in Singapore are beer (45 per cent), wine (36 per cent) and spirits (14 per cent), according to the Ministry of Health's National Health Survey.
These contain different quantities of alcohol and they are often stated on the can or bottle consumed in terms of per cent ethanol or alcohol.
Here's how to calculate the actual volume of alcohol in a drink: multiply the actual volume consumed in millilitres with the per cent alcohol. For example, a glass of wine is 175 ml (14 per cent alcohol) is 24.5gm of alcohol and a pint of beer of 565ml (5 per cent brew) is 28.3gm of alcohol.
5. Are there people who are genetically predisposed to developing alcohol-related cancer?
Some Asians of Chinese descent have a variant of the gene that metabolises alcohol, a defective form of ADH (alcohol dehydrogenase) or ALDH2 (acetaldehyde dehydrogenase).
This variant gene is 'superactive' and can speed up the conversion of alcohol to acetaldehyde - a toxin that promotes cancer.
In these people, drinking leads to unpleasant side effects like uncomfortable facial flushing and palpitations.
As many of them are unable to consume moderate to large amounts of alcohol, they have very low risk of developing alcohol-related cancers.
But if they drink persistently, these people can become tolerant of the side effects and in turn have higher risks of developing alcohol-related cancers of the head, neck, oesophagus and pancreas.
6. How should a heavy/habitual drinker go about reducing his/her alcohol intake? For smokers, there are nicotine patches, is there anything similar for heavy drinkers?
There are no magic pills to make a person stop drinking.
But psychiatrists who treat alcoholics may prescribe drugs such as Antabuse (disulfiram), Naltrexone and Baclofen, which makes a patient's stomach feel upset when he drinks, and reduce alcohol cravings respectively.