For Cancer Prevention it's Best Not to Drink Alcohol.


The International Agency for Research on Cancer (IARC) has classified alcohol as a group 1 carcinogen. This is the risk category and means that there is ‘convincing evidence’ that alcohol causes cancer in humans. The strongest evidence is for to cancers of the mouth, throat, larynx (voice box), oesophagus (squamous cell carcinoma), liver, colorectum (bowel), stomach, and breast (pre- and post-menopause).

There is no safe level of alcohol when it comes to cancer. Simply put, the risk of alcohol-related cancers increases the more you drink. And the less alcohol you drink, the lower your risk of these cancers. Drinking no alcohol at all offers the best possible protection against alcohol-related cancers. The cancer risks from alcohol are the same regardless of the type of alcoholic beverage consumed (wine, beer, spirits, etc). It is the ethanol, or pure alcohol, rather than any other ingredient of the alcoholic beverage that causes cancer.


Alcohol increases the risk of cancer in a number of different ways. Firstly alcohol is a carcinogen. It is converted in our bodies to a toxic chemical called acetaldehyde. This can cause cancer by damaging our DNA and stopping cells from repairing the damage. Alcohol can also increase the levels of some hormones, such as oestrogen, which particularly increases the risk of breast cancer.


Yes, more than you might imagine. According to the National Cancer Control Programme, 900 people are diagnosed with alcohol-related cancers every year in Ireland, and some 500 people will die from these diseases. Alcohol is responsive for 1 in 8 breast cancers in Ireland. The proportion of alcohol-related deaths from cancer in Ireland is higher than the European average, and rates in Europe are the highest globally.

In Irish men, the majority of alcohol-related cancer deaths occur due to cancers of the mouth, throat and larynx. The risk of developing these cancers is far greater in those who smoke and drink, compared to those who do one or the other.

In women, most alcohol-related cancer deaths occur due to breast cancer. Irish women are now drinking more alcohol, more often, than previous generations, and it is having very real cancer implications. Consuming just one standard drink per day (e.g. one small glass of wine) is associated with a 9% increase in the risk of developing breast cancer, compared to non-drinkers. Consuming 3 to 6 standard drinks per day increases the risk of breast cancer by 41%, compared to a non-drinker. A full bottle of wine at 12.5% alcohol contains about 7 standard drinks, meaning the risk of developing breast cancer is significantly increased in women who consume the equivalent of a half bottle of wine, or more, daily.


There is evidence that modest amounts of alcohol may reduce the risk of coronary heart disease in people who are already at some risk (e.g. in older adults with high cholesterol). For these people, there is a recommendation to take modest amounts of alcohol daily where there is no risk of addiction (although the benefits are not considered strong enough to encourage non-drinkers to take up alcohol). This is not the case for cancer. Because of the strong scientific evidence that drinking all types of alcoholic drinks can increase your risk of cancer, it is recommended that individuals do not drink alcohol at all.


Ideally in terms of cancer prevention zero alcohol consumption is best. However, for those that choose to drink, staying within the low-risk weekly guidelines for alcohol consumption could prevent over half of all alcohol related cancers in Ireland. The guidelines are:

  • For men, no more than 17 standard drinks spread out over the course of a week, with at least 2-3 alcohol-free days
  • For women, no more than 11 standard drinks spread out over the course of a week, with at least 2-3 alcohol-free days

In Ireland, one standard drink contains around 10g of ethanol, or pure alcohol. Here are some examples of one standard drink:

  • A pub measure of spirits (35.5ml)
  • A small glass of wine (100ml)
  • A half pint of normal-strength beer
  • An alcopop (275ml bottle)

For those individuals drinking more than this at present, aiming to meet these guidelines would be a great start. In terms of cancer risk, however, it would be better still to reduce our alcohol consumption to levels below this.

Alcohol has long been a part of Irish culture. We use it to celebrate, to relax and to commiserate. A shift in this culture is unlikely, but it’s important that we are aware of the extent of the alcohol and cancer relationship. Then, at least, we have the choice to reduce our intake and give ourselves a better outlook in terms of cancer risk. So, why not offer to be the designated driver on a night out? Or try a lower-strength beer or wine? Or a tasty spritzer or shandy? Your body will thank you in the long term for it.