Alcohol and Cancer

Perhaps no illness is more feared in the developed world than cancer as few direct causes have been identified, with the exception of cigarette smoking. However, research is increasingly showing that obesity, poor diet, lack of exercise and heavy alcohol consumption increase our risk of contracting cancers of several kinds.

Alcohol and cancer is a sensitive area, and certainly there is an increased risk of many cancers if consumers regularly drink more than moderately (30g a day in most cases), including colorectal and cancers of upper digestive tract  (especially if you smoke). Much evidence now shows that risk of breast cancer and alcohol use is linear (i.e. some increase of risk at any dose, especially if overweight or if you eat a diet low in folate).

Scientists don’t know exactly why alcohol may increase the risk of developing some cancers, but research indicates that the following play a part:

• Acetaldehyde - As alcohol  is metabolised in your body it is converted into a toxic chemical called acetaldehyde which circulates before being broken down into harmless CO2 and water. Acetaldehyde can damage your DNA and stop your cells from repairing that damage, which could lead to cancer.
• Oestrogen and other hormones - Alcohol can increase the levels of some hormones, such as oestrogen, testosterone and insulin. The risk of some forms of breast cancer, for example, can be increased when there are unusually high levels of oestrogen.
• Liver Cirrhosis - Cirrhosis of the liver, a result of heavy drinking, makes you more vulnerable to liver cancer.
• Folate - Folate is an important vitamin found in whole grain cereals and green leafy vegetables that helps our cells produce new DNA correctly. Some studies have found that cancer is more common in people with low levels of folate in their blood.

However, the diseases where alcohol poses ‘significant risk’ at moderate levels of consumption are rare with the exception of breast cancer and for drinkers who also smoke.

For example: ‘Alcohol As A Cause Of Cancer’ published by the Australian Cancer Institute in 2008 concluded that moderate alcohol consumption two drinks of alcohol (10g) per day does not increase the risk of cancer in general. However, four drinks per day increases the risk of cancer by 22%. High alcohol consumption (8 daily drinks) increases the risk of cancer at any site by 90%. Evidence is clear, that alcohol is carcinogenic for some types of cancer, and that the risk is dose dependent.

The full 500+ page report is available at: Cancerinstitute.org.au/cancer_inst/publications/pdfs/ pm-2008-03_alcohol-as-a-cause-of-cancer.pdf

As part of its guidelines on Nutrition and Pysical Activity for CAncer Preventio, The American Cancer Society "Recommends that people who drink alcohol limit their intake to no more than 2 drinks per day for men and 1 drink per day for women. The recommended limit is lower for women because of their smaller body size and because their bodies tend to break down alcohol more slowly. These daily limits do not mean it's safe to drink larger amounts on fewer days of the week, which can lead to health, socail and other problems.

Alcohol use has been linked to several types of cancer and other health risks, but this is complicated by the fact that low-to-moderate alcohol intake has been linked to a lower risk of heart disease. Still, lowering the risk of heart disease is not a compelling reason for adults who don't drink alcohol to start"

www.cancer.org/cancer/cancercauses/dietandphysicalactivity/alcohol-use-and-cancer

There have been few studies describing the relation between varying levels of alcohol consumption and the total risk of cancer. A paper published in the annals of oncology in May 2013 presents a meta-analysis that relates alcohol consumption to all-cancer mortality; it was based on almost 50,000 deaths reported in the literature from 18 prospective cohort studies. As expected, the reported average consumption of 50 or more grams of alcohol per day (equivalent to 4 or more typical drinks each day) was associated with an estimated 32% increased risk of dying from cancer, But, surprisingly, the analyses demonstrated a J-shaped curve for alcohol and cancer. Light drinkers (12g a day) showed a statistically significant 9% lower risk, moderate drinkers showed no effect, while heavier drinkers showed a 32% increased risk of all cancer mortality.

Reference: Jin M, Cai S, Guo J, Zhu Y, Li M, Yu Y, Zhang S, Chen K. Alcohol drinking and all cancer mortality: a meta-analysis. Ann Oncol 2013;24:807-816. doi: 10.1093/annonc/mds508.Y, Zhang S, Chen K. Alcohol drinking and all cancer mortality: a meta-analysis. Ann Oncol 2013;24:807-816. doi: 10.1093/annonc/mds508.

Breast Cancer (Click for more information)

Drinking and smoking combined

Smoking and drinking together greatly increases your risk of developing throat and mouth cancer than doing either on their own. That’s because when you drink alcohol it’s easier for the mouth and throat to absorb the chemicals in tobacco that cause cancer. 

It’s also true with oesophageal (gullet) cancer. One study found that people who drank up to five units of alcohol and smoked up to eight cigarettes per day could increase their risk of oesophageal cancer between 13 (for men) and 19 times (for women).

Further information

Cancer statistics for the US

Lung, breast, colorectal and prostate cancer are the most common types of cancer in the United States. About 1,658,370 new cancer cases are expected to be diagnosed in 2015 and about 589,430 Americans are expected to die of cancer in 2015. Of new cases for men, Prostate (26%),  Lung & bronchus (14%) and Colon & rectum (8%) and Urinary bladder cancer  (7%) are the most common. For women, the most prevalent sites are the breast  (29%), Lung & bronchus (13%), Colon & rectum 63,610 (8%) and Uterine corpus  (7%).

Read more:

cancer.org/acs/groups/content/@editorial/documents/document/acspc-044552.pdf

The American Cancer Society cancer.org

Please visit the gateway to sensible drinking and health, alcoholinmoderation.com for specific studies and summary papers.

Your doctor can help you figure out if you should make any changes in your drinking, and offer help and advice along the way.