Alcohol and Cancer Risk

Byron's Comments:

The primary toxin of alcohol, acetaldehyde, increases cancer risk.

Study Title:

Carcinogenicity of acetaldehyde in alcoholic beverages: risk assessment outside ethanol metabolism.

Study Abstract:

Aims In addition to being produced in ethanol metabolism, acetaldehyde occurs naturally in alcoholic beverages. Limited epidemiological evidence points to acetaldehyde as an independent risk factor for cancer during alcohol consumption, in addition to the effects of ethanol. This study aims to estimate human exposure to acetaldehyde from alcoholic beverages and provide a quantitative risk assessment.

Methods The human dietary intake of acetaldehyde via alcoholic beverages was estimated based on World Health Organization (WHO) consumption data and literature on the acetaldehyde contents of different beverage groups (beer, wine, spirits and unrecorded alcohol). The risk assessment was conducted using the European Food Safety Authority’s margin of exposure (MOE) approach with benchmark doses obtained from dose–response modelling of animal experiments. Life-time cancer risk was calculated using the T25 dose descriptor.

Results The average exposure to acetaldehyde from alcoholic beverages was estimated at 0.112 mg/kg body weight/day. The MOE was calculated to be 498, and the life-time cancer risk at 7.6 in 10 000. Higher risk may exist for people exposed to high acetaldehyde contaminations, as we have found in certain unrecorded alcohol beverages in Guatemala and Russia, for which we have demonstrated possible exposure scenarios, with risks in the range of 1 in 1000.

Conclusions The life-time cancer risks for acetaldehyde from alcoholic beverages greatly exceed the usual limits for cancer risks from the environment set between 1 : 10 000 and 1 : 1 000 000. Alcohol consumption has thus been identified as a direct source of acetaldehyde exposure, which in conjunction with other sources (food flavourings, tobacco) results in a magnitude of risk requiring intervention. An initial public health measure could be to reduce the acetaldehyde content in alcoholic beverages as low as technologically possible, and to restrict its use as a food flavour additive.

From press release:

New evidence by researchers at the Centre for Addiction and Mental Health (CAMH) and researchers in Germany shows that drinking alcohol is the greatest risk factor for acetaldehyde-related cancer. Heavy drinkers may be at increased risk due to exposure from multiple sources.

Acetaldehyde is ubiquitous in daily life in Ontario. Widely present in the environment, it is inhaled from the air and tobacco smoke, ingested from alcohol and foods, and produced in the human body during the metabolism of alcoholic beverages. Research indicates that this organic chemical plays a significant role in the development of certain types of cancers (especially of the upper digestive tract), and it is currently classified as possibly carcinogenic by the International Agency for Research on Cancer of the World Health Organization.

New research from CAMH in Toronto and the Chemical and Veterinary Investigation Laboratory Karlsruhe (CVUA) in Germany recently provided the necessary methodology for calculating the risk for the ingestion of alcoholic beverages.

The team found that risk from ingesting acetaldehyde via alcoholic beverages alone may exceed usual safety limits for heavy drinkers. Their risk assessment study found that the average exposure to acetaldehyde from alcoholic beverages resulted in a life-time cancer risk of 7.6/10,000, with higher risk scenarios (e.g. contaminations in unrecorded alcohol) in the range of 1 in 1,000. As such, the life-time cancer risks for acetaldehyde from ingestion of alcoholic beverages greatly exceed the usual limits for cancer risks from the environment.

The research team noted, however, that this risk is compounded by the addition of acetaldehyde exposure from different sources. “The problem with acetaldehyde has been that although it has been recognized as toxic by Health Canada some years ago, most risk assessments to date were based on one source of exposure only” explained Dr. Jürgen Rehm, the lead scientist of the Toronto group and head of the Public Health and Regulatory Policies section at CAMH. “This has led to a negligence of the overall risk.”

For example, in Toronto, even though there are limits for air exposure of acetaldehyde set by the responsible Public Health agency, these limits have been surpassed in the past. Alone, the risks associated with surpassing limits of acetaldehyde from the air may not yet be alarming, but for heavy drinkers and smokers, it adds to the acetaldehyde levels already received from these sources. This overall risk then surpasses established safety limits.

“Their risk assessment of acetaldehyde present as a congener in alcoholic beverages touches the tip of the iceberg,” according to a Commentary on the CAMH/CVUA study in the journal Addiction.

Based on their study the scientists of CAMH recommend:

That the classification of acetaldehyde with respect to cancer be re-examined, incorporating new evidence which points to an additional cancer risk to humans.
* That a further risk assessment should take into consideration all sources of exposure from this substance.
* That the risk for cancer stemming from acetaldehyde from alcoholic beverages is recognized, and necessary preventive steps are taken to reduce the acetaldehyde content in alcoholic beverages.
* That the overall level of acetaldehyde exposure be minimized to the lowest level technically possible.

Study Information:

Lachenmeier, D.W., Kanteres, F., Rehm, J. Carcinogenicity of acetaldehyde in alcoholic beverages: risk assessment outside ethanol metabolism. Addiction 2009 March
Centre for Addiction and Mental Health (CAMH), Toronto, Canada.

Full Study:

http://www3.interscience.wiley.com/cgi-bin/fulltext/122265507/HTMLSTART