Acetaldehyde

Acetaldehyde is an aldehyde of acetic acid. It is also known as ethanal, acetic aldehyde and ethyl aldehyde. The agent is a metabolite of ethanol.

Acetaldehyde in food

Acetaldehyde is found in low levels in some foods prepared by fermentation, such as milk products, soy products, canned vegetables and non-alcoholic beverages. It is also found in fruit and fruit juices.

Fermentation is a method used traditionally for the preparation and preservation of food. It is used to affect the acidity, aromas, consistency and shelf-life of foods; for example dairy starters (souring agents) give fermented milk products their typical characteristics. By preserving vegetables by fermentation, the activity of harmful microbes is inhibited. During fermentation small amounts of acetaldehyde are formed as a metabolite of alcohol.

Acetaldehyde is also used as a food flavouring agent which is added to some pastries, fruit juices, soft drinks, sweet desserts and milk products.

Adverse effects of acetaldehyde

In October 2009 the International Agency for Research on Cancer (IARC) changed the cancer risk classification of acetaldehyde from an agent possibly carcinogenic to humans (Group 2B) to an agent carcinogenic to humans (Group 1).

The most important sources of exposure to acetaldehyde are high consumption of alcoholic beverages, smoking and possible exposure via the respiratory tract at workplaces.

Many alcoholic beverages contain acetaldehyde that is formed as a by-product during the production process. In addition, the microbes of the intestinal tract can produce acetaldehyde in saliva, gastric juices and in the contents of the colon from the intake of alcohol. Poor mouth hygiene adds to local formation of acetaldehyde from alcohol.

People with a certain genotype suffer especially from the adverse effects of acetaldehyde. People with this genotype are found especially in East Asia. In Finland, the trait related to the metabolism of acetaldehyde is very rare.

High consumption of alcohol and the combined effect of alcohol and smoking have been presented as adding to the risk of falling ill especially with the cancers of the upper digestive tract. 

No cause-effect relationship has been established between food-borne exposure to acetaldehyde and cancers. In addition, the occurrence of the aforementioned cancers has decreased continuously in the Finnish population since 1950s.

How will the matter proceed?

The latest research data has raised a suspicion regarding the safety of foods containing acetaldehyde. 
 
Evira has submitted data on studies conducted in Finland to the European Commission and the European Food Safety Authority EFSA for information to promote further research in the subject.

Due to the extent of the matter all action shall be taken at European Community level and the scientific risk assessment of the role of acetaldehyde from the perspective of chemical food safety will be presented by EFSA.

Evira's own research activities will be started in the spring of 2010 focusing on the determination of acetaldehyde levels in foodstuffs. Evira has submitted an initiative for a research project to the European Community.