In August last year, a study published in Chemical Research in Toxicology suggested that the flavouring ingredient – found in margarines, snack foods, sweets, baked goods, some types of microwave popcorn, pet foods, and certain alcoholic beverages – could intensify the damaging effects of beta-amyloid protein clumping linked to Alzheimer’s disease. The effect was suggested for food industry workers inhaling the substance, rather than for consumers of diacetyl-containing foods.
In EFSA’s opinion, the research methods used meant that it was not possible to extrapolate the data to be used to assess the safety of diacetyl in foods or in terms of occupational exposure.
“The authors have not provided any correlation between occupational exposure and systemic exposure,” the opinion said.
“Based on these considerations, EFSA concluded that the information in scientific paper does not bring any new scientific elements for the safe use of diacetyl in food.”
The EFSA opinion only assessed the conclusions of this one study linking diacetyl to Alzheimer’s and did not assess diacetyl in relation to respiratory conditions.
The ingredient has been the focus of a several recent studies because of links to respiratory and other problems in workers at microwave popcorn and food-flavouring factories.
Concerns about diacetyl were initially raised after researchers from the Netherlands linked industrial use of the flavouring with the debilitating lung disease bronchiolitis obliterans syndrome (BOS).
Since then, several studies have linked the butter flavour to the development of the lung disease among workers, and many companies have sought alternatives.
Diacetyl is an authorised flavouring substance in the European Union to give foods a buttery flavour, and is naturally produced during fermentation. A safety assessment for diacetyl consumption carried out by the Joint FAO/WHO Expert Committee on Food Additives (JEFCA) in 1998 concluded that the use of diacetyl in foods at current consumption levels was of no safety concern.