Written by Tatjana Djakovic, Staff Writer. Diacetyl, used in butter flavoring is able to form the plaques found in the brains of Alzheimer’s patients.
Alzheimer’s disease is a form of dementia that progressively destroys parts of the brain that are involved in thinking, memory and language and eventually performing every day activities. (1) It is the sixth leading cause of all deaths in the United States, and Alzheimer’s related deaths have dramatically risen by 47% between 2000 and 2006, whereas other major causes of death have been on the decrease. It also places a significant burden on the economy, costing an estimated $148 billion annually. (2) It is vital to look for factors that are potentially involved in the development of the disease so that precautions can be taken for prevention.
A hallmark of Alzheimer’s disease is an accumulation of amyloid plaques between nerve cells in the brain. Amyloid is a term used to describe protein fragment that body produces normally, whereas beta amyloid (Aβ) are protein fragments that have snipped from an amyloid precursor protein (APP). In a healthy brain, these protein fragments are broken down and eliminated, whereas in Alzheimer’s disease fragment accumulate and form hard, insoluble plaques. (3)
A factor that is thought to be involved in the formation of Alzheimer’s disease is a compound known as diacetyl which is used as a butter flavoring agent in microwave popcorn and various other snack related foods. The interest in the potential negative health effects of diacetyl is due to a large amount of evidence showing that is causes obstructive lung disease in popcorn factor workers upon chronic exposure. (4)
The researchers wanted to find if the diacetyl is implicated in the formation of plaques on the brain that are a hallmark of Alzheimer’s. Diacetyl is a chemical that is thought to cause a change in the shape of a beta amyloid proteins which is a pathological sign of the Alzheimer’s disease.
The researchers quantified the amount of misfolding of beta-amyloid by measuring the fluorescence emitted by a dye that only binds to a misfolded beta-amyloid protein. When it is bound to a misfolded protein, it fluoresces between with a wavelengths of 440 to 490 nm. The results suggest that diacetyl induces misfolding of the beta-amyloid protein because there were increases in fluorescence after 48 hours of exposure to dacetyl. They also found that diacetyl accelerates beta-amyloid protein aggregation, by inducing the formation of beta-pleated sheets, (a type of protein structure). In fact, a concentration of 25 micro-molar was able to induce the change in the conformation.
The researchers also investigated if the diacetyl would be toxic to cells. They added diacetyl to amyloid proteins and found that the combination was toxic over a period of 24 hours, which of concern because diacetyl is able to cross the blood brain barrier. (5) The study suggests that diacetyl induces aggregation of beta-amyloid proteins that form plaques which are found in the Alzheimer’s patients. The study needs to be conducted in animals and humans in order to determine the level of danger that this butter flavoring agent poses to health.
Source: More, Swati S., Ashish P. Vartak, and Robert Vince. “The butter flavorant, diacetyl, exacerbates β-amyloid cytotoxicity.” Chemical research in toxicology 25.10 (2012): 2083-2091.
© 2012 American Chemical Society
Posted January 28, 2013.
References:
- Obtained from National Institutes of Aging. “About Alzheimer’s Disease: Alzheimer’s Basics.”
- Mebane-Sims, Irma. “2009 Alzheimer’s disease facts and figures.” Alzheimer’s & Dementia (2009).
- Obtained from Alzheimer’s Disease Research. “Amyloid Plaques and Tangles”
Schrater, E. N. (2002) Popcorn worker’s lung. N. Engl. J. Med.347, 360−361. - More, Swati S., Ashish P. Vartak, and Robert Vince. “The Butter Flavorant, Diacetyl, Exacerbates β-Amyloid Cytotoxicity.” Chemical Research in Toxicology (2012).
