Fatty Acid Ethyl Esters: A New Method to Detect Heavy Alcohol Consumption in Hair

American Biotechnology Laboratory, 23(7), 16-17.

P. Bean, C. Plate, J. Jones, & D. Lewis

Ethanol is metabolized via both oxidative and nonoxidative pathways. The predominant oxidative
pathway results in the formation of acetaldehyde; one of the nonoxidative pathway results in the production of fatty acid ethyl esters (FAEEs). Measurable concentrations of FAEEs are normally
present in the circulation of individuals who consume alcohol, and in organs damaged by alcohol
abuse such as the brain and the liver. In fact, the formation of FAEEs accounts, at least in part, for the organ damage associated with chronic alcohol abuse.

In addition to their potentially cytotoxic effect, levels of circulating FAEEs have been used as markers for acute as well as chronic alcohol use. Previous studies have shown that subjects who were given a controlled amount of alcohol over a 90-min period exhibited increases in serum FAEE levels.1 Among individuals with blood alcohol levels greater than 1.5 g/L, serum FAEE concentrations correlated very closely with blood alcohol concentrations (BACs). Furthermore, serum FAEE levels were measurable 24 hr after alcohol intake, even among subjects with very low BACs (<0.10 g/L), suggesting that FAEE analysis represents a sensitive measure for ethanol exposure.

Analysis of FAEE concentrations in adipose tissue is also useful in determining alcohol intake. In fact, since the estimated half-life of FAEEs in adipose tissue (16 hr) is significantly greater than that of alcohol itself (4 hr), the presence of measurable concentrations of FAEEs in adipose tissue represents a valuable marker for previous alcohol use.2 Interestingly, the composition of FAEEs is tissue specific, with different fatty acids present in FAEEs from blood, liver, pancreas, and adipose tissues. The levels of a particular fatty acid also vary according to the frequency of alcohol consumed. For example, levels of ethyl oleate (E18:1) are higher in chronic alcoholics versus binge alcohol abusers, thus providing a marker that could be used to differentiate distinct patterns of alcohol abuse.3 This article describes new advances in the area of alcohol abuse diagnosis that relate to the development of a new test to detect and quantify FAEE in hair.

1. Wurst FM, Alexson S, Wolfersdorf M, et al. Concentration of fatty acid ethyl esters in hair of alcoholics: comparison to other biological state markers and self-reported ethanol intake. Alcohol Alcohol 2004; 39(1):33–8.
2. Refaai MA, Nguyen PN, Steffensen TS, et al. Liver and adipose tissue fatty acid ethyl esters obtained at autopsy are postmortem markers for premortem ethanol intake. Clin Chem 2002; 48(1):77–83.
3. Soderberg BL, Salem RO, Best CA, et al. Fatty acid ethyl esters. Ethanol metabolites that reflect ethanol intake. Am J Clin Pathol 2003; 119 suppl:S94-9.