Correlation of urinary furan with plasma gamma-glutamyltranspeptidase levels in healthy men and women.

Furan is a colorless, volatile compound that is found in heat-treated foods, such as canned and jarred foods, at levels up to 100 ppb. When animals ingest high doses, furan metabolites, such as cis-2-butene-1,4-dial, cause severe hepatotoxicity and carcinogenicity. However, the levels and effects of furan on humans are not known. Therefore, we measured urinary furan in 100 healthy individuals consumed normal diet (49 men, 51 women) using solid phase micro-extraction-gas chromatography-mass spectrometry (SPME-GCMS). Urinary furan was detected in 56 subjects (31 males, 25 females) and ranged up to 3.14 ppb. In individuals with detectable urinary furan, the level of gamma-glutamyltranspeptidase (gamma-GT), a marker for liver damage, was strongly correlated with the urinary furan concentration (r=0.56, p<0.0001). Linear regression analysis indicated that the urinary furan level was significantly associated with gamma-GT in both univariate (p<0.0001) and multiple (p=0.0001) models including age, sex, body weight, and blood pressure as covariates. To our knowledge, this is the first study to measure detectable levels of furan in human urine. These levels of urinary furan, which may be dietary origin, could be hepatotoxic in humans; therefore; the metabolic fates and potential toxicity of dietary furan in humans should be investigated further.