Increased urinary hydrogen peroxide levels caused by coffee drinking

Biol Pharm Bull. 2002 Nov;25(11):1467-71. doi: 10.1248/bpb.25.1467.


Experiments with volunteers in Singapore have demonstrated that coffee drinking increases urinary hydrogen peroxide levels (Long, Halliwell, Free Rad. Res., 32, 463-467 (2000)). We re-examined the effect of coffee drinking of healthy Japanese subjects on urinary hydrogen peroxide levels. A cup of brewed or canned coffee commercially available in Japan generated 120-420 micro mol hydrogen peroxide in incubation in a neutral medium at 37 degrees C for 6 h. The increased levels were higher than those obtained from a cup of green tea extract or a glass of red wine. After the subject drank a cup of coffee, apparent hydrogen peroxide levels (micro mol/g creatinine) in urine collected 1-2 h after coffee drinking increased 3-10-fold compared to the levels before coffee drinking. The increased urinary hydrogen peroxide levels are likely derived mainly from 1,2,4-benzenetriol excreted in urine, because the major component that generates hydrogen peroxide is found to be 1,2,4-benzenetriol, and storing urine collected after coffee drinking increased hydrogen peroxide levels in a time-dependent fashion. Total hydrogen peroxide equivalent levels excreted in 3 h-urine after coffee drinking were estimated to be 0.5-10% that of coffee consumed. A residual amount of hydrogen peroxide may be retained or consumed in human bodies.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Coffee / metabolism*
  • Female
  • Humans
  • Hydrogen Peroxide / urine*
  • Male
  • Middle Aged
  • Time Factors


  • Coffee
  • Hydrogen Peroxide