Pulmonary pentane excretion increases with age in healthy subjects

Excessive lipid peroxidation occurs in various diseases. However, even in health low levels of lipid peroxidation can be detected by measuring the pulmonary excretion of pentane. Lipid peroxidation has been postulated to be one of the causes of the ageing process. In order to test whether pentane excretion is related to age, we measured breath pentane in 47 healthy subjects (ages 21-79). We also measured serum levels of the antioxidants tocopherol, retinol, lycopene, beta carotene, ascorbate and zinc. We found that pentane excretion significantly (P < 0.05, r = 0.32) increased with age. Of the six antioxidants measured, only lycopene decreased significantly (P < 0.05, r = -0.47) with age, however, this decline did not statistically correlate with pentane excretion. The remaining five antioxidants either remained stable or increased over the age range studied. We conclude that lipid peroxidation, as assessed by pentane excretion, increases with advancing age but that this increase is independent of dietary antioxidant levels.