Probabilistic health risk assessment of caffeine intake from milk tea among college students in Wuhan, China by Monte Carlo simulation

Abstract Milk tea has become increasingly popular among young Chinese consumers, yet caffeine exposure through this beverage has not been systematically quantified. This study conducted the first probabilistic risk assessment of daily caffeine intake from milk tea among college students. Caffeine concentrations were measured in 154 freshly prepared milk tea samples across five tea base categories using HPLC. Consumption data were obtained from a cross-sectional survey of 1,495 college students in Wuhan, China. A Monte Carlo simulation was applied to characterize variability in caffeine concentration and milk tea consumption and to estimate daily caffeine intake. Caffeine exposure was additionally expressed on a body-weight basis for habitual intake (mg/kg bw/day) and single-occasion intake (mg/kg bw), and compared with the corresponding EFSA reference levels. Uncertainty in the summary exposure estimates was quantified using bootstrap resampling. The overall median caffeine concentration in milk tea was 178.2 mg/kg (range: 30.7–476.9 mg/kg), with borderline differences across tea bases ( P- value = 0.057). Monte Carlo simulation yielded a median daily caffeine intake of 13.1 mg/day (95% CI 12.9–13.3) and a P95 of 29.0 mg/day (95% CI 28.2–29.7), with no simulated intake exceeding 400 mg/day. The median body-weight-normalized habitual exposure was 0.21 mg/kg bw/day (95% CI 0.21–0.21), with a P95 of 0.50 mg/kg bw/day (95% CI 0.49–0.52), and no simulated exposure exceeded the EFSA adult reference level of 5.7 mg/kg bw/day. For single-occasion exposure, the median was 1.45 mg/kg bw (95% CI 1.42–1.48), while the P95 was 3.35 mg/kg bw (95% CI 3.25–3.45), with 7.7% of simulated exposures exceeding 3.0 mg/kg bw. Overall, caffeine exposure from milk tea was low on a habitual basis, although higher exposure levels were observed for some simulated single-consumption occasions. These findings provide a more comprehensive characterization of milk–tea-derived caffeine exposure among college students.