Antioxidant supplements reduced oxidative stress and stabilized liver function tests but did not reduce inflammation in a randomized controlled trial in obese children and adolescents.

Randomized controlled trial in overweight or obese children and adolescents aged 10 to 18 years enrolled in six outpatient lifestyle modification programs in the German-speaking part of Switzerland. Participants had BMI above the sex-specific 85th CDC BMI-for-age percentile and were followed during a 4-month intervention period.

Oral antioxidant supplementation for 4 months consisted of three identically appearing tablets taken daily: ascorbic acid 500 mg, a-tocopherol (vitamin E) 400 IU, and selenium 50 mg. The regimen was given 7 days/week and was compared with placebo alongside ongoing lifestyle modification.

Antioxidant supplementation improved antioxidant status and reduced markers of oxidative stress, and liver function tests were modestly stabilized, but systemic inflammation was not reduced. In the active treatment arm, a-tocopherol increased from 28.8 6 5.5 to 51.7 6 11.9 (P < 0.001), ascorbic acid increased from 136 6 36 to 178 6 36 (P < 0.001), selenium increased from 1.06 6 0.12 to 1.15 6 0.14 (P = 0.019), and 8-iso-PGF2a decreased from 0.28 (0.19, 0.90) to 0.21 (0.12, 0.79) (P = 0.014). Inflammation markers did not meaningfully change, with CRP showing a treatment effect of 0.07 (-0.08, 0.23) and AGP 0.11 (-0.01, 0.24). The treatment was well tolerated, with no serious adverse events and adherence of 94.7%.

The intervention lasted only 4 months, so longer-term clinical impact and durability are unknown. Several baseline differences favored the treatment group, including higher a-CEHC, uric acid, AST, and ALT, and IL-6 data were not provided. The study was conducted within lifestyle modification programs in a specific Swiss setting, which may limit generalizability.