Summary: In a 12-week trial in obesity, gallic acid combined with physical training produced modest reductions in waist circumference, waist-hip ratio, and skinfolds, with gains concentrated in the trained-and-supplemented group rather than from the supplement alone.
PICO Summary
| Element | Detail |
|---|---|
| Population | 150 adults recruited (107 completed), normal-weight or obese, in eight groups by nutritional status, training, and supplementation; 12-week double-blind, placebo-controlled randomised trial, Brazil. |
| Intervention | Gallic acid 200 mg/day combined with structured physical training for 12 weeks. |
| Comparison | Placebo with or without physical training, across the stratified groups. |
| Outcome | In the trained, gallic-acid-supplemented obese group, waist-hip ratio (p=0.031), waist circumference (p=0.041), and pectoral (p=0.044) and abdominal (p=0.036) skinfolds fell. Fat-free mass showed a non-significant upward trend (p=0.054) and serum albumin rose (p=0.043). Benefits appeared mainly with the exercise-plus-supplement combination. |
Expert Commentary
This is a modest trial whose most honest reading is that exercise did the heavy lifting and gallic acid may have added a little on top. The improvements were real but small and clustered in the group that both trained and took the supplement, appearing as interaction effects rather than a standalone supplement benefit, which fits a recurring theme in this literature that polyphenols tend to help, if at all, only alongside physical activity. The fat-free-mass signal was a non-significant trend, so it should not be over-claimed. Several limitations temper confidence: an eight-group design spread across only 150 enrolled with 107 completing means small per-cell numbers and substantial dropout, the endpoints are anthropometric surrogates over a short 12 weeks, and multiple comparisons across eight groups raise the chance of incidental findings. Can I use this with my patients? Mainly as reinforcement of exercise. I would not recommend gallic acid as a weight or body-composition treatment in its own right, and where a patient is interested, only as a possible adjunct to a structured exercise programme, with the clear message that the training, not the supplement, is the established intervention and that the added benefit here was small and needs larger confirmation.
References
Barbosa BK, Silva DVA, Batista-Jorge GC, et al. Combined effects of gallic acid supplementation and physical training on body composition and biochemical parameters in obese patients: a randomized, double-blinded, placebo-controlled clinical trial. Nutrients. 2026;18(2):311. doi:10.3390/nu18020311