Endpoint
Total antioxidant capacity
CAT:outcome/total-antioxidant-capacityreported in mmol/L
Method
Total antioxidant capacity of plasma or serum by a bulk redox colorimetric assay (FRAP, TEAC/ABTS or equivalent), performed on a sample drawn from the subject. The assay is recorded on the edge, since FRAP and ABTS-based methods weight individual antioxidants differently.
The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.
Notes
TAS added 2026-08-23. Total Antioxidant Status and Total Antioxidant Capacity name the same bulk redox assay and the literature uses them interchangeably; a two-pass-agreed curcumin claim was refused on the span "TAS" for an assay this entry already describes. SIGN INVERSION HAZARD against malondialdehyde and other lipid-peroxidation products: both are called 'oxidative status', both appear in the same table in concentration units, but this improves by RISING and damage products improve by FALLING. The second confusion is the sample: PMID 26873098 measures Trolox-equivalent antioxidant capacity of the INGESTED PRODUCT using the same chemistry — that is a composition measurement of the intervention, not an outcome in a subject, and an edge built from it inverts the direction of causation. Third, this assay is dominated by urate in human serum, so it rises when serum uric acid rises — which is itself a harmful direction on that node — without any change in glutathione or enzymatic defence.
Findings
6 findings from 3 compounds, strongest first.
coenzyme Q10 — no detected effect on
Well establishedGrade A, Well established. Replicated human trial evidence, consistent direction.FindingNull resultreplicated ×1“As shown in Table 2, the between-group comparison revealed no significant difference between CoQ10 and placebo groups at the end of the study for MDA (P = 0.692), SOD activity (P = 0.633), and TAC (P = 0.865).”
Quoted verbatim from Coenzyme Q10 supplementation in burn patients: a double-blind placebo-controlled randomized clinical trial.. - Study
- RCT
- Participants
- 52
- Duration
- 10 days
- Dose
- 100 mg three times a day after meals, total 300 mg/day
- Population
- Adults aged 18-65 with 20-60% total body surface area burns admitted to a burn ICU in Isfahan, Iran, all receiving routine burn care and the unit's standard vitamin, selenium, zinc and B-complex supplementation in both arms; primary outcome.
Coenzyme Q10 supplementation in burn patients: a double-blind placebo-controlled randomized clinical trial.2024PMID:38431600
melatonin — increases
LikelyGrade B, Likely. Human evidence, limited replication or design limits.Finding“Our meta-analysis indicated that melatonin intake significantly increase TAC levels (SMD: 0.87, 95% CI: 0.46, 1.28, I2 = 00.00%) compare to placebo (Table 2).”
Quoted verbatim from Effect of melatonin supplementation on cardiometabolic risk factors, oxidative stress and hormonal profile in PCOS patients: a systematic review and meta-analysis of randomized clinical trials.. - Study
- meta-analysis
- Dose
- 3-10 mg/day oral
- Population
- women with polycystic ovary syndrome; 6 double-blind RCTs
Effect 0.87 standardised mean difference, 95% CI 0.46 to 1.28
curcumin — increases
LikelyGrade B, Likely. Human evidence, limited replication or design limits.Findingreplicated ×2“TAS levels were significantly higher in the curcumin group than in the placebo group (1.85 [1.74–1.95] vs. 1.65 [1.55–1.79], p < 0.001), with a large effect size ( r = 0.72, 95% CI: 0.61–0.81).”
Quoted verbatim from Curcumin Supplementation Reduces Inflammation, Neutrophil-to-Lymphocyte Ratio (NLR), and Antioxidant Status in Obese Patients with Type 2 Diabetes: A Randomized Controlled Trial.. - Study
- RCT
- Duration
- 12 months
- Dose
- Curcumin 1500 mg/day orally for 12 months
- Population
- Adults with type 2 diabetes mellitus and obesity (n=114 randomised); secondary endpoint; between-group comparison at 12 months; total antioxidant status reported in micromol trolox equivalent/L
Curcumin Supplementation Reduces Inflammation, Neutrophil-to-Lymphocyte Ratio (NLR), and Antioxidant Status in Obese Patients with Type 2 Diabetes: A Randomized Controlled Trial.2026PMID:42123439Industry funded
curcumin — increases
LikelyGrade B, Likely. Human evidence, limited replication or design limits.Findingreplicated ×2“Compared to the placebo group, curcumin supplementation significantly enhanced antioxidant defenses, as evidenced by increased levels of total antioxidant capacity (TAC), glutathione peroxidase (GPx), and superoxide dismutase (SOD) activity at 3, 6, 9, and 12 months.”
Quoted verbatim from Curcumin Attenuates Liver Steatosis via Antioxidant and Anti-Inflammatory Pathways in Obese Patients with Type 2 Diabetes Mellitus: A Randomized Controlled Trial.. - Study
- RCT
- Duration
- 12 months
- Dose
- Oral ethanolic Curcuma longa rhizome extract standardised to 75-85% total curcuminoids, 250 mg curcuminoids per capsule, three capsules twice daily (1500 mg curcuminoids/day) for 12 months
- Population
- Obese adults with type 2 diabetes mellitus managed on metformin (age >=35 y, BMI >=23 kg/m2, HbA1c <6.5%), Nakhon Nayok, Thailand; 227 randomised, per-protocol analysis and the analysed count is not reported in the paper; secondary endpoint (declared primary outcome: liver steatosis by controlled attenuation parameter on transient elastography); total antioxidant capacity by the automated Erel assay
Curcumin Attenuates Liver Steatosis via Antioxidant and Anti-Inflammatory Pathways in Obese Patients with Type 2 Diabetes Mellitus: A Randomized Controlled Trial.2025PMID:41096556Industry funded
curcumin — increases
LikelyGrade B, Likely. Human evidence, limited replication or design limits.Findingreplicated ×2“In contrast, nanocurcumin significantly increased total antioxidant capacity (SMD: 1.60; 95% CI: 0.93 to 2.31) and reduced malondialdehyde levels (SMD: -1.93; 95% CI: -3.19 to -0.66), indicating a robust antioxidative effect.”
Quoted verbatim from Evaluating the Effects of Nanocurcumin Supplementation in Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.. - Study
- meta-analysis
- Participants
- 153
- Population
- adults with type 2 diabetes mellitus (T2DM)
coenzyme Q10 — no detected effect on
SuggestiveGrade C, Suggestive. Weak human evidence, or strong evidence in a mismatched population.FindingNull resultreplicated ×1“There was no statistically significant change in TAC between the patients treated with doxorubicin + CoQ10 and doxorubicin + placebo.”
Quoted verbatim from Phase I Randomized, Placebo-Controlled, Cross-Over Dose-Finding Study of Coenzyme Q10 on Doxorubicin Pharmacokinetics during Breast Cancer Treatment.. - Study
- crossover
- Participants
- 6
- Dose
- 300 mg/day, two 150 mg softgel capsules once daily with food
- Population
- Women aged 21 or older with stage I-III breast cancer receiving dose-dense doxorubicin plus cyclophosphamide, each acting as her own control across one cycle with coenzyme Q10 and one with placebo; secondary endpoint.
Phase I Randomized, Placebo-Controlled, Cross-Over Dose-Finding Study of Coenzyme Q10 on Doxorubicin Pharmacokinetics during Breast Cancer Treatment.2025PMID:41261512