Table 1. Characteristics of studies and subjects included in this systematic review.
| No. | Author, year | Country | n | Sex (M/F) | Mean Age (yr) | Population | Design | Duration (month) | T3 type (dosage)* | Placebo | Biomarkers | Funder |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. | Azman, 2018 [16], Goon 2017 [17] | Malaysia | 47 | 17/30 | 52.8 | Healthy | Parallel | 6 | TRF (150 mg/d) | Olive oil | SOD, CAT, GPx, MDA, PC, GSH | UKM |
| 2. | Chin, 2011 [18] | Malaysia | 62 | 0/62 | ≥ 35 | Healthy | Parallel | 6 | TRF (160 mg/d) | Palm oil | SOD, CAT, GPx, PC, AGE, MDA | Malaysian government & UKM |
| 3. | Daud, 2013 [19] | USA | 81 | 43/38 | 58.5 | HD | Parallel | 4 | TRF (180 mg/d) | Wheat germ oil | CRP, IL-6, TAP, TBARS | MPOC |
| 4. | Gan, 2017 [20] | Malaysia | 31 | 15/16 | 37.9 | Metabolic syndrome | Cross-over | 0.5 | PTT (400 mg/d) | Palm olein | hsCRP | MBOB |
| 5. | Gopalan, 2014 [21] | Malaysia | 121 | 48/73 | 52.0 | Subjects with WML | Parallel | 24 | Mixed T3 (400 mg/d) | Palm olein | hsCRP | MPOB |
| 6. | Haghighat, 2013 [22], Vafa, 2015 [23] | Iran | 45 | 22/33 | 55.6 | T2DM | Parallel | 2 | T3-enriched canola oil (200 mg/d) | Canola oil | hsCRP, MDA, TAC | Tehran University of Medical Sciences |
| 7. | Heng, 2015 [24] | Malaysia | 57 | 20/37 | 41.2 | Metabolic syndrome | Parallel | 4 | Mixed T3 (400 mg/d) | Soy bean oil | CRP, IL-6, TNF-α | Malaysian MOHE |
| 8. | Kooyenga, 1997 [25] | USA | 50 | 23/27 | 66.6 | CAD | Parallel | 24 | α- and γ-T3 (160–240 mg/d) | Palm superolein | LOPs, TBARS | N/A |
| 9. | Magosso, 2013 [26] | Malaysia | 87 | 34/53 | 51.0 | Hypercho-lesterolemic & NAFLD | Parallel | 12 | Mixed T3 (400 mg/d) | Placebo† | hsCRP | MPOB |
| 10. | Nazaimoon, 1996 [27] | Malaysia | 32 | 9/23 | 41.3 | T2DM | Cross-over | 6 | T3 (288 mg/d) | Palm olein | MDA | MPOB |
| 11. | Ng, 2020 [28] | Malaysia | 80 | 52/28 | 63.5 | T2DM | Parallel | 2 | T3 (400 mg/d) | Palm oil | MDA | Malaysian MOHE & MUM |
| 12. | O’Byrne, 2000 [29] | USA | 51 | 22/29 | 40.8 | Hypercho-lesterolemic | Parallel | 2 | α- or γ- or δ- tocotrienyl acetate (250 mg/d) | MCT oil | LDL oxidation status | BASF (Germany) & NIH |
| 13. | Pervez, 2020 [30] | Pakistan | 71 | 34/37 | 44.4 | NAFLD | Parallel | 6 | δ-T3 (600 mg/d) | Sucrose | hsCRP, IL-6, TNF-α, MDA | Government of Pakistan |
| 14. | Rasool, 2006 [31] | Malaysia | 36 | 36/0 | 23.3 | Healthy | Parallel | 2 | TRE (80–320 mg/d) | N/A† | TAS | Malaysian MOSTI |
| 15. | Stonehouse, 2016 [32] | Australia | 57 | 36/21 | 60.8 | T2DM, IFG or elevated WC | Parallel | 2 | TRF (420 mg/d) | Palm olein | hsCRP, IL-6, TNF-α | MPOB |
| 16. | Tan, 2018 [33] | Malaysia | 45 | 31/14 | 61.6 | T2DM | Parallel | 2 | TRE (400 mg/d) | N/A† | AGE | MUM |
| 17. | Tan, 2019 [34] | Malaysia | 54 | 35/19 | 61.3 | T2DM | Parallel | 3 | TRE (400 mg/d) | N/A† | MDA | Malaysian MOHE & MUM |
*Detailed composition of the supplements is presented in S3 Table
† The composition of placebo was not stated.
Abbreviation: AGE, advanced glycosylation end-product, CAD, carotid artery disease, CAT, catalase, CRP, C-reactive protein, F, female, GPx, glutathione peroxidase, GSH, gluthathione, HD, hemodialysis, hsCRP, high sensitivity C-reactive protein, IFG, impaired fasting glucose, IL-6, interleukin-6, LDL, low-density lipoprotein, LOPs, lipid peroxidation products, M, male, MCT, medium chain triglyceride, MDA, malondialdehyde, MOSTI, Ministry of Science, Technology & Innovation Malaysia, MPOB, Malaysian Palm Oil Board, MPOC, Malaysian Palm Oil Council, MUM, Monash University Malaysia, N/A, not available, NAFLD, non-alcoholic fatty liver disease, NIH, National Institutes of Health, PC, protein carbonyl, PTT, palm based tocotrienols and tocopherol, SOD, superoxide dismutase, T2DM, type 2 diabetes mellitus, T3, tocotrienols, TAC, total antioxidant capacity, TAP, total antioxidant power, TAS, total antioxidant status, TBARS, thiobarbituric acid reactive substances, TNF-α, tumor necrosis factor-alpha, TRE, tocotrienol-rich vitamin E, TRF, tocotrienol-rich fraction, UKM, Universiti Kebangsaan Malaysia, USA, United States of America, WC, waist circumference, WML, white matter lesions.