Table 1.
Eligible randomized controlled trials on supplementation with the CLA isomeric mixture with different proportions
| Reference | Population | Age (mean±SD) | Duration (wk) | CLA Dose and Form | Isomers | Placebo Dose and Form | Results |
|---|---|---|---|---|---|---|---|
| Mullen and colleagues,2 2007 | 30 healthy men | 49.4±1.8 | 8 | 2.2 g/d of CLA | (50:50) c9,t11 t10,c12 | 2.2 g/d of placebo | CLA supplementation significantly changed CRP levels. |
| Gaullier and colleagues,11 2004 | 180 men and women: healthy overweight | 45.83±10.3 | 48 | 3·4 g/d of CLA-TAG 3·6 g/d of CLA-NEFA | (50:50) c9,t11 t10,c12 | 4.5 g/d of olive oil | CLA supplementation increased the level of Lp(a). |
| Gaullier and colleagues,12 2007 | 118 men and women: healthy overweight or obese | 47.25± 9.6 | 24 | 3·4 g/d of CLA-TAG | (37.5:38) c9,t11 t10,c12 | 4·5 g/d of olive oil | Six months’ CLA supplementation marginally but significantly increased Lp(a) in both the CLA and placebo groups. CRP levels were significantly increased in the CLA group compared with the placebo group. |
| Tholstrup and colleagues,14 2008 | 75 healthy postmenopausal women | 60.16±4.46 | 16 | 4·6 g/d of CLA-mix | (41·17:39·90:1·79) c9,t11-t10,c12- other CLA | 5·5 g/d of olive oil | CRP was significantly higher in women supplemented with the CLA mixture than in those supplemented with CLA milk and the placebo. |
| 5·1 g/d of CLA-TAG (85·03:7·11:0·47) | c9,t11-t10,c12- other CLA | ||||||
| Ormsbee and colleagues,17 2014 | 22 men and women: inactive healthy overweight or obese | 35±3.45 | 8 | 1 g of fat, 99 mg of caffeine, 1510 of mg/d blend of: (green tea, CLA, and BCAA) | soybean oil | CLA supplementation had no effect on hs-CRP concentrations. | |
| Tarnopolsky and colleagues,18 2007 | 39 community-dwelling older adults | 71.1±5 | 24 | 5 g/d of CrM + 6 g/d of CLA-mix | (50:50) c9,t11 t10,c12 | 7 g/d of dextrose + 6 g/d of safflower oil | CrM+CLA supplementation had no significant effect on CRP levels. |
| Yonei and colleagues,19 2007 | 17 men and 18 women | 48.3±6.6 | 8 | 700 mg/d of CLA + 200 mg/d of L-carnitine | (33.1 : 33.9 ) c9, t11 t10, c12 | placebo | A small increase in serum levels of CRP was noted in the study group. |
| Watras and colleagues,20 2007 | 40 men and women: healthy overweight | 33±7.5 | 24 | 3·2 g/d of CLA-mix | (39·2:38·5) c9,t11 t10,c12 | 4 g/d of safflower oil | Within the CLA group, the CRP level was increased. |
| Steck and colleagues,21 2007 | 48 men and women: healthy obese | 34·50±4·85 | 12 | 3·2 g/d of CLA-TAG 6·4 g/d of CLA-TAG | (50:50) c9,t11 t10,c12 | 8 g/d of safflower oil | CLA increased the CRP level, although the absolute mean values remained within the normal limits. |
| Joseph and colleagues,22 2011 | 27 overweight hyperlipidemic men | 18-60 (range) | 8 | 3.5 g/d of CLA-mix 3.5 g/d of c9,t11 | (50:50) c9,t11 t10,c12 | 3.5 g/d of safflower oil | CRP was not significantly different in men supplemented with the CLA mixture than in those supplemented with c9, t11 or the placebo. |
| Pfeuffer and colleagues,23 2011 | 85 men: healthy overweight or obese | 45-68 (range) | 4 | 3·4 g/d of CLA-TAG | (50:50) c9,t11 t10,c12 | 4·5 g/d of safflower oil | No significant treatment-dependent changes in Lp(a) and hs-CRP were noted. |
| Gaullier and colleagues,24 2005 | 134 men and women: healthy overweight | 46.26±9.96 | 96 | 3·4 g/d of CLA-TAG | (50:50) c9,t11 t10,c12 | 3·4 g/d of placebo | Within-group comparisons showed that Lp(a) levels were increased significantly. |
| 3·4 g/d of CLA-NEFA | (50:50) c9,t11 t10,c12 | ||||||
| Blankson and colleagues,25 2000 | 60 men and women: healthy overweight or obese | 44.35±12.95 | 12 | 1·7 g/d of CLA-TAG 3·4 g/d of CLA-TAG 5·1 g/d of CLA-TAG 6·8 g/d of CLA-TAG | (50:50) c9,t11 t10,c12 | 9 g/d of olive oil | Changes in Lp(a) were not significantly different from the baseline values. |
| Berven and colleagues,26 2000 | 60 men and women: healthy overweight or obese | 47·05±3·9 | 12 | 3·4 g/d of CLA-TAG | (50:50) c9,t11 t10,c12 | 4·5 g/d of olive oil | Blood Lp(a) remained unchanged during the study. |
| Kim and colleagues,27 2008 | 51 women: healthy overweight Korean women | 28·24±20·3 | 12 | 2·25 g/d of CLA-NEFA | (37·95:38·84:0·96:1·35) c9,t11-CLA-t10, c12-CLA-c9,c11- CLA-t9, t11-CLA | 3 g/d of olive oil | Lp(a) changes between the treatment groups had no significant difference and the values were in the normal range. |
| 2·25 g/d of CLA-TAG | (37·83:38·55:0·98:1·86) c9,t11-CLA-t10, c12-CLA-c9,c11- CLA-t9,t11-CLA | ||||||
| Smedman and colleagues,28 2001 | 27 men and 26 women | 45.5±11.45 | 12 | 4·2 g/d of CLA | (50:50) c9,t11 t10,c12 | 4.2 g/d of olive oil | CLA supplementation increased levels of CRP. |
| Taylor and colleagues,29 2006 | 40 men: healthy overweight or obese | 46±7 | 12 | 4.5 g/d of CLA-mix | (35:36) c9,t11-t10,c12 (1-2%) c9,c11-c10,c12 (1·5%) t9,t11- t10,t11 (<1%) t8,c10-c11,t13 | 4.5 g/d of olive oil | There was no change in the estimated CRP concentration. |
CLA: Conjugated linoleic acid; CRP: C-reactive protein; Lp(a): Lipoprotein (a); CrM: Creatine monohydrate