I'll feel free to repost this:
http://forum.bodybuilding.com/showpo...3&postcount=11
Overview: controlled clinical trials of CLA effects in humans
Compiled by Dr.P
When judging the effects of a substance it is of highest importance to base one's opinion oh
human trials.
Here I present a small compliation / overview of all studies that I found in Medline by searching after "conjugated linoleic acid" and with the limits: clinical trials and which report effects on body composition parameters.
In sum, CLA appears to have some small effects, especially when higher dosed. not all studies showed "significant" effects, which, IMO is due to the rather small effect size of CLA.
colour code:
------------
blue = positive result (12 studies)
red = negative result (10 studies)
PART I.: Effects on body weight and fat:
1. Steck et al. (2007)
50:50 ratio of CLA isomers, 3.2 g/d vs. 6.4 g/d vs. placebo group
N = 48 (13 males and 35 females) obese, otherwise healthy subjects
Duration: 12 weeks
Outcome: increase of lean body mass by 0.64 kg in the 6.4g/d CLA-group; significant decreases in serum HDL, sodium haemoglobin and hematocrit; significant increases in alkaline phosphatise, CRP and IL-6
2. Gaullier et al., (2007)
12 g/d CLA vs. placebo
N=118 (BMI: 28-32 kg/m2), healthy overweight/obese subjects
Duration: 6 months
Outcome: reduction of body fat mass at 3.4 % at month 6; mostly located in legts and in women. No effects on bone mineral density.
3. Nazare et al. (2007)
3.76 g/d of CLA (50:50) vs placebo
Duration: 98 days
N = 44
Outcome: No effects on body weight, fat mass or free fat mass; increase of basal energy expenditure; increase of PPAR Gamma gene expression; reduction of mRNA of HSL. No effects on UCP-2 and LPL mRNA.
4.Colakoglu et al. (2007)
3.6 g/ CLA with and without exercise vs. placebo
Duration: 6 weeks
Outcome: reduction of fat mass in all experimental groups and body weight reduction in the CLA-only group. Decrease of serum glucose in CLA and CLA+exercise groups and decrease of insulin in CLA +exercise group only.
5. Watras et al. (2007)
3.2 g/d CLA vs. placebo
Duration: 6 months
N = 40, healthy, overweight subjects
Reduced weight gain during holiday seson; after 6 months reduced body fat in CLA vs placebo (1 kg). No effects on restin g metabolic rate, and markers for liver function, inflammation, blood lipids. Significant decrease of markers of endothelial dysfunction.
6. Tricon et al. (2006)
0.15 g of cis-9,t-11-CLA (control) vs. 1.42 g of cis-9, t11-CLA (treatment)
N = 32 of middle aged, healthy men
Duration: 6 weeks, 7 weeks wash-out, cross-over
Outcome: no effects on body weight, inflammatory markers, insulin, glucose, trigycerdes, total-, HDL and LDL-cholesterol. However, increased ratio of LDL : HDL.
7. Pinkoski et al. (2006)
CLA 5g/d vs. Placebo
N = 76
Duration: 7 weeks with exercise; 17 subjects crossed over
Outcome: greater increase in lean mass (1.4 kg vs. 0.2 kg), greater loss of fat mass (-0.8 kg vs. +0.4 kg) smallr increase of 3-MH (marker of myofibrillar degradation). Greater increase in bench press.
8. Larsen et al. (2006)
CLA 3.4g/d vs. Placebo
Duration: 1 year
N = 101 obese healthy subjects who lost >8% of their initial body weight during a 8-week weight-loss program; during the trial: hypocaloric diet (-1250 kJ/d)
Outcome: no difference in body weight or body fat regain. No index of insulin resistence. Increased leukocyte numbers.
9. Gaullier et al. (2005)
3.4 g/d CLA vs. Placebo
N = 157 (134 during the second 12 months)
Duration: 24 months (during the second 12 months: open study, no control group)
Outcome: during the extended (second 12 months) trial period reduction of body weight in the group that received placebo during the first year. No body weight or fat changes in the group that received CLA during the first year (=stabilisation of weight)
10. Whigham et al. (2004)
CLA 6g/d
N = n/a, healthy obese subjects
Duration: 1 year (first part: 13 kcal/kg/d; second part: refeeding with 25-30kcal/kg; third part: open label, all subjects receiving CLA)
Outcome: no difference in body composition between groups.
11. Riserus et al. (2004)
c9,t11-CLA 3 g/d vs Placebo
N = 25 of abdominally obese men
Duration : 3 months
Outcome: no difference of body composition between groups; decrease of insulin-sensitivity by 15% in the CLA-group, increase of iso-8-PGF2alpha (by 50%) and 15-keto-dihydro-PGF2alpha (15%).
12. Gaullier et al. (2004)
CLA-FFA, CLA-TG and Placebo (amount?)
N=180 overweight males and females
Duration: 1 year
Outcome: reduced body fat mass in the CLA groups, increased lean body mass in CLA-FFA. Increased LDL, decreased HDL. Increased Lp(a). glycated haemoglobin increased in all groups.
13. Malpuech-Brugere et al. (2004)
1.5g/d and 3.0 g/d of c9,t11 vs 1.5/d and 3.0g/d of t10,c12) vs placebo
N=81 overweight healthy men
No significant differences of body fat mass, lean mass between groups
14. Petridou et al. (2003)
2.1 g/d CLA
N=16 young non-obese healthy women
duration: 45 days CLA vs 45 days placebo (cross-over design)
outcome: no difference in body-fat, serum-leptin,, TAG, total cholesterol, HDL and ALT.
15. Kamphuis et al. (2003)
1.5 g/d vs. 3.6 g/d of CLA vs. Placebo
N = 26 men and 28 women, overweight
Duration: 3 weeks of very low calorie diet; after that 13 weeks intervention period with CLA groups vs. placebo
Outcome: CLA did not have an effect on body weight regain after the diet phase. Favourable effects of CLA on appetite.
16. Belury et al. (2003)
CLA 8g/d vs. Placebo
N= n/a, subjects with diabetes mellitus type II
Duration: 8 weeks
Outcome: Plasma-levels of t10,c12- but not c9,t11-CLA were negatively associated with body weight and serum-leptin
17. Kreider et al. (2002)
6g/d CLA vs Placebo
N = 23 healthy, training-experienced subjects
Duration: 28 days during an exercise program
Outcome: no significant effects of CLA on total body mass, fat-free mass, fat-mass, percent body-fat, bone-mass, strength.
18.Thom et al. (2001)
1.8 g/d CLA vs. placebo
N=20 healthy subjects with normal weight and BMI, exercising 3 x per week
Outcome: reduced body fat, no effects on body weight
19.Smedman and Vessby (2001)
4.2 g/d CLA vs. Placebo
N = 53 healthy subjects
Duration: 12 weeks
Outcome: reduction of body fat (3.8%). No effects on bodyweight, BMI, and sagittal abdominal diameter.
20. Riserus et al. (2001)
4.2 g/d CLA vs. Placebo
N=25 abdominally obese men
Duration: 4 weeks
Outcome: reduction of sagittal abdominal diameter.
21. Blankson et al. (2000)
CLA: 1.7 vs. 3.4 vs. 5.1 vs. 6.8 g/d vs. Placebo
N = 60 (47 completed the study), obese subjects
Duration: 12 weeks
Outcome: reduced body fat mass in the CLA groups (3.4 and 6.8 g/d). no effects on lean mass, BMI and blood variables.
22. Zambell et al. (2000)
3 g/d of CLA vs. Placebo
N = 17 healthy women
Duration: 64 days
Outcome: no effect of CLA on fat mass, fat-free mass and percentage body fat, energy expenditure, fat oxidation and respiratory exchange ratio.
CLA good or bad?
Linear Mode
