Welcome to “Ask your pharmacist!”
D. is asking: « What is the optimal dose of conjugated linoleic acid (CLA) during dieting ? Are there any scientific studies proving its effect on weight loss? »
First off, thank you D. for your question! It’s a good one and is on the same track with the discussions we had last week on dieting. Here’s what we found out from scientific medical data bases:
With the increase of the prevalence of obesity on a global scale, using dietary supplements to help us lose weight faster and more efficient has become a trend. The efficiency of the majority of supplements used in weight loss has not been proven (yet).
One of these supplements is conjugated linoleic acid, or CLA. Conjugated linoleic acids represent a group if isomers of linoleic acid. These isomers are normally found in the fat of herbivores. The meat and milk of these animals contain moderate quantities of CLA. CLA has been investigated for a variety of effects on humans, ranging from anti-cancer effect to modifying the human body conformation. Some authors suggest that ingestion CLA will determine a loss in weight prin reducing the size of adipocytes and by altering their differentiation. They are thought to stimulate apoptosis and regulated the lipid metabolism. There is proof regarding the beneficial effects on the composition of the body of animals and humans.
A series of studies have linked CLA supplementation to weight loss and fatty depots decrease in humans.
A meta-analysis from 2012 has identified 15 clinical studies and evaluated the results of 7 of these studies (they chose the ones that met their criteria – one of which was that the study must have been at least 6 months in duration). An older meta-analysis shows significant differences between the weights of the patients from the CLA treated group and the placebo-treated one. A difference of 0.7 kg (medium; confidence level 95%: -1.09,-0.32). This new analysis shows a significant difference of 1.33 kg (medium; confidence level 95%: -1.79; -0.86) between the group treated with CLA and the placebo treated patients. This means that, in average, patients treated with CLA had a body weight of 1.33 kg smaller that the patients treated with placebo. The clinical relevance of these studies is small. Side-effects included diarrhea and constipation. Their conclusion is that the proof from the clinical studies is not sufficient to conclude that CLA supplementation has a beneficial effect in dieting.
Daily, a regular person will get between 15-174 mg of CLA, depending on their diet habits. Studies have shown doses of CLA up to 3.2g / day. (1, 2)
- Onakpoya IJ, Posadzki PP, Watson LK, Davies LA, Ernst E. The efficacy of long-term conjugated linoleic acid (CLA) supplementation on body composition in overweight and obese individuals: a systematic review and meta-analysis of randomized clinical trials. Eur J Nutr. 2012 Mar;51(2):127-34. PubMed PMID: 21990002. Epub 2011/10/13. eng.
- Whigham LD, Watras AC, Schoeller DA. Efficacy of conjugated linoleic acid for reducing fat mass: a meta-analysis in humans. Am J Clin Nutr. 2007 May;85(5):1203-11. PubMed PMID: 17490954. eng.
D., we hope you are satisfied with our answer to your question and do not hesitate to ask us another one 🙂
We would like your opinion on the matter. Have you used CLA to help you weight loss? What were the results? Leave your comment below!