DDW: Diet Supplement Reduces Abdominal Fat But Fails to Help Insulin Sensitivity
By Peggy Peck, MedPage Today Staff Writer
Reviewed by Rubeen K. Israni, M.D., Fellow, Renal-Electrolyte and Hypertension Division, University of Pennsylvania School of Medicine
May 23, 2006
MedPage Today Action Points
* Explain to patients who ask that conjugated linoleic acid is an ingredient in many over-the-counter supplements.
* This study was published as an abstract and presented in a poster at a conference. These data and conclusions should be considered to be preliminary as they have not yet been reviewed and published in a peer-reviewed publication.
Review
Lee M. Kaplan, M.D., Ph.D. Massachusetts General
LOS ANGELES, May 23 — Overweight and obese patients who used a conjugated linoleic acid supplement for six months reduced abdominal fat, but that reduction failed to increase insulin sensitivity, researchers reported here.
Overweight and obese volunteers who took 3.5 grams/day of conjugated linoleic acid reduced waist circumference by a little less than 1.5 inches (P<0.001) and waist-hip ration was reduced by -0.024 (P=0.017), said Sandra Einerhand, Ph.D., research director at Lipid Nutrition, a division of Loders Croklaan in Wormerveer, The Netherlands.
Conjugated linoleic acid is sold under a number of brand names as an over-the-counter supplement.
Working with independent research centers in Norway, Dr. Einerhand recruited 118 obese and overweight adults, who were evenly randomized to conjugated linoleic acid supplementation or olive-oil capsule placebo, she reported at Digestive Disease Week sessions here.
In addition to height and weight measurements, Dr. Einerhand and colleagues assessed insulin sensitivity by use of euglycemic clamp.
After six months, patients in the conjugated linoleic acid group had reduced body fat mass by 5.6% (P=0.004 compared with placebo) and the reduction in fat mass was observed beginning at three months, she said.
Dr. Einerhand said conjugated linoleic acid was not associated with adverse effects on lipids, but she did not present lipid data.
Asked about a potential mechanism, Dr. Einerhand said that evidence from animal studies suggests that two conjugated linoleic acid isomers (cis-9, trans-11 conjugated linoleic acid and trans-10, cis-12 conjugated linoleic acid) work together to inhibit fat uptake by fat cells and instead send fat to muscle cells where it is burned off.
Among the findings:
* At three months, patients in the conjugated linoleic acid group had lost an average of 0.7 kg (1.54 pounds).
* In women fat reduction occurred in abdomen and legs, but in men fat loss was confined to the abdomen.
* After six months the average weight loss was 1.5 kg or about 3.3 pounds (P=0.05 compared with placebo).
But while the conjugated linoleic acid treatment did appear to reduce abdominal fat, insulin sensitivity was unaffected.
Lee M. Kaplan, M.D., Ph.D, director of the MGH Weight Center at Massachusetts General Hospital, said that disconnect between loss of visceral fat and evidence of metabolic change may reflect the study design. "The study many not be powered to detect a metabolic change or it may be that weight loss associated with CLA really has no effect on metabolism," he said.
Dr. Kaplan moderated a DDW press conference where Dr. Einerhand presented her findings.
Primary source: Digestive Disease Week
Source reference:
Einerhand, AW et al "Six months supplementation with conjugated linoleic acid decreases fat mass region-specifically in overweight and obese," Abstract 360.
By Peggy Peck, MedPage Today Staff Writer
Reviewed by Rubeen K. Israni, M.D., Fellow, Renal-Electrolyte and Hypertension Division, University of Pennsylvania School of Medicine
May 23, 2006
MedPage Today Action Points
* Explain to patients who ask that conjugated linoleic acid is an ingredient in many over-the-counter supplements.
* This study was published as an abstract and presented in a poster at a conference. These data and conclusions should be considered to be preliminary as they have not yet been reviewed and published in a peer-reviewed publication.
Review
Lee M. Kaplan, M.D., Ph.D. Massachusetts General
LOS ANGELES, May 23 — Overweight and obese patients who used a conjugated linoleic acid supplement for six months reduced abdominal fat, but that reduction failed to increase insulin sensitivity, researchers reported here.
Overweight and obese volunteers who took 3.5 grams/day of conjugated linoleic acid reduced waist circumference by a little less than 1.5 inches (P<0.001) and waist-hip ration was reduced by -0.024 (P=0.017), said Sandra Einerhand, Ph.D., research director at Lipid Nutrition, a division of Loders Croklaan in Wormerveer, The Netherlands.
Conjugated linoleic acid is sold under a number of brand names as an over-the-counter supplement.
Working with independent research centers in Norway, Dr. Einerhand recruited 118 obese and overweight adults, who were evenly randomized to conjugated linoleic acid supplementation or olive-oil capsule placebo, she reported at Digestive Disease Week sessions here.
In addition to height and weight measurements, Dr. Einerhand and colleagues assessed insulin sensitivity by use of euglycemic clamp.
After six months, patients in the conjugated linoleic acid group had reduced body fat mass by 5.6% (P=0.004 compared with placebo) and the reduction in fat mass was observed beginning at three months, she said.
Dr. Einerhand said conjugated linoleic acid was not associated with adverse effects on lipids, but she did not present lipid data.
Asked about a potential mechanism, Dr. Einerhand said that evidence from animal studies suggests that two conjugated linoleic acid isomers (cis-9, trans-11 conjugated linoleic acid and trans-10, cis-12 conjugated linoleic acid) work together to inhibit fat uptake by fat cells and instead send fat to muscle cells where it is burned off.
Among the findings:
* At three months, patients in the conjugated linoleic acid group had lost an average of 0.7 kg (1.54 pounds).
* In women fat reduction occurred in abdomen and legs, but in men fat loss was confined to the abdomen.
* After six months the average weight loss was 1.5 kg or about 3.3 pounds (P=0.05 compared with placebo).
But while the conjugated linoleic acid treatment did appear to reduce abdominal fat, insulin sensitivity was unaffected.
Lee M. Kaplan, M.D., Ph.D, director of the MGH Weight Center at Massachusetts General Hospital, said that disconnect between loss of visceral fat and evidence of metabolic change may reflect the study design. "The study many not be powered to detect a metabolic change or it may be that weight loss associated with CLA really has no effect on metabolism," he said.
Dr. Kaplan moderated a DDW press conference where Dr. Einerhand presented her findings.
Primary source: Digestive Disease Week
Source reference:
Einerhand, AW et al "Six months supplementation with conjugated linoleic acid decreases fat mass region-specifically in overweight and obese," Abstract 360.