Note: CLA is found mainly in meat and dairy products, and in greater amounts from grass-fed animals.
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Unique Identifier
   20287658
  Authors
   Azain MJ.  Hausman DB.  Sisk MB.  Flatt WP.  Jewell DE.
  Institution
   Departments of Animal and Dairy Science and. Foods and Nutrition,
   University of Georgia, Athens, GA 30602, USA.
  Title
   Dietary conjugated linoleic acid reduces rat adipose tissue cell size
   rather than cell number.
  Abbreviated Source
   J Nutr.  130(6):1548-54, 2000 Jun.
  
  Abstract
   We investigated the basis for the reduction in fat pad size in rats fed
   conjugated linoleic acid (CLA). In the first study, growing female
   Sprague-Dawley rats (initial weight150 g) were fed diets containing 0,
   0.25 and 0.5 g/100 g diet of a purified (97% CLA) and 0.5% of a feed-grade
   (55% CLA) source of CLA for 5 wk to determine the effects on growth
   performance and fat mass. There was no effect of CLA on growth rate or
   food intake. Dietary CLA reduced retroperitoneal fat pad weight 13, 25 and
   32% in rats fed 0.25 and 0. 5% of the pure CLA and 0.5% of the feed-grade
   CLA, respectively (P < 0.05). Similar effects were observed in the
   parametrial fat pad. The reduced pad size was due to smaller adipocyte
   size rather than a reduced cell number. Relative to the control group,
   mean cell volume was 15, 28 and 29% lower in tissue from rats fed 0.25 and
   0.5% of the pure CLA and 0.5% of the feed-grade CLA, respectively (P <
   0.01). In the second study, rats were fed CLA (0 vs. 0.5%) for 7 or 49 d.
   Reductions in fat pad weight were observed within 7 d. In addition, the
   effects of CLA on energy metabolism were studied in the chronically fed
   rats. There were no significant effects of CLA on oxygen consumption,
  CO(2) or heat production. During wk 4 of feeding, but not at other times,
   there was a 5% lower respiratory quotient in CLA-fed rats (P < 0.05).
   There was a time-dependent accumulation of CLA in adipose tissue and a
   decrease in monounsaturated fatty acids. These results suggest that the
   reduction in fat mass in rats fed CLA can be accounted for by a reduction
   in cell size rather than a change in cell number.