Effects of conjugated linoleic acid on long term feeding in Fischer 344 rats.

Weanling male Fischer 344 rats were fed either control or diet containing 1% CLA for 18 months. Weight gain and survival rate were not different between treatments, but CLA-fed animals ate slightly less food. CLA feeding did not significantly reduce body fat compared to that of control. Clinical chemistry and hematology analyses were performed on blood samples at week 69-72. CLA had no effects except on blood glucose, which was reduced in CLA-fed animals compared to control. All animals had chronic renal failure at the end of the study; however, CLA decreased the amount of protein in urine at week 70 of feeding. Necropsy and histo-pathology results indicated that there was no difference between treatment groups. Although this study used a limited number of animals and a single dose of CLA, our results suggest that long term CLA feeding did not cause any adverse effects in rats.