Bk. Herbel et al., SAFFLOWER OIL CONSUMPTION DOES NOT INCREASE PLASMA CONJUGATED LINOLEIC-ACID CONCENTRATIONS IN HUMANS, The American journal of clinical nutrition, 67(2), 1998, pp. 332-337
Conjugated linoleic acid (CLA) is a mixture of positional and geometri
c isomers of linoleic acid (LA) with conjugated double bonds. CLA has
anticarcinogenic properties and has been identified in human tissues,
dairy products, meats, and certain vegetable oils. A variety of animal
products are good sources of CLA, but plant oils contain much less. H
owever, plant oils are a rich source of LA, which may be isomerized to
CLA by intestinal microorganisms in humans. To investigate the effect
of triacylglycerol-esterified LA consumption on plasma concentrations
of esterified CLA in total lipids, a dietary intervention (6 wk) was
conducted with six men and six women. During the intervention period a
salad dressing containing 21 g safflower oil providing 16 g LA/d was
added to the subjects' daily diets. Three-day diet records and fasting
blood were obtained initially and during dietary and postdietary inte
rvention periods. Although LA intake increased significantly during th
e dietary intervention, plasma CLA concentrations were not affected. P
lasma total cholesterol and LDL-cholesterol concentrations were signif
icantly lower after addition of safflower oil to the diet. In summary,
consumption of triacylglycerol-esterified LA in safflower oil did not
increase plasma concentrations of esterified CLA in total lipids.