Effect of cheddar cheese consumption on plasma conjugated linoleic acid concentrations in men

Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of linoleic acid with conjugated double bonds. Conjugated linoleic acid has anticarcinogenic properties and has been identified in human biological fluids and adipose tissue. The origin of CLA in humans is not known, but diet may be contributory. A variety of cheeses, including Cheddar, are good sources of CLA. To investigate the effect of Cheddar cheese consumption (112 g/day) on plasma phospholipid-esterified CLA concentrations, nine healthy men were studied. Cheddar cheese was added to their daily diets for four weeks. Three-day diet records and fasting blood samples were obtained. Protein and total fat intakes increased significantly during dietary intervention. Plasma CLA was significantly higher following Cheddar cheese feeding, exceeding by 19-27% the concentrations observed initially and following intervention. The molar ratio of CLA to linoleic acid also increased significantly following dietary intervention. Plasma concentrations of linoleic and arachidonic acids, cholesterol and phospholipids were not affected by cheese feeding. Since CLA may represent a protective factor against cancer, further study identifying dietary sources and the health benefits of CLA are warranted.