The knowledge of the health effects of CLA on the human body is limited. However, CLA supplements are sold over the counter in several countries and various techniques are used to increase the content of CLA in food.

The CLARINeT study will be performed to investigate the effect of CLA on blood lipoproteins, inflammatory markers, blood pressure and insulin status in human volunteers relative to industrial trans fatty acids and to oleic acid.

It will be a double-blind randomized multiple cross-over trial with 3 treatments:

• CLA;
• Industrial trans fatty acids (as a positive control);
• Oleic acid (Cis 18:1, the monounsaturated fatty acid in unhydrogenated vegetable oils) as a reference fat.

Each volunteer receives each diet for three weeks, in random order, for a total of 9 weeks. Three weeks is sufficient to reach new stable lipoprotein levels.

Inclusion Criteria:

• age 18-65 years
• healthy

Exclusion Criteria:

• serum total cholesterol >= 6,5 mmol/L
• serum triglycerides > 2,3 mmol/L
• chronic diseases (such as diabetes, cardiovascular disease, kidney and liver dysfunction)
• use of cholesterol lowering medication
• use of blood pressure lowering medication
• high alcohol intake
• BMI > 30
• pregnant and lactation women
• unusual dietary requirements