The objective of this study is to investigate the conversion of the precursors ALA and SDA into n-3 LC-PUFA (EPA, DPA and DHA) in humans by oral supplementation of Echium oil in comparison with SDA soybean oil (positive control). In addition, the accumulation of n-3 LC-PUFA is compared between subpopulations of different age, gender and physiological conditions (overweight, increased serum total cholesterol).

N-3 PUFA are important for human health and nutrition. Due to the increasing world population, overfishing of the seas and generally low amounts of n-3 PUFA in major oil crops, there is a demand for new sources of n-3 PUFA.

One approach involves searching for potential vegetable sources of n-3 PUFA; especially those rich in ALA and SDA. The conversion of ALA to SDA in humans depends on the rate-limiting ∆6-desaturation. Plant-derived SDA is therefore a promising precursor regarding endogenous synthesis of n-3 LC-PUFA in humans. The enrichment of n-3 LC-PUFA in human lipids during the supplementation of ALA- and SDA-rich Echium oil will be compared with SDA-rich soybean oil.

Eighty volunteers will be recruited and allocated into four study groups depending on age and BMI. Three groups (each n=20) will receive daily ca. 20 g Echium oil ( group 1 and 2: mean BMI < 25, with mean age: 25 or 55 years; group 3: mean age 55 and BMI > 25). One group (n=20) will receive SDA soybean oil ( dose with comparable amount of SDA; BMI < 25; mean age 25 and 55). The double-blind, randomized, parallel-designed study will start with a two-weeks run-in period, followed by an eight-weeks supplementation period. After the run-in period, one week and eight weeks of oil supplementation blood will be drawn and 24-h urine will be sampled.

Inclusion Criteria:

• healthy subjects

Exclusion Criteria:

• cholesterol lowering drugs
• chronic diseases
• pregnancy, lactation
• intake of nutritional supplements