Incorporation and metabolism of punicic acid in healthy young humans

The objective of this study was to investigate the incorporation and metabolism of punicic acid (PA, cis9,trans11,cis13-18:3) in healthy young humans. The study was a randomized controlled trial. After 7 days adaptation with sunflower seed kernels supplementation, 30 subjects were then divided into the control and test group (n = 15). The test group was supplemented with Trichosanthes kirilowii (TK) seed kernels containing 3 g of PA per day in the form of triacylglycerols for 28 days. The control group was provided with sunflower seed kernels. After consumption of TK seeds containing 3 g PA per day for 28 days, the proportion of PA was increased from 0.00 to 0.47% in plasma and 0.00 to 0.37% in red blood cell membranes (RBCM), respectively. The proportion of cis9,trans11-18:2 was increased from 0.05 to 0.23% in plasma and 0.03 to 0.17% in RBCM after 28 days of intervention, respectively. Our results suggest that PA can be effectively incorporated into human plasma and RBCM, and is also associated with the increasing proportion of cis9,trans11-18:2 in humans, presumably as a result of metabolism by a saturation reaction. Edible TK seeds could be a potential dietary source of conjugated linoleic acids.