Effects of Δ5 polyunsaturated fatty acids of maritime pine (Pinus pinaster) seed oil on the fatty acid profile of the developing brain of rats

Conifer (pine) seeds are a potential source of dietary oils, but their safety and nutritional properties are nor well established. Conifer seed oils differ from common edible vegetable oils in having a series of unusual polyunsaturated fatty acids (PUFA) with a polymethylene-interrupted (PMI) double bond system and a double bond at the Delta5 position. A rat study was conducted to assess whether Delta5 PMI-PUFA of conifer seeds could alter the levels of n-6 and n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in mothers' milk and the developing brain of fetuses and pups. Feeding maritime pine (Pinus pinaster) seed oil (MPO) diet with a Delta5 PMI-PUFA content of 1.4 g/100 g throughout pregnancy and lactation resulted in a large incorporation of Delta5 PMI-PUFA in mothers' milk (5.1 +/- 0.5% of total fatty acids). The fetus (17 d old) and pup (22 d) brains, however, accumulated very little (0.6 and 0.4% of total fatty acids, respectively) Delta5 PMI-PUFA. Mother's milk and pup's brain of the MPO group contained normal levels of 20:4n-6, 22:4n-6, and 20:5n-3 compared to a reference group of rats fed a fat blend of sunflower, high-oleic sunflower, and canola oils. The level of 22:6n-3, however, was slightly but significantly (P < 0.05) higher in milk and pup brain of the MPO group. These results show that <Delta>5 PMI-PUFA of MPO exert no negative effect on the levels of n-6 and n-3 LC-PU FA in rat brain during its early development.