Addition of phospholipids to diet to enhance the bioavailability and incorporation of fish oil - omega-3-fatty acids

Long-chain (LC) omega-3 polyunsaturated fatty acids (LC omega-3 PUFA) are important in regulating inflammation, maintaining cell membrane integrity, and are required for healthy growth and development. For omega-3 fatty acids to perform their biological function, they must first be bioavailable to the target tissues. Studies have shown that numerous factors affect their bioavailability, such as the molecular carrier (ethyl ester (EE), triacylglycerol (TAG), phospholipid (PL), positional distribution, and the amount and type of fat consumed in the diet. While fatty fish is the best dietary source of LC omega- 3 PUFA, fish oil supplements are a common source for many people. Phospholipids, such as phosphatidylcholine, may improve the efficiency of the omega-3 fatty acids in target tissues when added to a diet containing added fish oil. Twenty-four adult Yucatan miniature pigs (females, 6-8 months old) were used in this study and divided into three iso-caloric diet groups (Western diet (WD), Western diet plus fish oil (FO), and Western diet plus fish oil and phospholipid (FO-PL)); they were fed ad-libitum for four hours per day. The first objective of this study was to determine the distribution of fatty acids in various organs of pigs consuming a diet containing FO (EPA+DHA, 2.7% of total fat) compared to pigs consuming a diet without fish oil (WD). The second objective of this study was to determine if PL added to a diet containing fish oil increased the tissue content of omega-3 fatty acids compared to a FO diet without added PL. The third objective of this study was to determine if PL added to a diet containing fish oil decreased the concentration of serum pro-inflammatory cytokines compared to FO diet. After four months of feed intake, various tissue samples were collected to analyze different fatty acid distributions. Fatty acid and lipid analysis were assessed in various organs and tissues. The total omega-3 fatty acid level was significantly higher in the FO group compared to the WD group. Interestingly, PL added to the diet increased the incorporation of the total omega-3 fatty acids measured in the brain (17.0%±8.0%) and heart (13.4% ±6.6%) compared to the other diet groups (p<0.05). For the distribution of omega-3 fatty acid in tissue PL, I found a significant increase in the distribution of total omega-3 fatty acid in the brain (9.7% ±4.1%) and retina (9.9 %±3.1%) in the FOPL group compared to FO group. Surprisingly, FOPL had a significantly higher serum concentration of tumor necrosis factor (TNFα) (0.098±0.067 ng/ml) compared to the FO group, and there was no significant effect observed for serum concentration of interleukin (IL-6) (p<0.05) across the dietary groups. It could be concluded that dietary FO and FOPC had a negligible effect on serum pro-inflammatory cytokines levels. However, adding phospholipid to the diet with fish oil improved the bioavailability of omega-3 fatty acids in most tissues.