Factors Affecting the Absorption and Distribution of Omega-3 Fatty Acids When Supplemented as Fish Oil Triacylglycerides: What is the impact of Supplemental Phosphatidylcholine?

Efe Obade, Ph.D. student

Monday 29^th Nov

Time: 1-2 PM

Direct link Webex.

https://mun.webex.com/mun/j.php?MTID=me15d64a2acaec2b0b4c7530018f87ebe

Abstract

Omega-3 fatty acids (n3-FAs) are long-chain - polyunsaturated fatty acids; they are necessary for neuronal development in infants and children, important in regulating inflammation and maintaining cell membrane integrity. Alpha-linolenic acid (ALA) is an essential n3-FA that must be acquired in the diet by most animals. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are two biologically important, but non-essential n3-FAs synthesized from ALA. For n3-FAs 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 molecular carrier (ethyl ester (EE), triacylglycerol (TAG), phospholipid (PL), positional distribution, and high-fat consumption.  Fish oils are a good source of n3-FAs, primarily as triglycerides, but studies have shown that fish oil alone does not increase tissue accretion of n3-FAs. Supplemental phosphatidylcholine (PC) participates in lipid reassembling in the enterocyte and micelles formation, which may impact the speed of fat absorption.  Recent studies indicate that PC-n3-FA (e.g., krill oil) shows promise as a dietary source with high bioavailability but is cost-prohibitive for many consumers. Therefore, combining n3-FA in TAG form with supplemental PC (e.g., PC as soy lecithin) may be an alternative approach to increasing bioavailability. In this study, 24 adult Yucatan miniature pigs (females, 6-8 months old) were divided into three iso-caloric diet groups (Western diet (WD), Western diet plus fish oil (FO), and WD plus FO and PC  (FO-PC)); they were fed ad-libitum for four hours per day.  This study investigated 1) if adding PC would enhance the incorporation of n3-FAs into selected tissues. 2) the FO-PC group will have an increase n3-FAs – PC concentrations in tissues. After four months of feeding, the pigs underwent necropsy, and various tissue samples were collected to analyze different fatty acid distribution. Fatty acid and lipid analysis was assessed in various organs and tissues. As expected, the level of n3-FAs was significantly increased in FO and FO-PC groups compared to the WD group. Interestingly, FO-PC had the highest distribution of omega-3 fatty acid in the brain (16.31%±5.68%), heart (16.71%±12.82%), retina (30.89%±8.28%) compared to FO groups. However, the FO group had the highest distribution of n3-FAs in the liver (13.0%±6.30%) than the FO-PC group(p<0.05). This study's outcomes could identify the beneficial effects of supplemental phosphatidylcholine in improving the bioavailability of n3-FAs.

Funding: NSERC, Ocean Frontier Institute