For several years, ITERG has been studying how to improve the bioavailability of omega-3s, and in particular that of the precursor alpha linolenic acid (ALA), in order to improve the nutritional status of the population.
ITERG is the benchmark in this sector, being one of the few teams to conduct numerous projects on this omega-3 of plant origin. Among the factors that influence the bioavailability of a fatty acid, the molecular distribution on the food TG is of particular importance. Indeed, ALA is a preferential substrate for beta-oxidation. Keeping ALA internally from the dietary structure to the target tissues of the body would allow it to be preserved and favour its storage and bioconversion into long n-3 chains (EPA and DHA) with recognised health properties.
In this context, ITERG is the only one to have monitored the impact of the molecular structure of TGs on the absorption phase of ALA, through projects carried out using combined oils (Boulos and Combe, 2000) or synthetic molecules in which the position of ALA was perfectly controlled (Couëdelo et al. 2011). These first data had reformed the received ideas according to which the internal position was strictly maintained by demonstrating that it was evolving during the stages of lipid absorption.
In the METATRIAL project, ITERG went further by studying the enrichment of ALA to be preferred in the internal position of TG food to improve both its bioavailability and its bioconversion into long chain omega 3 during a long-term diet.
ITERG was able to determine that in a diet, a distribution of up to 40% of ALA in the internal position of a dietary oil is necessary and sufficient to improve the levels of ALA in the blood and tissues of interest. Furthermore, ITERG has observed that enriching the internal position of ALA not only improves its bioavailability but also its bioconversion to EPA in red blood cells and liver. Above 40% in the internal position, it would then be the bioavailability of DHA that would be improved and not those of ALA and EPA.
This study demonstrates the interest in favouring the consumption of dietary triglycerides whose internal position is relatively rich in ALA (up to 40%) to improve its blood and tissue bioavailability as well as its bioconversion into EPA.
Contact: Leslie Couëdelo, Health Nutrition & Lipid Biochemistry Project Manager, ITERG