A novel isotope ratio mass spectrometry method for the characterization of the effects of linoleic acid intake on DHA synthesis and turnover rates

在过去的世纪，饮食中ω-6多不饱和脂肪酸（PUFA）的比例，主要是亚油酸（LA）的形式，与ω-3多不饱和脂肪酸（PUFA）相比，已经大幅增加。我们饮食模式的这种变化被认为是降低omega-3状态的重要因素，特别是二十二碳六烯酸（DHA，22：6 n-3）。然而，大幅增加海洋来源的ω-3脂肪酸在生态上是不可持续的，需要替代和可持续的植物来源来解决人口ω-3状态下降的问题。据信，LA的高膳食摄入与从α-亚麻酸（ALA，18：3 n-3）合成DHA竞争，从而导致人群的低DHA状态。我们将使用一种新兴但强大的营养和代谢评估技术-化合物特异性同位素分析-根据碳13水平的自然变化来跟踪特定omega-3脂肪酸的代谢命运。具体而言，Ahiflower将被评估为高omega-3植物来源，与亚麻籽油相比，在高和低LA背景饮食中，DHA的合成和周转更快。在高或低LA背景饮食的存在下，将小鼠平衡到高碳-13藻类DHA饮食。6周后，动物将维持LA背景饮食，并从藻类DHA转换为低碳-13 Ahiflower油，亚麻籽油或鱼类DHA饮食。将测定组织和血液中ω-3碳-13含量的变化，并测定合成和周转率。Ahiflower油，由于其特定的omega-3脂肪酸配置文件将能够合成和周转DHA在血液和组织比亚麻籽快。因此，Ahiflower油可以提供一种可持续的，生态和环境可持续的替代海洋来源的omega-3，这是上级相比，亚麻籽油。此外，这项研究的结果将有助于扩大Ahiflower在加拿大的农业业务，并为加拿大人创造新的就业机会。

Over the past century, the ratio of dietary omega-6 polyunsaturated fatty acids (PUFA), primarily in the form oflinoleic acid (LA), has increased substantially compared to omega-3 PUFA. This change in our dietary patterns is believed to be a significant contributor to a lower omega-3 status, particularly in docosahexaenoic acid (DHA, 22:6n-3). However, substantial increases to marine sources of omega-3 fatty acids are ecologically unsustainable and alternative and sustainable plant sources are required to address lowered omega-3 status of the population. It is believed that the high dietary intake of LA competes with the synthesis of DHA from alpha-linolenic acid (ALA, 18:3n-3) thereby contributing to the low DHA status of the population. We will use an emerging but powerful technology for nutrition and metabolic assessment - compound-specific isotope analysis - to track the metabolic fate of specific omega-3 fatty acids based on natural variations in carbon-13 levels. Specifically, Ahiflower will be assessed as a high omega-3 plant source for a more rapid synthesis and turnover of DHA compared to flaxseed oil on both a high and low LA background diet. Mice will be equilibrated to high carbon-13 algal DHA diets in the presence of either high or low LA background diet. After 6 weeks, animals will be maintained on the LA background diet and switch from algal DHA to a low carbon-13 Ahiflower oil, flaxseed oil or fish DHA diet. Changes in omega-3 carbon-13 content of tissues and blood will be determined and synthesis and turnover rates determined. Ahiflower oil, due to it's specific omega-3 fatty acid profile will be able to synthesis and turn over DHA in blood and tissues faster than flaxseed. Therefore, Ahiflower oil may provide a sustainable, ecologically and environmentally sustainable alternative to marine sources of omega-3 that is superior compared to flaxseed oils. Furthermore, the results of this study will serve to expand the Ahiflower agriculture business in Canada and create new jobs for Canadians.