Can oils derived from genetically-modified plants replace fish oil as a source of long chain n-3 polyunsaturated fatty acids in the human diet?

Omega-3脂肪称为EPA和DHA，对人体健康有益。它们降低了患心脏病的几率，并可以控制关节炎等炎症的症状。EPA和DHA的主要食物来源是富含脂肪的鱼类，如鲑鱼和沙丁鱼。EPA和DHA也存在于鱼油补充剂中。英国政府建议人们定期食用EPA和DHA以保持健康，特别是在衰老期间。然而，许多人并不遵循这些建议，部分原因是他们不喜欢吃脂肪鱼或觉得它太贵。此外，海洋中没有足够的鱼类为世界上每个人提供足够的EPA和DHA来保持健康，鱼类资源正在下降。因此，需要找到一种可持续的EPA和DHA来源，可以增加，以满足对这些健康脂肪的需求。由BBSRC赞助的研究导致了可以生产EPA和DHA的植物的发展。这是通过将制造EPA和DHA所需的基因插入通常不具有这些基因的植物中来实现的。这些所谓的转基因植物的种子中产生的油含有与鱼油相似数量的EPA和DHA。因此，这种种子油可以用来取代脂肪鱼和鱼油补充剂，作为EPA和DHA的可持续和廉价来源。然而，植物产生的油的结构与鱼油不同，并且不知道这种差异是否会导致植物油成为人们更好或更差的EPA和DHA来源。了解这一点很重要，因为如果植物油在增加人们血液和组织中EPA和DHA的含量以及有益健康方面不如鱼油有效，那么它作为饮食中EPA和DHA的来源可能不那么有吸引力。该项目将确定植物油是否与鱼油一样有效地改变血液中EPA和DHA的含量，并改变与健康相关的一些过程。在后者方面，我们计划研究血液中胆固醇等脂肪的浓度，以及从血液中提取的免疫细胞在实验室刺激时的反应能力。我们将从两个方面实现我们的目标。首先，我们将招募两个年龄组（18至30岁或50至65岁）的健康男性和女性参加一项研究，该研究涉及食用含有鱼油或新植物油的单一膳食。然后，我们将在接下来的8小时内采集一系列血液样本。这将使我们能够评估来自植物油的EPA和DHA是否能像鱼油一样被肠道有效吸收。我们还将比较两种油对脂肪水平和血液中免疫功能相关物质的影响。第二，我们将招募另一组健康志愿者，并为他们提供鱼油或植物油作为膳食补充剂，为期8周以上。我们将在4周和8周后采集血液样本，比较不同油对血液和血细胞中EPA和DHA水平的影响。我们还将比较这些油对免疫功能、血液中脂肪水平和白色血细胞中基因活性的影响。研究结果将显示植物油在提高血液中EPA和DHA水平以及改变免疫功能方面是否与鱼油一样有效。我们期望，该项目的研究结果将为支持或反对使用植物油作为鱼油的替代品提供强有力的证据。此外，这些结果将有助于继续辩论转基因作物引入农业实践。最终，我们希望积极的结果将导致使用植物油作为英国饮食中EPA和DHA的主要来源，因为这将对海洋生态和英国人口的健康产生重要的积极影响。

Omega-3 fats called EPA and DHA are known to be beneficial to human health. They lower the chance of getting heart disease and can control the symptoms of conditions that involve inflammation such as arthritis. The main food source of EPA and DHA is fatty fish like salmon and sardines. EPA and DHA are also found in fish oil supplements. The UK government recommends that people consume EPA and DHA regularly in order to stay healthy, particularly during ageing. However, many people do not follow these recommendations, partly because they do not like to eat fatty fish or find it too expensive. Also, there are not enough fish in in the sea to provide everyone in the world with enough EPA and DHA to stay healthy, and fish stocks are declining. Therefore, there is a need to find a sustainable source of EPA and DHA that can be increased in order to meet the need for these healthy fats. Research sponsored by the BBSRC has led to the development of plants that can make EPA and DHA. This has been achieved by inserting the genes needed for making EPA and DHA into plants that do not normally have those genes. The oil produced in the seeds of these so-called transgenic plants contains similar amounts of EPA and DHA to fish oils. Therefore, it is possible that this seed oil could be used to replace fatty fish and fish oil supplements as a sustainable and inexpensive source of EPA and DHA. However, the structure of the oil produced by the plants is different from that of fish oils, and it is not known whether this difference would result in the plant oil being a better or worse source of EPA and DHA for people. It is important to know this, because if the plant oil was less effective than fish oil in increasing the amount of EPA and DHA in people's blood and tissues, and in benefiting health, then it may be less attractive as a source of EPA and DHA in the diet. This project will determine whether the plant oil is as effective as fish oil in changing the amounts of EPA and DHA in the blood and in modifying some processes that are related to health. In the latter regard, we plan to study the concentrations of fats like cholesterol in the blood and the ability of immune cells taken from the blood to respond when stimulated in the laboratory. We will address our aims in two ways. First, we will recruit healthy men and women in two age groups (18 to 30 years or 50 to 65 years) to take part in a study that involves consuming a single meal containing either fish oil or new plant oil. We will then take a series of blood samples over the following 8 hours. This will allow us to assess whether EPA and DHA derived from the plant oil are absorbed as efficiently by the gut as when they are provided as fish oil. We will also compare the effect of the two oils on the levels of fat and on substances involved in immune function in blood. Second, we will recruit another group of healthy volunteers as above, and provide them with fish oil or plant oil as a dietary supplement to take over 8 weeks. We will take blood samples after 4 and 8 weeks and compare the effect of the different oils on the levels of EPA and DHA in blood and in blood cells. We will also compare the effect of these oils on immune function, the levels of fat in blood, and on the activity of genes in white blood cells. The findings will show whether the plant oil is as effective as fish oil in raising the levels of EPA and DHA in blood and in changing immune function. We expect that the findings of this project will provide strong evidence for or against using the plant oil as a replacement for fish oil. Furthermore, these results will contribute to the continuing debate about the introduction of transgenic crops into agricultural practice. Ultimately, we hope that a positive outcome will lead to the use of the plant oil as a major source of EPA and DHA in the UK diet as this would have important positive implications for marine ecology and for health of the UK population.