Improved glycaemic response and attenuated post-prandial sugar-induced endothelial dysfunction by polyphenol-rich foods

英国广播公司今年（2014年6月10日）的新闻标题称“英格兰三分之一的成年人处于糖尿病的风口浪尖”。饮食（与运动）在许多疾病中起作用，但对于2型糖尿病，它几乎是唯一的风险因素。富含糖分的食物也是头条新闻，这个领域充满了争议。高糖食品受到了负面的报道，但在消费者中很受欢迎。制糖厂有一些问题，这些问题往往会改变食物的性质。人造甜味剂具有不希望的余味，并且不提供糖的口感或感官特性。一些企业和消费者都在寻求减糖，但很难实现。在这里，我们建议可以保持血糖水平，但使用多酚来减弱餐后的即时血糖峰值。这也将有助于减少糖，但不完全取代。我们将关注多酚，一组天然存在于水果、蔬菜、茶、咖啡和可可中的成分。我们将确定从富含多酚的食物补充剂或提取物中添加多酚是否能够通过两种方式降低患糖尿病的风险：通过减弱食用高糖餐后的糖峰值;也有助于保护血管壁细胞--内皮细胞的健康。由于糖峰值也损害这些血管壁，因此多酚被认为通过降低餐后糖水平间接地起作用，并且还通过直接作用于内皮细胞以通过各种生化机制提供保护，因此存在组合效应的可能性。首先，我们将评估哪种多酚是最好的，使用测定来测量它们抑制葡萄糖从食物进入血液的过程的能力。这些测定可以在数十种不同的多酚上相当快速地进行。我们还将培养血管细胞，并测试哪种多酚最能保护这些细胞免受高糖的破坏作用。这些重要的实验将使我们能够确定最适合人类研究的多酚。虽然在这方面已经有了一些知识，但我们已经改进了一些检测方法，并认为有必要确保我们拥有最好的多酚。然后，我们将使用数据库选择最好的多酚，并选择用于人类研究的食物。在这项研究中，我们将要求志愿者消耗碳水化合物，如面包和糖中的淀粉，并确定富含多酚的食物是否会抑制餐后血糖峰值。同时，我们将使用非侵入性技术测量血管壁的健康状况。这些实验将向我们展示志愿者体内的多酚是否可以改善血管健康并抑制葡萄糖峰值。我们还将在代谢综合征患者中测试这一点，这些人更超重，血糖水平永久性较高（但其水平低于糖尿病患者）。为了确定机制，我们将进行两种类型的实验。第一种是从正在接受手术的人身上提取细胞，用压力和多酚处理这些细胞，看看是否有任何保护作用。这些细胞代表了我们目前在体外实验室实验中最大的努力，以模拟人体内发生的事情。我们还将测试哪种食物在钝化糖峰值方面具有活性，但只使用健康正常体重的志愿者。所有这些本身不会导致索赔，但它会为潜在的应用打开大门，导致索赔或一系列索赔。食品工业将受益于潜在的成分来管理代谢综合征和降低发展2型糖尿病的风险，以及未来衡量成分这种影响的策略。公众将受益于获得改善糖代谢和处理的食物，从而降低糖尿病风险。

A BBC news headline this year (10th June 2014) stated "One in three adults in England 'on cusp' of diabetes". Diet (with exercise) plays a role in many diseases, but for type 2 diabetes, it is almost the only risk factor. Sugar-rich foods are also in the headlines, and the area is full of controversy. High sugar foods have received bad press, but are popular with the consumer. Sugar replacers have some problems, and these often change the food properties. Artificial sweeteners have undesirable aftertastes and provide none of the mouth-feel or sensory properties of sugar. Sugar reduction is sought by some companies and consumers, but is difficult to achieve. Here we suggest that it may be possible to retain sugar levels but use polyphenols to blunt the immediate sugar spike after a meal. This would also assist where sugar is reduced but not completely replaced. We will focus on polyphenols, a group of naturally occurring components of fruits, vegetables, tea, coffee and cocoa.We will determine if either adding polyphenols from sources such as polyphenol rich foods supplements or extracts are able to reduce the risk of developing diabetes in two ways: by blunting the sugar-spikes seen after consumption of a high sugar meal; and also by helping to preserve the health of the cells lining the blood vessel walls - the endothelial cells. There is the possibility of a combined effect, since the sugar spikes also damage these blood vessel walls, and hence polyphenols are proposed to act both indirectly by decreasing the after-meal sugar levels, and also by acting directly on the endothelial cells to give protection by various biochemical mechanisms. Firstly we will assess which polyphenols are best, using assays to measure their ability to inhibit the processes involved in getting glucose into the blood from the food. These assays can be performed quite rapidly on tens of different polyphenols. We will also grow cultured blood vessel cells and test which polyphenols are best at protecting these cells from the damaging effects of high glucose. These important experiments will allow us to determine the best polyphenols for the human study. Although there is already some knowledge in this area, we have improved some of the assays and feel it is necessary to be sure we have the best polyphenols.We will then choose the best polyphenols using a database and select the foods for the human study. In this study, we will ask volunteers to consume carbohydrates, as starch in bread and sugar, and determine if the polyphenol rich foods dampen down the after-meal sugar spikes. In parallel, we will measure the health of the blood vessel wall using a technique which is non-invasive. These experiments will show us whether polyphenols in volunteers can improve blood vessel health as well as dampen glucose spikes. We will also test this in people with metabolic syndrome, who are more overweight and have permanently higher blood sugar levels (but whose levels are lower than in diabetic patients).To determine the mechanisms, we will perform two types of experiment. The first is to take cells from people who are undergoing an operation and treat these cells with stresses and polyphenols to see if there is any protective effect. These cells represent our best effort currently for in vitro lab experiments to mimic what is going on in the human body. We will also test which of the individual foods are active in blunting the sugar spikes, but just using healthy normal weight volunteers.All of this will not lead to a claim itself, but it will open the door for potential applications leading to claims or series of claims. The food industry will benefit from potential ingredients to manage metabolic syndrome and reduce the risk of developing type 2 diabetes, and strategies to measure such effects of ingredients in the future. The public will benefit from access to foods which improve their sugar metabolism and handling, and so decrease diabetes risk.