Ⅰ.Lower Lipid and Lose Weight by Pu’er Tea
In recent years, with the continuous improvement of people’s living standard, great changes have taken place in diet and living habits, and the problems of overweight and obesity have followed.Pu’er tea is favored by people because of its weight-losing and lipid-lowering effects.There have been many reports on the effect of Pu’er tea on weight loss in previous researches.It is particularly important to find out the mechanism of Pu’er tea for lowering lipid and losing weight and to drink tea scientifically and reasonably.
图6-4 普洱茶的降脂作用
研究发现，普洱茶能诱导3T3-L1前脂肪细胞内活性氧增加，抑制3T3-L1前脂肪细胞的增殖与分化，从而抵抗和防治代谢肥胖。此外，普洱茶可抑制体内脂肪合成途径中的关键酶——脂肪酸合成酶（FAS）的活性，从而阻滞生脂通路，使脂肪合成减少，并升高丙二酰辅酶A浓度，降低食欲，从而产生减肥作用。通过采用高脂饲料诱导肥胖大鼠模型研究了普洱茶的对肥胖、动脉粥样硬化的影响和抗氧化作用，发现普洱茶可显著抑制肥胖大鼠的体重增加，降低动脉粥样硬化风险因素，并抑制自由基活性。普洱茶以剂量依赖性的方式降低肥胖大鼠的体重和血清TC和TG水平，增加HDL-C水平、提高SOD等抗氧化酶的活性，降低脂质过氧化产物MDA的水平，这表明普洱茶可能具有清除过度积累的ROS和改善肥胖大鼠血脂氧化状态的功能。
Fig.6-4 Lipid-lowering effect of Pu’er tea
According to Yang Xinhe’s research, it is found that Pu’er tea can induce the increase of reactive oxygen in 3T3-L1 preadipocytes and inhibit the proliferation and differentiation of 3T3-L1 preadipocytes, thus resisting and preventing metabolic obesity.In addition, Pu’er tea can inhibit the activity of fatty acid synthase (FAS), a key enzyme in the body’s fat synthesis pathway, blocking the fat production pathway, reducing fat synthesis, increasing malonyl-CoA concentration and lowering appetite, thus reducing weight.Xiong Changyun et al.have found through research that Pu’er tea can significantly inhibit the weight gain of obese rats, reduce the risk factors of atherosclerosis, and inhibit the free radical activity.Pu’er tea lowers the weight and serum TC and TG levels of obese rats in a dose-dependent manner, increases HDL-C level, improves the activities of antioxidant enzymes such as SOD, and reduces the level of lipid peroxidation product MDA, which indicates that Pu’er tea might have the function of scavenging excessive accumulated ROS and improving the oxidation state of blood lipids in obese rats.
图6-5 普洱茶的减肥作用
用普洱茶对膳食诱导肥胖大鼠降低体质量及调节细胞因子的作用研究证实，普洱茶能降低饮食诱导的肥胖大鼠的体质量，Lee’s指数和脂肪系数，通过降低LDL-C水平和升高HDL-C水平，纠正失衡的脂质代谢。实验可见普洱茶具有显著降低血糖和胰岛素水平的功能，仅使用低剂量的普洱茶，肥胖小鼠的血糖和胰岛素水平就能回到正常对照水平。此外，普洱茶能降低炎症因子TNF-α和VEGF的质量浓度，提高脂联素等抗炎细胞因子水平，调节炎症和抗炎过程的平衡，调节IL-1α/IL-1β的比例。因此，普洱茶可以用作潜在的健康饮料，用于预防或治疗许多与营养性肥胖相关的疾病。同样通过高脂小鼠模型实验，发现晒青毛茶和普洱茶均能有效地抑制高脂饮食小鼠血脂的升高，并能使血清TG、TC、低密度脂蛋白胆固醇（LDL-C）水平全面降至正常值范围，同时升高高密度脂蛋白胆固醇（HDL-C）。另有研究发现普洱茶及其多酚氧化产物能有效调节预防性高脂小鼠血清血脂水平。还有研究表明乌龙茶和普洱茶均能显著调节机体的血脂水平，从而有效预防高脂血症。
Fig.6-5 Weight-losing effect of Pu’er tea
Feng Wei et al.have studied the effects of Pu’er tea on reducing weight and regulating cytokines in diet-induced obese rats.Pu’er tea can reduce the weight, Lee’s index and fat coefficient of diet-induced obese rats, and correct the unbalanced lipid metabolism by reducing LDL-C level and increasing HDL-C level.It can be seen from the experiment that Pu’er tea has the function of significantly reducing blood glucose and insulin level.With only low dose of Pu’er tea, the blood glucose and insulin level of obese rats can return to the normal control level.In addition, Pu’er tea can reduce the mass concentration of inflammatory factors TNF-α and VEGF,increase the level of anti-inflammatory cytokines such as adiponectin, coordinate the balance between inflammation and anti-inflammatory process, and regulate the ratio of IL-1α/IL-1β.Therefore, Pu’er tea can be used as a potential health beverage to prevent or treat many diseases related to nutritional obesity.Wu Wenhua et al.have found that sun-dried crude tea and Pu’er tea can effectively inhibit the increase of blood lipid in mice fed with high-fat diet, reduce serum TG and low-density lipoprotein cholesterol (LDL-C)level to normal values, and increase HDL-C at the same time.Fan Rong et al.have found in the research that Pu’er tea and its polyphenol oxidation products can effectively regulate the serum and blood lipid level of preventive hyperlipidemia mice.In 2009, the research of Jiang Xinfeng et al.showed that Wulong Tea and Pu’er tea can significantly regulate the level of blood lipid and effectively prevent hyperlipidemia.