Upritchard J E, Sutherland W H, Mann J I
Department of Human Nutrition, University of Otago, Dunedin, New Zealand.
Diabetes Care. 2000 Jun;23(6):733-8. doi: 10.2337/diacare.23.6.733.
To compare the effects of short-term dietary supplementation with tomato juice, vitamin E, and vitamin C on susceptibility of LDL to oxidation and circulating levels of C-reactive protein (C-RP) and cell adhesion molecules in patients with type 2 diabetes.
There were 57 patients with well-controlled type 2 diabetes aged <75 years treated with placebo for 4 weeks and then randomized to receive tomato juice (500 ml/day), vitamin E (800 U/day), vitamin C (500 mg/day), or continued placebo treatment for 4 weeks. Susceptibility of LDL to oxidation (lag time) and plasma concentrations of lycopene, vitamin E, vitamin C, C-RP, vascular cell adhesion molecule 1, and intercellular adhesion molecule 1 were measured at the beginning of the study, after the placebo phase, and at the end of the study.
Plasma lycopene levels increased nearly 3-fold (P = 0.001), and the lag time in isolated LDL oxidation by copper ions increased by 42% (P = 0.001) in patients during supplementation with tomato juice. The magnitude of this increase in lag time was comparable with the corresponding increase during supplementation with vitamin E (54%). Plasma C-RP levels decreased significantly (-49%, P = 0.004) in patients who received vitamin E. Circulating levels of cell adhesion molecules and plasma glucose did not change significantly during the study.
This study indicates that consumption of commercial tomato juice increases plasma lycopene levels and the intrinsic resistance of LDL to oxidation almost as effectively as supplementation with a high dose of vitamin E, which also decreases plasma levels of C-RP, a risk factor for myocardial infarction, in patients with diabetes. These findings may be relevant to strategies aimed at reducing risk of myocardial infarction in patients with diabetes.
比较短期膳食补充番茄汁、维生素E和维生素C对2型糖尿病患者低密度脂蛋白（LDL）氧化易感性、C反应蛋白（C-RP）循环水平及细胞黏附分子的影响。
57例年龄<75岁、2型糖尿病病情控制良好的患者接受4周安慰剂治疗，然后随机分为接受番茄汁（500毫升/天）、维生素E（800国际单位/天）、维生素C（500毫克/天）或继续接受4周安慰剂治疗。在研究开始时、安慰剂治疗阶段结束后及研究结束时，测量LDL氧化易感性（延迟时间）以及血浆中番茄红素、维生素E、维生素C、C-RP、血管细胞黏附分子1和细胞间黏附分子1的浓度。
在补充番茄汁期间，患者血浆番茄红素水平增加近3倍（P = 0.001），分离出的LDL被铜离子氧化的延迟时间增加42%（P = 0.001）。延迟时间增加的幅度与补充维生素E期间相应的增加幅度（54%）相当。接受维生素E的患者血浆C-RP水平显著降低（-49%，P = 0.004）。在研究期间，细胞黏附分子的循环水平和血浆葡萄糖水平无显著变化。
本研究表明，饮用市售番茄汁可提高血浆番茄红素水平，且LDL对氧化的内在抵抗力提高的效果几乎与补充高剂量维生素E一样，维生素E还可降低糖尿病患者血浆中C-RP（心肌梗死的一个危险因素）的水平。这些发现可能与旨在降低糖尿病患者心肌梗死风险的策略相关。
