Effect of supplementation with tomato juice, vitamin E, and vitamin C on LDL oxidation and products of inflammatory activity in type 2 diabetes.

Abstract

Abbreviations: apo(a1), apolipoprotein A1; apo(b), apolipoprotein B; CHD, coronary heart disease; C-RP, C-reactive protein; ELISA, enzyme-linked immunosorbent assay; ICAM-1, intercellular adhesion molecule 1; IL, interleukin; PBS, phosphate-buffered saline; VCAM-1, vascular cell adhesion molecule 1.A OBJECTIVE -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.RESEARCH DESIGN AND METHODS -There were 57 patients with well-controlled type 2 diabetes aged Ͻ75 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.RESULTS -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 (Ϫ49%, 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.CONCLUSIONS -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.

Association between the intake of vitamins and trace elements from supplements and C-reactive protein: results of the MONICA/KORA Augsburg study

“…CRP levels were significantly lower in the multivitamin group after 6 months, but only plasma levels of vitamin B 6 and vitamin C were inversely associated with CRP levels Contrary to our results, where no significant effect of high dose vitamin C on levels of CRP was observed, Block et al (2004) demonstrated a 17% (À0.5 mg/l) reduction of plasma CRP (24% after adjustment for baseline plasma CRP and BMI) after 2 months supplementation with high dose vitamin C in healthy adults, actively or passively exposed to cigarette smoke. Our observations of a CRP lowering effect of vitamin E from supplements in women is supported by several intervention studies: A 49% (À2.7 mg/l) significant decrease in CRP levels was shown in patients with type 2 diabetes after 4 weeks of vitamin E (800 IU), but not for vitamin C (Upritchard et al, 2000). Furthermore, CRP was significantly lower after 6 months intake of vitamin E (400 IU) in smokers with acute coronary syndrome (Murphy et al, 2004).…”

Effect of supplementation with B vitamins and antioxidants on levels of asymmetric dimethylarginine (ADMA) and C-reactive protein (CRP): a double-blind, randomised, factorial design, placebo-controlled trial

“…Intervention studies have tried to clarify these ambiguous results; but these have also been inconclusive. Of those looking at the effects of vitamin E, three studies found statistically significant treatment effects [18][19][20]; and four found no treatment effect [24][25][26][27]. Most of these studies were conducted in disease state subjects, especially those which reported an effect, unlike the apparently healthy men with mildly elevated tHcy levels used in the current study; healthy subjects were also used in three of the four studies reporting no effect [24,25,27].…”

“…Additionally, those which reported an effect often used doses of vitamin E that were higher than those employed in the current study (e.g. 200 mg/d [18], 800 IU/d [19] and 1,200 IU/d [20]). With regard to vitamin C, three studies found statistically significant treatment effects [21][22][23], and two found no treatment effect [28,29].…”

“…As for ADMA, therapies that lower CRP as a marker of inflammation may therefore be expected to reduce CVD risk. A number of studies have suggested that antioxidant supplementation may lower CRP [18][19][20][21][22][23], but this is not always consistent [24][25][26][27][28][29][30]. Similarly, increasing levels of tHcy in cell cultures seems to promote IL-6 production by monocytes [31] and endothelial cells [32] and, therefore, B vitamins may also reduce CRP as a result of their tHcy-lowering potential.…”

Tomatoes versus lycopene in oxidative stress and carcinogenesis: conclusions from clinical trials

“…Upritchard et al (2000) showed a protective effect of 500 ml/day of tomato juice consumption on lipoprotein oxidation (42% increase in LDL lag time) in well-controlled type II diabetic patients.…”