Cobalamin status is negatively correlated with vascular endothelial-cadherin in vegetarian and vegan women with vitamin B12 deficiency.

Optimal vitamin B12 status is important for vascular health. Vascular endothelial (VE) cadherin is an adherent junction protein involved in the maintenance of a functional endothelium. We hypothesized that vitamin B12 deficiency can negatively affect markers of vascular function, such as VE-cadherin. Within a human intervention study, we explored the possible association between cobalamin status (i.e., vitamin B12, holotranscobalamin, and homocysteine) and VE-cadherin (as marker of vascular health) in vegetarians/vegans (VEG) with B12 deficiency. The associations were evaluated at baseline and after 90-day supplementation with 2000 µg/wk of vitamin B12. On the whole, an inverse association between VE-cadherin and holotranscobalamin (P = .014) and a positive association between VE-cadherin and homocysteine (P = .041) was documented at baseline. VEG women showed higher levels of VE-cadherin compared with VEG men (P = .044), suggesting an increase in endothelial permeability. The intervention with vitamin B12 restored serum vitamin levels and improved the overall cobalamin status, whereas it did not affect VE-cadherin levels. The inverse association between holotranscobalamin and VE-cadherin was also maintained after intervention in women, corroborating the strong correlation between these 2 parameters. The results obtained seem to suggest a possible association between cobalamin status and VE-cadherin even if the intervention with B12 failed to positively affect VE-cadherin levels. Thus, further studies are needed to corroborate these findings and clarify the contribution of a vitamin B12 intervention on VE-cadherin levels in this target population. This trial was registered at ISRCTN registry (ISRCTN75099618).

Effect of two different sublingual dosages of vitamin B12 on cobalamin nutritional status in vegans and vegetarians with a marginal deficiency: A randomized controlled trial.

BACKGROUND & AIMS: Vegetarians and vegans are more vulnerable to vitamin B12 deficiency with severe risks of megaloblastic anemia, cognitive decline, neuropathy, and depression. An easy and simple method of supplementation consists of taking one weekly dosage of 2000 µg. However, single large oral doses of vitamin B12 are poorly absorbed. The present research evaluates the ability of two different sublingual dosages of vitamin B12 (350 µg/week vs 2000 µg/week) in improving cyanocobalamin (vitamin B12) nutritional status in vegans and vegetarians with a marginal deficiency. METHODS: A 12-week randomized, double-blind, controlled, parallel intervention trial was performed. Forty subjects with marginal vitamin B12 deficiency were enrolled and randomly divided into two groups: test group Ld (low dose, 350 µg/week) and control group Hd (high dose, 2000 µg/week) vitamin B12 supplementation. Blood samples were collected at baseline and after 15, 30, 60, and 90 days from the intervention for the determination of vitamin B12, related metabolic markers, and blood cell counts. RESULTS: Two-way analysis of variance showed a significant effect of time (P < 0.0001) and of time × treatment interaction (P = 0.012) on serum concentration of vitamin B12 that increased after 90-day supplementation (Ld and Hd) compared to baseline. Both the supplements increased (P < 0.0001, time effect) the levels of holotranscobalamin, succinic acid, methionine and wellness parameter, while decreased (P < 0.0001, time effect) the levels of methylmalonic acid, homocysteine and folate compared to baseline. No difference was observed between groups (Ld vs Hd). No effect was detected for vitamin B6 and blood cell count. CONCLUSIONS: In our experimental conditions, both supplements were able to restore adequate serum concentrations of vitamin B12 and to improve the levels of related metabolic blood markers in subjects with a marginal deficiency. The results support the use of a sublingual dosage of 50 µg/day (350 µg/week) of cobalamin, instead of 2000 µg/week (provided as a single dose), to reach a state of nutritional adequacy of vitamin B12 in this target population. This study was registered at www.isrctn.org as ISRCTN75099618.

Benefits of breakfast meals and pattern of consumption on satiety-related sensations in women.

This study evaluated the effects on satiety-related sensations of seven isoenergetic cereal-based breakfasts and two fruit products (salad and juice) consumed within breakfast or as a midmorning snack. Nine healthy women participated to 11 sessions following a randomized repeated-measures design. Subjects were asked to consume seven breakfasts consisting of a standard beverage and a different cereal-based product, and also fruit salad or apricot juice consumed within breakfast or as a midmorning snack. Satiety, desire-to-eat and perceived characteristics of products consumed were monitored on Visual Analog Scales from 8:30 am until lunch. Ratings registered and areas under the curve of sensations were analyzed by repeated-measures ANOVA. All breakfast meals maintained the satiety-related sensations at lunch time higher than basal values. The best satiety control was obtained when the fruit salad was consumed as a midmorning snack. Consequently, regular consumption of breakfast and of whole fruit as midmorning snack may be a valid strategy to achieve appetite control.

Modulation of plasma antioxidant levels, glutathione S-transferase activity and DNA damage in smokers following a single portion of broccoli: a pilot study.

BACKGROUND: Broccoli is a rich source of bioactive compounds (i.e. glucosinolates, carotenoids, vitamin C and folate) that may exert an antioxidant effect and reduce oxidative damage. The objective of this pilot study was to investigate the effect of broccoli consumption on carotenoids, vitamin C and folate absorption, glutathione S-transferase (GST) activity, and oxidatively induced DNA damage in male smokers. METHODS: Ten healthy subjects consumed a single portion of steamed broccoli (250 g) with cooked pasta. Blood was drawn at baseline and at 3, 6 and 24 h from consumption. RESULTS: Broccoli significantly (P ≤ 0.01) increased plasma level of vitamin C and folate (+35% and 70%, respectively) at 3 h, and ß-carotene (+8%) at 6 h. A modulation of GST activity occurred in plasma 6 h after broccoli consumption. A significant (P ≤ 0.01) reduction of the levels of H2O2-induced DNA damage (-18%) was observed in blood mononuclear cells 24 h after broccoli intake in GSTM1 positive, but not in GSTM1 null subjects. CONCLUSION: One portion of broccoli increased plasma antioxidant levels, modulated plasma GST activity and improved cell resistance against H2O2-induced DNA damage in healthy smokers. These results support the importance of consuming fruit and vegetable regularly.

Lycopene absorption in humans after the intake of two different single-dose lycopene formulations.

Lycopene is the main carotenoid present in tomato and its derivatives. It can also be obtained from the fungus Blakeslea trispora and its use as novel food ingredient was recently approved. The aim of the present study was to investigate the absorption of lycopene, in humans, after the intake of a single dose providing 15mg of lycopene from tomato extract (oleoresin 6%) or B. trispora (oil suspension 6%). Twelve female subjects were enrolled and divided into two groups: group 1 was assigned to the sequence tomato lycopene/wash-out/B. trispora lycopene, whereas group 2 followed the sequence B. trispora lycopene/wash-out/tomato lycopene. The formulations were consumed early in the morning with 5mL of sunflower oil, 100g of bread and 150mL of water. Blood was collected before consumption and after 2, 4, 6, 8, 10, 12 and 24h. Plasma lycopene concentrations were determined by HPLC analysis. On the whole, statistical analysis of data did not demonstrate a different effect of the type of lycopene source on the carotenoid absorption. The maximum increase in plasma lycopene concentration was about 40nmol/L for both products at 10-12h (p<0.05) post-consumption and decreased to basal values at 24h. A transient higher increase in lycopene concentration at 4-6h (p<0.05) after tomato lycopene with respect to B. trispora lycopene intake was observed. In conclusion, the intake of a single dose of the two liposoluble lycopene formulations revealed a comparable, small, but significant increase in plasma lycopene concentrations.

Absorption of bioactive compounds from steamed broccoli and their effect on plasma glutathione S-transferase activity.

Cruciferous vegetables are characterized by high amounts of glucosinolates (GLSs) that are hydrolysed to isothiocyanates (ITCs) and other phytochemicals. The aim of the study was to verify the effect of broccoli intake on plasma levels of carotenoids, vitamins and ITCs and on glutathione S-transferase (GST) activity. Twenty healthy subjects, characterized for GSTM1 and GSTT1 genotype, participated in a cross-over intervention study (broccoli diet versus cruciferous-free diet). Subjects consumed a daily portion of broccoli (10 days, 200 g) providing glucosinolates (200 micromol non-indolyl ITCs evaluated by cyclocondensation reaction after myrosinase treatment), vitamin C (about 100 mg) and carotenoids (about 5 mg lutein and beta-carotene). An increase of folate, carotenoids and ITC plasma concentrations was found. The increase of plasma ITC concentration was independent of the GST genotype. Broccoli intervention did not affect plasma GST activity. Broccoli is a bioavailable source of diverse compounds whose effects on endogenous defence systems deserve further investigation.

Effect of a tomato drink intervention on insulin-like growth factor (IGF)-1 serum levels in healthy subjects.

There is concern that dietary factors can modulate the insulin-like growth factor (IGF) system. The aim of this work was to evaluate the effect of a tomato drink intervention providing small amounts of lycopene and other carotenoids on serum levels of IGF-1. Twenty healthy young subjects participated in a repeated measure double-blind, cross-over design. Subjects consumed 250 ml of a tomato drink or a placebo drink for 26 days separated by 26 days wash-out. The tomato drink intake increased plasma lycopene, phytoene, phytofluene, and beta-carotene concentrations by 0.22, 0.12, 0.13, and 0.18 micromol/L, respectively (P < 0.05). No significant effect of the tomato drink intake on IGF-1 levels was observed. However, changes in lycopene before and after each experimental period were inversely and significantly correlated with those of IGF-1 (r = -0.33, P < 0.05, N = 20). No correlation was found with the other carotenoids. A significant reduction of IGF-1 serum level (-5.7%) was observed in subjects (n = 11) with the highest plasma lycopene response but also IGF-1 levels following the tomato drink intake (P < 0.05). No effect was evident after the placebo treatment. The results suggest that further exploration of the role of tomato lycopene on IGF-1 modulation both on healthy and on subjects at risk is necessary.

Effect on appetite control of minor cereal and pseudocereal products.

Recent findings suggest that Western diets based on highly palatable foods are likely to be much less satiating than more traditional diets or those typical of less developed countries. In particular, some alternative crops (for example, buckwheat, oat, barley, spelt, rye, quinoa, amaranth) seem to be of great nutritional interest and to represent important recipes for healthier and typical regional foods. The objective of the present study was to investigate the effect on subsequent food intake and feelings of satiety of alternative oat bread, oat and buckwheat pasta and of quinoa as compared with their wheat counterparts and rice, respectively. Three different experiments (one specific for each alternative crop food) were conducted, all with a within-subjects design. The preloading paradigm strategy was used. Results showed that preload energy level influenced total energy intake (preload plus ad libitum test meal intake), larger preloads inducing more eating than smaller preloads. No effect of formulation was observed on energy intake, as the consumption of alternative crop formulations did not decrease the total energy intake as compared with that of the counterparts. Satiating efficiency indices (SEI) for alternative crop foods were higher with respect to traditional cereal foods. In particular, white bread was the least satisfying food (SEI =0.2) and the different time of consumption (for lunch or as a snack) did not affect energy intake. In conclusion, oat or buckwheat formulations, and also quinoa, may be exploited for their potential impact on eating behaviour, particularly considering they are good sources of functional substances.

Daily intake of a formulated tomato drink affects carotenoid plasma and lymphocyte concentrations and improves cellular antioxidant protection.

The salutary characteristics of the tomato are normally related to its content of carotenoids, especially lycopene, and other antioxidants. Our purpose was to verify whether the daily intake of a beverage prototype called Lyc-o-Mato((R)) containing a natural tomato extract (Lyc-o-Mato((R)) oleoresin 6 %) was able to modify plasma and lymphocyte carotenoid concentrations, particularly those of lycopene, phytoene, phytofluene and beta-carotene, and to evaluate whether this intake was sufficient to improve protection against DNA damage in lymphocytes. In a double-blind, cross-over study, twenty-six healthy subjects consumed 250 ml of the drink daily, providing about 6 mg lycopene, 4 mg phytoene, 3 mg phytofluene, 1 mg beta-carotene and 1.8 mg alpha-tocopherol, or a placebo drink. Treatments were separated by a wash-out period. Plasma and lymphocyte carotenoid and alpha-tocopherol concentrations were determined by HPLC, and DNA damage by the comet assay. After 26 d of consumption of the drink, plasma carotenoid levels increased significantly: concentrations of lycopene were 1.7-fold higher (P<0.0001); of phytofluene were 1.6-fold higher (P<0.0001); of phytoene were doubled (P<0.0005); of beta-carotene were 1.3-fold higher (P<0.05). Lymphocyte carotenoid concentrations also increased significantly: that of lycopene doubled (P<0.001); that of phytofluene was 1.8-fold higher (P<0.005); that of phytoene was 2.6-fold higher (P<0.005); that of beta-carotene was 1.5-fold higher (P<0.01). In contrast, the alpha-tocopherol concentration remained nearly constant. The intake of the tomato drink significantly reduced (by about 42 %) DNA damage (P<0.0001) in lymphocytes subjected to oxidative stress. In conclusion, the present study supports the fact that a low intake of carotenoids from tomato products improves cell antioxidant protection.

Effects of blood orange juice intake on antioxidant bioavailability and on different markers related to oxidative stress.

Orange juice is a source of antioxidants that might afford in vivo protection from oxidative stress. To test this hypothesis, we carried out a human intervention study with blood orange juice containing high amounts of vitamin C, anthocyanins, and carotenoids. Sixteen healthy female volunteers were enrolled in a crossover study and were given 600 mL/day of blood orange juice or a diet without juice for 21 days. Before and after each intervention period, plasma vitamin C, cyanidin-3-glucoside, and carotenoids were quantified. Furthermore, plasma antioxidant capacity, malondialdehyde concentration in plasma, 11-dehydrotromboxane B(2) urinary excretion, and lymphocyte DNA damage were evaluated as biomarkers of oxidative stress. Blood orange juice consumption determined a significant increase in plasma vitamin C, cyanidin-3-glucoside, beta-cryptoxanthin, and zeaxanthin. Also, lymphocyte DNA resistance to oxidative stress was improved whereas no effect was observed on the other markers that we analyzed. In turn, these results suggest that blood orange juice is a bioavailable source of antioxidants, which might moderately improve the antioxidant defense system; however, the long-term effects of its consumption are to be further investigated.

Comparison of lutein bioavailability from vegetables and supplement.

Lutein is a carotenoid present in dark green leafy vegetables and it may be involved in the prevention of several diseases related to oxidative stress. The aim of this study was to evaluate bioavailability of lutein from different food sources (150 g spinach and 200 g broccoli) and a supplement in oil (300 mg VEGEX), all providing about 9 mg lutein. Eight healthy females were instructed to eat a low-carotenoid diet for the period of experimentation. On three different occasions, three weeks apart, volunteers ate the lutein sources together with 10 g olive oil and 40 g bread. Blood samples were collected just before eating, every two hours for 12 hours, and at 24, 32, 56, 80 and 104 hours. Lutein concentration increased significantly after six to eight hours and peaked after 10-12 hours, with the highest concentration reached after VEGEX intake. Lutein concentration remained significantly elevated for up to 80 hours (VEGEX and spinach). On the whole, our results suggest that the intake of one single dose of lutein from different sources is able to bring about a significant plasma response in the short term.