4-Week consumption of anthocyanin-rich blood orange juice does not affect LDL-cholesterol or other biomarkers of CVD risk and glycaemia compared with standard orange juice: a randomised controlled trial.

Elevated circulating cholesterol levels are a risk factor for CVD which is also associated with sub-optimal vascular function. There is emerging evidence that anthocyanins can cause beneficial cardio-protective effects by favourably modulating lipoprotein profiles. We compared the effects of blood orange juice which is rich in anthocyanins and blonde orange juice without anthocyanins on LDL-cholesterol and other biomarkers of CVD risk, vascular function and glycaemia. In all, forty-one participants (aged 25-84 years) with a waist circumference >94 cm (men) and >80 cm (women) completed a randomised, open label, two-arm cross-over trial. For 28 d participants ingested (i) 500 ml blood orange juice providing 50 mg anthocyanins/d and (ii) 500 ml blonde orange juice without anthocyanins. There was a minimum 3-week washout period between treatments. LDL-cholesterol and other biomarkers associated with CVD risk and glycaemia were assessed at the start and end of each treatment period. No significant differences were observed in total, HDL- and LDL-cholesterol, TAG, glucose, fructosamine, nitric oxide, C-reactive protein, aortic systolic blood pressure and diastolic blood pressure or carotid-femoral and brachial-ankle pulse wave velocity after 28 d ingestion of blood orange juice compared with standard orange juice. The lack of effect on LDL-cholesterol may be due to the modest concentration of anthocyanins in the blood orange juice.

Selenium supplementation has beneficial and detrimental effects on immunity to influenza vaccine in older adults.

BACKGROUND & AIMS: Mortality resulting from influenza (flu) virus infections occurs primarily in the elderly through declining immunity. Studies in mice have suggested beneficial effects of selenium (Se) supplementation on immunity to flu but similar evidence is lacking in humans. A dietary intervention study was therefore designed to test the effects of Se-supplementation on a variety of parameters of anti-flu immunity in healthy subjects aged 50-64 years. METHODS: A 12-week randomized, double-blinded, placebo-controlled clinical trial (ClinicalTrials.govNCT00279812) was undertaken in six groups of individuals with plasma Se levels <110 ng/mL. Four groups were given daily capsules of yeast enriched with 0 µg Se/day (SeY-0/d; n = 20), 50 µg Se/d (SeY-50/d; n = 18), 100 µg Se/d (SeY-100/d; n = 21) or 200 µg Se/d (SeY-200/d; n = 23). Two groups were given onion-containing meals with either <1 µg Se/d (SeO-0/d; n = 17) or 50 µg Se/d (SeO-50/d; n = 18). Flu vaccine was administrated at week 10 and immune parameters were assessed until week 12. RESULTS: Primary study endpoints were changes in cellular and humoral immune responses. Supplementation with SeY and SeO affected different aspects of cellular immunity. SeY increased Tctx-ADCC cell counts in blood (214%, SeY-100/d) before flu vaccination and a dose-dependent increase in T cell proliferation (500%, SeY-50/100/200/d), IL-8 (169%, SeY-100/d) and IL-10 (317%, SeY-200/d) secretion after in vivo flu challenge. Positive effects were contrasted by lower granzyme B content of CD8 cells (55%, SeY-200/d). SeO (Se 50 µg/d) also enhanced T cell proliferation after vaccination (650%), IFN-γ (289%), and IL-8 secretion (139%), granzyme (209%) and perforin (190%) content of CD8 cells but inhibited TNF-α synthesis (42%). Onion on its own reduced the number of NKT cells in blood (38%). These effects were determined by comparison to group-specific baseline yeast or onion control groups. Mucosal flu-specific antibody responses were unaffected by Se-supplementation. CONCLUSION: Se-supplementation in healthy human adults with marginal Se status resulted in both beneficial and detrimental effects on cellular immunity to flu that was affected by the form of Se, supplemental dose and delivery matrix. These observations call for a thorough evaluation of the risks and benefits associated with Se-supplementation.

Diet rich in high glucoraphanin broccoli reduces plasma LDL cholesterol: Evidence from randomised controlled trials.

SCOPE: Cruciferous-rich diets have been associated with reduction in plasma LDL-cholesterol (LDL-C), which may be due to the action of isothiocyanates derived from glucosinolates that accumulate in these vegetables. This study tests the hypothesis that a diet rich in high glucoraphanin (HG) broccoli will reduce plasma LDL-C. METHODS AND RESULTS: One hundred and thirty volunteers were recruited to two independent double-blind, randomly allocated parallel dietary intervention studies, and were assigned to consume either 400 g standard broccoli or 400 g HG broccoli per week for 12 weeks. Plasma lipids were quantified before and after the intervention. In study 1 (37 volunteers), the HG broccoli diet reduced plasma LDL-C by 7.1% (95% CI: -1.8%, -12.3%, p = 0.011), whereas standard broccoli reduced LDL-C by 1.8% (95% CI +3.9%, -7.5%, ns). In study 2 (93 volunteers), the HG broccoli diet resulted in a reduction of 5.1% (95% CI: -2.1%, -8.1%, p = 0.001), whereas standard broccoli reduced LDL-C by 2.5% (95% CI: +0.8%, -5.7%, ns). When data from the two studies were combined the reduction in LDL-C by the HG broccoli was significantly greater than standard broccoli (p = 0.031). CONCLUSION: Evidence from two independent human studies indicates that consumption of high glucoraphanin broccoli significantly reduces plasma LDL-C.

A diet rich in high-glucoraphanin broccoli interacts with genotype to reduce discordance in plasma metabolite profiles by modulating mitochondrial function.

BACKGROUND: Observational and experimental studies suggest that diets rich in cruciferous vegetables and glucosinolates may reduce the risk of cancer and cardiovascular disease (CVD). OBJECTIVE: We tested the hypothesis that a 12-wk dietary intervention with high-glucoraphanin (HG) broccoli would modify biomarkers of CVD risk and plasma metabolite profiles to a greater extent than interventions with standard broccoli or peas. DESIGN: Subjects were randomly assigned to consume 400 g standard broccoli, 400 g HG broccoli, or 400 g peas each week for 12 wk, with no other dietary restrictions. Biomarkers of CVD risk and 347 plasma metabolites were quantified before and after the intervention. RESULTS: No significant differences in the effects of the diets on biomarkers of CVD risk were found. Multivariate analyses of plasma metabolites identified 2 discrete phenotypic responses to diet in individuals within the HG broccoli arm, differentiated by single nucleotide polymorphisms associated with the PAPOLG gene. Univariate analysis showed effects of sex (P < 0.001), PAPOLG genotype (P < 0.001), and PAPOLG genotype × diet (P < 0.001) on the plasma metabolic profile. In the HG broccoli arm, the consequence of the intervention was to reduce variation in lipid and amino acid metabolites, tricarboxylic acid (TCA) cycle intermediates, and acylcarnitines between the 2 PAPOLG genotypes. CONCLUSIONS: The metabolic changes observed with the HG broccoli diet are consistent with a rebalancing of anaplerotic and cataplerotic reactions and enhanced integration of fatty acid ß-oxidation with TCA cycle activity. These modifications may contribute to the reduction in cancer risk associated with diets that are rich in cruciferous vegetables. This trial was registered at clinicaltrials.gov as NCT01114399.

Effects of selenium supplementation on selenoprotein gene expression and response to influenza vaccine challenge: a randomised controlled trial.

BACKGROUND: The uncertainty surrounding dietary requirements for selenium (Se) is partly due to limitations in biomarkers of Se status that are related to health outcomes. In this study we determined the effect of different doses and forms of Se on gene expression of selenoprotein S (SEPS1), selenoprotein W (SEPW1) and selenoprotein R (SEPR), and responses to an immune function challenge, influenza vaccine, were measured in order to identify functional markers of Se status. METHODS AND FINDINGS: A 12 week human dietary intervention study was undertaken in 119 volunteers who received placebo, 50, 100 or 200 µg/day Se-enriched yeast (Se-yeast) or meals containing unenriched or Se-enriched onions (50 µg/day). Gene expression was quantified in RNA samples extracted from human peripheral blood mononuclear cells (PBMC's) using quantitative RT-PCR. There was a significant increase in SEPW1 mRNA in the Se-enriched onion group (50 µg/day) compared with the unenriched onion group. SEPR and SEPW1 did not change significantly over the duration of the supplementation period in the control or Se-yeast groups, except at week 10 when SEPW1 mRNA levels were significantly lower in the 200 µg/day Se-yeast group compared to the placebo group. Levels of SEPS1 mRNA increased significantly 7 days after the influenza vaccine challenge, the magnitude of the increase in SEPS1 gene expression was dose-dependent, with a significantly greater response with higher Se supplementation. CONCLUSIONS: This novel finding provides preliminary evidence for a role of SEPS1 in the immune response, and further supports the relationship between Se status and immune function. TRIAL REGISTRATION: ClinicalTrials.gov [NCT00279812].

Establishing optimal selenium status: results of a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Dietary recommendations for selenium differ between countries, mainly because of uncertainties over the definition of optimal selenium status. OBJECTIVE: The objective was to examine the dose-response relations for different forms of selenium. DESIGN: A randomized, double-blind, placebo-controlled dietary intervention was carried out in 119 healthy men and women aged 50-64 y living in the United Kingdom. Daily placebo or selenium-enriched yeast tablets containing 50, 100, or 200 microg Se ( approximately 60% selenomethionine), selenium-enriched onion meals ( approximately 66% gamma-glutamyl-methylselenocysteine, providing the equivalent of 50 microg Se/d), or unenriched onion meals were consumed for 12 wk. Changes in platelet glutathione peroxidase activity and in plasma selenium and selenoprotein P concentrations were measured. RESULTS: The mean baseline plasma selenium concentration for all subjects was 95.7 +/- 11.5 ng/mL, which increased significantly by 10 wk to steady state concentrations of 118.3 +/- 13.1, 152.0 +/- 24.3, and 177.4 +/- 26.3 ng/mL in those who consumed 50, 100, or 200 microg Se-yeast/d, respectively. Platelet glutathione peroxidase activity did not change significantly in response to either dose or form of selenium. Selenoprotein P increased significantly in all selenium intervention groups from an overall baseline mean of 4.99 +/- 0.80 microg/mL to 6.17 +/- 0.85, 6.73 +/- 1.01, 6.59 +/- 0.64, and 5.72 +/- 0.75 microg/mL in those who consumed 50, 100, or 200 microg Se-yeast/d and 50 microg Se-enriched onions/d, respectively. CONCLUSIONS: Plasma selenoprotein P is a useful biomarker of status in populations with relatively low selenium intakes because it responds to different dietary forms of selenium. To optimize the plasma selenoprotein P concentration in this study, 50 microg Se/d was required in addition to the habitual intake of approximately 55 microg/d. In the context of established relations between plasma selenium and risk of cancer and mortality, and recognizing the important functions of selenoprotein P, these results provide important evidence for deriving estimated average requirements for selenium in adults. This trial was registered at clinicaltrials.gov as NCT00279812.

L-alpha-glycerophosphocholine contributes to meat's enhancement of nonheme iron absorption.

In this research, our aim was to isolate and characterize the substance known as "meat factor," which is reported to enhance nonheme iron absorption. We used various analytical techniques, and the final step was a human study to measure the effect of a candidate compound on iron absorption. Lean beef was selected for study, as it is known to increase nonheme iron absorption. Cooked ground beef was homogenized and aliquots were taken through a simulated gastric and intestinal digestion. This was followed by purification using fast protein liquid chromatography. The fractions were collected and applied to a Caco-2 cell system designed to measure iron absorption using radioiron. Fractions with an enhancing effect were analyzed by mass spectrometry, nuclear magnetic resonance, and HPLC, and a proposed empirical formula was obtained for the substance in the most active fraction (C(8)H(20) NO(6)P). Tandem mass spectrometry was used to identify the compound as L-alpha-glycerophosphocholine (L-alpha) by comparing the spectra against authentic material. We added a commercially available food grade source of L-alpha to vegetarian lasagna, with and without 100 mg ascorbic acid (a known enhancer of nonheme iron absorption), at the same enhancer:iron molar ratio (2:1), and fed meals to 13 women of child-bearing age with low iron stores. The nonheme iron was labeled with stable isotopes of iron to provide a total dose per meal of 10 mg iron, and absorption was measured from erythrocyte incorporation. Nonheme iron absorption from lasagna was increased by the addition of either ascorbic acid (P = 0.010) or L-alpha (P = 0.023). We have identified L-alpha as a component of muscle tissue that enhances nonheme iron absorption, and this finding provides new opportunities for iron fortification of foods.

Impact of menstrual blood loss and diet on iron deficiency among women in the UK.

Women of childbearing age are at risk of Fe deficiency if insufficient dietary Fe is available to replace menstrual and other Fe losses. Haem Fe represents 10-15 % of dietary Fe intake in meat-rich diets but may contribute 40 % of the total absorbed Fe. The aim of the present study was to determine the relative effects of type of diet and menstrual Fe loss on Fe status in women. Ninety healthy premenopausal women were recruited according to their habitual diet: red meat, poultry/fish or lacto-ovo-vegetarian. Intake of Fe was determined by analysing 7 d duplicate diets, and menstrual Fe loss was measured using the alkaline haematin method. A substantial proportion of women (60 % red meat, 40 % lacto-ovo-vegetarian, 20 % poultry/fish) had low Fe stores (serum ferritin <10 microg/l), but the median serum ferritin concentration was significantly lower in the red meat group (6.8 microg/l (interquartile range 3.3, 16.25)) than in the poultry/fish group (17.5 microg/l (interquartile range 11.3, 22.4) (P<0.01). The mean and standard deviation of dietary Fe intake were significantly different between the groups (P=0.025); the red meat group had a significantly lower intake (10.9 (sd 4.3) mg/d) than the lacto-ovo-vegetarians (14.5 (sd 5.5) mg/d), whereas that of the poultry/fish group (12.8 (sd 5.1) mg/d) was not significantly different from the other groups. There was no relationship between total Fe intake and Fe status, but menstrual Fe loss (P=0.001) and dietary group (P=0.040) were significant predictors of Fe status: poultry/fish diets were associated with higher Fe stores than lacto-ovo-vegetarian diets. Identifying individuals with high menstrual losses should be a key component of strategies to prevent Fe deficiency.