Is Iron Supplementation Influenced by Sub-Clinical Inflammation?: A Randomized Controlled Trial Among Adolescent Schoolgirls in Myanmar

Iron absorption was impaired in the presence of sub-clinical inflammation (SCI) and might hamper the effect of iron supplementation. The purpose of the study was to identify the influence of SCI on iron supplementation. A randomized, double-blinded, placebo-controlled experimental study was conducted among anaemic adolescent schoolgirls in Ayeyarwady region, Myanmar. A total of 402 schoolgirls were recruited from six schools screened from 1269 girls who were assigned into one of four groups: Folate group (2.5 mg of folate), Vitamin A group (15,000 IU of vitamin), Iron folate group (60 mg elemental iron and folate) and Iron, and vitamin A and folate group. Supplementation was done once a week for 12 weeks. Iron, vitamin A and inflammation were measured at the baseline, middle and endline. Changes in serum ferritin and body iron were significantly higher in the IFA and IFA + vitA among those without SCI. There was interaction between vitamin A and SCI on Hb changes. Analysis of GLM repeated measure showed interactions between treatment and SCI for hemoglobin and serum transferrin receptor. Those treated with vitamin A had better outcomes when there was SCI. Inflammation accompanied a negative effect on iron supplementation and vitamin A improved efficacy of iron supplementation in the presence of SCI.

Inflammation and biomarkers of micronutrient status

PURPOSE OF REVIEW

Investigations to discover new biomarkers of nutrition highlighted the fact that inflammation and infection were cross-cutting issues complicating interpretation of status. Collaborative groups of nutritionists, immunologists, clinicians and statisticians were set up to investigate the issues, and some are now reporting their findings.

RECENT FINDINGS

Recent work on the vitamins A, D, E and C and the elements iron, zinc and selenium are reported in this review. In clinical settings, experts emphasize the unreliability of nutritional biomarkers to reflect status, but some advocate the use of albumin to assist interpretation. In apparently healthy people with subclinical inflammation, one method to correct data on vitamin A and iron stores using C-reactive protein and alpha-1-acid glycoprotein is available, and two studies report on its use; others methods are currently being investigated.

SUMMARY

Biomarkers of most micronutrients are the plasma concentrations of the respective vitamins or minerals and, irrespective of nutritional status, many are reduced by inflammation; the main exception is ferritin which is increased. Different methods are being investigated to better interpret nutritional data in the presence of infection or inflammation, and nutritionists who work with apparently healthy people need to be aware of subclinical inflammation to avoid exaggerating or underreporting nutritional results.

Inflammation and Vitamin A

Background:

Serum retinol concentrations are homeostatically controlled and only fall when liver stores of vitamin A are very low. Nevertheless, low concentrations of serum retinol occur in apparently healthy people where there is no evidence of vitamin A deficiency (VAD).

Objective:

To determine the reason for low serum vitamin A concentrations where there is no VAD.

Methods:

We observed that elevated acute-phase protein (APP) concentrations often accompanied low retinol concentrations, and we developed a model of the inflammatory response to categorize 4 groups of participants termed reference (no raised APP), incubation (raised acute APP only), early convalescence (both acute and chronic APP raised), and late convalescence (raised chronic APP only). We identified 7 studies with participants who could be allocated to the 4 groups, and using meta-analysis methods we calculated correction (ie, multiplication) factors 1.13, 1.24, and 1.11 to remove the influence of inflammation from the incubation, early, and late convalescent groups, respectively.

Conclusion:

In nutrition surveys or intervention studies to measure vitamin A status, workers should measure APP and correct retinol concentrations using the multiplication factors where inflammation is found.

Macular pigment, visual function, and macular disease among subjects with Alzheimer's disease: an exploratory study

BACKGROUND

The macula (central retina) contains a yellow pigment, comprising the dietary carotenoids lutein (L), zeaxanthin (Z), and meso-zeaxanthin, known as macular pigment (MP). The concentrations of MP's constituent carotenoids in retina and brain tissue correlate, and there is a biologically-plausible rationale, supported by emerging evidence, that MP's constituent carotenoids are also important for cognitive function.

OBJECTIVE

To investigate if patients with Alzheimer's disease (AD) are comparable to controls in terms of MP and visual function.

METHODS

36 patients with moderate AD and 33 controls with the same age range participated. MP was measured using dual-wavelength autofluorescence (Heidelberg Spectralis®); cognitive function was assessed using a battery of cognition tests (including Cambridge Neuropsychological Test Automated Battery). Visual function was recorded by measuring best corrected visual acuity (BCVA) and contrast sensitivity (CS). Serum L and Z concentrations (by HPLC) and age-related macular degeneration (AMD, by retinal examination) status were also assessed.

RESULTS

In the AD group, central MP (i.e., at 0.23°) and MP volume were significantly lower than the control group (p < 0.001 for both), as were measures of BCVA, CS, and serum L and Z concentrations (p < 0.05, for all).

CONCLUSION

AD patients were observed to exhibit significantly less MP, lower serum concentrations of L and Z, poorer vision, and a higher occurrence of AMD when compared to control subjects. A clinical trial in AD patients designed to investigate the impact of macular carotenoid supplementation with respect to MP, visual function, and cognitive function is merited.

The use of adjustment factors to address the impact of inflammation on vitamin A and iron status in humans

Many nutrient biomarkers are altered by inflammation. We calculated adjustment factors for retinol and ferritin by using meta-analyses of studies containing the respective biomarker and 2 acute phase proteins in serum, C-reactive protein (CRP), and α1-acid glycoprotein (AGP). With the use of CRP and AGP we identified 4 groups in each study: reference (CRP ≤5 mg/L, AGP ≤1 g/L), incubation (CRP >5 mg/L, AGP ≤1 g/L), early convalescence (CRP >5 mg/L, AGP >1 g/L), and late convalescence (CRP ≤5 mg/L, AGP >1 g/L). For each biomarker, ratios of the geometric means of the reference to each inflammation group concentration were used to calculate adjustment factors for retinol (1.13, 1.24, and 1.11) and ferritin (0.77, 0.53, and 0.75) for the incubation, early, and late convalescent groups, respectively. The application of the meta-analysis factors in more recent studies compares well with study-specific factors. The same method was used to calculate adjustment factors for soluble transferrin receptor (sTfR) and body iron stores (BISs) in Lao children. We found no advantage in adjusting sTfR for inflammation; in fact, adjustment decreased iron deficiency. Neither adjusted (10% <0 mg/kg) nor nonadjusted (12% <0 mg/kg) BISs detected as much iron deficiency as did ferritin (18% <12 μg/L) and adjusted ferritin (21% <12 μg/L) unless the cutoff for BISs was increased from 0 to <3 mg/kg. However, we could find no evidence that the larger number of children identified as having BISs <3 mg/kg had risks of anemia comparable to those identified by using ferritin <12 μg/L. In conclusion, both corrected and uncorrected ferritin concentrations <12 μg/L are associated with more iron deficiency and anemia than either sTfR >8.3 mg/L or BISs <0 mg/kg in Lao children.

Macular response to supplementation with differing xanthophyll formulations in subjects with and without age-related macular degeneration

PURPOSE

Our aim was to investigate the macular response to three different supplements containing lutein (L), zeaxanthin (Z) and meso-zeaxanthin (MZ) in normal subjects and those with age-related macular degeneration (AMD).

MATERIALS AND METHODS

Macular pigment optical density (MPOD) and serum xanthophyll concentrations were measured in normal (n = 31) and AMD subjects (n = 32), randomly assigned to: group 1 (20 mg L, 2 mg Z, 0.3 mg MZ), group 2 (10 mg L, 2 mg Z, 10 mg MZ) or group 3 (3 mg L, 2 mg Z, 17 mg MZ). MPOD was measured at baseline, 2, 4, 6 and 8 weeks and at 0.25°, 0.5°, 1.0° and 1.75° of eccentricity using customised heterochromatic flicker photometry and serum xanthophylls by HPLC.

RESULTS

MPOD increased significantly at all eccentricities in each group (p < 0.05), except at 1.75° in group 3 (p = 0.242). There was no difference in MPOD measurements between AMD and normal subjects, except for group 2, where AMD subjects exhibited a greater response at 1.75° (p = 0.012). Final serum concentrations of MZ were positively and significantly related to final MPOD values at each eccentricity in all subjects. Targeted analysis of those subjects receiving the MZ-containing supplements exhibited stronger relationships between serum MZ concentrations and MPOD at 0.25° in group 3 than group 2; in group 2 all associations were positive, but only significant at 1.75°.

CONCLUSIONS

Serum concentrations of MZ were strongly correlated with MPOD after 8 weeks of supplementation with the group 3 formulation, but the inclusion of L in the group 2 formulation may result in greater MPOD augmentation across the spatial profile.

The influence of vitamin A status on iron-deficiency anaemia in anaemic adolescent schoolgirls in Myanmar

OBJECTIVE

The present study was conducted to investigate reasons for the high prevalence of anaemia among adolescent schoolgirls and to elucidate the role of vitamin A in contributing to Fe-deficiency anaemia (IDA).

DESIGN

Among 1269 schoolgirls who were previously screened for anaemia (Hb < 120 g/l), 391 anaemic girls were further assessed for Fe, vitamin A and subclinical inflammation status. Fe and vitamin A indicators were corrected for inflammation and were compared in the Fe-deficient and non-deficient groups as well as between those with and without inflammation. Logistic regression was done to determine whether vitamin A status and subclinical inflammation were risk factors for Fe deficiency. The differences in Fe status among tertiles of vitamin A concentrations were assessed using ANOVA.

SETTING

Myanmar.

SUBJECTS

Adolescent schoolgirls (n 391).

RESULTS

One-third of the anaemia (30·4%) was IDA. Prevalence of low vitamin A status (serum retinol <1·05 μmol/l) was 31·5%. Fe and vitamin A status were significantly different between the IDA and non-IDA groups and also based on their inflammation status. Logistic regression showed that low vitamin A status was a significant predictor for being Fe deficient (OR = 1·81; 95% CI 1·03, 3·19 and OR = 2·31; 1·31, 4·07 in the middle (1·056-1·298 μmol/l) and low (≤1·056 μmol/l) vitamin A tertiles, respectively). ANOVA showed that better Fe status was associated with a higher concentration of serum retinol but only in IDA.

CONCLUSIONS

Fe deficiency was not the main cause of anaemia in the present population. The role of vitamin A as well as other micronutrients should be taken into account in addressing the problem of anaemia.

Hepcidin Profile of Anemic Adolescent Schoolgirls in Indonesia at the End of 12 Weeks of Iron Supplementation

Background

Iron deficiency is still the major nutritional problem in the developing world, and iron supplementation remains one of the most effective intervention strategies. Hepcidin, a newly discovered iron regulatory hormone, is an acute phase protein, and its role in iron supplementation has not been well explored.

Objective

To investigate the hepcidin profiles of anemic adolescent girls who had received weekly iron supplementation.

Methods

A cross-sectional study was conducted at the end of iron supplementation among adolescent schoolgirls ( n = 83) in Pramuka Island, Indonesia. All the girls were anemic at the beginning and received 60 mg of elemental iron twice weekly for 12 weeks. Hemoglobin, hepcidin, serum ferritin, and red cell parameters were measured, together with inflammation markers.

Results

At the end of the 12-week supplementation, 65.1% (n=64) of the girls were no longer anemic, but 43.4% ( n = 36) were still iron deficient. The rate of sub-clinical inflammation, measured by C-reactive protein (CRP) and α-1-acid glycoprotein (AGP), was 38.6% ( n = 32). Hepcidin was not correlated with either ferritin or red cell parameters. There was no association between hepcidin and the inflammatory markers CRP and AGP. The mean hepcidin concentration was 42.9 ± 17.9 ng/mL and was not significantly different between anemic and nonanemic girls (44.2 ± 14.9 and 42.3 ± 19.2 ng/mL, respectively; p = .708). However, hepcidin concentration was slightly higher in the iron replete-group than in the iron-deficient group (45.2 ± 20.0 and 39.3 ± 13.5 ng/mL, respectively), a suggestive trend that did not reach statistical significance ( p = .218).

Conclusions

Hepcidin concentrations tended to be higher among the subset of girls who responded poorly to iron supplementation as a consequence of increased subclinical inflammation. A longitudinal study should be conducted to explore the role of hepcidin in iron supplementation.

Verification of Meso-Zeaxanthin in Fish

Background/Objectives

The carotenoids lutein (L), zeaxanthin (Z), and meso-zeaxanthin (MZ) accumulate in the central retina (the macula), where they are collectively known as macular pigment (MP). MP has been shown to enhance visual function in both diseased and non-diseased retinae, and therefore an understanding and confirmation of, the origins of these carotenoids is needed. Studies have shown that L and Z are present in many foodstuffs found in a typical Western diet (e.g. spinach, kale, peppers, yellow corn and eggs). It has been shown that MZ is generated from L in the primate retina and earlier reports suggested that MZ was present in some fish species. Recently, however, one research group reported that MZ is not present in fish and suggested that the earlier reports showing MZ in these marine species were a methodological artefact. The current study was designed to investigate the reason for the contradiction, and test for the presence of MZ in fish and some other foods.

Methods

Raw fruits, vegetables and fish were extracted for carotenoid analysis by high performance liquid chromatography.

Results

MZ was not detected in any of the fruits or vegetables tested in our study. However, using retention time matching, absorption spectrum comparison, and sample spiking, we verified the presence of MZ in salmon skin, sardine skin, trout skin and trout flesh.

Conclusion

This study confirmed the presence MZ in nature, and in the human food chain.

Studies on meso-zeaxanthin for potential toxicity and mutagenicity

The purpose of these studies was to examine the potential toxicity and genotoxicity of meso-zeaxanthin (MZ). Toxicity was assessed by administering MZ daily to rats for 13 weeks followed by a 4-week recovery period. Potential genotoxicity was assessed in separate experiments using the Ames test method. Rats were randomly assigned to four groups to receive corn oil (control) or MZ at dose levels of 2, 20 and 200 mg/kg/day by oral gavage (10/sex/group). Additional rats (five of each sex) in the control and the 200 mg/kg/day groups were retained for the recovery period. No compound-related clinical, biochemical or pathological signs or symptoms were noted and the no-observed-adverse-effect-level (NOAEL) of MZ was >200 mg/kg/day. To investigate genotoxicity, MZ was tested for its ability to induce reverse mutations (±microsomal enzymes) at 2 genomic loci; the histidine locus of 4 strains of Salmonella typhimurium and the tryptophan locus of Escherichia coli strain WP2uvrA. Six doses of MZ ranging from 10 to 5000 μg/plate were tested twice with vehicle and positive controls using 3 plates/dose. MZ did not cause any increase in the mean number of revertants/plate with any bacterial strain, with or without microsomal enzymes, and was therefore unlikely to be mutagenic.

Biomarkers for the differentiation of anemia and their clinical usefulness

The World Health Organization defines anemia as the point at which the amount of hemoglobin in the circulation falls below World Health Organization cutoffs for specific age and sex groups. Anemia is a worldwide problem of complex etiology and is associated with many factors. The purpose of this review was to describe the biomarkers used to identify the nature of anemia in patients and in the community. The important biomarkers are the automated red cell counts, tests for nutritional deficiencies, hemoglobinopathies, and inflammation. Diseases are important potential initiators of anemia, but biomarkers of specific diseases are not included in this review, only the underlying feature common to all disease - namely, inflammation.

Microcytic anaemia predominates in adolescent school girls in the delta region of Myanmar

OBJECTIVE

Anaemia is one of major nutritional problems in Myanmar affecting all age groups. However, there is lack of recent information and a study was conducted to acquire information on the current status of anaemia among adolescent schoolgirls in Nyaung Done township, Ayeyarwady division where an intervention study was planned.

SUBJECTS AND METHODS

A cross-sectional survey was conducted on 1269 subjects to obtain complete blood count, anthropometry and socioeconomic characteristics were obtained by questionnaire. Using red cell indices, we applied Bessman's, and Green and King's index classification to differentiate the types of anaemia. Electrophoresis was also done on a subsample (n=228).

RESULTS

Stunting was 21.2% and wasting was 10.7% respectively. Prevalence of anaemia was 59.1% and was mainly microcytic. Green and King's index showed 35.8% were iron deficient. Electrophoresis revealed 36 cases of Hb E haemoglobinopathy in the subsample.

CONCLUSION

Anaemia is still a major nutrition problem in Myanmar. The reasons for this high prevalence should be explored and properly addressed. The study highlights the need for a comprehensive and large scale survey for the anaemia control programme in Myanmar.

A retrospective investigation of thiamin and energy intakes following an outbreak of beriberi in The Gambia

In the early part of the rainy season in 1988, an outbreak of beriberi occurred in free-living adults in a relatively small area in the North Bank region of The Gambia. In 1995 we selected two compounds in a village called Chilla situated within the affected district to retrospectively examine dietary factors potentially contributing to the outbreak. There had previously been cases of beriberi in one compound (BBC) but not in the other (NBC). We measured energy and thiamin intakes for four days on six occasions during the year. We calculated energy and thiamin intakes of people living in the two compounds and foods were collected for thiamin analysis through the year. Thiamin:Energy ratios only met international recommendations in the immediate post‑harvest season when energy and thiamin intakes were highest and then fell through the year. In the rainy season when food was short and labour was heaviest, energy intakes were lower in the NBC but thiamin:energy ratios were lower in BBC. Records of rainfall in 1988 collected near the village indicated that the amount in August was twice the average. We suggest the heavy rainfall may have increased farm workload and reduced income from outside-village work activity. The lower energy intakes in the NBC may have forced adults to rest thus sparing thiamin demands and delaying onset of beriberi. In contrast, the higher energy intake of adults in the BBC may have enabled them to continue working, thus increasing demands for thiamin and inducing the earlier onset of beriberi.

Adjusting plasma ferritin concentrations to remove the effects of subclinical inflammation in the assessment of iron deficiency: a meta-analysis

BACKGROUND

The World Health Organization recommends serum ferritin concentrations as the best indicator of iron deficiency (ID). Unfortunately, ferritin increases with infections; hence, the prevalence of ID is underestimated.

OBJECTIVE

The objective was to estimate the increase in ferritin in 32 studies of apparently healthy persons by using 2 acute-phase proteins (APPs), C-reactive protein (CRP) and alpha(1)-acid glycoprotein (AGP), individually and in combination, and to calculate factors to remove the influence of inflammation from ferritin concentrations.

DESIGN

We estimated the increase in ferritin associated with inflammation (ie, CRP gt 5 mg/L and/or AGP gt 1 g/L). The 32 studies comprised infants (5 studies), children (7 studies), men (4 studies), and women (16 studies) (n = 8796 subjects). In 2-group analyses (either CRP or AGP), we compared the ratios of log ferritin with or without inflammation in 30 studies. In addition, in 22 studies, the data allowed a comparison of ratios of log ferritin between 4 subgroups: reference (no elevated APP), incubation (elevated CRP only), early convalescence (both APP and CRP elevated), and late convalescence (elevated AGP only).

RESULTS

In the 2-group analysis, inflammation increased ferritin by 49.6% (CRP) or 38.2% (AGP; both P lt 0.001). Elevated AGP was more common than CRP in young persons than in adults. In the 4-group analysis, ferritin was 30%, 90%, and 36% (all P lt 0.001) higher in the incubation, early convalescence, and late convalescence subgroups, respectively, with corresponding correction factors of 0.77, 0.53, and 0.75. Overall, inflammation increased ferritin by ap 30% and was associated with a 14% (CI: 7%, 21%) underestimation of ID.

CONCLUSIONS

Measures of both APP and CRP are needed to estimate the full effect of inflammation and can be used to correct ferritin concentrations. Few differences were observed between age and sex subgroups.

Augmentation of macular pigment following supplementation with all three macular carotenoids: an exploratory study

PURPOSE

At the macula, the carotenoids meso-zeaxanthin (MZ), lutein (L), and zeaxanthin (Z) are collectively referred to as macular pigment (MP). This study was designed to measure serum and macular responses to a macular carotenoid formulation.

MATERIALS AND METHODS

Ten subjects were recruited into this study (five normal and five with early age-related macular degeneration [AMD]). Subjects were instructed to consume a formulation containing 7.3 mg of MZ, 3.7 mg of L, and 0.8 mg of Z everyday over an eight-week period. The spatial profile of MP optical density (i.e., MPOD at 0.25 degrees , 0.5 degrees , 1 degrees , and 1.75 degrees ) was measured using customized heterochromatic flicker photometry, and a blood sample was collected at each study visit in order to analyze serum concentrations of MZ, L, and Z.

RESULTS

There was a significant increase in serum concentrations of MZ and L after two weeks of supplementation (p < 0.05). Baseline serum carotenoid analysis detected a small peak eluting at the same time as MZ in all subjects, with a mean +/- SD of 0.02 +/- 0.01 micromol/L. We report significant increases in MPOD at 0.25 degrees , 0.5 degrees , 1 degree , and average MPOD across its spatial profile after just two weeks of supplementation (p < 0.05, for all). Four subjects (one normal and three AMD) who had an atypical MPOD spatial profile (i.e., central dip) at baseline had the more typical MPOD spatial profile (i.e., highest MPOD at the center) after eight weeks of supplementation.

CONCLUSION

We report significant increases in serum concentrations of MZ and L following supplementation with MZ, L, and Z and a significant increase in MPOD, including its spatial profile, after two weeks of supplementation. Also, this study has detected the possible presence of MZ in human serum pre-supplementation and the ability of the study carotenoid formulation to rebuild central MPOD in subjects who have atypical profiles at baseline.

The influence of inflammation on plasma zinc concentration in apparently healthy, HIV+ Kenyan adults and zinc responses after a multi-micronutrient supplement

BACKGROUND/OBJECTIVES

Plasma zinc is an important biomarker of zinc status, but the concentration is depressed by inflammation.

SUBJECTS/METHODS

Apparently healthy adults, who tested positive twice for human immunodeficiency virus (HIV) but who had not reached stage IV or clinical AIDS, were randomly allocated to receive a food supplement (n=17 and 21) or the food plus a micronutrient capsule (MN; n=10 men and n=33 women) containing 15 mg zinc/day. We used the inflammation biomarkers, C-reactive protein (CRP) and alpha1-acid glycoprotein (AGP), to identify subjects with and without inflammation and determine the effect of inflammation on the response of plasma zinc concentrations to the MN and food supplements.

RESULTS

There were no differences between men and women either in plasma zinc or in the responses to the supplements and their data were combined. Plasma zinc was lower in those with inflammation than without. Repeated measures analysis of variance (ANOVA) showed that inflammation blocked increases in plasma zinc, and there was an approximate 10% increase in plasma zinc concentration in response to the MN supplement (P=0.023) in those without inflammation. Subgroup analysis showed mean changes in plasma zinc of 0.95 and -0.83 micromol/l (P=0.031) in response to the MN and food treatments, respectively, in those without inflammation at both time points.

CONCLUSIONS

Inflammation seems to block any increase in plasma zinc after MN supplement and it is important to identify those without inflammation to determine the effectiveness of a zinc supplementation program.

The influence and benefits of controlling for inflammation on plasma ferritin and hemoglobin responses following a multi-micronutrient supplement in apparently healthy, HIV+ Kenyan adults

Hemoglobin and ferritin are important biomarkers of iron status but are both altered by inflammation. We used the inflammation biomarkers C-reactive protein (CRP) and alpha1-acid glycoprotein (AGP) to adjust hemoglobin and ferritin concentrations to clarify interpretation of iron status. Apparently healthy adults who tested positive twice for HIV but who had not reached stage IV or clinical AIDS were randomly allocated to receive a food supplement (n = 17 and 21) or the food plus a micronutrient capsule (MN; 10 men and 34 women, respectively) containing 30 mg iron/d. Hemoglobin, ferritin, CRP, and AGP concentrations were measured at baseline and 3 mo and subjects were divided into 4 groups (reference, no inflammation; incubating, raised CRP; early convalescence, raised AGP and CRP; and late convalescence, raised AGP). Correction factors (the ratios of the median for the reference group over each inflammatory group) improved the consistency of the ferritin but not the hemoglobin results. After correction, ferritin (but not hemoglobin) increased in both men (48 microg/L; P = 0.02) and women (12 microg/L; P = 0.04) who received MN but not in the food-only group. However, hemoglobin did improve in subjects who showed no inflammation both at baseline and mo 3 (P = 0.019), but ferritin did not increase in this group. In conclusion, ferritin concentrations were more closely linked to current inflammation than hemoglobin; hence, correction by inflammation biomarkers improved data consistency. However, low hemoglobin concentrations were the consequence of long-term chronic inflammation and improvements in response to MN supplements were only detected in subjects with no inflammation.

Wine polyphenols and promotion of cardiac health

Wine polyphenols are considered to have beneficial effects on CHD and atherosclerosis. The consumption of red wine is high in Italy and France, approximately four times greater than that in the UK. This disparity in red wine consumption is thought to be the reason for the ‘French paradox’, where France was shown to have a coronary mortality rate close to that of China or Japan despite saturated fat intakes and cholesterol levels similar to the UK and USA. In the present review, we discuss the effects of wine and some of its polyphenol constituents on early pathological indicators of CHD such as plasma lipids, the endothelium and vasculature, platelets and serum antioxidant activity. The review also examines whether the polyphenols or the alcohol in wine is responsible for the effects on markers of heart disease. The present review concludes that red wine polyphenols have little effect on plasma lipid concentrations but wine consumption appears to reduce the susceptibility of LDL to oxidation and increase serum antioxidant capacity. However, these effects do depend on the amount of wine and period of supplementation. Authors who have examined specific polyphenols suggest that some phenolics appear to have endothelium-dependent vaso-relaxing abilities and some a positive effect on NO concentrations. Red wine phenolics also have an inhibitory effect on platelet aggregation, and individual phenolics also have a similar effectin vitro, although it should be noted that there are often discrepancies as large as ten-fold between the concentrations of polyphenolics testedin vitroand their measured levelsin vivo. Evidence suggests that alcohol has a positive synergistic effect with wine polyphenols on some atherosclerotic risk factors. Thus evidence that wine drinking is beneficial for cardiac health continues to accumulate but more research is required to understand fully and exactly the functions of red wine polyphenols.

An overview of interactions between micronutrients and of micronutrients with drugs, genes and immune mechanisms

The objective of the present review is to examine critically the consequences of interactions that micronutrients undergo with nutrients and non-nutrients (mainly prescribed medicines) in diets and lifestyle factors (smoking, tea and alcohol consumption). In addition, the review describes recent work on interactions between nutrients and genes, the influence of gene polymorphisms on micronutrients, the impact of immune responses on micronutrients and specific interactions of antioxidant micronutrients in disease processes to minimise potential pro-oxidant damage.

Effectiveness of an early supplementation scheme of high-dose vitamin A versus standard WHO protocol in Gambian mothers and infants: a randomised controlled trial

BACKGROUND

Most developing countries have adopted a standard WHO dosing schedule for vitamin A supplementation. However, in 2002 the International Vitamin A Consultative Group (IVACG) Annecy Accord recommended a new high-dose regimen for mothers and infants. Our aim was to test whether the new high-dose regimen of vitamin A supplementation would increase maternal and infant plasma vitamin A, reduce infant Helicobacter pylori infection and nasopharyngeal pneumococcal carriage, and improve infant gut epithelial integrity.

METHODS

In an area of moderate vitamin A deficiency in rural Gambia, 220 mother-infant pairs were enrolled in a randomised double-blind trial between September, 2001, and October, 2004, that compared the IVACG high dose with the WHO dose. The primary endpoints were levels of maternal and infant plasma vitamin A, H pylori infection, pneumococcal carriage, and gut epithelial integrity. The trial is registered as ISRCTN 98554309.

FINDINGS

197 infants completed follow-up to 12 months (99 high dose and 98 WHO dose). There were no adverse events at dosing. No differences were found in the primary outcomes for high-dose versus WHO schedule: maternal vitamin A concentration at 2 months +0.02 micromol/L (95% CI -0.10 to 0.15); infant vitamin A at 5 months +0.01 micromol/L (-0.06 to 0.08); H pylori infection at 12 months -0.3% (-14.7 to 14.2); maternal pneumococcal carriage at 12 months -2.0% (-13.7 to 9.7); infant pneumococcal carriage at 12 months -4.1% (-15.8 to 7.6); infant gut mucosal damage at 12 months 5.2% (-8.7 to 19.2). There were more clinic attendances by the high-dose group in the first 6 months of life (p=0.018).

INTERPRETATION

Our results do not lend support to the proposal to increase the existing WHO standard dosing schedule for vitamin A in areas of moderate vitamin A deficiency. Caution is urged for future studies because trials have shown possible adverse effects of higher doses of vitamin A, and potential negative interactions with the expanded programme on immunisation (EPI) vaccines.

A European carotenoid database to assess carotenoid intakes and its use in a five-country comparative study

A food frequency questionnaire (FFQ) and carotenoid database with information onα- and β-carotene, lutein, lycopene and β-cryptoxanthin was prepared and used to compare the carotenoid intakes in five European countries: UK, Republic of Ireland, Spain, France and The Netherlands. Eighty, age- (25–45 years) and sex-matched volunteers were recruited in each of the five countries. A FFQ and carotenoid database was prepared of the most commonly consumed carotenoid rich foods in the participating countries and the information was used to calculate frequency and intake of carotenoid-rich foods. The median total carotenoid intake based on the sum of the five carotenoids, was significantly higher (P<0.05) in France (16.1 mg/day) and lower in Spain (9.5 mg/day,) than the other countries, where the average intake was approximately 14 mg/day. Comparison of dietary source of carotenoids showed that carrots were the major source of β-carotene in all countries except Spain where spinach was most important. Likewise, carrots were also the main source ofα-carotene. Tomato or tomato products, were the major source of lycopene. Lutein was mainly obtained from peas in Republic of Ireland and the UK, however, spinach was found to be the major source in other countries. In all countries, β-cryptoxanthin was primarily obtained from citrus fruit. Comparing the data with that from specific European country studies suggests that the FFQ and carotenoid database described in the present paper can be used for comparative dietary intake studies within Europe. The results show that within Europe there are differences in the specific intake of some carotenoids which are related to different foods consumed by people in different countries.

Vitamin E supplementation, cereal feed type and consumer sensory perceptions of poultry meat quality

Lipid oxidation leads to meat spoilage and has been reported to cause adverse changes in the flavour and texture of poultry meat. Vitamin E has been found to be effective in delaying lipid oxidation. The aim of this study was to determine whether the vitamin E supplementation of chicken feed influences the consumers' perception of the quality of chicken meat under normal display and storage conditions. Untrained consumers (n 32) evaluated cooked breast meat from chickens (both corn fed and wheat fed) supplemented with 75 250 or 500 mg/kg vitamin E and after storage at 4°C for 4 and 7 d. Factorial analysis found an interaction between vitamin E treatment and storage day upon the perceived juiciness (P=0·023) and tenderness (P=0·041) of the chicken meat. Perceptions of quality relative to vitamin E level were more evident on day 4 than day 7. When the two cereal types were compared, the time-related sub-group effects were observed only in meat from corn-fed chickens supplemented with either 75 or 250 mg/kg, which was perceived to be juicier (P=0·018) and more tender (P=0·020) than that supplemented at the 500 mg/kg level. These results imply that the two lower concentrations of vitamin E have some advantages over 500 mg/kg, but for optimal consumer acceptance of corn-fed chicken meat, we suggest that 250 mg/kg vitamin E should be added to corn-fed poultry feed. There was no evidence to suggest any advantages in changing the current amount of vitamin E (75 mg/kg) used to rear wheat-fed birds.

Monitoring micronutrients in cigarette smokers

Smoking is associated with oxidative stress and increased risks of many chronic diseases that both shorten life and impair its quality. Low concentrations of several micronutrients, especially the antioxidants vitamin C and beta-carotene, are also associated with smoking, and there has been much interest in determining whether deficiencies in micronutrients are involved etiologically in smoking-related diseases. The objective of this review was to bring together reports on dietary intakes, biochemical indicators of micronutrient status, and results of some intervention studies on micronutrients where authors had compared outcomes in smokers and non-smokers. The micronutrients discussed are vitamins A, E, and C; the carotenoids; some of the B-vitamin group; and the minerals selenium, zinc, copper, and iron. The data were then examined to determine whether effects on the biochemical markers of micronutrient status were due to differences in dietary intakes between smokers and non-smokers or to the consequences of inflammatory changes caused by the oxidative stress of smoking. It was concluded that although smoking is associated with reduced dietary intake of vitamin C and carotenoid-containing foods, inflammatory changes increase turnover of these micronutrients so that blood concentrations are still lower in smokers than non-smokers even when there is control for dietary differences. In the case of vitamin E, there is some evidence for increased turnover of this nutrient in smokers, but this has little to no influence on blood concentrations, and there are no differences in dietary intake of vitamin E between smokers and non-smokers. Serum concentrations of vitamin A, folate, and vitamin B12 and B6 markers do not appear to be influenced by smoking, although there is some influence of dietary intake on concentrations of these nutrients in the body. In the case of the minerals examined, the main effects on biochemical markers of mineral status were attributed to inflammation and were therefore greater in heavy or long-term smokers. Serum concentrations of selenium and erythrocyte GPx activity were lower in smokers. Erythrocyte CuZn-SOD activity and serum ceruloplasmin concentrations were elevated, while serum zinc concentrations were depressed only in heavy smokers. Lastly, smoking appears to affect iron homeostasis mainly by changing hemoglobin concentrations, which were in general increased. Serum iron, TfR, and ferritin were mostly unaffected by smoking, except in pregnancy where there is evidence of increased erythropoiesis causing lower saturation of plasma transferrin and some evidence of lowering of iron stores.

Micronutrients in childhood and the influence of subclinical inflammation

In the present paper biomarkers of micronutrient status in childhood and some of the factors influencing them, mainly dietary intake, requirements and inflammation will be examined. On a body-weight basis the micronutrient requirements of children are mostly higher than those of an adult, but most biomarkers of status are not age-related. A major factor that is often overlooked in assessing status is the influence of subclinical inflammation on micronutrient biomarkers. In younger children particularly the immune system is still developing and there is a higher frequency of sickness than in adults. The inflammatory response rapidly influences the concentration in the blood of several important micronutrients such as vitamin A, Fe and Zn, even in the first 24 h, whereas dietary deficiencies can be envisaged as having a more gradual effect on biomarkers of nutritional status. The rapid response to infection may be for protective reasons, i.e. conservation of reserves, or by placing demands on those reserves to mount an effective immune response. However, because there is a high prevalence of disease in many developing countries, an apparently-healthy child may well be at the incubation stage or convalescing when blood is taken for nutritional assessment and the concentration of certain micronutrient biomarkers will not give a true indication of status. Most biomarkers influenced by inflammation are known, but often they are used because they are convenient or cheap and the influence of subclinical inflammation is either ignored or overlooked. The objective of the present paper is to discuss: (1) some of the important micronutrient deficiencies in childhood influenced by inflammation; (2) ways of correcting the interference from inflammation.

Flesh colour dominates consumer preference for chicken

Existing research investigating interactions between visual and oral sensory cues has tended to use model food systems. In contrast, this study compared product quality assessments of corn-fed and wheat-fed chicken products among persons recruited in Northern Ireland. Three approaches have been adopted to investigate the effect of colour upon consumer choice of chicken: sensory assessment under normal lighting; focus group discussion; and sensory assessment under controlled lighting conditions. Initial consumer sensory assessment indicated that wheat-fed chicken was perceived to be tenderer and to have a more intense flavour than that which was corn-fed. Qualitative enquiry discerned that this was because consumers perceived the yellow colour of corn-fed chicken negatively. Yellow-coloured corn-fed chicken was therefore again compared with wheat-fed chicken in terms of flavour, texture and overall liking with the flesh colour disguised by means of controlled lighting. Quality ratings for corn-fed chicken were more positive when the yellow flesh colour was disguised, with corn-fed chicken judged to be tenderer than wheat-fed chicken and more flavoursome. This study illustrates the importance of using a combination of methods to gain insight into interactions between different sensory modalities in consumer quality judgements and adds to previous research on the importance of colour upon consumer choice of real foods.

A comparison of lutein and zeaxanthin concentrations in formula and human milk samples from Northern Ireland mothers

BACKGROUND

Two carotenoids, lutein and zeaxanthin are found in the retinal pigment epithelium of the eye where they are believed to protect it against oxidative and light damage. The amounts of these carotenoids consumed by premature infants are not known.

OBJECTIVE

The objective of the investigation was to measure these carotenoids in human and formulae milks.

DESIGN

In all, 28 human milk samples were obtained at various times between days 1 and 41 of lactation from 13 mothers. Six formula milks commonly used in hospitals were also analysed.

SETTING

Mothers who provided the milk samples had infants in the neonatal ward at the Royal Maternity Hospital, Belfast.

RESULTS

Median lutein and zeaxanthin concentrations in human milk were 4.79 (range 0.42-9.98) nmol/g fat and 0.55 (0.00-1.70) nmol/g fat, respectively. Five of the six formula milks also contained lutein and zeaxanthin with concentrations that varied over a wide range (0.7-9.7 and 0.1-1.2 nmol/g fat, respectively).

CONCLUSIONS

Carotenoid concentrations usually decreased with the duration of lactation. Some formula milks that were specially formulated for premature infants contained high concentrations of the lutein and zeaxanthin and the source may be egg yolk.

SPONSORSHIP

These studies were supported by the University of Ulster and the Northern Ireland Mother and Baby Appeal.

Effects of subclinical infection on plasma retinol concentrations and assessment of prevalence of vitamin A deficiency: meta-analysis

BACKGROUND

Vitamin A deficiency adversely affects child morbidity and survival. This deficiency is estimated by measurement of plasma retinol concentrations, but because plasma retinol is reduced by clinical and subclinical infection, this proxy measure can lead to overestimation. Infection and trauma are accompanied by rises in concentrations of acute-phase proteins in plasma. We aimed to estimate vitamin A deficiency more accurately by measuring changes in plasma retinol and acute-phase proteins associated with subclinical infection or convalescence.

METHODS

We analysed data for concentrations of plasma retinol and one or more acute-phase proteins (alpha1-acid-glycoprotein, alpha1-antichymotrypsin, C-reactive protein, or serum amyloid A) from 15 studies of apparently healthy individuals. We generated summary estimates of differences in retinol concentrations for incubation, early, and late convalescent phases of infection between people with none and those with one or more raised acute-phase proteins. We compared these groups in two, three, and four group analyses. We also compared a subgroup of apparently healthy preschool (1-5 years) children with results from all other studies.

FINDINGS

For all four proteins, retinol values were much higher in people with normal concentrations of protein, than in individuals with raised concentrations (16% higher for alpha1-antichymotrypsin, 18% for alpha1-acid-glycoprotein, 25% for C-reactive protein, and 32% for serum amyloid A). Estimates of the reduction in plasma retinol for individuals with infection compared with healthy individuals, were 13% (incubation), 24% (early convalescent), and 11% (late convalescent). Estimates of vitamin A deficiency in individuals with no raised acute-phase proteins (healthy group) were much the same as those obtained by adjustment of plasma retinol concentrations in the whole group using acute-phase proteins.

INTERPRETATION

We recommend that surveys to estimate vitamin A deficiency should include measurements of serum C-reactive protein and alpha1-acid-glycoprotein concentrations. Information about acute-phase proteins will enable plasma retinol concentrations to be corrected where sub-clinical infection exists, and the healthy sub-group to be identified.

Micronutrient deficiencies

OBJECTIVE

The aim of this study was to consider the risk of micronutrient deficiencies and approaches for intervention, and to summarize existing knowledge and identify areas of ignorance.

DESIGN

Experts from a range of relevant disciplines received and considered a series of questions related to aspects of the topic.

INTERVENTION

The experts met and discussed the questions and arrived at a consensus.

CONCLUSION

Though healthy balanced diet is available for the general European population, a few defined groups are at risk of micronutrient deficiencies. In addition, the intake of specific micronutrients such as iron, folic acid, vitamin D and vitamin B12 are often marginal. To overcome these deficiencies, either selected micronutrients or a mixture of different micronutrients might be recommended. However, to define and detect micronutrient deficiencies, specific biomarkers are only available for a few micronutrients (e. g. vitamin D, folic acid, vitamin C, iron). The definition of a risk group, based on scientific data, might be an appropriate way to justify intervention with supplements.

Use of biomarkers of sub-clinical infection, nutrition and neonatal maturity to interpret plasma retinol in Nigerian neonates

Using the World Health Organization criterion, the prevalence of sub-clinical vitamin A deficiency can be assessed using plasma retinol concentrations <0.7 micromol/l. However, plasma retinol can be depressed by infection; thus, the use of this criterion alone may overestimate deficiency. In the present study, we investigated the usefulness of the acute-phase proteins (APP) alpha1-antichymotrypsin (ACT) and alpha1-acid glycoprotein (AGP), plasma carotenoids and anthropometric and gestational indices to interpret plasma retinol in the blood of 192 apparently healthy Nigerian neonates collected randomly during days 1-20 postpartum. The mean weight (2.64 kg) and length (0.458 m) of the neonates and plasma concentrations (geometric mean, micromol/l) of retinol (0.54), alpha-carotene (0.072), ss-carotene (0.076) and lutein (0.080) were low. The prevalence of vitamin A deficiency was 72 %, indicating a severe public health problem. Babies who were of low birth weight (P<0.003) or premature and low birth weight (P<0.023) had significantly lower retinol concentrations than full-term normal weight babies. Thirty-two neonates had abnormal ACT and forty-four abnormal AGP concentrations. Positive correlations between retinol and ACT (r 0.186, P=0.05) and AGP (r 0.31, P=0.0001) during days 1-5 may be due to the increasing plasma retinol from maternal milk and a coincidental increasing capacity to synthesise APP. Subsequently, negative correlations between retinol and ACT (r -0.28, P=0.02) and AGP (r -0.29, P=0.018) from day 6 onwards reflected the continuing increase in plasma retinol, but no further increase in the APP. Overall, weight, ACT, lutein and age explained 30 % of the variance in retinol, but lutein was the most significant (r(2) 0.18, P<0.0001). Hence, the distribution of plasma retinol concentrations in this group of neonates was more strongly linked with nutrition (via the surrogate marker lutein) than infection.

Redistribution of vitamin A after iron supplementation in Indonesian infants

BACKGROUND

Deficiencies of iron and vitamin A are prevalent worldwide. Single-micronutrient supplementation is widely used to combat these deficiencies. However, micronutrient deficiencies often occur concurrently, and there are many interactions between micronutrients.

OBJECTIVE

This study investigated interactions among 3 important micronutrients--iron, vitamin A, and zinc--when they are given as supplements.

DESIGN

In a randomized, double-blind, placebo-controlled supplementation trial, 387 Indonesian infants aged 4 mo were supplemented 5 d/wk for 6 mo with 10 mg Fe, 10 mg Zn, 2.4 mg beta-carotene, 10 mg each of Fe and Zn, 10 mg Zn + 2.4 mg beta-carotene, or placebo. Complete data on micronutrient status, including hemoglobin, ferritin, retinol, zinc, and the modified relative dose response (a measure of liver retinol stores), were available from 256 infants at the end of the study.

RESULTS

Iron-supplemented infants had significantly lower plasma retinol concentrations and a significantly higher prevalence of vitamin A deficiency, as defined by a plasma retinol concentration <0.70 micromol/L, than did the non-supplemented infants. In contrast, the modified relative dose response of the iron-supplemented infants indicated greater liver stores of vitamin A. Iron supplementation improved iron status, and zinc supplementation improved zinc status, but beta-carotene supplementation did not significantly improve vitamin A status.

CONCLUSIONS

In this study, iron supplementation in infants with marginal vitamin A status led to lower plasma vitamin A concentrations and simultaneously to greater vitamin A liver stores. This implies a redistribution of retinol after iron supplementation, which might induce vitamin A deficiency. Therefore, iron supplementation in infants should be accompanied by measures to improve vitamin A status.

Lack of influence of red palm oil on severity of malaria infection in pre-school Nigerian children

Vitamin A supplements are reported to reduce febrile episodes of malaria and parasite counts, especially in children aged 12-36 months. Red palm oil (RPO) is a good source of vitamin A, is rich in alpha- and beta-carotene and is as effective as high-dose retinyl palmitate supplements in improving vitamin A status. In western Nigeria, where malaria is endemic, RPO is widely used and consumption can be measured using plasma alpha-carotene as a proxy biomarker since there are few other prominent sources of this carotene in the diet. The influence of RPO consumption on malaria was investigated in 207 children (aged 0-60 months) who presented with fever in August-October 1999 at several hospital clinics around Ile-Ife. Medical and anthropometric data, body temperature, parasitaemia and plasma C-reactive protein (CRP), retinol, carotenoids and tocopherols were measured in the children. Mothers were interviewed on usage of cooking oil and mosquito nets in the home, education and occupation. Most families used RPO and median plasma concentrations of both alpha-carotene (0.518 mumol/L) and beta-carotene (0.698 mumol/L) in the children were high. Using body temperature, parasite density and plasma CRP as markers of disease severity, multiple linear regression analysis was carried out on those for whom complete data were available (n = 138), separated into 3 age-groups of < 12 months (n = 37), 12-36 months (n = 68) and > 36 months (n = 33). In the absence of plasma retinol, plasma alpha-carotene explained 13.9% of the variance in parasite density (P = 0.013) but only in children aged > 36 months. The relationship with disease severity was negative, i.e., there was some evidence that RPO usage protected against malaria, and other dietary indices generally indicated that better nutritional status was associated with a lower severity of malaria.

Comparison of LDL fatty acid and carotenoid concentrations and oxidative resistance of LDL in volunteers from countries with different rates of cardiovascular disease

Within Europe there are differences in cardiovascular disease (CVD) risk between countries and this might be related to dietary habits. Oxidative modification of LDL is suggested to increase the risk of CVD and both the fatty acid and antioxidant content of LDL can affect its oxidation. In the present study, concentration of LDL fatty acid and antioxidant micronutrients (tocopherols and carotenoids) and ex vivo oxidative resistance of LDL (lag phase) was compared in volunteers from five countries with different fruit and vegetable intakes and reported rates of CVD. Eighty volunteers (forty males, forty females per centre), age range 25-45 years, were recruited from France, Northern Ireland, UK, Republic of Ireland, The Netherlands, and Spain, and their LDL composition and lag phase were measured. There were some differences in LDL carotenoid and alpha-tocopherol concentrations between countries. alpha-Tocopherol was low and beta- + gamma-tocopherol were high (P<0.001) in the Dutch subjects. Beta-Carotene concentrations were significantly different between the French and Spanish volunteers, with French showing the highest and Spanish the lowest concentration. LDL lycopene was not different between centres in contrast to lutein, which was highest in French (twofold that in the Dutch and Spanish and threefold that in Northern Ireland and the Republic of Ireland, P<0.001). However absolute LDL saturated, monounsaturated, polyunsaturated and total unsaturated fatty acid concentrations were different between countries (P<0.001, total unsaturated highest in Northern Ireland) there was little difference in unsaturated:saturated fatty acid concentration ratios and no difference in polyunsaturated:saturated fatty acid concentration ratios. LDL from the Republic of Ireland (a region with a high rate of CVD) had greater resistance to Cu-stimulated oxidation than samples obtained from volunteers in other countries. In conclusion, LDL composition did not predict resistance to Cu-stimulated oxidation, nor is there evidence that LDL from volunteers in countries with lower rates of CVD have greater resistance to oxidation.

Nutritional factors and visual function in premature infants

Approximately 5-7% of all infants are born prematurely, and birth before 37 weeks is the most common cause of neonatal mortality, morbidity and long-term disability. Premature infants are poorly equipped for life outside the womb, and oxidant stress has been implicated in the aetiology of visual impairment in these infants, who are often exposed to increased O2 concentrations and high light intensity in neonatal units. The carotenoids lutein and zeaxanthin, which give the macular area of the eye its yellow colour, are located in the retinal pigment epithelium of the eye, and are believed to play a role in protecting it against oxidative and light damage. The macular pigments are of dietary origin, and green leafy vegetables are the primary source of lutein and zeaxanthin. Lutein is one of the five most common carotenoids found in the diet. There is current interest in the macular pigment in relation to age-related macular degeneration, but these pigments may also have a protective role in the retinal pigment epithelium of the newborn infant. Little information is available on blood lutein and zeaxanthin levels in neonates. Levels of lutein in human milk are two to three times higher than those of beta-carotene, whereas their concentrations in the mothers' blood are approximately the same. Human milk is the main dietary source of lutein and zeaxanthin for infants until weaning occurs. The biochemical mechanisms which mediate the transport of the macular carotenoids into the eye are not known, but tubulin has been identified as the major carotenoid-binding protein, and may play a role in the physiology of the macula.

Serum concentrations of carotenoids and vitamins A, E, and C in control subjects from five European countries

High intakes of fruits and vegetables, or high circulating levels of their biomarkers (carotenoids, vitamins C and E), have been associated with a relatively low incidence of cardiovascular disease, cataract and cancer. Exposure to a high fruit and vegetable diet increases antioxidant concentrations in blood and body tissues, and potentially protects against oxidative damage to cells and tissues. This paper describes blood concentrations of carotenoids, tocopherols, ascorbic acid and retinol in well-defined groups of healthy, non-smokers, aged 25-45 years, 175 men and 174 women from five European countries (France, UK (Northern Ireland), Republic of Ireland, The Netherlands and Spain). Analysis was centralised and performed within 18 months. Within-gender, vitamin C showed no significant differences between centres. Females in France, Republic of Ireland and Spain had significantly higher plasma vitamin C concentrations than their male counterparts. Serum retinol and alpha-tocopherol levels were similar between centres, but gamma-tocopherol showed a great variability being the lowest in Spain and France, and the highest in The Netherlands. The provitamin A: non-provitamin A carotenoid ratio was similar among countries, whereas the xanthophylls (lutein, zeaxanthin, beta-cryptoxanthin) to carotenes (alpha-carotene, beta-carotene, lycopene) ratio was double in southern (Spain) compared to the northern areas (Northern Ireland and Republic of Ireland). Serum concentrations of lutein and zeaxanthin were highest in France and Spain; beta-cryptoxanthin was highest in Spain and The Netherlands; trans-lycopene tended to be highest in Irish males and lowest in Spanish males; alpha-carotene and beta-carotene were higher in the French volunteers. Due to the study design, the concentrations of carotenoids and vitamins A, C and E represent physiological ranges achievable by dietary means and may be considered as 'reference values' in serum of healthy, non-smoking middle-aged subjects from five European countries. The results suggest that lutein (and zeaxanthin), beta-cryptoxanthin, total xanthophylls and gamma-tocopherol (and alpha- : gamma-tocopherol) may be important markers related to the healthy or protective effects of the Mediterranean-like diet.

Dialysis and gel filtration of isolated low density lipoproteins do not cause a significant loss of low density lipoprotein tocopherol and carotenoid concentration

The resistance of isolated low density lipoprotein (LDL) to copper-initiated oxidation is often used as a measure of effectiveness of an antioxidant intervention. Prior to oxidation, excess salt and EDTA are removed via dialysis or gel filtration of the LDL sample. However, there is concern over whether the antioxidant content of dialyzed or gel-filtered LDL is truly representative of native LDL extracted from a blood sample. Previously, the experiments done after the storage of native and dialyzed LDL at -80 degrees C showed that the dialysis step can cause a loss of up to 60% in the tocopherol and carotenoid content of LDL. In the present study, a comparison of the micronutrient concentration in freshly prepared dialyzed and native LDL from 35 subjects showed that after the correction for cholesterol, only lycopene (13%, P < 0.001) and to a lesser extent alpha-carotene (8%, P < 0.02) were significantly decreased, and the absolute fall in concentration was far smaller than previously reported. Other experiments done with smaller numbers of samples suggested that there were minimal micronutrient losses following gel filtration and that it was important to include 10 micromol/L EDTA in the dialysis and elution buffer; otherwise micronutrient losses did occur. In summary, immediate dialysis of freshly isolated LDL in the presence of 10 micromol/L EDTA does not cause any major loss in the concentration of tocopherol and most carotenoids.

Consumption of tomato products with olive oil but not sunflower oil increases the antioxidant activity of plasma

Health benefits of lycopene from tomato products have been suggested to be related to its antioxidant activity. Dietary fat may influence the absorption and hence the plasma levels and antioxidant activity of lycopene. In the present study, we have compared the effect of consumption of tomato products with extra-virgin olive oil vs. tomato products plus sunflower oil on plasma lycopene and antioxidant levels. Results show that the oil composition does not affect the absorption of lycopene from tomato products because similar levels of plasma lycopene (mean +/- SD) were obtained on feeding tomatoes (providing approximately 46 mg lycopene/d) for 7 d with either olive oil (0.66 +/- 0.26 vs 1.20 +/- 0.20 micromol/l, p <.002) or sunflower oil (0.67 +/- 0.27 vs. 1.14 micromol/l, p <.001). However, consumption of tomato products with olive oil significantly raised the plasma antioxidant activity (FRAP) from 930 +/- 150 to 1118 +/- 184 micromol/l, p <.01) but no effect was observed when the sunflower oil was used. The change (supplementation minus start values) in FRAP following the consumption of tomato products with oil was significantly higher for olive oil (190 +/- 101) than for sunflower oil (-9.6 +/- 99, p <. 005). In conclusion, the results of the study show that consumption of tomato products with olive oil but not with sunflower oil improves the antioxidant activity of the plasma.

Interpretation of vitamin A status in apparently healthy Pakistani children by using markers of subclinical infection

BACKGROUND

Plasma retinol concentrations are depressed by infection but are commonly used to assess vitamin A status.

OBJECTIVE

We measured 2 acute phase proteins, alpha(1)-antichymotrypsin (ACT) and alpha(1)-acid glycoprotein (AGP), to determine whether they could be used to assist in interpreting vitamin A status.

DESIGN

In 1997, a 2-stage cluster-sampling procedure was used to select 3074 apparently healthy, 6-60-mo-old children from rural and urban areas of North West Frontier Province, Pakistan. Plasma retinol, ACT, AGP, and ferritin measurements and anthropometric measurements were obtained for 2519 children.

RESULTS

Median plasma retinol, ACT, AGP, and ferritin concentrations were 0.86 micromol/L, 0.39 g/L, 1.14 g/L, and 5.5 microg/L, respectively. There were no significant (P: > 0.05) differences in retinol, ACT, or AGP by sex or age. Some 797 children (32%) had retinol concentrations <0.7 micromol/L and 87 (4%) had retinol concentrations <0.35 micromol/L; 274 children (11%) had elevated ACT (>0.6 g/L) and 1141 (45%) had elevated AGP (>1.2 g/L). Retinol concentration correlated with ACT (r = -0.141), AGP (r = -0.138), and ferritin (r = -0.09) (all P: < 0.001), but stepwise multiple regression indicated that these 3 variables made a minimal although quantifiable contribution to the variance of retinol (ACT, r(2) = 0.02; all 3 variables, r(2) = 0.03).

CONCLUSIONS

The transient depression in plasma retinol produced by subclinical infection increased the number of at-risk children by 10% (76 of 797) and 56% (49 of 87) for plasma retinol concentrations <0.7 and <0.35 micromol/L, respectively. In addition, dietary inadequacy may be responsible for retinol concentrations being approximately 16% lower in Pakistani children than in children in the United Kingdom, where dietary vitamin A is adequate.

Influence of Increased Fruit and Vegetable Intake on Plasma and Lipoprotein Carotenoids and LDL Oxidation in Smokers and Nonsmokers

Background: Epidemiological studies suggest a cardioprotective role for carotenoid-rich foods. Smokers have a high risk of cardiovascular disease and low dietary intake and plasma concentrations of carotenoids. The aim of this study was to determine the carotenoid response of smokers and nonsmokers to increased intake of 300–400 g of vegetables and its effect on LDL oxidation.

Methods: After a depletion period of 8 days, 34 healthy females (18 nonsmokers, 16 smokers) were supplemented with β-carotene- and lutein-rich (green) and lycopene-rich (red) vegetable foods, each for 7 days.

Results: Baseline concentrations (mean ± SD) of plasma β-carotene (0.203 ± 0.28 μmol/L vs 0.412 ± 0.34 μmol/L; P &lt;0.005) and lutein (0.180 ± 0.10 vs 0.242 ± 0.11 μmol/L; P &lt;0.05) but not lycopene (0.296 ± 0.10 vs 0.319 ± 0.33 μmol/L) were significantly lower in smokers compared with nonsmokers. After supplementation, the change (supplementation minus depletion) in plasma β-carotene (0.152 ± 0.43 vs 0.363 ± 0.29 μmol/L in smokers vs nonsmokers; P = 0.002) and LDL lutein (0.015 ± 0.03 vs 0.029 ± 0.03 μmol/mmol cholesterol; P = 0.01) was significantly lower in smokers than nonsmokers. Green-vegetable supplementation had no effect on the resistance of LDL to oxidation (lag-phase) in either group. After red-vegetable supplementation, plasma and LDL lycopene concentrations were increased in both groups, but only nonsmokers showed a significant increase in the lag-phase (44.9 ± 9.5 min at baseline, 41.4 ± 6.5 min after depletion, and 49.0 ± 8.9 min after supplementation; P &lt;0.01) compared with depletion.

Conclusions: In this short-term intervention study, a dietary intake of &gt;40 mg/day of lycopene by a group of nonsmoking individuals significantly reduced the susceptibility of LDL to oxidation, whereas an equivalent increase in lycopene by a group of smokers showed no such effect.

Influence of increased fruit and vegetable intake on plasma and lipoprotein carotenoids and LDL oxidation in smokers and nonsmokers

BACKGROUND

Epidemiological studies suggest a cardioprotective role for carotenoid-rich foods. Smokers have a high risk of cardiovascular disease and low dietary intake and plasma concentrations of carotenoids. The aim of this study was to determine the carotenoid response of smokers and nonsmokers to increased intake of 300-400 g of vegetables and its effect on LDL oxidation.

METHODS

After a depletion period of 8 days, 34 healthy females (18 nonsmokers, 16 smokers) were supplemented with beta-carotene- and lutein-rich (green) and lycopene-rich (red) vegetable foods, each for 7 days.

RESULTS

Baseline concentrations (mean +/- SD) of plasma beta-carotene (0.203+/-0.28 micromol/L vs. 0.412+/-0.34 micromol/L; P <0.005) and lutein (0.180 +/-0.10 vs. 0.242+/-0.11 micromol/L; P<0.05) but not lycopene (0.296+/-0.10 vs. 0.319+/-0.33 micromol/L) were significantly lower in smokers compared with nonsmokers. After supplementation, the change (supplementation minus depletion) in plasma beta-carotene (0.152+/- 0.43 vs. 0.363+/-0.29 micromol/L in smokers vs. nonsmokers; P = 0.002) and LDL lutein (0.015+/-0.03 vs. 0.029+/-0.03 micromol/mmol cholesterol; P = 0.01) was significantly lower in smokers than nonsmokers. Green-vegetable supplementation had no effect on the resistance of LDL to oxidation (lag-phase) in either group. After red-vegetable supplementation, plasma and LDL lycopene concentrations were increased in both groups, but only nonsmokers showed a significant increase in the lag-phase (44.9+/-9.5 min at baseline, 41.4+/-6.5 min after depletion, and 49.0+/-8.9 min after supplementation; P<0.01) compared with depletion.

CONCLUSIONS

In this short-term intervention study, a dietary intake of >40 mg/day of lycopene by a group of nonsmoking individuals significantly reduced the susceptibility of LDL to oxidation, whereas an equivalent increase in lycopene by a group of smokers showed no such effect.

Frequency of fruit and vegetable consumption and blood antioxidants in the Caerphilly cohort of older men

OBJECTIVE

To assess the number of portions of fruit and vegetables consumed daily by a large representative sample of older men, and to determine how blood antioxidant (vitamins E, A and carotenoids) concentrations vary with fruit and vegetable consumption.

DESIGN

Cross-sectional study of free-living men.

SUBJECTS

Men aged 55-69 y (dietary data, n=1957; blood data, n=1874) participating in Phase III (1989-1993) of the Caerphilly and Speedwell Collaborative Heart Disease Studies.

METHODS

Dietary data were obtained by semi-quantitative food-frequency questionnaire and blood samples were analysed for antioxidant vitamins. Men were subdivided into groups on the basis of portions per day of fruit and vegetables. Within these sub-groups, mean and 95% ranges of intakes and of blood antioxidant levels were obtained. Log transformations were performed where appropriate.

RESULTS

Only 4.3% of the men met the recommended target of five portions, while 33.3% of the men consumed one or fewer portions of fruit and vegetables per day. Those men who consumed the poorest diets with respect to fruit and vegetable intakes were more likely to be from lower socio-economic classes, drink more alcohol and be current smokers. Fruit and vegetable intake reflected plasma concentrations of antioxidants, which showed a dose-response relationship to frequency of consumption.

CONCLUSIONS

Older men in the UK consume much less fruit and vegetables than current recommendations. Major difficulties are likely to be encountered in trying to meet a dietary target that is clearly much higher than the fruit and vegetable consumption of large sections of the older population in the UK.

SPONSORSHIP

This work was supported by the Medical Research Council.

Innate immunity, gut integrity, and vitamin A in Gambian and Indian infants

Gut integrity, which can be measured by the urinary lactulose:mannitol excretion test, deteriorates with the introduction of weaning foods. In The Gambia, gut integrity measured monthly over 15 months in 119 infants (aged 2-15 months) was least impaired from April to June. This coincides with the time of year of maximum vitamin A (VA) intake-the mango season. Subsequently, two VA intervention studies were done in infants in India. Eighty infants attending a community health center received 16,700 IU weekly or placebo. In another study, 94 hospitalized infants were given 200, 000 IU VA or placebo: 31 received VA on admission, while the rest (32 VA, 31 placebo) received treatment on discharge. All VA-treated groups had more rapid improvement in gut integrity than the placebo groups, but no group had gut integrity normalized by Western standards. The data suggest that VA status may influence gut integrity.

Nonalcoholic red wine extract and quercetin inhibit LDL oxidation without affecting plasma antioxidant vitamin and carotenoid concentrations

BACKGROUND

Antioxidant enrichment of LDL can increase its resistance to oxidation and hence reduce its atherogenicity. The objective of the present study was to investigate whether in vivo supplementation with nonalcoholic red wine extract and quercetin can increase the oxidative resistance of LDL, and also whether the supplementation has any effect on other antioxidative micronutrients present in the blood.

METHODS

Twenty-one male subjects were supplemented with a placebo drink for 2 weeks and randomized into two groups. One group (n = 11) received the red wine extract (1 g/day, equivalent to 375 mL of red wine) and the other group (n = 10) quercetin (30 mg/day) for 2 weeks, followed by a 5-week washout period.

RESULTS

In the red wine extract-supplemented group, ex vivo copper-initiated oxidation of LDL (lag phase, mean +/- SD) was 40 +/- 11 min at the baseline, and increased significantly to 47 +/- 6 min [P <0.05 compared with placebo (38 +/- 4 min) and the washout values (40 +/- 5 min)]. In the quercetin-supplemented group, the lag phase was 44 +/- 11 and 40 +/- 5 min for the baseline and placebo, respectively, and increased significantly to 51 +/- 7 min [P <0.05 compared with placebo and washout (41 +/- 9 min)] after supplementation. Plasma lipids (triglycerides, total cholesterol, LDL- and HDL-cholesterol) did not change during the study period. Supplementation with red wine extract or quercetin had no effect on plasma vitamin C and E, retinol, and carotenoid concentrations.

CONCLUSIONS

Alcohol-free red wine extract and one of its components, quercetin, can inhibit LDL oxidation after in vivo supplementation; such "inhibition" is unrelated to changes in antioxidant vitamin and carotenoid concentrations.

Nonalcoholic Red Wine Extract and Quercetin Inhibit LDL Oxidation without Affecting Plasma Antioxidant Vitamin and Carotenoid Concentrations

Background: Antioxidant enrichment of LDL can increase its resistance to oxidation and hence reduce its atherogenicity. The objective of the present study was to investigate whether in vivo supplementation with nonalcoholic red wine extract and quercetin can increase the oxidative resistance of LDL, and also whether the supplementation has any effect on other antioxidative micronutrients present in the blood.

Methods: Twenty-one male subjects were supplemented with a placebo drink for 2 weeks and randomized into two groups. One group (n = 11) received the red wine extract (1 g/day, equivalent to 375 mL of red wine) and the other group (n = 10) quercetin (30 mg/day) for 2 weeks, followed by a 5-week washout period.

Results: In the red wine extract-supplemented group, ex vivo copper-initiated oxidation of LDL (lag phase, mean ± SD) was 40 ± 11 min at the baseline, and increased significantly to 47 ± 6 min [P &lt;0.05 compared with placebo (38 ± 4 min) and the washout values (40 ± 5 min)]. In the quercetin-supplemented group, the lag phase was 44 ± 11 and 40 ± 5 min for the baseline and placebo, respectively, and increased significantly to 51 ± 7 min [P &lt;0.05 compared with placebo and washout (41 ± 9 min)] after supplementation. Plasma lipids (triglycerides, total cholesterol, LDL- and HDL-cholesterol) did not change during the study period. Supplementation with red wine extract or quercetin had no effect on plasma vitamin C and E, retinol, and carotenoid concentrations.

Conclusions: Alcohol-free red wine extract and one of its components, quercetin, can inhibit LDL oxidation after in vivo supplementation; such “inhibition” is unrelated to changes in antioxidant vitamin and carotenoid concentrations.

Antioxidant enzymes, inflammatory indices and lifestyle factors in older men: a cohort analysis

We examined the relationship between blood antioxidant enzyme activities, indices of inflammatory status and a number of lifestyle factors in the Caerphilly prospective cohort study of ischaemic heart disease. The study began in 1979 and is based on a representative male population sample. Initially 2512 men were seen in phase I, and followed-up every 5 years in phases II and III; they have recently been seen in phase IV. Data on social class, smoking habit, alcohol consumption were obtained by questionnaire, and body mass index was measured. Antioxidant enzyme activities and indices of inflammatory status were estimated by standard techniques. Significant associations were observed for: age with alpha-1-antichymotrypsin (p < 0.0001) and with caeruloplasmin, both protein and oxidase (p < 0.0001); smoking habit with alpha-1-antichymotrypsin (p < 0.0001), with caeruloplasmin, both protein and oxidase (p < 0.0001) and with glutathione peroxidose (GPX) (p < 0.0001); social class with alpha-1-antichymotrypsin (p < 0.0001), with caeruloplasmin both protein (p < 0.001) and oxidase (p < 0.01) and with GPX (p < 0.0001); body mass index with alpha-1-antichymotrypsin (p < 0.0001) and with caeruloplasmin protein (p < 0.001). There was no significant association between alcohol consumption and any of the blood enzymes measured. Factor analysis produced a three-factor model (explaining 65.9% of the variation in the data set) which appeared to indicate close inter-relationships among antioxidants.