Evaluating the relationship between the nutrient intake of lactating women and their breast milk nutritional profile: a systematic review and narrative synthesis.

Maternal diet influences breast milk nutritional profile; however, it is unclear which nutrients and contaminants are particularly responsive to short- and long-term changes in maternal intake, and the impact of specific exclusion diets, such as vegan or vegetarian. This study systematically reviewed the literature on the effects of maternal nutrient intake, including exclusion diets, on both the nutrient and contaminant content of breast milk. The electronic databases, PubMed, CENTRAL, Web of Science and CINALH were systematically searched until 4 June 2023, with additionally searches of reference lists (PROSPERO, CRD42020221577). The quality of the studies was examined using Cochrane Risk of Bias tool and Newcastle-Ottawa scale. Eighty-eight studies (n 6577) met the search criteria. Due to high heterogeneity, meta-analysis was not possible. There was strong evidence of response to maternal intakes for DHA and EPA, vitamins A, E and K, iodine and Se in breast milk composition, some evidence of response for α-linolenic acid, B vitamins, vitamin C and D, ovalbumin, tyrosine and contaminants, and insufficient evidence to identify the effects arachidonic acid, Cu, Fe, Zn and choline. The paucity of evidence and high heterogeneity among studies reflects the need for more high-quality trials. However, this review identified the importance of maternal intake in the nutritional content of breast milk for a wide range of nutrients and supports the recommendation for supplementation of DHA and vitamin B12 for those on restrictive diets.

Who gets an annual review for coeliac disease? Patients with lower health literacy and lower dietary adherence consider them important.

BACKGROUND: A lifelong gluten-free (GF) diet to manage coeliac disease is recognised to be challenging. This paper comprises two studies: study one aimed to report the opinions of adults with coeliac disease on review provision and explore factors influencing dietary adherence. Study two aimed to report dietetic provision for adults with coeliac disease. METHODS: A cross-sectional online survey was completed by 722 adults with coeliac disease, including validated dietary adherence, health literacy and quality-of-life questionnaires. An online and paper survey designed to capture the provision of dietetic services to adults with coeliac disease was completed by 88 dietetic departments within the United Kingdom. RESULTS: Only 26% of adults with coeliac disease were offered annual reviews. In contrast, 85% considered reviews important, with 62% preferring dietetic provision. Those who considered reviews important had lower health literacy, greater dietary burden, poorer GF dietary adherence and lower GF food knowledge (all p < 0.05) compared with those who did not consider reviews important. GF dietary adherence was associated with health literacy, self-regulatory behaviours, dietary burden and GF food knowledge; 53% agreed with the 'cost of GF food restricts what I eat'; they had poorer GF dietary adherence compared with those who disagreed (p < 0.001). More than 72% of dietetic coeliac review provision provided content on improving access to GF foods and eating out of the home. CONCLUSIONS: A subpopulation of adults with coeliac disease have a greater need for support and guidance, which supports the viewpoint that limited resources should be targeted towards patients with the most need for support to enable successful disease management.

Metabolic consequences of obesity and insulin resistance in polycystic ovary syndrome: diagnostic and methodological challenges.

Women with polycystic ovary syndrome (PCOS) have a considerable risk of metabolic dysfunction. This review aims to present contemporary knowledge on obesity, insulin resistance and PCOS with emphasis on the diagnostic and methodological challenges encountered in research and clinical practice. Variable diagnostic criteria for PCOS and associated phenotypes are frequently published. Targeted searches were conducted to identify all available data concerning the association of obesity and insulin resistance with PCOS up to September 2016. Articles were considered if they were peer reviewed, in English and included women with PCOS. Obesity is more prevalent in women with PCOS, but studies rarely reported accurate assessments of adiposity, nor split the study population by PCOS phenotypes. Many women with PCOS have insulin resistance, though there is considerable variation reported in part due to not distinguishing subgroups known to have an impact on insulin resistance as well as limited methodology to measure insulin resistance. Inflammatory markers are positively correlated with androgen levels, but detailed interactions need to be identified. Weight management is the primary therapy; specific advice to reduce the glycaemic load of the diet and reduce the intake of pro-inflammatory SFA and advanced glycation endproducts have provided promising results. It is important that women with PCOS are educated about their increased risk of metabolic complications in order to make timely and appropriate lifestyle modifications. Furthermore, well-designed robust studies are needed to evaluate the mechanisms behind the improvements observed with dietary interventions.

Long-term follow-up in patients with coeliac disease in the pandemic-era: a view from Sheffield the NHS England national centre for adult coeliac disease.

Aim: To explore patients' follow-up preferences. Background: Optimal follow-up strategies for patients with coeliac disease remain a subject of debate. Research suggests patients' prefer review by dietitians with a doctor available as required. Methods: Patients with coeliac disease under review at our centre, completed a questionnaire assessing their views on what makes follow-up useful based on specific criteria. Bloods tests, symptoms review, dietary assessment, opportunity to ask questions and reassurance. Patients' preferences between follow-up with a hospital doctor, a hospital dietitian, a hospital dietitian with a doctor available, a general practitioner, no follow-up or access when needed were also evaluated. Results: 138 adult patients completed the questionnaire, 80% of patients reported following a strict gluten free diet (mean diagnosis was 7.2 years). Overall, 60% found their follow-up to be 'very useful' valuing their review of blood tests and symptoms (71%) reassurance (60%) and opportunity to ask questions (58%). Follow-up by a dietitian with a doctor available was the most preferred option of review (p<0.001) except when compared to hospital doctor (p=0.75). Novel modalities of follow-up such as telephone and video reviews were regarded as of equal value to face-to-face appointments (65% and 62% respectively). Digital applications were significantly less preferable (38%, p<0.001). Conclusion: Follow-up by a dietitian with a doctor available as needed was the most preferred follow-up method. However, in this study follow-up by a dietitian with doctor available and hospital doctor alone was statistically equivalent. Many patients consider telephone and video follow-up of equal value to face-to-face reviews.

Relationships between self-management strategies and physical activity and diet quality in women with polycystic ovary syndrome.

OBJECTIVE: To determine the relationships of self-management strategies and physical activity (PA) and diet quality in women with PCOS. METHODS: An online cross-sectional study involving women (n = 501), 18-45 years in the general Australian community with a self-reported PCOS diagnosis. The self-management and lifestyle behaviour questionnaires were completed between August 2017 and March 2018. RESULTS: Implementation of PA related self-management strategies increased the odds of meeting PA recommendations [Odds ratio (OR): 2.929 (95%CI: 2.172, 3.951), p < 0.001] but had no association with body mass index (BMI) [OR: 0.-0.984 (95%CI: -1.010, 0.959), p = 0.217] nor perception of self weight [OR: 1.382 (95% CI: 0.700, 2.725), p = 0.352]. Nutrition related self-management strategies were inversely associated with BMI [OR: - 0.115 (95%CI: -7.159, -0.980), p = 0.010] but had no association with diet quality [OR: 0.183 (95%CI: -2.328, 2.800), p = 0.855], energy intake [OR: - 0.092 (95%CI: -1204.443, 527.496) p = 0.438] or weight [OR: - 0.034 (95%CI: -4.020, 1.930), p = 0.491]. CONCLUSIONS: PA self-management strategies were associated with meeting PA recommendations. Nutrition strategies were associated with lower BMI but not diet quality, energy intake or weight in women with PCOS. PRACTICE IMPLICATIONS: Other behaviour change determinants (e.g. education, skills and self-efficacy) should be considered when designing a PCOS lifestyle programme in conjunction with self-management strategies.

Effects of peer influence on dietary intake and physical activity in schoolchildren.

OBJECTIVE: To investigate the dietary intake and physical activity of boys and girls aged 9-13 years, and the influence of peers on these behaviours. DESIGN: Cross-sectional study. SETTING: Nine primary and secondary schools in south-west London. SUBJECTS: A total of 315 children wore sealed pedometers, provided self-report measures of dietary intake and answered a questionnaire relating to peer influence. Anthropometric measures of height and weight were also obtained. RESULTS: Obese children had the lowest reported energy intakes and the lowest step counts per day. Boys took significantly more steps per day than girls, however girls were closer to achieving their recommended cut-offs for physical activity. Girls had lower energy intakes per day and lower BMI Z-scores than boys, however both genders, across all age groups, had higher than recommended intakes of saturated fat. There were significant associations between peer influence and physical activity levels but not between peer influence and dietary intake. CONCLUSIONS: Low energy intake and physical activity levels but high saturated fat intakes among boys and girls across all age groups highlight the importance of promoting both physical activity and healthy food choices. The finding that peers have a significant effect on physical activity levels but not on dietary intake offers an important approach for the design of health promotion interventions and obesity prevention programmes. Such designs may be particularly beneficial for obese youth, since the low physical activity levels found could be a major contributing factor to the maintenance of the condition.

Are gluten-free food staples accessible to all patients with coeliac disease?

INTRODUCTION: Within England the removal of prescribed gluten-free (GF) foods from many Clinical Commissioning Groups has resulted in a greater reliance on commercially available GF food by adults and children with coeliac disease (CD). High cost and limited availability of GF foods are associated with poorer dietary adherence in people with CD. AIM: To assess if the rise in popularity of GF diets globally has improved the cost or availability of cereal-based GF foods over the past 6 years. DESIGN: Observational study where data were collected on cereal-based GF foods from 50 stores and 10 internet retailers. The number of GF foods within each food category and the cost per 100 g of GF and gluten-containing (GC) foods were compared by store type. RESULTS: GF food availability has increased in premium stores and online. The majority (82%) of GF food categories were significantly more expensive online compared with regular supermarkets. On average, GF breads were 400% more expensive compared with GC breads (p<0.001); no narrowing in cost difference over time observed. Convenience stores did not stock any GF bread nor GF pasta and only one of the budget supermarkets stocked them, similar to data reported 6 years ago. CONCLUSIONS: GF food availability has increased, predominately in premium markets. The GF food desert within convenience and budget stores will continue to disproportionately impact poor socioeconomic cohorts, the elderly and physically disabled. A lack of accessibility to GF foods impacts GF dietary adherence, increasing related comorbidities and healthcare costs.

Disordered Eating Behaviours and Eating Disorders in Women in Australia with and without Polycystic Ovary Syndrome: A Cross-Sectional Study.

Psychological co-morbidities common in polycystic ovary syndrome (PCOS) may contribute to disordered eating and subsequent weight gain. This cross-sectional study aimed to determine the prevalence of disordered eating and a range of eating disorders and demographic risk factors associated with these behaviours within an Australian group of women with and without PCOS. Data from 899 women with (n = 501) and without (n = 398) PCOS were analysed as possibly indicative of disordered eating or eating disorders using the Eating Disorder Examination Questionnaire (EDE-Q) and The Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5) criteria. Disordered eating (p = 0.012) but not eating disorders (p = 0.076) were more prevalent in women with PCOS compared to controls. Increased body mass index (BMI) [Odds Ratio (OR): 1.03; 95%; Confidence Interval (CI): 1.01, 1.05, p = 0.012] and older age [OR: 1.05; 95%CI: 1.02, 1.08, p = 0.002] but not PCOS diagnosis [OR: 1.43; 95%CI: 0.96, 2.13 p = 0.078] increased the odds of disordered eating. Increased BMI [OR: 1.04; 95%CI: 1.02, 1.06, p < 0.001] and younger age [OR: -0.95; 95%CI: 0.93-0.95, p < 0.001] but not PCOS diagnosis [OR: 1.38; 95%CI: 0.97, 1.95, p = 0.076] increased the odds of an eating disorder. Clinicians are recommended to screen all women with PCOS for possible disordered eating behaviours, with particular attention to women with elevated BMI.

Adherence to a Gluten Free Diet Is Associated with Receiving Gluten Free Foods on Prescription and Understanding Food Labelling.

Treatment of coeliac disease requires a strict gluten-free (GF) diet, however, a high proportion of patients do not adhere to a GF diet. The study explores the practical challenges of a GF diet and dietary adherence in Caucasian and South Asian adults with coeliac disease. Patients with biopsy- and serology-proven coeliac disease were recruited from a hospital database. Participants completed a postal survey (n = 375), including a validated questionnaire designed to measure GF dietary adherence. Half of Caucasians (53%) and South Asians (53%) were adhering to a GF diet. The quarter of patients (n = 97) not receiving GF foods on prescription had a lower GF dietary adherence score compared with those receiving GF foods on prescription (12.5 versus 16.0; p < 0.001). Not understanding food labelling and non-membership of Coeliac UK were also associated with lower GF dietary adherence scores. A higher proportion of South Asian patients, compared with Caucasians, reported difficulties understanding what they can eat (76% versus 5%; p < 0.001) and understanding of food labels (53% versus 4%; p < 0.001). We recommend retaining GF foods on prescription, membership of a coeliac society, and regular consultations with a dietitian to enable better understanding of food labels. Robust studies are urgently needed to evaluate the impact of reducing the amount of GF foods prescribed on adherence to a GF diet in all population groups.

Micronutrient Status in Morbidly Obese Patients Prior to Laparoscopic Sleeve Gastrectomy and Micronutrient Changes 5 years Post-surgery.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) has become more popular in recent years. The aim of this study was to determine the vitamin and mineral status in patients up to 5 years after LSG and to explore changes that occurred from pre-operatively to 1, 2 and 5 years after surgery. METHODS: Data reviewed included age, sex, weight and body mass index (BMI), micronutrient supplements consumed and blood levels of 25 hydroxyvitamin D (25 (OH) D), PTH (parathyroid hormone), ferritin, haemoglobin, folate and vitamin B12, prior to and post-LSG. Data was collated from medical records of morbidly obese patients who had undergone LSG surgery. RESULTS: There were a maximum of 336 patients with pre-operative and 1 year after surgery values, n = 272 for 2 years and n = 116 for 5 years after surgery. At 5 years, only 54 % (58/107) of patients reported taking daily multivitamin supplements. Whilst most patients had values within the reference range for haemoglobin, vitamin B12, folate and vitamin D 5 years after LSG, 36 % (34/94) of the patients had serum ferritin below reference value. CONCLUSION: This study has highlighted a low micronutrient supplementation adherence. Ferritin levels decreased over time even with multivitamin supplementation. To improve micronutrient guidelines prior to and after LSG, more research, including controlled supplementation studies, are necessary.

Physiological factors influencing vitamin E biokinetics.

Limited information is available on factors that can influence vitamin E bioavailability. In several studies we have investigated the influence of dietary, biochemical, and genetic factors on vitamin E biokinetics. In these studies, subjects ingested a capsule containing 150 mg deuterated RRR-alpha-tocopheryl acetate, blood was taken up to 48 hr, and tocopherols were analyzed by liquid chromatography and mass spectroscopy. There was significantly greater plasma-labeled alpha-tocopherol concentrations when the capsule was consumed with a high-fat meal (17.5 g) versus a low-fat meal (2.7 g), and there was also a difference between a high-fat toast and butter and a cereal with full-fat milk meal (both 17.5 g fat), indicating that both the amount of fat and food matrix is important for vitamin E absorption. Dyslipidemic subjects displayed a reduced plasma uptake of newly absorbed alpha-tocopherol, and differences were also apparent in individual lipoproteins. A decreased uptake of labeled alpha-tocopherol was also observed in erythrocytes, platelets, and lymphocytes of dyslipidemics. Following vitamin E supplementation (400 mg/day, 4 weeks), the uptake of newly absorbed alpha-tocopherol was decreased, presumably because of saturation of alpha-tocopherol transfer protein. We also found that apoE3 subjects displayed a considerably reduced uptake of newly absorbed labeled alpha-tocopherol compared to apoE4 subjects, which may be a consequence of the reduced low-density lipoprotein catabolic rate in these subjects. Taken together, these data show that several physiological factors influence the uptake of newly absorbed alpha-tocopherol, and that this is an important consideration in the design of future vitamin E supplementation studies.

Cigarette smokers have decreased lymphocyte and platelet alpha-tocopherol levels and increased excretion of the gamma-tocopherol metabolite gamma-carboxyethyl-hydroxychroman (gamma-CEHC).

Cigarette smoking is associated with increased oxidative stress and increased risk of degenerative disease. As the major lipophilic antioxidant, requirements for vitamin E may be higher in smokers due to increased utilisation. In this observational study we have compared vitamin E status in smokers and non-smokers using a holistic approach by measuring plasma, erythrocyte, lymphocyte and platelet alpha- and gamma-tocopherol, as well as the specific urinary vitamin E metabolites alpha- and gamma-carboxyethyl-hydroxychroman (CEHC). Fifteen smokers (average age 27 years, smoking time 7.5 years) and non-smokers of comparable age, gender and body mass index (BMI) were recruited. Subjects completed a 7-day food diary and on the final day they provided a 24 h urine collection and a 20 ml blood sample for measurement of urinary vitamin E metabolites and total vitamin E in blood components, respectively. No significant differences were found between plasma and erythrocyte alpha- and gamma-tocopherol in smokers and non-smokers. However, smokers had significantly lower alpha-tocopherol (mean+/-SD, 1.34+/-0.31 micromol/g protein compared with 1.94+/-0.54, P = 0.001) and gamma-tocopherol (0.19+/-0.04 micromol/g protein compared with 0.26+/-0.08, P = 0.026) levels in their lymphocytes, as well as significantly lower alpha-tocopherol levels in platelets (1.09+/-0.49 micromol/g protein compared with 1.60+/-0.55, P = 0.014; gamma-tocopherol levels were similar). Interestingly smokers also had significantly higher excretion of the urinary gamma-tocopherol metabolite, gamma-CEHC (0.49+/-0.25mg/g creatinine compared with 0.32+/-0.16, P = 0.036) compared to non-smokers, while their alpha-CEHC (metabolite of alpha-tocopherol) levels were similar. There was no significant difference between plasma ascorbate, urate and F2-isoprostane levels. Therefore in this population of cigarette smokers (mean age 27 years, mean smoking duration 7.5 years), alterations to vitamin E status can be observed even without the more characteristic changes to ascorbate and F2-isoprostanes. We suggest that the measurement of lymphocyte and platelet vitamin E may represent a valuable biomarker of vitamin E status in relation to oxidative stress conditions.

An isocaloric low glycemic index diet improves insulin sensitivity in women with polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a common endocrine disorder affecting 5% to 10% of women worldwide. Approximately half of women with PCOS are lean, yet may still present with central obesity and metabolic disturbances. Low-glycemic index (GI) dietary intervention studies have demonstrated improvements in insulin sensitivity in insulin-resistant populations; however, there is little evidence of this effect in women with PCOS. This research aimed to determine the efficacy of an isocaloric low-GI dietary intervention on insulin sensitivity, independent of weight change, in women with PCOS. A nonrandomized 12-week low-GI dietary intervention, preceded by a 12-week habitual diet control phase and proceeded by a 12-week follow-up phase was conducted. Dietary intake, body composition, and metabolic risk markers were determined at baseline, after completion of the habitual diet control phase, and after the low-GI dietary intervention. Twenty-six participants were recruited at baseline, 22 commenced and 21 participants completed the low-GI dietary intervention phase. The primary outcome was change in insulin sensitivity. Secondary outcomes included assessment of changes to lipids, body composition, and estimated macronutrient intake. Repeated measures analysis of variance with Bonferroni correction were used to detect changes to outcomes across study timepoints. Twenty-one women with PCOS with mean (± standard deviation) age of 32.1±6.7 years completed the 12-week low-GI dietary intervention. As expected, no significant changes occurred during the 12-week habitual diet control phase. However, during the dietary intervention phase, dietary GI decreased from 54.5±3.5 to 48.6±5.1 (P<0.001) with a concurrent small reduction in saturated fat intake (12.4%±3% to 11.7%±3% contribution from energy, P=0.03), despite no specific recommendations to modify fat intake. Measures of insulin sensitivity and nonesterified fatty acid improved after intervention (P=0.03 and P=0.01, respectively). This is the first study to implement an isocaloric low-GI diet in women with PCOS and findings may contribute to the limited research in this area.

Habitual fat intake predicts memory function in younger women.

High intakes of fat have been linked to greater cognitive decline in old age, but such associations may already occur in younger adults. We tested memory and learning in 38 women (25 to 45 years old), recruited for a larger observational study in women with polycystic ovary syndrome. These women varied in health status, though not significantly between cases (n = 23) and controls (n = 15). Performance on tests sensitive to medial temporal lobe function (CANTABeclipse, Cambridge Cognition Ltd, Cambridge, UK), i.e., verbal memory, visuo-spatial learning, and delayed pattern matching (DMS), were compared with intakes of macronutrients from 7-day diet diaries and physiological indices of metabolic syndrome. Partial correlations were adjusted for age, activity, and verbal IQ (National Adult Reading Test). Greater intakes of saturated and trans fats, and higher saturated to unsaturated fat ratio (Sat:UFA), were associated with more errors on the visuo-spatial task and with poorer word recall and recognition. Unexpectedly, higher UFA intake predicted poorer performance on the word recall and recognition measures. Fasting insulin was positively correlated with poorer word recognition only, whereas higher blood total cholesterol was associated only with visuo-spatial learning errors. None of these variables predicted performance on a DMS test. The significant nutrient-cognition relationships were tested for mediation by total energy intake: saturated and trans fat intakes, and Sat:UFA, remained significant predictors specifically of visuo-spatial learning errors, whereas total fat and UFA intakes now predicted only poorer word recall. Examination of associations separately for monounsaturated (MUFA) and polyunsaturated fats suggested that only MUFA intake was predictive of poorer word recall. Saturated and trans fats, and fasting insulin, may already be associated with cognitive deficits in younger women. The findings need extending but may have important implications for public health.

Comparative (2)H-labelled alpha-tocopherol biokinetics in plasma, lipoproteins, erythrocytes, platelets and lymphocytes in normolipidaemic males.

The biokinetics of newly absorbed vitamin E in blood components was investigated in normolipidaemic males. Subjects (n 12) ingested encapsulated 150 mg (2)H-labelled RRR-alpha-tocopheryl acetate with a standard meal. Blood was collected at 3, 6, 9, 12, 24 and 48 h post-ingestion. (2)H-Labelled and pre-existing unlabelled alpha-tocopherol (alpha-T) was determined in plasma, lipoproteins, erythrocytes, platelets and lymphocytes by LC-MS. In all blood components, labelled alpha-T concentration significantly increased while unlabelled decreased following ingestion (P<0.0001). Significant differences in labelled alpha-T biokinetic parameters were found between lipoproteins. Time of maximum concentration was significantly lower in chylomicrons, while VLDL had a significantly greater maximum alpha-T concentration and area under the curve (AUC) (P<0.05). The largest variability occurred in chylomicron alpha-T transport. Erythrocyte labelled alpha-T concentrations increased gradually up to 24 h while alpha-T enrichment of platelets and lymphocytes was slower, plateauing at 48 h. Platelet enrichment with labelled alpha-T was biphasic, the initial peak coinciding with the labelled alpha-T peak in chylomicrons. Erythrocyte and HDL AUC were significantly correlated (P<0.005), as was platelet and HDL AUC (P<0.05). There was a lower turnover of pre-existing alpha-T in platelets and lymphocytes (maximum 25 % labelled alpha-T) compared to plasma and erythrocytes (maximum 45 % labelled alpha-T). These data indicate that different processes exist in the uptake and turnover of alpha-T by blood components and that chylomicron alpha-T transport is a major determinant of inter-individual variation in vitamin E response. This is important for the understanding of alpha-T transport and uptake into tissues.

Hyperlipidemic subjects have reduced uptake of newly absorbed vitamin E into their plasma lipoproteins, erythrocytes, platelets, and lymphocytes, as studied by deuterium-labeled alpha-tocopherol biokinetics.

Vitamin E homeostasis in hyperlipidemia is poorly understood. The biokinetics of deuterated alpha-tocopherol (alpha-T) in blood components was investigated in normolipidemic (N; total cholesterol < 5.5 mmol/L and triglycerides < 1.5 mmol/L, n = 9), hypercholesterolemic (HC; total cholesterol > 6.5 mmol/L and triglycerides < 1.5 mmol/L, n = 10), and combined hypercholesterolemic and hypertriglyceridemic (HCT; total cholesterol > 6.5 mmol/L and triglycerides > 2.5 mmol/L, n = 6) subjects. Subjects ingested 150 mg hexadeuterated RRR-alpha-tocopheryl acetate, and blood was collected up to 48 h after ingestion. Labeled alpha-T was measured in plasma, lipoproteins, erythrocytes, platelets, and lymphocytes by liquid chromatography/mass spectroscopy. In plasma, HC had an earlier time of maximum concentration (6 h) compared with N and HCT (12 h) (P < 0.05). HCT had a lower uptake of labeled alpha-T (P < 0.005) and a longer half-life (P < 0.05). In chylomicrons, the maximum labeled alpha-T concentration was higher in HC compared with N and HCT (P < 0.00005); however, HCT had a lower uptake of labeled alpha-T in LDL. In all groups, the lowest density LDL subfraction contained more labeled alpha-T than denser subfractions (P < 0.05). In platelets, lymphocytes, and erythrocytes, the areas under the labeled alpha-T concentration vs. time curves were in the order N > HC > HCT. In lymphocytes, differences in labeled alpha-T were found at 6 and 48 h (P < 0.05). These data demonstrate that there are differences in the uptake of newly absorbed alpha-T into blood components in hyperlipidemia. Because these blood components are functionally affected by vitamin E, reduced uptake of alpha-T may be relevant to the pathogenesis of atherosclerosis.

The absorption of vitamin E is influenced by the amount of fat in a meal and the food matrix.

Vitamin E absorption requires the presence of fat; however, limited information exists on the influence of fat quantity on optimal absorption. In the present study we compared the absorption of stable-isotope-labelled vitamin E following meals of varying fat content and source. In a randomised four-way cross-over study, eight healthy individuals consumed a capsule containing 150 mg (2)H-labelled RRR-alpha-tocopheryl acetate with a test meal of toast with butter (17.5 g fat), cereal with full-fat milk (17.5 g fat), cereal with semi-skimmed milk (2.7 g fat) and water (0 g fat). Blood was taken at 0, 0.5, 1, 1.5, 2, 3, 6 and 9 h following ingestion, chylomicrons were isolated, and (2)H-labelled alpha-tocopherol was analysed in the chylomicron and plasma samples. There was a significant time (P<0.001) and treatment effect (P<0.001) in (2)H-labelled alpha-tocopherol concentration in both chylomicrons and plasma between the test meals. (2)H-labelled alpha-tocopherol concentration was significantly greater with the higher-fat toast and butter meal compared with the low-fat cereal meal or water (P<0.001), and a trend towards greater concentration compared with the high-fat cereal meal (P=0.065). There was significantly greater (2)H-labelled alpha-tocopherol concentration with the high-fat cereal meal compared with the low-fat cereal meal (P<0.05). The (2)H-labelled alpha-tocopherol concentration following either the low-fat cereal meal or water was low. These results demonstrate that both the amount of fat and the food matrix influence vitamin E absorption. These factors should be considered by consumers and for future vitamin E intervention studies.

Development of a liquid chromatographic time-of-flight mass spectrometric method for the determination of unlabelled and deuterium-labelled alpha-tocopherol in blood components.

A method is described for the analysis of deuterated and undeuterated alpha-tocopherol in blood components using liquid chromatography coupled to an orthogonal acceleration time-of-flight (TOF) mass spectrometer. Optimal ionisation conditions for undeuterated (d0) and tri- and hexadeuterated (d3 or d6) alpha-tocopherol standards were found with negative ion mode electrospray ionisation. Each species produced an isotopically resolved single ion of exact mass. Calibration curves of pure standards were linear in the range tested (0-1.5 microM, 0-15 pmol injected). For quantification of d0 and d6 in blood components following a standard solvent extraction, a stable-isotope-labelled internal standard (d3-alpha-tocopherol) was employed. To counter matrix ion suppression effects, standard response curves were generated following identical solvent extraction procedures to those of the samples. Within-day and between-day precision were determined for quantification of d0- and d6-labelled alpha-tocopherol in each blood component and both averaged 3-10%. Accuracy was assessed by comparison with a standard high-performance liquid chromatography (HPLC) method, achieving good correlation (r(2) = 0.94), and by spiking with known concentrations of alpha-tocopherol (98% accuracy). Limits of detection and quantification were determined to be 5 and 50 fmol injected, respectively. The assay was used to measure the appearance and disappearance of deuterium-labelled alpha-tocopherol in human blood components following deuterium-labelled (d6) RRR-alpha-tocopheryl acetate ingestion. The new LC/TOFMS method was found to be sensitive, required small sample volumes, was reproducible and robust, and was capable of high throughput when large numbers of samples were generated.