Dietary Patterns Associated with Breast Cancer in the Middle East: A Scoping Review.

Breast cancer (BC) is the most predominant malignancy in Arab women in the Middle East, and yearly increases in occurrence by 37.5 and mortality rates by 15.2 for every 100,000 in 2019. This review explores the gap in research investigating the role of dietary patterns and BC in Middle Eastern countries. Furthermore, we analyze the evidence connecting these patterns to BC prevalence in the region, discussing implications for public health and preventive strategies. PubMed, ProQuest, and Cochrane databases were searched up to November 2023. Articles published in English from 2000 to 2023 were identified. Our search included dietary patterns (DP), their association with BC and specific to Middle Eastern Regions. The majority of existing research is concentrated in Iran, with limited illustration from Saudi Arabia, Turkey, and Jordan, and a notable absence of studies from other Middle Eastern countries. We found that dietary intervention is closely related to the occurrence, development, and prognosis of BC. Most DPs such as the Dietary Approaches to Stop Hypertension, Mediterranean, Plant-based and Paleolithic diets are identified to decrease the probability of BC by being rich sources of fiber, healthy fats, and vitamins and minerals. However, there are few DPs that increase the risk of BC, because of the existence of foods such as unhealthy fats, low fiber, sugars, and fried foods in those patterns which contribute to increasing the risk factors associated with BC. This review highlights the intricate connection between DPs and the risk of BC in the Middle East, revealing potential protective effects and heightened risks linked to specific dietary elements.

UAE Women's Knowledge and Attitudes towards Physical Activity during Pregnancy.

The benefits of being physically active during pregnancy are widely acknowledged. It is important for the prevention of chronic diseases and the promotion of good health for mothers and children. However, physical activity by women in the UAE is notoriously low and reduced further during pregnancy. The same can be said regarding research about the knowledge and understanding of the benefits and risks associated with exercise as a predictor of behavior. We aimed to assess knowledge and attitudes towards physical activity during pregnancy amongst Emirati women. A cross-sectional digital survey was designed to assess knowledge and attitudes and distributed to women, aged 18-40 years, using non-randomized, purposeful snowball sampling. A total of 1538 women were recruited. Most participants were aged 20-29 years (53.5%), were Emiratis (88.9%), and had no history of chronic disease (68.6%). The participants self-reported very low levels of PA (75.5%) and had a below-average level of knowledge overall (40.6 ± 20). Younger ages (p < 0.001), lower educational levels (p = 0.004), being employed (p = 0.014), and having a history of chronic disease (p = 0.016) were significantly associated with lower mean knowledge scores, while being married (p = 0.003) was significantly associated with higher scores. The participants also exhibited a positive attitude towards physical activity during pregnancy by selecting answers that they supported it. To encourage physical activity, women living in the UAE could benefit from clear advice about safe physical activity during pregnancy.

The attitudes and practices of United Arab Emirates consumers towards food waste: A nationwide cross-sectional study.

Background: Reducing global food waste is an international environmental, health, and sus-tainability priority. Although significant reductions have been achieved across the food chain, progress by UAE households and consumers remain inadequate. This study seeks to understand the association between consumer attitudes, knowledge, and awareness relating to food waste practice of residents living in the UAE. to help inform policy and action for addressing this national priority. Methods: A cross-sectional study was conducted using a validated semi-structured online questionnaire through stratified sampling (n =1052). The Spearman correlation coefficient was performed to determine the correlations. Two independent regression analysis were used to determine the association between food waste practice with: 1) knowledge and awareness and attitude subdomains, and 2) sociodemographic characteristics. Respondents (n=1072) largely reflect the socio-demographic characteristics and population distribution across the seven Emirates. Results: As expected, a significant and negative correlation was found between food waste practice knowledge and awareness and overall attitude. The regression models showed reduced food waste practice was associated with better knowledge, personal attitude, financial attitude (first model), older age and fewer adults in the household (second model). We found a significant and negative association of personal attitude (a commitment, intention), financial attitude (cost-saving motivation), and (existing) knowledge of Food waste (FW) with practice of food waste, indicating that better knowledge about FW, personal attitude or financial attitude was associated with reduction in undesirable food waste practice. While awareness and emotional attitude (moral concerns) were positively and significantly associated with food waste practice (undesirable behaviour). Conclusions: Food waste poses significant challenges in the UAE, and addressing it requires a comprehensive understanding of the multifaceted factors influencing consumer behavior. By promoting knowledge, fostering positive attitudes, and considering socio-cultural factors, policymakers can develop effective strategies to reduce food waste in households and contribute to sustainable development goals.

Towards refining World Cancer Research Fund/American Institute for Cancer Research cancer prevention recommendations for red and processed meat intake: insights from Alberta's Tomorrow Project cohort.

Current cancer prevention recommendations advise limiting red meat intake to <500 g/week and avoiding consumption of processed meat, but do not differentiate the source of processed meat. We examined the associations of processed meat derived from red v. non-red meats with cancer risk in a prospective cohort of 26 218 adults who reported dietary intake using the Canadian Diet History Questionnaire. Incidence of cancer was obtained through data linkage with Alberta Cancer Registry with median follow-up of 13·3 (interquartile range (IQR) 5·1) years. Multivariable Cox proportional hazards regression models were adjusted for covariates and stratified by age and sex. The median consumption (g/week) of red meat, processed meat from red meat and processed meat from non-red meat was 267·9 (IQR 269·9), 53·6 (IQR 83·3) and 11·9 (IQR 31·8), respectively. High intakes (4th Quartile) of processed meat from red meat were associated with increased risk of gastrointestinal cancer adjusted hazard ratio (AHR): 1·68 (95 % CI 1·09, 2·57) and colorectal cancers AHR: 1·90 (95 % CI 1·12, 3·22), respectively, in women. No statistically significant associations were observed for intakes of red meat or processed meat from non-red meat. Results suggest that the carcinogenic effect associated with processed meat intake may be limited to processed meat derived from red meats. The findings provide preliminary evidence towards refining cancer prevention recommendations for red and processed meat intake.

The effect of different methods to identify, and scenarios used to address energy intake misestimation on dietary patterns derived by cluster analysis.

BACKGROUND: All self-reported dietary intake data are characterized by measurement error, and validation studies indicate that the estimation of energy intake (EI) is particularly affected. METHODS: Using self-reported food frequency and physical activity data from Alberta's Tomorrow Project participants (n = 9847 men 16,241 women), we compared the revised-Goldberg and the predicted total energy expenditure methods in their ability to identify misreporters of EI. We also compared dietary patterns derived by k-means clustering under different scenarios where misreporters are included in the cluster analysis (Inclusion); excluded prior to completing the cluster analysis (ExBefore); excluded after completing the cluster analysis (ExAfter); and finally, excluded before the cluster analysis but added to the ExBefore cluster solution using the nearest neighbor method (InclusionNN). RESULTS: The predicted total energy expenditure method identified a significantly higher proportion of participants as EI misreporters compared to the revised-Goldberg method (50% vs. 47%, p < 0.0001). k-means cluster analysis identified 3 dietary patterns: Healthy, Meats/Pizza and Sweets/Dairy. Among both men and women, participants assigned to dietary patterns changed substantially between ExBefore and ExAfter and also between the Inclusion and InclusionNN scenarios (Hubert and Arabie's adjusted Rand Index, Kappa and Cramer's V statistics < 0.8). CONCLUSIONS: Different scenarios used to account for EI misreporters influenced cluster analysis and hence the composition of the dietary patterns. Continued efforts are needed to explore and validate methods and their ability to identify and mitigate the impact of EI misestimation in nutritional epidemiology.

Administering a combination of online dietary assessment tools, the Automated Self-Administered 24-Hour Dietary Assessment Tool, and Diet History Questionnaire II, in a cohort of adults in Alberta's Tomorrow Project.

BACKGROUND: Evidence suggests that combining tools that gather short- and long-term dietary data may be the optimal approach for the assessment of diet-disease associations in epidemiologic studies. Online technology can reduce the associated burdens for researchers and participants, but feasibility must be demonstrated in real-world settings before wide-scale implementation. OBJECTIVE: The objective of this study was to determine the feasibility and acceptability of combining web-based tools (the Automated Self-Administered 24-hour Dietary Assessment Tool [ASA24-2016] and the past-year Diet History Questionnaire II [DHQ-II]) in a subset of participants in Alberta's Tomorrow Project, a prospective cohort. DESIGN: For this feasibility study, invitations were mailed to 550 randomly selected individuals enrolled in Alberta's Tomorrow Project. Consented participants (n = 331) were asked to complete a brief sociodemographic and health questionnaire, four ASA24-2016 recalls, the DHQ-II, and an evaluation survey. PARTICIPANTS/SETTING: The study was conducted from March 2016 to December 2016 in Alberta, Canada. The majority of participants, mean age (SD) = 57.4 (9.8) years, were women (70.7%), urban residents (85.5%), and nonsmokers (95.7%). MAIN OUTCOME MEASURES: Primary outcomes were number of ASA24-2016 recalls completed, response rate of DHQ-II completion, and time to complete each assessment. STATISTICAL ANALYSES: The Wilcoxon signed rank sum test was used to assess differences in completion time. RESULTS: One-third (n = 102) of consenting participants did not complete any ASA24-2016 recalls. The primary reason to withdraw from the feasibility study was a lack of time. Among consenting participants, 51.9% (n = 172), 41.1% (n = 136), and 36.5% (n = 121) completed at least two ASA24-2016 recalls, the DHQ-II, and at least two ASA24-2016 recalls plus the DHQ-II, respectively. Median (25th to 75th percentile) completion times for participants who completed all recalls were 39 minutes (25 to 53 minutes) for the first ASA24-2016 recall and 60 minutes (40 to 90 minutes) for the DHQ-II. CONCLUSIONS: Findings indicate combining multiple ASA24-2016 recalls and the DHQ-II is feasible in this subset of Alberta's Tomorrow Project participants. However, optimal response rates may be contingent on providing participant support. Completion may also be sensitive to timing and frequency of recall administration.

Co-consumption of Vegetables and Fruit, Whole Grains, and Fiber Reduces the Cancer Risk of Red and Processed Meat in a Large Prospective Cohort of Adults from Alberta's Tomorrow Project.

We examined whether co-consumption of red and processed meat with key foods items and food constituents recommended for cancer prevention (vegetables and fruit, whole grains, and fiber) mitigates cancer incidence. In a prospective cohort of 26,218 adults aged 35-69 years at baseline, dietary intake was collected through 124-item past-year food frequency questionnaire. Incidence of all-cause and 15 cancers previously linked to red and processed meat intake was obtained through data linkage with a cancer registry (average follow-up 13.5 years). Competing risk Cox Proportional Hazard models estimated cancer risk and Accelerated Failure Time models estimated time-to-cancer occurrence for different combinations of intake levels while considering mortality from vital statistics and established confounders. Co-consumption of low vegetables and fruit intake with high processed meat was associated with higher incidence of all-cause and 15 cancers (men: HR = 1.85, 1.91; women: HR = 1.44, 1.49) and accelerated time-to-cancer occurrence (men: 6.5 and 7.1 years and women: 5.6 and 6.3 years, respectively), compared to high vegetables and fruit with low processed meat intake. Less pronounced and less consistent associations were observed for whole grains and fiber and for red meat. The findings provide initial evidence toward refining existing cancer prevention recommendations to optimize the intake and combination of foods in the general adult population.

Perturbed Mitochondrial Dynamics Is a Novel Feature of Colitis That Can Be Targeted to Lessen Disease.

BACKGROUND & AIMS: Mitochondria exist in a constantly remodelling network, and excessive fragmentation can be pathophysiological. Mitochondrial dysfunction can accompany enteric inflammation, but any contribution of altered mitochondrial dynamics (ie, fission/fusion) to gut inflammation is unknown. We hypothesized that perturbed mitochondrial dynamics would contribute to colitis. METHODS: Quantitative polymerase chain reaction for markers of mitochondrial fission and fusion was applied to tissue from dextran sodium sulfate (DSS)-treated mice. An inhibitor of mitochondrial fission, P110 (prevents dynamin related protein [Drp]-1 binding to mitochondrial fission 1 protein [Fis1]) was tested in the DSS and di-nitrobenzene sulfonic acid (DNBS) models of murine colitis, and the impact of DSS ± P110 on intestinal epithelial and macrophage mitochondria was assessed in vitro. RESULTS: Analysis of colonic tissue from mice with DSS-colitis revealed increased mRNA for molecules associated with mitochondrial fission (ie, Drp1, Fis1) and fusion (optic atrophy factor 1) and increased phospho-Drp1 compared with control. Systemic delivery of P110 in prophylactic or treatment regimens reduced the severity of DSS- or DNBS-colitis and the subsequent hyperalgesia in DNBS-mice. Application of DSS to epithelial cells or macrophages caused mitochondrial fragmentation. DSS-evoked perturbation of epithelial cell energetics and mitochondrial fragmentation, but not cell death, were ameliorated by in vitro co-treatment with P110. CONCLUSIONS: We speculate that the anti-colitic effect of systemic delivery of the anti-fission drug, P110, works at least partially by maintaining enterocyte and macrophage mitochondrial networks. Perturbed mitochondrial dynamics can be a feature of intestinal inflammation, the suppression of which is a potential novel therapeutic direction in inflammatory bowel disease.

Strategies to Address Misestimation of Energy Intake Based on Self-Report Dietary Consumption in Examining Associations Between Dietary Patterns and Cancer Risk.

The objective of this study was to determine the influence of strategies of handling misestimation of energy intake (EI) on observed associations between dietary patterns and cancer risk. Data from Alberta's Tomorrow Project participants (n = 9,847 men and 16,241 women) were linked to the Alberta Cancer Registry. The revised-Goldberg method was used to characterize EI misestimation. Four strategies assessed the influence of EI misestimation: Retaining individuals with EI misestimation in the cluster analysis (Inclusion), excluding before (ExBefore) or after cluster analysis (ExAfter), or reassigning into ExBefore clusters using the nearest neighbor method (InclusionNN). Misestimation of EI affected approximately 50% of participants. Cluster analysis identified three patterns: Healthy, Meats/Pizza and Sweets/Dairy. Cox proportional hazard regression models assessed associations between the risk of cancer and dietary patterns. Among men, no significant associations (based on an often-used threshold of p < 0.05) between dietary patterns and cancer risk were observed. In women, significant associations were observed between the Sweets/Dairy and Meats/Pizza patterns and all cancer risk in the ExBefore (HR (95% CI): 1.28 (1.04-1.58)) and InclusionNN (HR (95% CI): 1.14 (1.00-1.30)), respectively. Thus, strategies to address misestimation of EI can influence associations between dietary patterns and disease outcomes. Identifying optimal approaches for addressing EI misestimation, for example, by leveraging biomarker-based studies could improve our ability to characterize diet-disease associations.

Plasma Response to Deuterium-Labeled Vitamin K Intake Varies by TG Response, but Not Age or Vitamin K Status, in Older and Younger Adults.

Background: Phylloquinone is the primary form of vitamin K in the diet and circulation. Large intra- and interindividual variances in circulating phylloquinone have been partially attributed to age. However, little is known about the nondietary factors that influence phylloquinone absorption and metabolism. Similarly, it is not known if phylloquinone absorption is altered by the individual's existing vitamin K status. Objective: The purpose of this secondary substudy was to compare plasma response with deuterium-labeled phylloquinone intake in older and younger adults after dietary phylloquinone depletion and repletion. Methods: Forty-two older [mean ± SD age: 67.2 ± 8.0 y; body mass index (BMI; in kg/m2): 25.4 ± 4.6; n = 12 men, 9 women] and younger (mean ± SEM age: 31.8 ± 6.6 y; BMI: 25.5 ± 3.3; n = 9 men, 12 women) adults were maintained on sequential 28-d phylloquinone depletion (∼10 µg phylloquinone/d) and 28-d phylloquinone repletion (∼500 µg phylloquinone/d) diets. On the 23rd d of each diet phase, participants consumed deuterated phylloquinone-rich collard greens (2H-phylloquinone). Plasma and urinary outcome measures over 72 h were compared by age group, sex, and dietary phase via 2-factor repeated-measures ANOVA. Results: The plasma 2H-phylloquinone area under the curve (AUC) did not differ in response to phylloquinone depletion or repletion, but was 34% higher in older than in younger adults (P = 0.02). However, plasma 2H-phylloquinone AUC was highly correlated with the serum triglyceride (TG) AUC (r2 = 0.45). After adjustment for serum TG response, the age effect on the plasma 2H-phylloquinone AUC was no longer significant. Conclusions: Plasma 2H-phylloquinone response did not differ between phylloquinone depletion and repletion in older and younger adults. The age effect observed was explained by the serum TG response and was completely attenuated after adjustment. Plasma response to phylloquinone intake, therefore, seems to be a predominantly lipid-driven effect and not dependent on existing vitamin K status. More research is required to differentiate the effect of endogenous compared with exogenous lipids on phylloquinone absorption. This trial was registered at clinicaltrials.gov as NCT00336232.

Hepatic Expression of PEMT, but Not Dietary Choline Supplementation, Reverses the Protection against Atherosclerosis in Pemt-/-/Ldlr-/- Mice.

Background: Phosphatidylethanolamine N-methyltransferase (PEMT) converts phosphatidylethanolamine to phosphatidylcholine. Pemt-/-/low density lipoprotein receptor (Ldlr)-/- mice have significantly reduced plasma lipids and are protected against atherosclerosis. Recent studies have shown that choline can be metabolized by the gut flora into trimethylamine-N-oxide (TMAO), which is an emerging risk factor for atherosclerosis. Objective: The objective of this study was to determine whether ectopic hepatic PEMT expression or choline supplementation would promote atherosclerosis in Pemt-/-/Ldlr-/- mice. Methods: Male 8- to 10-wk-old Pemt+/+/Ldlr-/- (SKO) and Pemt-/-/Ldlr-/- (DKO) mice were injected with an adeno-associated virus (AAV) expressing green fluorescent protein (GFP) or human PEMT and fed a Western diet (40% of calories from fat, 0.5% cholesterol) for 8 wk. In a separate experiment, 8- to 10-wk-old SKO and half of the DKO male mice were fed a Western diet with normal (3 g/kg) choline for 12 wk. The remaining DKO mice [choline-supplemented (CS) DKO] were fed a CS Western diet (10 g choline/kg). Plasma lipid concentrations, choline metabolites, and aortic atherosclerosis were measured. Results: Plasma cholesterol, plasma TMAO, and aortic atherosclerosis were reduced by 60%, 40%, and 80%, respectively, in DKO mice compared with SKO mice. AAV-PEMT administration increased plasma cholesterol and TMAO by 30% and 40%, respectively, in DKO mice compared with AAV-GFP-treated DKO mice. Furthermore, AAV-PEMT-injected DKO mice developed atherosclerotic lesions similar to SKO mice. In the second study, there was no difference in atherosclerosis or plasma cholesterol between DKO and CS-DKO mice. However, plasma TMAO concentrations were increased 2.5-fold in CS-DKO mice compared with DKO mice. Conclusions: Reintroducing hepatic PEMT reversed the atheroprotective phenotype of DKO mice. Choline supplementation did not increase atherosclerosis or plasma cholesterol in DKO mice. Our data suggest that plasma TMAO does not induce atherosclerosis when plasma cholesterol is low. Furthermore, this is the first report to our knowledge that suggests that de novo choline synthesis alters TMAO status.

ER-stress mobilization of death-associated protein kinase-1-dependent xenophagy counteracts mitochondria stress-induced epithelial barrier dysfunction.

The gut microbiome contributes to inflammatory bowel disease (IBD), in which bacteria can be present within the epithelium. Epithelial barrier function is decreased in IBD, and dysfunctional epithelial mitochondria and endoplasmic reticulum (ER) stress have been individually associated with IBD. We therefore hypothesized that the combination of ER and mitochondrial stresses significantly disrupt epithelial barrier function. Here, we treated human colonic biopsies, epithelial colonoids, and epithelial cells with an uncoupler of oxidative phosphorylation, dinitrophenol (DNP), with or without the ER stressor tunicamycin and assessed epithelial barrier function by monitoring internalization and translocation of commensal bacteria. We also examined barrier function and colitis in mice exposed to dextran sodium sulfate (DSS) or DNP and co-treated with DAPK6, an inhibitor of death-associated protein kinase 1 (DAPK1). Contrary to our hypothesis, induction of ER stress (i.e. the unfolded protein response) protected against decreased barrier function caused by the disruption of mitochondrial function. ER stress did not prevent DNP-driven uptake of bacteria; rather, specific mobilization of the ATF6 arm of ER stress and recruitment of DAPK1 resulted in enhanced autophagic killing (xenophagy) of bacteria. Of note, epithelia with a Crohn's disease-susceptibility mutation in the autophagy gene ATG16L1 exhibited less xenophagy. Systemic delivery of the DAPK1 inhibitor DAPK6 increased bacterial translocation in DSS- or DNP-treated mice. We conclude that promoting ER stress-ATF6-DAPK1 signaling in transporting enterocytes counters the transcellular passage of bacteria evoked by dysfunctional mitochondria, thereby reducing the potential for metabolic stress to reactivate or perpetuate inflammation.

Patterns and predictors of adherence to colorectal cancer screening recommendations in Alberta's Tomorrow Project participants stratified by risk.

BACKGROUND: Colorectal cancer (CRC) screening is an important modifiable behaviour for cancer control. Regular screening, following recommendations for the type, timing and frequency based on personal CRC risk, contributes to earlier detection and increases likelihood of successful treatment. METHODS: To determine adherence to screening recommendations in a large provincial cohort of adults, participants in Alberta's Tomorrow Project (n = 9641) were stratified based on increasing level of CRC risk: age (Age-only), family history of CRC (FamilyHx), personal history of bowel conditions (PersonalHx), or both (Family/PersonalHx) using self-reported information from questionnaires. Provincial and national guidelines for timing and frequency of screening tests were used to determine if participants were up-to-date based on their CRC risk. Screening status was compared between enrollment (2000-2006) and follow-up (2008) to determine screening pattern over time. RESULTS: The majority of participants (77%) fell into the average risk Age-only strata. Only a third of this strata were up-to-date for screening at baseline, but the proportion increased across the higher risk strata, with > 90% of the highest risk Family/PersonalHx strata up-to-date at baseline. There was also a lower proportion (< 25%) of the Age-only group who were regular screeners over time compared to the higher risk strata, though age, higher income and uptake of other screening tests (e.g. mammography) were associated with a greater likelihood of regular screening in multinomial logistic regression. CONCLUSIONS: The low (< 50%) adherence to regular CRC screening in average and moderate risk strata highlights the need to further explore barriers to uptake of screening across different risk profiles.

The Comparative Reliability and Feasibility of the Past-Year Canadian Diet History Questionnaire II: Comparison of the Paper and Web Versions.

Advances in technology-enabled dietary assessment include the advent of web-based food frequency questionnaires, which may reduce costs and researcher burden but may introduce new challenges related to internet connectivity and computer literacy. The purpose of this study was to evaluate the intra- and inter-version reliability, feasibility and acceptability of the paper and web Canadian Diet History Questionnaire II (CDHQ-II) in a sub-sample of 648 adults (aged 39-81 years) recruited from Alberta's Tomorrow Project. Participants were randomly assigned to one of two groups: (1) paper, web, paper; or (2) web, paper, web over a six-week period. With few exceptions, no statistically significant differences in mean nutrient intake were found in the intra- and inter-version reliability analyses. The majority of participants indicated future willingness to complete the CDHQ-II online, and 59% indicated a preference for the web over the paper version. Findings indicate that, in this population of adults drawn from an existing cohort, the CDHQ-II may be administered in paper or web modalities (increasing flexibility for questionnaire delivery), and the nutrient estimates obtained with either version are comparable. We recommend that other studies explore the feasibility and reliability of different modes of administration of dietary assessment instruments prior to widespread implementation.

Novel insights on interactions between folate and lipid metabolism.

Folate is an essential B vitamin required for the maintenance of AdoMet-dependent methylation. The liver is responsible for many methylation reactions that are used for post-translational modification of proteins, methylation of DNA, and the synthesis of hormones, creatine, carnitine, and phosphatidylcholine. Conditions where methylation capacity is compromised, including folate deficiency, are associated with impaired phosphatidylcholine synthesis resulting in non-alcoholic fatty liver disease and steatohepatitis. In addition, folate intake and folate status have been associated with changes in the expression of genes involved in lipid metabolism, obesity, and metabolic syndrome. In this review, we provide insight on the relationship between folate and lipid metabolism, and an outlook for the future of lipid-related folate research.

Choline supplementation protects against liver damage by normalizing cholesterol metabolism in Pemt/Ldlr knockout mice fed a high-fat diet.

Dietary choline is required for proper structure and dynamics of cell membranes, lipoprotein synthesis, and methyl-group metabolism. In mammals, choline is synthesized via phosphatidylethanolamine N-methyltransferase (Pemt), which converts phosphatidylethanolamine to phosphatidylcholine. Pemt(-/-) mice have impaired VLDL secretion and developed fatty liver when fed a high-fat (HF) diet. Because of the reduction in plasma lipids, Pemt(-/-)/low-density lipoprotein receptor knockout (Ldlr(-/-)) mice are protected from atherosclerosis. The goal of this study was to investigate the importance of dietary choline in the metabolic phenotype of Pemt(-/-)/Ldlr(-/-) male mice. At 10-12 wk of age, Pemt(+/+)/Ldlr(-/-) (HF(+/+)) and half of the Pemt(-/-)/Ldlr(-/-) (HF(-/-)) mice were fed an HF diet with normal (1.3 g/kg) choline. The remaining Pemt(-/-)/Ldlr(-/-) mice were fed an HF diet supplemented (5 g/kg) with choline (HFCS(-/-) mice). The HF diet contained 60% of calories from fat and 1% cholesterol, and the mice were fed for 16 d. HF(-/-) mice lost weight and developed hepatomegaly, steatohepatitis, and liver damage. Hepatic concentrations of free cholesterol, cholesterol-esters, and triglyceride (TG) were elevated by 30%, 1.1-fold and 3.1-fold, respectively, in HF(-/-) compared with HF(+/+) mice. Choline supplementation normalized hepatic cholesterol, but not TG, and dramatically improved liver function. The expression of genes involved in cholesterol transport and esterification increased by 50% to 5.6-fold in HF(-/-) mice when compared with HF(+/+) mice. Markers of macrophages, oxidative stress, and fibrosis were elevated in the HF(-/-) mice. Choline supplementation normalized the expression of these genes. In conclusion, HF(-/-) mice develop liver failure associated with altered cholesterol metabolism when fed an HF/normal choline diet. Choline supplementation normalized cholesterol metabolism, which was sufficient to prevent nonalcoholic steatohepatitis development and improve liver function. Our data suggest that choline can promote liver health by maintaining cholesterol homeostasis.

Age group and sex do not influence responses of vitamin K biomarkers to changes in dietary vitamin K.

Inadequate vitamin K intake has been associated with abnormal soft tissue calcification. Older adults may have insufficient intakes of vitamin K and respond less to vitamin K supplementation compared with younger adults. However, little is known about the determinants that influence the response to vitamin K supplementation. Our primary objective was to assess dietary and nondietary determinants of vitamin K status in healthy younger and older adults. In a nonrandomized, nonmasked study, 21 younger (18-40 y) and 21 older (55-80 y) men and women consumed a baseline diet (200 µg phylloquinone/d) for 5 d, a phylloquinone-restricted diet (10 µg phylloquinone/d) for 28 d, and a phylloquinone-supplemented diet (500 µg phylloquinone/d) for 28 d. Changes in vitamin K status markers in response to vitamin K depletion and repletion were studied and the influences of BMI, body fat, and circulating TG were assessed by including them as covariates in the model. Despite baseline differences in measures of vitamin K status, plasma phylloquinone tended to increase (P = 0.07) and the percentage of uncarboxylated osteocalcin and uncarboxylated prothrombin both improved with phylloquinone supplementation (P < 0.007), regardless of age group or sex. Only the excretion of urinary menadione, a vitamin K metabolite, was greater among younger adults in response to depletion than in older adults (P = 0.012), regardless of sex. Adiposity measures and circulating TG did not predict response of any measures. In conclusion, poor vitamin K status can be similarly improved with vitamin K supplementation, regardless of age group or sex.

Deuterium-labeled phylloquinone has tissue-specific conversion to menaquinone-4 among Fischer 344 male rats.

Phylloquinone (PK) is converted into menaquinone-4 (MK-4) via side chain removal-addition. Stable isotope use is an effective approach to identify the tissue location of this conversion, which is currently unknown. Following a 14-d PK-deficient diet, male Fischer 344 rats (8 mo; n = 15) were fed 1.6 mg deuterium-labeled PK (L-PK) per kg diet for 0 (control), 1 d (PK-1d), and 7 d (PK-7d). Both L-PK and deuterium-labeled MK-4 (L-MK-4) were detected in tissues in PK-1d and PK-7d, although the results varied. Whereas some tissues had an overall increase in MK-4 in response to L-PK, total brain, testes, and fat MK-4 concentrations did not. In contrast, L-MK-4 concentrations increased in all 3 tissues. The deuterium label was found only on the L-MK-4 naphthoquinone ring, confirming the need for side chain removal for the formation of MK-4. Labeled menadione (MD) was detected in urine and serum in PK-1d and PK-7d, confirming its role as an intermediate. A Caco-2 cell monolayer model was used to study the role of the enterocytes in the conversion process. Neither MK-4 nor MD was detected in Caco-2 cells treated with PK. However, when Caco-2 cells were treated with MD, MK-4 was formed. Similarly, MK-4 was formed in response to MD-treated 293T kidney cells, but not HuH7 liver cells. These data demonstrate that MK-4 is the predominant form of vitamin K in multiple tissues, but there appears to be a tissue-specific regulation for the conversion of PK to MK-4.

Measurement of menadione in urine by HPLC.

Menadione is a metabolite of vitamin K that is excreted in urine. A high performance liquid chromatography (HPLC) method using a C(30) column, post-column zinc reduction and fluorescence detection was developed to measure urinary menadione. The mobile phase was composed of 95% methanol with 0.55% aqueous solution and 5% DI H(2)O. Menaquinone-2 (MK-2) was used as an internal standard. The standard calibration curve was linear with a correlation coefficient (R(2)) of 0.999 for both menadione and MK-2. The lower limit of quantification (LLOQ) was 0.3pmole menadione/mL urine. Sample preparation involved hydrolysis of menadiol conjugates and oxidizing the released menadiol to menadione. Using this method, urinary menadione was shown to increase in response to 3 years of phylloquinone supplementation. This HPLC method is a sensitive and reproducible way to detect menadione in urine.

Determinants of vitamin K status in humans.

To understand the role of vitamin K in human health, it is important to identify determinants of vitamin K status throughout the life cycle. Our current understanding of vitamin K physiology and metabolism only partially explains why there is wide interindividual variation in vitamin K status, as measured by various biochemical measures. Dietary intake of vitamin K is one of the primary determinants of vitamin K status, and intakes vary widely among age groups and population subgroups. How dietary sources of vitamin K are absorbed and transported varies with the form and food source of vitamin K. Likewise, the role of plasma lipids as a determinant of vitamin K status varies with the form of vitamin K ingested. There is also some evidence that other fat-soluble vitamins antagonize vitamin K under certain physiological conditions. Infants are at the greatest risk of vitamin K deficiency because of a poor maternal-fetal transfer across the placenta and low vitamin K concentrations in breast milk. During adulthood, there may be subtle age-related changes in vitamin K status but these are inconsistent and may be primarily related to dietary intake and lifestyle differences among different age groups. However, there is some suggestion that absence of estrogen among postmenopausal women may be a determinant of vitamin K, status. Genetics may explain some of the observed interindividual variability in vitamin K, but to date, there are few studies that have systematically explored the associations between individual genetic polymorphisms and biochemical measures of vitamin K status.