Dietary choline and betaine assessed by food-frequency questionnaire in relation to plasma total homocysteine concentration in the Framingham Offspring Study

Dietary choline and betaine; associations with subclinical markers of cardiovascular disease risk and incidence of CVD, coronary heart disease and stroke: the Jackson Heart Study

PURPOSE

Several mechanisms have been described through which dietary intake of choline and its derivative betaine may be associated in both directions with subclinical atherosclerosis. We assessed the association of dietary intake of choline and betaine with cardiovascular risk and markers of subclinical cardiovascular disease.

METHODS

Data from 3924 Jackson Heart Study (JHS) African-American participants with complete food frequency questionnaire at baseline and follow-up measurements of heart disease measures were used. Multivariable linear regression models were employed to assess associations between choline and betaine intake with carotid intima-media thickness, coronary artery calcium, abdominal aortic calcium and left ventricular mass. Cox proportional hazards regression models were used to estimate associations with time to incident coronary heart disease (CHD), ischemic stroke and cardiovascular disease (CVD).

RESULTS

During an average nine years of follow-up, 124 incident CHD events, 75 incident stroke events and 153 incident CVD events were documented. In women, greater choline intake was associated with lower left ventricular mass (p = 0.0006 for trend across choline quartiles) and with abdominal aortic calcium score. Among all JHS participants, there was a statistically significant inverse association between dietary choline intake and incident stroke, β = -0.33 (p = 0.04). Betaine intake was associated with greater risk of incident CHD when comparing the third quartile of intake with the lowest quartile of intake (HR 1.89, 95 % CI 1.14, 3.15).

CONCLUSIONS

Among our African-American participants, higher dietary choline intake was associated with a lower risk of incident ischemic stroke, and thus putative dietary benefits. Higher dietary betaine intake was associated with a nonlinear higher risk of incident CHD.

The metabolism and significance of homocysteine in nutrition and health

An association between arteriosclerosis and homocysteine (Hcy) was first demonstrated in 1969. Hcy is a sulfur containing amino acid derived from the essential amino acid methionine (Met). Hyperhomocysteinemia (HHcy) was subsequently shown in several age-related pathologies such as osteoporosis, Alzheimer's disease, Parkinson's disease, stroke, and cardiovascular disease (CVD). Also, Hcy is associated with (but not limited to) cancer, aortic aneurysm, hypothyroidism and end renal stage disease to mention some. The circulating levels of Hcy can be increased by defects in enzymes of the metabolism of Met, deficiencies of vitamins B6, B12 and folate or by feeding Met enriched diets. Additionally, some of the pharmaceuticals currently in clinical practice such as lipid lowering, and anti-Parkinsonian drugs are known to elevate Hcy levels. Studies on supplementation with folate, vitamins B6 and B12 have shown reduction in Hcy levels but concomitant reduction in certain associated pathologies have not been definitive. The enormous importance of Hcy in health and disease is illustrated by its prevalence in the medical literature (e.g. > 22,000 publications). Although there are compelling data in favor of Hcy as a modifiable risk factor, the debate regarding the significance of Hcy mediated health effects is still ongoing. Despite associations between increased levels of Hcy with several pathologies being well documented, whether it is a causative factor, or an effect remains inconclusive. The present review though not exhaustive, is focused on several important aspects of Hcy metabolism and their relevance to health.

Prospective study of plasma homocysteine, its dietary determinants, and risk of age-related macular degeneration in men

PURPOSE

Cross-sectional and case-control studies generally support a direct association between elevated plasma homocysteine and age-related macular degeneration (AMD), but data from prospective studies are limited. We examined the prospective relation of plasma homocysteine level, its dietary determinants, and risk of AMD in a large cohort of apparently healthy male physicians.

METHODS

During a mean follow-up of 11.2 years, we identified 146 incident cases of visually significant AMD (responsible for a reduction of visual acuity to 20/30 or worse), and 146 controls matched for age, smoking status, and time of blood draw. We measured concentration of homocysteine in blood samples collected at baseline using an enzymatic assay. and we assessed dietary intake of B vitamins and related compounds betaine and choline with a food frequency questionnaire administered at baseline.

RESULTS

AMD was not associated with plasma level of homocysteine; the multivariable-adjusted odds ratio (OR) of AMD comparing the highest and lowest quartile of homocysteine was 1.09 (95% confidence interval [95% CI]: 0.52-2.31; p for trend = 0.99). However, AMD was inversely associated with quartile of intake of total folate (OR: 0.55; 95% CI: 0.24-1.23; p for trend = 0.08), vitamin B₆ from food (OR: 0.39; 95% CI: 0.17-0.88; p for trend = 0.01), and betaine (OR: 0.53; 95% CI: 0.22-1.27; p for trend = 0.048).

CONCLUSIONS

These prospective data from a cohort of apparently healthy men do not support a major role for homocysteine in AMD occurrence, but do suggest a possible beneficial role for higher intake of several nutrients involved in homocysteine metabolism.

Dietary Choline and Betaine and Risk of CVD: A Systematic Review and Meta-Analysis of Prospective Studies

Studies implicate choline and betaine metabolite trimethylamine N-oxide (TMAO) in cardiovascular disease (CVD). We conducted a systematic review and random-effects meta-analysis to quantify a summary estimated effect of dietary choline and betaine on hard CVD outcomes (incidence and mortality). Eligible studies were prospective studies in adults with comprehensive diet assessment and follow-up for hard CVD endpoints. We identified six studies that met our criteria, comprising 18,076 incident CVD events, 5343 CVD deaths, and 184,010 total participants. In random effects meta-analysis, incident CVD was not associated with choline (relative risk (RR): 1.00; 95% CI: 0.98, 1.02) or betaine (RR: 0.99; 95% CI: 0.98, 1.01) intake. Results did not vary by study outcome (incident coronary heart disease, stroke, total CVD) and there was no evidence for heterogeneity among studies. Only two studies provided data on phosphatidylcholine and CVD mortality. Random effects meta-analysis did not support an association between choline and CVD mortality (RR: 1.09, 95% CI: 0.89, 1.35), but one study supported a positive association and there was significant heterogeneity (I² = 84%, p-value < 0.001). Our findings do not support an association between dietary choline/betaine with incident CVD, but call for further research into choline and CVD mortality.

Enhancement of the Antitumor Effect of Methotrexate on Colorectal Cancer Cells via Lactate Calcium Salt Targeting Methionine Metabolism

Methionine (Met) is involved in one-carbon de novo nucleotide synthesis and is an essential amino acid for cell survival. The impact of lactate calcium salt (CaLa) on the Met metabolism was investigated to evaluate the enhanced antitumor effect of methotrexate (MTX) on colorectal cancer (CRC) cells. Met dependency relating to homocysteine (Hcy) and betaine was investigated in human CRC cells (HCT-116 and HT-29) using a viability assay and liquid chromatography-mass spectrometry. Expression of betaine transporter-1 (BGT-1) following treatment with MTX alone or with CaLa was determined by Western blot. Enhanced antitumor effect due to malfunction of Met synthesis was confirmed. CRC cell viability decreased in Met-restricted medium, but was maintained after Hcy and betaine treatment while overcoming Met restriction. BGT-1 expression was downregulated following the treatment of dose-increased CaLa, whereas there was no effect on BGT-1 expression after MTX treatment. CaLa in combination with MTX induced reduced Met synthesis when CRC cell viability was reduced. The results indicated that CaLa-mediated BGT-1 downregulation inhibits Met synthesis by disrupting betaine homeostasis. CaLa raised the antitumor effect of MTX via secondary role in the inhibition of the de novo nucleotide synthesis. Combination therapy of MTX and CaLa could maximize the effectiveness of CRC treatment.

Choline, Other Methyl-Donors and Epigenetics

Choline dietary intake varies such that many people do not achieve adequate intakes. Diet intake of choline can modulate methylation because, via betaine homocysteine methyltransferase (BHMT), this nutrient (and its metabolite, betaine) regulate the concentrations of S-adenosylhomocysteine and S-adenosylmethionine. Some of the epigenetic mechanisms that modify gene expression without modifying the genetic code depend on the methylation of DNA or of histones; and diet availability of choline and other methyl-group donors influences both of these methylations. Examples of methyl-donor mediated epigenetic effects include the changes in coat color and body weight in offspring when pregnant agouti mice are fed high choline, high methyl diets; the changes in tail kinking in offspring when pregnant Axin(Fu) mice are fed high choline, high methyl diets; the changes in Cdkn3 methylation and altered brain development that occurs in offspring when pregnant rodents are fed low choline diets. When choline metabolism is disrupted by deleting the gene Bhmt, DNA methylation is affected (especially in a region of chromosome 13), expression of specific genes is suppressed, and liver cancers develop. Better understanding of how nutrients such as choline and methyl-donors influence epigenetic programs has importance for our understanding of not only developmental abnormalities but also for understanding the origins of chronic diseases.

Higher dietary intakes of choline and betaine are associated with a lower risk of primary liver cancer: a case-control study

The dietary intake of methyl donors is favorably associated with many diseases, but the findings regarding primary liver cancer (PLC) risk are limited. This study investigated the association between the intake of choline, betaine and methionine and PLC risk in adults. This 1:1 matched case-control study enrolled 644 hospital-based PLC patients and 644 community-based controls who were matched by sex and age, in Guangzhou, China. An interviewer-administered questionnaire and a food-frequency questionnaire were used to collect general information and dietary intake information. Conditional logistic regression showed a significantly inverse association between total choline and betaine intakes and PLC risk. The multivariable-adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) for PLC for the top (vs. bottom) tertile were 0.34 (0.24–0.49; P_-trend < 0.001) for total choline and 0.67 (0.48–0.93; P_-trend = 0.011) for betaine. No significant association was observed between the intake of methionine and PLC risk (P > 0.05). For individual choline compounds, higher consumptions of free choline, glycerophosphocholine, phosphocholine, phosphatidylcholine and sphingomyelin were associated with a lower PLC risk (all P-trend < 0.05). The studied associations were not significantly modified by the folate intake (P-interactions: 0.488–0.890). Our findings suggest that higher choline and betaine intakes may be associated with a lower risk of PLC.

Dietary, anthropometric, and biochemical factors influencing plasma choline, carnitine, trimethylamine, and trimethylamine-N-oxide concentrations

The objective of the study was to evaluate the nutritional, anthropometric, and biochemical factors that influence choline, l-carnitine, trimethylamine (TMA), and trimethylamine-N-oxide (TMAO) metabolism in elderly women. The volunteers' diet was assessed using a food frequency questionnaire. Dietary patterns were estimated using a self-established score method. Body mass index (BMI), serum glucose, total, HDL, LDL cholesterol, triacylglycerol, homocysteine (tHcy), free choline (fchol), L-carnitine, TMA, and TMAO were assessed. Higher concentrations of l-carnitine, fchol, and TMAO were found in those women who had more western-style dietary patterns. Nor choline or betaine intake affected plasma fchol, TMA, or TMAO. BMI was positively correlated with fchol and TMA. tHcy was positively correlated with fchol, TMA, and TMAO, while fchol was also positively correlated with TMA and TMAO. Dietary patterns and plasma tHcy concentration influence fchol, TMA, and TMAO plasma concentration. Plasma TMA and fchol may be associated with BMI.

Dietary choline deficiency and excess induced intestinal inflammation and alteration of intestinal tight junction protein transcription potentially by modulating NF-κB, STAT and p38 MAPK signaling molecules in juvenile Jian carp

This study investigated the effects of choline on intestinal mucosal immune and the possible mechanisms in fish by feeding juvenile Jian carp (Cyprinus carpio var. Jian) with graded levels of dietary choline (165-1820 mg/kg diet) for 65 days. The results firstly showed that choline deficiency induced inflammatory infiltration in the proximal intestine (PI), mid intestine (MI) and distal intestine (DI) of fish. Meanwhile, compared with the optimal choline group, choline deficiency decreased the activities of lysozyme and acid phosphatase, contents of complement 3 and IgM in the intestine, downregulated the mRNA levels of antimicrobial peptides (liver-expressed antimicrobial peptide (LEAP) 2A and defensin-3 in the PI and MI, LEAP-2B and hepcidin in the PI, MI and DI), anti-inflammatory cytokines (interleukin (IL) 10 and transforming growth factor β2 in the PI, MI and DI), and signaling molecule IκB in the PI, MI and DI; while upregulated the mRNA levels of pro-inflammatory cytokines (IL-6a and tumor necrosis factor α in the MI and DI, interferon γ2b in the PI and MI, IL-1β and IL-6b in the PI, MI and DI), and signaling molecules (Toll-like receptor 4 in the MI, myeloid differentiation primary response 88 in the PI and MI, Janus kinase 3 and tyrosine kinase 2 in the MI and DI, nuclear factor kappa B (NF-κB), signal transducers and activators of transcription (STAT) 4 and STAT5 in the PI, MI and DI) of juvenile Jian carp, further indicating that choline deficiency caused inflammation and immunity depression in the intestine of fish. But choline deficiency decreased the PI IL-6a mRNA level, and increased the DI LEAP-2A and defensin-3 mRNA levels with unknown reasons. Furthermore, dietary choline deficiency downregulated mRNA levels of tight junction (TJ) proteins (claudin 3c in the PI and MI, claudin 7, claudin 11 and occludin in the PI, MI and DI) and signaling molecule mitogen-activated protein kinases p38 in the PI, MI and DI of juvenile Jian carp, whereas upregulated the mRNA levels of claudin 3b in the MI and DI, and claudin 3c in the DI. Moreover, the excessive choline exhibited negative effects on intestinal immunity and TJ proteins that were similar to the choline deficiency. In summary, dietary choline deficiency or excess caused the depression of intestinal mucosal immune by inducing inflammation and dysfunction of the intestinal physical barrier, and regulating related signaling molecules of fish.

Choline and betaine consumption lowers cancer risk: a meta-analysis of epidemiologic studies

A number of human and animal in vitro or in vivo studies have investigated the relationship between dietary choline and betaine and cancer risk, suggesting that choline and betaine consumption may be protective for cancer. There are also a few epidemiologic studies exploring this relationship, however, with inconsistent conclusions. The PubMed and Embase were searched, from their inception to March 2016, to identify relevant studies and we brought 11 articles into this meta-analysis eventually. The pooled relative risks (RRs) of cancer for the highest versus the lowest range were 0.82 (95% CI, 0.70 to 0.97) for choline consumption only, 0.86 (95%CI, 0.76 to 0.97) for betaine consumption only and 0.60 (95%CI, 0.40 to 0.90) for choline plus betaine consumption, respectively. Significant protective effect of dietary choline and betaine for cancer was observed when stratified by study design, location, cancer type, publication year, sex and quality score of study. An increment of 100 mg/day of choline plus betaine intake helped reduce cancer incidence by 11% (0.89, 95% CI, 0.87 to 0.92) through a dose-response analysis. To conclude, choline and betaine consumption lowers cancer incidence in this meta-analysis, but further studies are warranted to verify the results.

Phosphatidylethanolamine N-methyltransferase gene rs7946 polymorphism plays a role in risk of nonalcoholic fatty liver disease: evidence from meta-analysis

BACKGROUND

Phosphatidylethanolamine N-methyltransferase (PEMT) governs the secretion of hepatic triglycerides in the form of very low-density lipoprotein and has been implicated in nonalcoholic fatty liver disease (NAFLD). Studies on the role of the PEMT rs7946 polymorphism as a genetic modifier of NAFLD have reported inconsistent results. This meta-analysis was carried out to evaluate and summarize the association of PEMT rs7946 with susceptibility to NAFLD.

METHODS

A comprehensive literature search in Scopus, PubMed, Embase, Science Direct and Google Scholar was performed up to 31 August 2015, followed by data extraction and examination of summary estimates.

RESULTS

Six independent studies with a total of 792 NAFLD cases and 2722 controls fulfilled the inclusion criteria. Pooled results indicated that the rs7946 A-allele was associated significantly with an increased risk of NAFLD [odds ratio (OR) 1.55, 95% confidence interval (CI) 1.14-2.11, P=0.005]. A significant association was also found in alternative genetic models of inheritance: dominant, recessive and homozygote (OR 1.62, 95% CI 1.10-2.39, P=0.01; OR 1.42, 95% CI 1.12-1.81, P=0.003; and OR 1.64, 95% CI 1.18-2.29, P=0.004, respectively). Subgroup analysis by ethnicity indicated a significant association only in the East-Asians in the additive (OR=2.08, 95% CI 1.12-3.86, P=0.02), recessive (OR=2.94, 95% CI 1.60-5.37, P=0.0005) and homozygote (OR=1.86, 95% CI 1.15-3.01, P=0.01) models.

CONCLUSION

This study provides evidence of a significant association between the PEMT rs7946 A-allele and a risk of NAFLD, with the effect being more prominent in East-Asians, but not in non-Asians.

Assessment of Total Choline Intakes in the United States

OBJECTIVE

Choline is an essential nutrient and plays a critical role in brain development, cell signaling, nerve impulse transmission, and lipid transport and metabolism. This analysis aimed to assess usual intakes of choline and compare them with the dietary reference intakes for U.S. residents aged ≥ 2 years.

METHODS

The National Cancer Institute method was used to assess usual intakes of choline from foods according to data for participants in the 2009-2012 National Health and Nutrition Examination Survey (NHANES; n = 16,809).

RESULTS

Suboptimal intakes of choline are prevalent across many life-stage subpopulations in the United States. Only 10.8 ± 0.6% of 2009-2012 NHANES participants aged ≥ 2 years (15.6 ± 0.8% of males and 6.1 ± 0.6% of females) achieved the adequate intake (AI) for choline. Children aged 2-3 years were the most likely to exceed the AI (62.9 ± 3.1%), followed by children aged 4-8 years (45.4 ± 1.6%) and children aged 9-13 years (9.0 ± 1.0%), compared to adolescents aged 14-18 years (1.8 ± 0.4%) and adults aged ≥ 19 years (6.6 ± 0.5%). When comparing by age and gender, males consumed significantly more choline than females for all age groups.

CONCLUSIONS

These data indicate that there is a need to increase awareness among health professionals and consumers regarding potential suboptimal intakes of choline in the United States, as well as the critical role that choline plays in health maintenance throughout the lifespan. Food scientists and the food and dietary supplement industries should consider working collectively with government agencies to discuss strategies to help offset the percentage of the population that does not meet the AI. Revision of the dietary reference intakes for choline should include replacement of the AI with an estimated average requirement and a recommended dietary allowance, so that more accurate population estimates of inadequate intakes may be calculated.

Choline and Betaine Intakes Are Not Associated with Cardiovascular Disease Mortality Risk in Japanese Men and Women

BACKGROUND

Dietary intakes of betaine and choline may reduce the risk of cardiovascular disease; however, epidemiologic evidence is limited. Seafood is a rich source of betaine and is a popular traditional food in Japan.

OBJECTIVE

We examined the associations of betaine and choline intakes with cardiovascular disease mortality in a population-based cohort study in Japan.

METHODS

Study subjects were 13,355 male and 15,724 female residents of Takayama City, Japan, who were aged ≥35 y and enrolled in 1992. Their diets were assessed by a validated food frequency questionnaire. Deaths from coronary heart disease and stroke were identified from death certificates over 16 y. Multivariable-adjusted HRs were computed by using Cox regression models.

RESULTS

During follow-up, we documented 308 deaths from coronary heart disease and 676 deaths from stroke (393 from ischemic and 153 from hemorrhagic strokes). Compared with the lowest quartile, the second, third, and highest quartiles of betaine intake were significantly associated with a decreased risk of mortality from coronary heart disease in men after controlling for covariates. The HRs were 0.58 (95% CI: 0.36, 0.93), 0.62 (95% CI: 0.39, 0.998), and 0.60 (95% CI: 0.37, 0.97), respectively. The trend was not statistically significant (P = 0.08). There was no significant association between betaine intake and the risk of mortality from ischemic stroke. In women, betaine intake was unrelated risk of mortality from coronary heart disease and stroke (P = 0.32 and 0.73, respectively, for interaction by sex). There was no significant association between choline intake and cardiovascular disease mortality risk in men or women.

CONCLUSION

Overall, we found no clear evidence of significant associations between choline and betaine intakes and cardiovascular disease mortality risk in Japanese men and women.

Mechanisms and correlates of a healthy brain: a commentary

In this monograph, the message is that early inactivity and obesity lead to later chronic disease, and, as such, physical inactivity should be recognized as a public health crisis. Sedentary behavior, to some extent, serves a purpose in our current culture (e.g., keeping children indoors keeps them safe), and, as such, may not be amenable to change. Thus, it is important that we understand the underpinnings of later-developing chronic disease as this complex public health issue may have roots that go deeper than sedentary behavior. In this commentary, I speculate on the mechanisms for physical activity exacting positive changes on cognitive abilities. Three potential mechanisms are discussed: glucose transport, postnatal neurogenesis, and vitamin synthesis, all of which are inextricably linked to nutrition. This discussion of mechanisms is followed by a discussion of tractable correlates of the progression to non-communicable disease in the adult.

Evidence for negative selection of gene variants that increase dependence on dietary choline in a Gambian cohort

Choline is an essential nutrient, and the amount needed in the diet is modulated by several factors. Given geographical differences in dietary choline intake and disparate frequencies of single-nucleotide polymorphisms (SNPs) in choline metabolism genes between ethnic groups, we tested the hypothesis that 3 SNPs that increase dependence on dietary choline would be under negative selection pressure in settings where choline intake is low: choline dehydrogenase (CHDH) rs12676, methylenetetrahydrofolate reductase 1 (MTHFD1) rs2236225, and phosphatidylethanolamine-N-methyltransferase (PEMT) rs12325817. Evidence of negative selection was assessed in 2 populations: one in The Gambia, West Africa, where there is historic evidence of a choline-poor diet, and the other in the United States, with a comparatively choline-rich diet. We used 2 independent methods, and confirmation of our hypothesis was sought via a comparison with SNP data from the Maasai, an East African population with a genetic background similar to that of Gambians but with a traditional diet that is higher in choline. Our results show that frequencies of SNPs known to increase dependence on dietary choline are significantly reduced in the low-choline setting of The Gambia. Our findings suggest that adequate intake levels of choline may have to be reevaluated in different ethnic groups and highlight a possible approach for identifying novel functional SNPs under the influence of dietary selective pressure.—Silver, M. J., Corbin, K. D., Hellenthal, G., da Costa, K.-A., Dominguez-Salas, P., Moore, S. E., Owen, J., Prentice, A. M., Hennig, B. J., Zeisel, S. H. Evidence for negative selection of gene variants that increase dependence on dietary choline in a Gambian cohort.

Derivation and validation of homocysteine score in u.s. Men and women

BACKGROUND

One-carbon metabolism, which is crucial in DNA synthesis and genomic stability, is an interrelated network of biochemical reactions involved in several dietary and lifestyle factors. The development of the homocysteine score using these factors may be useful to reflect the status of one-carbon metabolism in large epidemiologic studies without biologic samples to measure homocysteine directly.

OBJECTIVE

The aim of this study was to develop an homocysteine score that reflects one-carbon metabolism better than individual dietary or lifestyle factors.

METHODS

We divided 2023 participants with measured plasma total homocysteine data in the Nurses' Health Study and the Health Professionals Follow-Up Study into training (n = 1619) and testing (n = 404) subsets. Using multivariable linear regression, we selected lifestyle determinants of plasma homocysteine in the training set and derived the homocysteine score weighted by the β coefficient for each predictor. The validation of the homocysteine score was assessed using the plasma homocysteine in the independent samples of the training set.

RESULTS

In the training set, smoking, multivitamin use, and caffeine, alcohol, and dietary and supplemental folate intake were significant independent determinants of plasma homocysteine in multivariable linear regression (P ≤ 0.01) and were included in the derivation of the homocysteine score. The Pearson correlation of the homocysteine score with plasma homocysteine was 0.30 in the testing subset (P < 0.001). The homocysteine score was positively associated with the plasma homocysteine concentration in the testing subset and in an independent population of women; the mean difference of plasma homocysteine concentration between the extreme quintiles of homocysteine score ranged from 0.83 μmol/L to 1.52 μmol/L. Population misclassification either from the lowest quintile of plasma homocysteine into the highest quintile of the homocysteine score or from the highest quintile of plasma homocysteine into the lowest quintile of the homocysteine score was ≤12%.

CONCLUSION

These data indicate that the homocysteine score may be used with relatively inexpensive and simple questionnaires to rank an individual's one-carbon metabolism status when homocysteine data are not available.

Higher dietary choline intake is associated with lower risk of nonalcoholic fatty liver in normal-weight Chinese women

BACKGROUND

Choline deficiency has been shown to induce liver fat accumulation in both rodent and human studies. However, it is unclear whether dietary choline intake is related to fatty liver in the general population.

OBJECTIVE

We examined the association between choline intake and nonalcoholic fatty liver.

METHODS

Participants included 56,195 Chinese women and men, 40-75 y of age, with no or negligible alcohol consumption and with no history of hepatitis, cardiovascular disease, or cancer. All participants reported undergoing liver ultrasonography. Fatty liver was defined by self-report of a physician diagnosis. Habitual dietary intakes were assessed via validated food-frequency questionnaires.

RESULTS

The average total choline intakes were 289 ± 85 mg/d in women and 318 ± 92 mg/d in men. Major food sources were eggs, soy foods, red meat, fish, and vegetables. A higher choline intake was associated with lower risk of fatty liver; after adjustment for sociodemographic characteristics, lifestyle factors, and other dietary intakes, the ORs (95% CIs) for the highest vs. the lowest quintiles of choline intake were 0.68 (0.59, 0.79) in women and 0.75 (0.60, 0.93) in men (both P-trend < 0.01). The inverse association was attenuated after further adjustment for history of metabolic disease and, in particular, BMI. The corresponding ORs (95% CIs) were 0.88 (0.75, 1.03) in women (P-trend = 0.05) and 0.85 (0.68, 1.06) in men (P-trend = 0.09). Stratified analyses suggested a potential effect modification by obesity status in women; the OR (95% CI) across extreme quintiles was 0.72 (0.57, 0.91) in normal-weight women vs. 1.05 (0.84, 1.31) in overweight or obese women (P-trend = 0.007 vs. 0.99, P-interaction < 0.0001).

CONCLUSION

Higher dietary choline intake may be associated with lower risk of nonalcoholic fatty liver only in normal-weight Chinese women.

Egg n-3 fatty acid composition modulates biomarkers of choline metabolism in free-living lacto-ovo-vegetarian women of reproductive age

The lacto-ovo-vegetarian (LOV) dietary regimen allows eggs, which are a rich source of choline. Consumption of eggs by LOV women may be especially important during pregnancy and lactation when demand for choline is high. The aim of this single blind, randomized, crossover-feeding study was to determine how near-daily egg consumption influenced biomarkers of choline metabolism in healthy LOV women of reproductive age (n=15). Because long-chain n-3 fatty acids could influence choline metabolism, the effect of n-3-enriched vs nonenriched eggs on choline metabolites was also investigated. Three 8-week dietary treatments consisting of six n-3-enriched eggs per week, six nonenriched eggs per week, and an egg-free control phase were separated by 4-week washout periods. Choline metabolites were quantified in fasted plasma collected before and after each treatment and differences in posttreatment choline metabolite concentrations were determined with linear mixed models. The n-3-enriched and nonenriched egg treatments produced different choline metabolite profiles compared with the egg-free control; however, response to the eggs did not differ (P>0.1). Consumption of the n-3-enriched egg treatment yielded higher plasma free choline (P=0.02) and betaine (P<0.01) (vs egg-free control) concentrations, whereas consumption of the nonenriched egg treatment yielded borderline higher (P=0.06) plasma phosphatidylcholine (vs egg-free control) levels. Neither egg treatment increased levels of plasma trimethylamine oxide, a gut-flora-dependent oxidative choline metabolite implicated as a possible risk factor for cardiovascular disease. Overall these data suggest that egg fatty-acid composition modulates the metabolic use of choline.

Total choline and choline-containing moieties of commercially available pulses

Estimating dietary choline intake can be challenging due to missing foods in the current United States Department of Agriculture (USDA) database. The objectives of the study were to quantify the choline-containing moieties and the total choline content of a variety of pulses available in North America and use the expanded compositional database to determine the potential contribution of pulses to dietary choline intake. Commonly consumed pulses (n = 32) were analyzed by hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC LC-MS/MS) and compared to the current USDA database. Cooking was found to reduce the relative percent from free choline and increased the contribution of phosphatidylcholine to total choline for most pulses (P < 0.05). Using the expanded database to estimate choline content of recipes using pulses as meat alternatives, resulted in a different estimation of choline content per serving (±30%), compared to the USDA database. These results suggest that when pulses are a large part of a meal or diet, the use of accurate food composition data should be used.

Validation of a food-frequency questionnaire assessment of methyl-group donors using estimated diet records and plasma biomarkers: the method of triads

In this study, the intake of methyl-group donors (methionine, folate, betaine, and choline) among Flemish women of reproductive age (n = 30) assessed by a 7-d estimated diet record (7 d EDR) and food-frequency questionnaire (FFQ) was compared with plasma S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), and SAH:SAM ratio. Pearson correlation coefficients were calculated between each of the dietary methods and the validity coefficient was calculated using the method of triads. Correlations were higher between intake assessed by the FFQ and biomarkers than between 7 d EDR and biomarkers. The validity coefficients of the FFQ, when using SAH as a biomarker, were high (0.86 for methionine to 0.94 for folate), when the SAH:SAM ratio was used as a biomarker the validity coefficients ranged from 0.63 to 1.00. These data indicate that the FFQ is a reliable tool to estimate the intake of the methyl-group donors in women of reproductive age.

A 24-hour dietary recall for assessing the intake pattern of choline among Bangladeshi pregnant women at their third trimester of pregnancy

Maternal choline intake during the third trimester of human pregnancy can modify systemic and local epigenetic marks in fetal-derived tissues, promoting better pregnancy outcomes, increased immunity, as well as improved mental and physical work capacity with proper memory and cognitive development. 103 pregnant women presenting to the antenatal care of Azimpur Maternity Hospital of Dhaka, Bangladesh in their third trimester of pregnancy were randomly selected for this cross sectional study exploring dietary intake patterns of choline. A dietary recall form was administered to estimate frequency and amount of food consumption of foods for the previous 24 hours. Most women reported diets that delivered less than the recommended choline intake (mean ± SD; 189.5 ± 98.2) providing only 42.72% of total RDA value. The results of this study may indicate that dietary choline among pregnant, Bangladeshi women may not be adequate to meet the needs of both, the mother and fetus. Further studies are warranted to determine clinical implications.

Estimation of choline intake from 24 h dietary intake recalls and contribution of egg and milk consumption to intake among pregnant and lactating women in Alberta

Despite recommendations for higher choline intakes during pregnancy and lactation, there is limited research regarding maternal intake during these important periods. In the present study, we estimated dietary choline intake during pregnancy and lactation in a population of Albertan women and the contribution of egg and milk consumption to intake. Dietary intake data were collected from the first 600 women enrolled in a prospective cohort study carried out in Alberta, Canada. During the first and/or second trimester, the third trimester and 3 months postpartum, 24 h dietary intake recall data were collected. A database was constructed including foods consumed by the cohort and used to estimate dietary choline intake. The mean total choline intake value during pregnancy was 347 (SD 149) mg/d, with 23% of the participants meeting the adequate intake (AI) recommendation. During lactation, the mean total choline intake value was 346 (SD 151) mg/d, with 10% of the participants meeting the AI recommendation. Phosphatidylcholine was the form of choline consumed in the highest proportion and the main dietary sources of choline were dairy products, eggs and meat. Women who consumed at least one egg in a 24 h period had higher (P< 0·001) total choline intake and were eight times more likely (95% CI 5·2, 12·6) to meet choline intake recommendations compared with those who did not consume eggs during pregnancy. Women who reported consuming ≥ 500 ml of milk in a 24 h period were 2·8 times more likely (95 % CI 1·7, 4·8) to meet daily choline intake recommendations compared with those consuming < 250 ml of milk/d during pregnancy. Choline intake is below the recommendation levels in this population and the promotion of both egg and milk consumption may assist in meeting the daily choline intake recommendations.

Identification of new genetic polymorphisms that alter the dietary requirement for choline and vary in their distribution across ethnic and racial groups

Effect alleles (alleles with a polymorphism that is associated with the effect being measured) in a small number of single-nucleotide polymorphisms (SNPs) are known to influence the dietary requirement for choline. In this study, we examined a much larger number of SNPs (n=200) in 10 genes related to choline metabolism for associations with development of organ dysfunction (liver or muscle) when 79 humans were fed a low-choline diet. We confirmed that effect alleles in SNPs such as the C allele of PEMT rs12325817 increase the risk of developing organ dysfunction in women when they consume a diet low in choline, and we identified novel effect alleles, such as the C allele of CHKA SNP rs7928739, that alter dietary choline requirements. When fed a low-choline diet, some people presented with muscle damage rather than liver damage; several effect alleles in SLC44A1 (rs7873937, G allele; rs2771040, G; rs6479313, G; rs16924529, A; and rs3199966, C) and one in CHKB (rs1557502, A) were more common in these individuals. This suggests that pathways related to choline metabolism are more important for normal muscle function than previously thought. In European, Mexican, and Asian Americans, and in individuals of African descent, we examined the prevalence of the effect alleles in SNPs that alter choline requirement and found that they are differentially distributed among people of different ethnic and racial backgrounds. Overall, our study has identified novel genetic variants that modulate choline requirements and suggests that the dietary requirement for choline may be different across racial and ethnic groups.-Da Costa, K.-A., Corbin, K. D., Niculescu, M. D., Galanko, J. A., Zeisel, S. H. Identification of new genetic polymorphisms that alter the dietary requirement for choline and vary in their distribution across ethnic and racial groups.

The role of the one-carbon cycle in the developmental origins of Type 2 diabetes and obesity

Vitamin B12 deficiency is common in certain populations, such as in India, where there is also a rising prevalence of Type 2 diabetes, obesity and their complications. Human cohorts and animal models provide compelling data suggesting the role of the one-carbon cycle in modulating the risk of diabetes and adiposity via developmental programming. Early mechanistic studies in animals suggest that alterations to the cellular provision of methyl groups (via the one-carbon cycle) in early developmental life may disrupt DNA methylation and induce future adverse phenotypic changes. Furthermore, replacement of micronutrient deficits at suitable developmental stages may modulate this risk. Current human studies are limited by a range of factors, including the accuracy and availability of methods to measure nutritional components in the one-carbon cycle, and whether its disruptions exert tissue-specific effects. A greater understanding of the causal and mechanistic role of the one-carbon cycle is hoped to generate substantial insights into its role in the developmental origins of complex metabolic diseases and the potential of targeted and population-wide prevention strategies.

Dietary intake and plasma levels of choline and betaine in children with autism spectrum disorders

Abnormalities in folate-dependent one-carbon metabolism have been reported in many children with autism. Because inadequate choline and betaine can negatively affect folate metabolism and in turn downstream methylation and antioxidant capacity, we sought to determine whether dietary intake of choline and betaine in children with autism was adequate to meet nutritional needs based on national recommendations. Three-day food records were analyzed for 288 children with autism (ASDs) who participated in the national Autism Intervention Research Network for Physical Health (AIR-P) Study on Diet and Nutrition in children with autism. Plasma concentrations of choline and betaine were measured in a subgroup of 35 children with ASDs and 32 age-matched control children. The results indicated that 60–93% of children with ASDs were consuming less than the recommended Adequate Intake (AI) for choline. Strong positive correlations were found between dietary intake and plasma concentrations of choline and betaine in autistic children as well as lower plasma concentrations compared to the control group. We conclude that choline and betaine intake is inadequate in a significant subgroup of children with ASDs and is reflected in lower plasma levels. Inadequate intake of choline and betaine may contribute to the metabolic abnormalities observed in many children with autism and warrants attention in nutritional counseling.

The metabolic burden of methyl donor deficiency with focus on the betaine homocysteine methyltransferase pathway

Methyl groups are important for numerous cellular functions such as DNA methylation, phosphatidylcholine synthesis, and protein synthesis. The methyl group can directly be delivered by dietary methyl donors, including methionine, folate, betaine, and choline. The liver and the muscles appear to be the major organs for methyl group metabolism. Choline can be synthesized from phosphatidylcholine via the cytidine-diphosphate (CDP) pathway. Low dietary choline loweres methionine formation and causes a marked increase in S-adenosylmethionine utilization in the liver. The link between choline, betaine, and energy metabolism in humans indicates novel functions for these nutrients. This function appears to goes beyond the role of the nutrients in gene methylation and epigenetic control. Studies that simulated methyl-deficient diets reported disturbances in energy metabolism and protein synthesis in the liver, fatty liver, or muscle disorders. Changes in plasma concentrations of total homocysteine (tHcy) reflect one aspect of the metabolic consequences of methyl group deficiency or nutrient supplementations. Folic acid supplementation spares betaine as a methyl donor. Betaine is a significant determinant of plasma tHcy, particularly in case of folate deficiency, methionine load, or alcohol consumption. Betaine supplementation has a lowering effect on post-methionine load tHcy. Hypomethylation and tHcy elevation can be attenuated when choline or betaine is available.

Plasma choline and betaine correlate with serum folate, plasma S-adenosyl-methionine and S-adenosyl-homocysteine in healthy volunteers

BACKGROUND

Choline is essential for mammalian cell function. It plays a critical role in cell membrane integrity, neurotransmission, cell signaling and lipid metabolism. Moreover, choline is involved in methylation in two ways: a) its synthesis requires methyl groups donated by S-adenosyl-methionine (AdoMet); and b) choline oxidation product betaine methylates homocysteine (Hcy) to methionine (Met) and produces dimethylglycine. This later donates one carbon units to tetrahydrofolate (THF).

METHODS

To evaluate the correlations of choline and betaine with folate, AdoMet, S-anenosyl-homocysteine (AdoHcy), total homocysteine (tHcy), and DNA methylation, choline, betaine and dimethylglycine were measured by LC-MS/MS in plasma of 109 healthy volunteers, in whom folate, AdoMet, AdoHcy, tHcy, and DNA methylation have previously been reported.

RESULTS

Using a bivariate model, choline and betaine showed strong positive correlations with folate (r = 0.346 and r = 0.226), AdoHcy (r = 0.468 and r = 0.296), and correlated negatively with AdoMet/AdoHcy ratio (r = – 0.246 and r = – 0.379). Only choline was positively correlated with AdoMet (r = 0.453). Using a multivariate linear regression model, choline correlated strongly with folate ( β = 17.416), AdoMet ( β = 61.272), and AdoHcy ( β = 9.215). Betaine correlated positively with folate ( β = 0.133) and negatively with tHcy ( β = – 0.194) ratio. Choline is an integral part of folate and methylation pathways.

CONCLUSIONS

Our data highlight the importance of integrating choline in studies concerning addressing pathological conditions related to folate, homocysteine and methylation metabolism.

Metabolic crosstalk between choline/1-carbon metabolism and energy homeostasis

There are multiple identified mechanisms involved in energy metabolism, insulin resistance and adiposity, but there are here-to-fore unsuspected metabolic factors that also influence these processes. Studies in animal models suggest important links between choline/1-carbon metabolism and energy homeostasis. Rodents fed choline deficient diets become hypermetabolic. Mice with deletions in one of several different genes of choline metabolism have phenotypes that include increased metabolic rate, decreased body fat/lean mass ratio, increased insulin sensitivity, decreased ATP production by mitochondria, or decreased weight gain on a high fat diet. In addition, farmers have recognized that the addition of a metabolite of choline (betaine) to cattle and swine feed reduces body fat/lean mass ratio. Choline dietary intake in humans varies over a > three-fold range, and genetic variation exists that modifies individual requirements for this nutrient. Although there are some epidemiologic studies in humans suggesting a link between choline/1-carbon metabolism and energy metabolism, there have been no controlled studies in humans that were specifically designed to examine this relationship.

Dietary choline modulates immune responses, and gene expressions of TOR and eIF4E-binding protein2 in immune organs of juvenile Jian carp (Cyprinus carpio var. Jian)

The present work evaluates the effects of various levels of dietary choline on immune parameters, immune-related gene expression and protection against Aeromonas hydrophila (AH) in juvenile Jian carp (Cyprinus carpio var. Jian). Fish were fed with six different experimental diets containing graded levels of choline at 165 (choline-deficient control), 310, 607, 896, 1167 and 1820 mg kg(-1) diet for 65 days. At the end of the feeding trail, Fish were challenged with AH and mortalities were recorded over 17 days. Dietary choline significantly enhanced spleen and head kidney weights, spleen index, red blood cell and white blood cell counts, and intestinal Lactobacillus counts of juvenile Jian carp; whereas, intestinal Escherichia coli and A. hydrophila counts decreased. Moreover, the post-challenge survival rate, leucocyte phagocytic capacity, serum lysozyme and acid phosphatase activities, hemagglutination titer, complement 3 and 4 contents, immunoglobulin M content, and anti-AH antibody titer were significantly enhanced by choline and the lowest in choline-deficient group, while serum total iron-binding capacity was the highest in choline-deficient group. The relative gene expressions of interleukin 10 in spleen and head kidney, target of rapamycin (TOR) in spleen and eIF4E-binding protein2 (4E-BP2) in head kidney significantly increased with increasing of dietary choline up to a certain point. However, the relative gene expressions of interleukin 1β, tumor necrosis factor α and transforming growth factor β2 in spleen and head kidney, TOR in head kidney and 4E-BP2 in spleen significantly decreased. In conclusion, dietary choline improved disease resistance, enhanced the immune function, and regulated immune-related gene expression of juvenile Jian carp.

Diet influences expression of autoimmune-associated genes and disease severity by epigenetic mechanisms in a transgenic mouse model of lupus

OBJECTIVE

Lupus flares occur when genetically predisposed individuals encounter appropriate environmental agents. Current evidence indicates that the environment contributes by inhibiting T cell DNA methylation, causing overexpression of normally silenced genes. DNA methylation depends on both dietary transmethylation micronutrients and ERK-regulated DNA methyltransferase 1 (DNMT-1) levels. We used transgenic mice to study the effect of interactions between diet, DNMT-1 levels, and genetic predisposition on the development and severity of lupus.

METHODS

A doxycycline-inducible ERK defect was bred into lupus-resistant (C57BL/6) and lupus-susceptible (C57BL/6 × SJL) mouse strains. Doxycycline-treated mice were fed a standard commercial diet for 18 weeks and then switched to a transmethylation micronutrient-supplemented (MS) or -restricted (MR) diet. Disease severity was assessed by examining anti-double-stranded DNA (anti-dsDNA) antibody levels, the presence of proteinuria and hematuria, and by histopathologic analysis of kidney tissues. Pyrosequencing was used to determine micronutrient effects on DNA methylation.

RESULTS

Doxycycline induced modest levels of anti-dsDNA antibodies in C57BL/6 mice and higher levels in C57BL/6 × SJL mice. Doxycycline-treated C57BL/6 × SJL mice developed hematuria and glomerulonephritis on the MR and standard diets but not the MS diet. In contrast, C57BL/6 mice developed kidney disease only on the MR diet. Decreasing ERK signaling and methyl donors also caused demethylation and overexpression of the CD40lg gene in female mice, consistent with demethylation of the second X chromosome. Both the dietary methyl donor content and the duration of treatment influenced methylation and expression of the CD40lg gene.

CONCLUSION

Dietary micronutrients that affect DNA methylation can exacerbate or ameliorate disease in this transgenic murine lupus model, and contribute to lupus susceptibility and severity through genetic-epigenetic interactions.

Egg consumption in relation to risk of cardiovascular disease and diabetes: a systematic review and meta-analysis

BACKGROUND

The associations of egg consumption with cardiovascular disease (CVD) and diabetes are still unclear.

OBJECTIVE

We aimed to quantitatively summarize the literature on egg consumption and risk of CVD, cardiac mortality, and type 2 diabetes by conducting a meta-analysis of prospective cohort studies.

DESIGN

A systematic literature review was conducted for published studies in PubMed and EMBASE through March 2012. Additional information was retrieved through Google or a hand review of the reference from relevant articles. Studies were included if they had a prospective study design, were published in English-language journals, and provided HRs and 95% CIs for the associations of interest. Data were independently extracted by 2 investigators, and the weighted HRs and 95% CIs for the associations of interest were estimated by using a random-effects model.

RESULTS

A total of 22 independent cohorts from 16 studies were identified, including participants ranging in number from 1600 to 90,735 and in follow-up time from 5.8 to 20.0 y. Comparison of the highest category (≥1 egg/d) of egg consumption with the lowest (<1 egg/wk or never) resulted in a pooled HR (95% CI) of 0.96 (0.88, 1.05) for overall CVD, 0.97 (0.86, 1.09) for ischemic heart disease, 0.93 (0.81, 1.07) for stroke, 0.98 (0.77, 1.24) for ischemic heart disease mortality, 0.92 (0.56, 1.50) for stroke mortality, and 1.42 (1.09, 1.86) for type 2 diabetes. Of the studies conducted in diabetic patients, the pooled HR (95% CI) was 1.69 (1.09, 2.62) for overall CVD.

CONCLUSIONS

This meta-analysis suggests that egg consumption is not associated with the risk of CVD and cardiac mortality in the general population. However, egg consumption may be associated with an increased incidence of type 2 diabetes among the general population and CVD comorbidity among diabetic patients.

Choline intake during pregnancy and child cognition at age 7 years

Animal models indicate that exposure to choline in utero improves visual memory through cholinergic transmission and/or epigenetic mechanisms. Among 895 mothers in Project Viva (eastern Massachusetts, 1999-2002 to 2008-2011), we estimated the associations between intakes of choline, vitamin B12, betaine, and folate during the first and second trimesters of pregnancy and offspring visual memory (measured by the Wide Range Assessment of Memory and Learning, Second Edition (WRAML2), Design and Picture Memory subtests) and intelligence (measured using the Kaufman Brief Intelligence Test, Second Edition (KBIT-2)) at age 7 years. Mean second-trimester intakes were 328 (standard deviation (SD), 63) mg/day for choline, 10.5 (SD, 5.1) µg/day for vitamin B12, 240 (SD, 104) mg/day for betaine, and 1,268 (SD, 381) µg/day for folate. Mean age 7 test scores were 17.2 (SD, 4.4) points on the WRAML 2 Design and Picture Memory subtests, 114.3 (SD, 13.9) points on the verbal KBIT-2, and 107.8 (SD, 16.5) points on the nonverbal KBIT-2. In a model adjusting for maternal characteristics, the other nutrients, and child's age and sex, the top quartile of second-trimester choline intake was associated with a child WRAML2 score 1.4 points higher (95% confidence interval: 0.5, 2.4) than the bottom quartile (P-trend = 0.003). Results for first-trimester intake were in the same direction but weaker. Intake of the other nutrients was not associated with the cognitive tests administered. Higher gestational choline intake was associated with modestly better child visual memory at age 7 years.

Dietary choline and betaine intakes vary in an adult multiethnic population

Choline and betaine are important nutrients for human health, but reference food composition databases for these nutrients became available only recently. We tested the feasibility of using these databases to estimate dietary choline and betaine intakes among ethnically diverse adults who participated in the Multiethnic Cohort (MEC) Study. Of the food items (n = 965) used to quantify intakes for the MEC FFQ, 189 items were exactly matched with items in the USDA Database for the Choline Content of Common Foods for total choline, choline-containing compounds, and betaine, and 547 items were matched to the USDA National Nutrient Database for Standard Reference for total choline (n = 547) and 148 for betaine. When a match was not found, choline and betaine values were imputed based on the same food with a different form (124 food items for choline, 300 for choline compounds, 236 for betaine), a similar food (n = 98, 284, and 227, respectively) or the closest item in the same food category (n = 6, 191, and 157, respectively), or the values were assumed to be zero (n = 1, 1, and 8, respectively). The resulting mean intake estimates for choline and betaine among 188,147 MEC participants (aged 45-75) varied by sex (372 and 154 mg/d in men, 304 and 128 mg/d in women, respectively; P-heterogeneity < 0.0001) and by race/ethnicity among Caucasians, African Americans, Japanese Americans, Latinos, and Native Hawaiians (P-heterogeneity < 0.0001), largely due to the variation in energy intake. Our findings demonstrate the feasibility of assessing choline and betaine intake and characterize the variation in intake that exists in a multiethnic population.

Choline's role in maintaining liver function: new evidence for epigenetic mechanisms

PURPOSE OF REVIEW

Humans eating diets low in choline develop fatty liver and liver damage. Rodents fed choline-methionine-deficient diets not only develop fatty liver, but also progress to develop fibrosis and hepatocarcinoma. This review focuses on the role of choline in liver function, with special emphasis on the epigenetic mechanisms of action.

RECENT FINDINGS

Dietary intake of methyl donors like choline influences the methylation of DNA and histones, thereby altering the epigenetic regulation of gene expression. The liver is the major organ within which methylation reactions occur, and many of the hepatic genes involved in pathways for the development of fatty liver, hepatic fibrosis, and hepatocarcinomas are epigenetically regulated.

SUMMARY

Dietary intake of choline varies over a three-fold range and many humans have genetic polymorphisms that increase their demand for choline. Choline is an important methyl donor needed for the generation of S-adenosylmethionine. Dietary choline intake is an important modifier of epigenetic marks on DNA and histones, and thereby modulates the gene expression in many of the pathways involved in liver function and dysfunction.

Nutrition in pregnancy: the argument for including a source of choline

Women, during pregnancy and lactation, should eat foods that contain adequate amounts of choline. A mother delivers large amounts of choline across the placenta to the fetus, and after birth she delivers large amounts of choline in milk to the infant; this greatly increases the demand on the choline stores of the mother. Adequate intake of dietary choline may be important for optimal fetal outcome (birth defects, brain development) and for maternal liver and placental function. Diets in many low income countries and in approximately one-fourth of women in high income countries, like the United States, may be too low in choline content. Prenatal vitamin supplements do not contain an adequate source of choline. For women who do not eat foods containing milk, meat, eggs, or other choline-rich foods, a diet supplement should be considered.

Diet and Neuroimaging Markers of Cerebrovascular Disease

Stroke is one of the leading causes of long-term disability and mortality. Mounting evidence from observational studies suggests that among lifestyle factors, diet may be playing an important role for the prevention of stroke. Neuroimaging markers, particularly white matter hyperintensity (WMH) volume and brain infarcts (BI) are more sensitive measurements of cerebrovascular disease than clinical assessments. We reviewed published observational and clinical studies that evaluate the association between dietary factors and WMH and BI. The few existing studies examined only a handful individual nutrients or foods (dietary intake of alcohol, B vitamins, fish, choline, serum markers of antioxidants, and a few food groups, Mediterranean-style diet, and nutrient biomarker patterns. Findings from these studies are inconclusive either due to conflicting results from different studies or due to lack of replication. Further studies are necessary to replicate the existing findings. Many other foods or nutrients or dietary patterns may worth of investigation and longitudinal studies are needed.

The nutritional burden of methylation reactions

PURPOSE OF REVIEW

Methyl group metabolism is a metabolically demanding process that has significant nutritional implications. Methionine is required not only for protein synthesis but also as the primary source of methyl groups. However, demethylated methionine can be remethylated by methyl groups from methylneogenesis (via folate) and betaine (synthesized from choline). This review discusses the impact of methylation precursors and products on the methionine requirement.

RECENT FINDINGS

Recent evidence has clearly demonstrated that transmethylation reactions can consume a significant proportion of the flux of methionine. In particular, synthesis of creatine and phosphatidylcholine consume most methyl groups and their dietary provision could spare methionine. Importantly, methionine can become limiting for protein and phosphatidylcholine synthesis when creatine synthesis is upregulated. Other research has shown that betaine and choline seem to be more effective than folate at reducing hyperhomocysteinemia and impacting cardiovascular outcomes suggesting they may be limiting.

SUMMARY

It appears that methyl groups can become limiting when dietary supply is inadequate or if transmethylation reactions are upregulated. These situations can impact methionine availability for protein synthesis, which can reduce growth. The methionine requirement can likely be spared by methyl donor and methylated product supplementation.

Choline and betaine intake is inversely associated with breast cancer risk: a two-stage case-control study in China

Few epidemiological studies have evaluated the association of choline and betaine intake with breast cancer risk and the results remain inconsistent. This study aimed to assess the relationship between dietary intake of choline and betaine and the risk of breast cancer among Chinese women. A two-stage case-control study was conducted, with 807 cases and 807 age- (5-year interval) and residence (rural/urban)-matched controls. A validated food frequency questionnaire was used to assess dietary intake by face-to-face interview. An unconditional logistic regression model was used to calculate multivariate-adjusted odds ratios (OR) and 95% confidence intervals (CI). A significant inverse association was found between dietary choline and betaine consumption and breast cancer risk. The adjusted OR for the highest quartile of intake compared with the lowest were 0.40 (95% CI = 0.28-0.57, P(trend) < 0.001) for total choline intake, 0.58 (95% CI = 0.42-0.80, P(trend) < 0.001) for betaine intake and 0.38 (0.27-0.53, P(trend) < 0.001) for choline plus betaine intake, respectively. Intakes of individual choline compouds, choline from glycerophosphocholine, phosphocholine, phosphatidylcholine, sphingomyelin and free choline were also negatively associated with breast cancer risk. The inverse association between choline intake and breast cancer risk was primarily confined to participants with low folate level (<242 g/day), with an OR (95% CI) of 0.46 (0.23-0.91) comparing the fourth quartile with the first quartile of choline intake (P(trend) = 0.005). The present study suggests that consumption of choline and betaine is inversely associated with the risk of breast cancer. The association of choline intake with breast cancer risk is probably modified by folate intake.

Nutrients related to one-carbon metabolism and risk of renal cell cancer

PURPOSE

Folate, vitamins B6 and B12, methionine, choline, and betaine are nutrients related to one-carbon metabolism and have been hypothesized to decrease cancer risk. Few studies have evaluated dietary intakes of these nutrients in relation to renal cell cancer (RCC).

METHODS

We conducted prospective follow-up studies of women in the Nurses' Health Study and men in the Health Professionals Follow-up Study. Diet was assessed repeatedly using a validated semi-quantitative food-frequency questionnaire in both studies.

RESULTS

During follow-up of 24 years among 77,208 women (918,891 person-years) and 22 years among 47,886 men (1,731,752 person-years), we accrued 436 cases of RCC (225 women and 211 men). Intakes of folate, vitamins B6 and B12, methionine, and betaine were not found to be related to RCC risk. Higher intake of free choline, but not other forms of choline, was associated with reduced RCC risk. The results were similar in men and women.

CONCLUSIONS

We found little evidence that higher intakes of nutrients related to one-carbon metabolism lower RCC risk. One-carbon metabolism may have little influence on renal carcinogenesis.