Thursday, December 27, 2012

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.

Cho, E., E. Giovannucci, and H.-K. Joh, Nutrients related to one-carbon metabolism and risk of renal cell cancer. Cancer Causes & Control 2012: p. 1-10

Betaine stabilizes cell volume and protects against apoptosis in human corneal epithelial cells under hyperosmotic stress

Elevated tear osmolarity is one of the key pathological factors in dry eye leading to ocular discomfort associated with damage to the ocular surface and inflammation. The aim of this study was to determine the capacity of the organic osmolyte, betaine, to act as an osmoprotectant against hypertonic stress-induced human corneal epithelial cell shrinkage and apoptosis using in vitro cell culture models. Human corneal limbal epithelial (HCLE) cells exposed to culture medium for 16 h at 300 mOsm (isotonic) or 500 mOsm (hyperosmotic) in the presence or absence of betaine (5 or 10 mM) were evaluated for cell volume changes; cell viability; and apoptosis. Betaine (10 mM) ameliorated hyperosmotically induced reduction of cell volume (from 27% reduction to 11%) and resulted in increased mitochondrial activity (by 17%) and an increase in viable cell numbers (by 12%) compared to controls (exposure to hyperosmotic medium without betaine). Hyperosmotically shocked HCLE cells in the presence of betaine (10 mM) halved the number of damaged cells (apoptotic/necrotic) compared to cells in the absence of betaine. The presence of betaine (at 5 or 10 mM) significantly reduced the activity of caspase-8, -9 and -3/7 and release of TNF-α was also reduced by 34% or 55% after exposure of HCLE to 500 mOsm in the presence of 5 or 10 mM betaine, respectively. Using polyclonal antibody against Betaine/GABA transporter 1 (BGT-1), we detected the presence of BGT-1 in HCLE. We demonstrated that the transport of betaine was facilitated by increased osmolarity. In conclusion, betaine stabilized corneal epithelial cell volume under hyperosmotic stress and limited hyperosmotic stress-induced HCLE apoptosis.

Garrett, Q., et al., Betaine stabilizes cell volume and protects against apoptosis in human corneal epithelial cells under hyperosmotic stress. Experimental Eye Research, 2013

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.

Bertolo, R.F. and L.E. McBreairty, The nutritional burden of methylation reactions. Current Opinion in Clinical Nutrition & Metabolic Care, 2013. 16(1): p. 102-8.

Betaine attenuates Alzheimer-like pathological changes and memory deficits induced by homocysteine

Hyperhomocysteinemia (Hhcy) may induce memory deficits with β-amyloid (Aβ) accumulation and tau hyperphosphorylation. Simultaneous supplement of folate and vitamin B12 partially restored the plasma homocysteine level and attenuated tau hyperphosphorylation, Aβ accumulation and memory impairments induced by Hhcy. However, folate and vitamin B12 treatment have no effects on Hhcy which has the methylenetetrahydrofolate reductase genotype mutation. In the present study, we investigated the effects of simultaneous supplement of betaine on Alzheimer-like pathological changes and memory deficits in hyperhomocysteinemic rats after a 2-week induction by vena caudalis injection of homocysteine (Hcy). We found that supplementation of betaine could ameliorate the Hcy-induced memory deficits, enhance LTP and increase dendritic branches numbers and the density of the dendritic spines, with upregulation of NR1, NR2A, synaptotagmin, synaptophysin and phosphorylated synapsin I protein levels. Supplementation of betaine also attenuated the Hcy-induced tau hyperphosphorylation at multiple AD-related sites through activation PP2A with decreased inhibitory demethylated PP2A(C) at Leu309 and phosphorylated PP2A(C) at Tyr307. In addition, supplementation of betaine also decreased Aβ production with decreased presenilin-1 protein levels. Our data suggest that betaine could be a promising candidate for arresting Hcy-induced AD-like pathological changes and memory deficits.

Chai, G.-S., et al., Betaine attenuates Alzheimer-like pathological changes and memory deficits induced by homocysteine. Journal of Neurochemistry, 2012 (10.1111/jnc.12094).

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. Unconditional logistic regression model was used to calculate multivariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs). A significant inverse association was found between dietary choline and betaine consumption and breast cancer risk. The adjusted ORs for the highest quartile of intake compared to the lowest were 0.40 (95%CI=0.28-0.57) for total choline intake, 0.58 (95%CI=0.42-0.80) for betaine intake, and 0.38 (0.27-0.53) 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 with an OR (95% CI) of 0.46 (0.23-0.91) comparing the fourth quartile with the first quartile of choline intake. This study suggested that consumption of choline and betaine was inversely associated with the risk of breast cancer. The association of choline intake with breast cancer risk was probably modified by folate intake.

Zhang, C.-X., et al., Choline and betaine intake is inversely associated with breast cancer risk: A two-stage case-control study in China. Cancer Science, 2012 (Dec 26).

Metabolomics reveals the metabolic shifts following an intervention with rye bread in postmenopausal women- a randomized control trial

BACKGROUND: Epidemiological studies have consistently shown that whole grain (WG) cereals can protect against the development of chronic diseases, but the underlying mechanism is not fully understood. Among WG products, WG rye is considered even more potent because of its unique discrepancy in postprandial insulin and glucose responses known as the rye factor. In this study, an NMR-based metabolomics approach was applied to study the metabolic effects of WG rye as a tool to determine the beneficial effects of WG rye on human health. METHODS: Thirty-three postmenopausal Finnish women with elevated serum total cholesterol (5.0-8.5 mmol/L) and BMI of 20-33 kg/m2 consumed a minimum of 20% of their daily energy intake as high fiber WG rye bread (RB) or refined wheat bread (WB) in a randomized, controlled, crossover design with two 8-wk intervention periods separated by an 8-wk washout period. At the end of each intervention period, fasting serum was collected for NMR-based metabolomics and the analysis of cholesterol fractions. Multilevel partial least squares discriminant analysis was used for paired comparisons of multivariate data. RESULTS: The metabolomics analysis of serum showed lower leucine and isoleucine and higher betaine and N,N-dimethylglycine levels after RB than WB intake. To further investigate the metabolic effects of RB, the serum cholesterol fractions were measured. Total- and LDL-cholesterol levels were higher after RB intake than after WB. CONCLUSIONS: This study revealed favorable shifts in branched amino acid and single carbon metabolism and an unfavorable shift in serum cholesterol levels after RB intake in postmenopausal women, which should be considered for evaluating health beneficial effects of rye products.

Moazzami, A.A., et al., Metabolomics reveals the metabolic shifts following an intervention with rye bread in postmenopausal women- a randomized control trial. Nutr J, 2012. 11: p. 88

Plasma betaine concentrations correlate with plasma cortisol but not with C-reactive protein in an elderly population

Background: Low plasma betaine concentrations are a feature of seriously ill patients. Increased dietary betaine intake has been associated with lowered systemic inflammation. We aimed to compare plasma cortisol (a stress marker) and C-reactive protein (an inflammation marker) as statistical predictors of plasma betaine concentrations.
Methods: Plasma carnitine, cortisol and C-reactive protein concentrations, other biochemical measures and urine betaine excretion, were compared with plasma betaine concentration by correlation and in multiple regression models, using morning blood and urine samples from 64 ambulant elderly subjects and from 55 patients admitted to hospital with hip fractures.
Results: In the ambulant elderly without acute trauma, plasma cortisol (with negative coefficients) and carnitine (with positive coefficients) statistically predicted plasma betaine concentrations. C-reactive protein was not a predictor. In the patients, the significant predictors were plasma carnitine (positive coefficient) and plasma homocysteine (negative coefficient) and C-reactive protein again was not a predictor. In regression models using combined patient and control data there were large ranges of both cortisol and especially C-reactive protein; cortisol and homocysteine (negative coefficients) and carnitine (positive coefficient) were significant predictors but C-reactive protein was not significant.
Conclusions: Stress rather than inflammation may affect plasma betaine concentrations.


Lever, M., et al., Plasma betaine concentrations correlate with plasma cortisol but not with C-reactive protein in an elderly population. Clin Chem Lab Med, 2012. 50(9): p. 1635-40

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 (beta=17.416), AdoMet (beta=61.272), and AdoHcy (beta=9.215). Betaine correlated positively with folate (beta=0.133) and negatively with tHcy (beta=-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.


Imbard, A., et al., Plasma choline and betaine correlate with serum folate, plasma S-adenosyl-methionine and S-adenosyl-homocysteine in healthy volunteers. Clin Chem Lab Med, 2012.

Early second trimester maternal plasma choline and betaine are related to measures of early cognitive development in term infants

BACKGROUND: The importance of maternal dietary choline for fetal neural development and later cognitive function has been well-documented in experimental studies. Although choline is an essential dietary nutrient for humans, evidence that low maternal choline in pregnancy impacts neurodevelopment in human infants is lacking. We determined potential associations between maternal plasma free choline and its metabolites betaine and dimethylglycine in pregnancy and infant neurodevelopment at 18 months of age.

METHODOLOGY: This was a prospective study of healthy pregnant women and their full-term, single birth infants. Maternal blood was collected at 16 and 36 weeks of gestation and infant neurodevelopment was assessed at 18 months of age for 154 mother-infant pairs. Maternal plasma choline, betaine, dimethylglycine, methionine, homocysteine, cysteine, total B12, holotranscobalamin and folate were quantified. Infant neurodevelopment was evaluated using the Bayley Scales of Infant Development-III. Multivariate regression, adjusting for covariates that impact development, was used to determine the associations between maternal plasma choline, betaine and dimethylglycine and infant neurodevelopment.

RESULTS: The maternal plasma free choline at 16 and 36 weeks gestation was median (interquartile range) 6.70 (5.78-8.03) and 9.40 (8.10-11.3) µmol/L, respectively. Estimated choline intakes were (mean ±SD) 383±98.6 mg/day, and lower than the recommended 450 mg/day. Betaine intakes were 142±70.2 mg/day. Significant positive associations were found between infant cognitive test scores and maternal plasma free choline (B = 6.054, SE = 2.283, p = 0.009) and betaine (B = 7.350, SE = 1.933, p = 0.0002) at 16 weeks of gestation. Maternal folate, total B12, or holotranscobalamin were not related to infant development.

CONCLUSION: We show that choline status in the first half of pregnancy is associated with cognitive development among healthy term gestation infants. More work is needed on the potential limitation of choline or betaine in the diets of pregnant women.

Wu, B.T., et al., Early second trimester maternal plasma choline and betaine are related to measures of early cognitive development in term infants. PLoS One, 2012. 7(8): p. e43448.

Betaine inhibits in vitro and in vivo angiogenesis through suppression of the NF-κB and Akt signaling pathways

Angiogenesis is defined as the formation of new blood vessels form existing vessels surrounding a tumor. The process of angiogenesis is an important step for tumor growth and metastasis, as is inflammation. Thus, angiogenesis inhibitors that suppress inflammation have been studied as an anticancer treatment. Recently, many research groups have investigated the anti-angiogenic activity of natural compounds since some have been demonstrated to have anticancer properties. Among many natural compounds, we focused on betaine, which is known to suppress inflammation. Betaine, trimethylglycine (TMG), was first discovered in the juice of sugar beets and was later shown to be present in wheat, shellfish and spinach. In Southeast Asia, betaine is used in traditional oriental medicine for the treatment of hepatic disorders. Here, we report the anti-angiogenic action of betaine. Betaine inhibited in vitro angiogenic cascade, tube formation, migration and invasion of human umbilical vein endothelial cells (HUVECs). Betaine also inhibited in vivo angiogenesis in the mouse Matrigel plug assay. The mRNA expression levels of basic fibroblast growth factor (bFGF), matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) in HUVECs were decreased by betaine treatment. In addition, betaine suppressed NF-kappaB and Akt activation.
Yi, E.Y. and Y.J. Kim, Betaine inhibits in vitro and in vivo angiogenesis through suppression of the NF-kappaB and Akt signaling pathways. Int J Oncol, 2012. 41(5): p. 1879-85

Neural tube defects and maternal intake of micronutrients related to one-carbon metabolism or antioxidant activity

BACKGROUND: Maternal nutritional status has been evaluated to clarify its role in development of neural tube defects (NTDs). Maternal folate intake during pregnancy has been closely evaluated for its association with NTDs. The study objective was to examine associations between NTDs and other dietary periconceptional micronutrient intake, particularly nutrients involved in one-carbon metabolism or antioxidant activity.

METHODS: Using data from the National Birth Defects Prevention Study, 1997-2005, logistic regression models were used to estimate the relative risk of NTDs based on maternal micronutrient intake.

RESULTS: Results were stratified according to folic acid supplement use, race/ethnicity, and maternal body mass index. Analyses included 954 cases (300 with anencephaly, 654 with spina bifida) and 6268 controls. Higher intakes of folate, thiamin, betaine, iron, and vitamin A were associated with decreased risk of anencephaly among some ethnic and clinical groups. In some groups, higher intakes of thiamin, riboflavin, vitamin B(6) , vitamin C, vitamin E, niacin, and retinol were associated with decreased risk of spina bifida.

CONCLUSION: In addition to folic acid, other micronutrients, including thiamin, betaine, riboflavin, vitamin B(6) , vitamin C, vitamin E, niacin, iron, retinol, and vitamin A, may decrease the risk of NTD occurrence.

Chandler, A.L., et al., Neural tube defects and maternal intake of micronutrients related to one-carbon metabolism or antioxidant activity. Birth Defects Res A Clin Mol Teratol, 2012. 94(11): p. 864-74

Dietary supplementation with methyl donors reduces fatty liver and modifies the fatty acid synthase DNA methylation profile in rats fed an obesogenic diet.

Non-alcoholic fatty liver disease (NAFLD) is one of the first hepatic manifestations of metabolic syndrome, whose progression can lead to cirrhosis and hepatic carcinoma. Interestingly, methyl donor supplementation could improve obesogenic diet-induced hepatic triglyceride accumulation. The aim of this research is to describe methyl donor effects on a high-fat-sucrose (HFS) diet in both sexes and epigenetic changes induced on fatty acid synthase (FASN) promoter methylation pattern as well as gene expression of NAFLD key metabolic genes. Twenty-four male and 28 female Wistar rats were assigned to three dietary groups: control, HFS, and HFS supplemented with methyl donors (choline, betaine, vitamin B12, and folic acid). After 8 weeks of treatment, somatic, biochemical, mRNA, and epigenetic measurements were performed. Rats fed the HFS diet presented an overweight phenotype and alterations in plasma biochemical measurements. Methyl donor supplementation reverted the HFS-diet-induced hepatic triglyceride accumulation. Analysis of FASN promoter cytosine methylation showed changes in both sexes due to the obesogenic diet at -1,096, -780, -778, and -774 CpG sites with respect to the transcriptional start site. Methyl donor supplementation modified DNA methylation at -852, -833, -829, -743, and -733 CpGs depending on the sex. RT-PCR analysis confirmed that FASN expression tended to be altered in males. Our findings reinforce the hypothesis that methyl donor supplementation can prevent hepatic triglyceride accumulation induced by obesogenic diets in both sexes. Changes in liver gene expression profile and epigenetic-mediated mechanisms related to FASN DNA hypermethylation could be involved in methyl donor-induced NAFLD improvement.

Cordero, P., et al., Dietary supplementation with methyl donors reduces fatty liver and modifies the fatty acid synthase DNA methylation profile in rats fed an obesogenic diet. Genes Nutr, 2012 (May 31)

Recognition of betaine as an inhibitor of lipopolysaccharide-induced nitric oxide production in activated microglial cells

Background: Neuroinflammation, as a major outcome of microglia activation, is an important factor for progression of neurodegenerative disorders including Alzheimer's disease and Parkinson's disease. Microglial cells, as the first-line defense in the central nervous system, act as a source of neurotoxic factors such as nitric oxide (NO), a free radical which is involved in neuronal cell death. The aim of this study was to inhibit production of NO in activated microglial cells in order to decrease neurological damages that threat the central nervous system. Methods: An in vitro model of a newborn rat brain cell culture was used to examine the effect of betaine on the release of NO induced by lipopolysaccharide (LPS). Briefly, primary microglial cells were stimulated by LPS and after 2 minutes, they were treated by different concentrations of betaine. The production of NO was assessed by the Griess assay while cell viability was determined by the MTT assay. Results: Our investigations indicated that LPS-induced NO release was attenuated by betaine, suggesting that this compound might inhibit NO release. The effects of betaine on NO production in activated microglial cells after 24 h were "dose-dependent". It means that microglial cells which were treated with higher concentrations of betaine, released lower amounts of NO. Also our observations showed that betaine compound has no toxic effect on microglial cells. Conclusion: Betaine has an inhibitory effect on NO release in activated microglial cells and may be an effective therapeutic component to control neurological disorders.

Amiraslani, B., et al., Recognition of betaine as an inhibitor of lipopolysaccharide-induced nitric oxide production in activated microglial cells. Iran Biomed J, 2012. 16(2): p. 84-9.

Effect of long-term betaine supplementation on chemical and physical characteristics of three muscles from the Alentejano pig

BACKGROUND: The use of betaine as a dietary supplement to reduce fat deposition and increase lean muscle mass in pigs is increasing. However, there is no available information on its effect on the physical and chemical (i.e. fatty acid (FA) profile) characteristics of pork. RESULTS: The effects of long-term betaine intake (1 g betaine kg(-1) diet for 20 weeks) on the chemical and physical characteristics of Musculus longissimus dorsi, M. biceps femoris and M. semimembranosus from the Alentejano pig were investigated. The contents of total protein, intramuscular lipids (neutral and polar), myoglobin and total collagen as well as the water-holding capacity, physical colour characteristics and FA profile of the three muscles were determined. With the exception of a significant increase in the intramuscular lipid content of M. longissimus dorsi and M. biceps femoris, betaine supplementation did not influence muscle chemical and colour characteristics or body fat deposition. CONCLUSION: These data suggest that long-term betaine supplementation selectively increases intramuscular lipid deposition (a trait related to meat quality) while not affecting other chemical (including the atheroprotective FA profile) and physical characteristics of the Alentejano pig muscles studied.
Martins, J.M., et al., Effect of long-term betaine supplementation on chemical and physical characteristics of three muscles from the Alentejano pig. J Sci Food Agric, 2012. 92(10): p. 2122-7

Plasma free choline, betaine and cognitive performance: the Hordaland Health Study

Choline and betaine are nutrients involved in one-carbon metabolism. Choline is essential for neurodevelopment and brain function. We studied the associations between cognitive function and plasma concentrations of free choline and betaine. In a cross-sectional study, 2195 subjects (55 % women), aged 70-74 years, underwent extensive cognitive testing including the Kendrick Object Learning Test (KOLT), Trail Making Test (part A, TMT-A), modified versions of the Digit Symbol Test (m-DST), Block Design (m-BD), Mini-Mental State Examination (m-MMSE) and Controlled Oral Word Association Test (COWAT). Compared with low concentrations, high choline (>8.4 mumol/l) was associated with better test scores in the TMT-A (56.0 v. 61.5, P = 0.004), m-DST (10.5 v. 9.8, P = 0.005) and m-MMSE (11.5 v. 11.4, P = 0.01). A generalised additive regression model showed a positive dose-response relationship between the m-MMSE and choline (P = 0.012 from a corresponding linear regression model). Betaine was associated with the KOLT, TMT-A and COWAT, but after adjustments for potential confounders, the associations lost significance. Risk ratios (RR) for poor test performance roughly tripled when low choline was combined with either low plasma vitamin B12 ( </= 257 pmol/l) concentrations (RRKOLT = 2.6, 95 % CI 1.1, 6.1; RRm-MMSE = 2.7, 95 % CI 1.1, 6.6; RRCOWAT = 3.1, 95 % CI 1.4, 7.2) or high methylmalonic acid (MMA) ( >/= 3.95 mumol/l) concentrations (RRm-BD = 2.8, 95 % CI 1.3, 6.1). Low betaine ( </= 31.1 mumol/l) combined with high MMA was associated with elevated RR on KOLT (RRKOLT = 2.5, 95 % CI 1.0, 6.2). Low plasma free choline concentrations are associated with poor cognitive performance. There were significant interactions between low choline or betaine and low vitamin B12 or high MMA on cognitive performance.

Nurk, E., et al., Plasma free choline, betaine and cognitive performance: the Hordaland Health Study. Br J Nutr, 2012 (May 1): p. 1-9

Deletion of murine betaine-homocysteine S-methyltransferase in mice perturbs choline and 1-carbon metabolism, resulting in fatty liver and hepatocellular carcinoma

Betaine-homocysteine S-methyltransferase (BHMT) uses betaine to catalyze the degradation of homocysteine (Hcy). There are common genetic polymorphisms in the BHMT gene in humans. To model the phenotype of mice with a loss of BHMT function, we generated the first Bhmt-/- mouse. Deletion of the gene resulted in a 6-fold increase in hepatic and an 8-fold increase in plasma Hcy concentrations, suggesting the importance of BHMT in Hcy removal. Deletion of the gene resulted in a 43% reduction in hepatic S-adenosylmethionine (AdoMet) and a 3-fold increase in hepatic S-adenosylhomocysteine (AdoHcy) concentrations, resulting in a 75% reduction in methylation potential (AdoMet:AdoHcy). Bhmt-/- mice accumulated betaine in most tissues, including a 21-fold increase in the liver concentration compared to wildtype (WT). These mice had lower concentrations of choline, phosphocholine, glycerophosphocholine, phosphatidylcholine and sphingomyelin in several tissues. At 5 weeks of age, Bhmt-/- mice had 36% lower total hepatic phospholipid concentrations and a 6-fold increase in hepatic triacyglycerol concentrations compared to WT, which was due to a decrease in the secretion of very low density lipoproteins. At 1 year of age, 64% of Bhmt-/- mice had visible hepatic tumors. Histopathological analysis revealed that Bhmt-/- mice developed hepatocellular carcinoma (HCC) or carcinoma precursors. These results indicate that BHMT has an important role in Hcy, choline and one-carbon homeostasis. A lack of BHMT also affects susceptibility to fatty liver and HCC. We suggest that functional polymorphisms in BHMT that significantly reduce activity may have similar effects in humans.

Teng, Y.W., et al., Deletion of murine betaine-homocysteine S-methyltransferase in mice perturbs choline and 1-carbon metabolism, resulting in fatty liver and hepatocellular carcinoma. J Biol Chem, 2011. 286: p. 36258-67

Wednesday, December 26, 2012

Thermal and refining processes, not fermentation, tend to reduce lipotropic capacity of plant-based foods

Plant-based foods (PBF) are relevant and diversified sources of lipotropes, which are compounds preventing excess hepatic fat deposits. In a first study, we defined the lipotropic capacity (LC, %) of raw PBF as the means of 8 lipotrope densities (LD, mg/100 kcal), each expressed relative to that of a reference food ranking the highest considering its mean 8 LD ranks (LCraw asparagus = 100%) (A. Fardet, J.-F. Martin and J. M. Chardigny, J. Food Comp. Anal., 2011, DOI: 10.1016/j.jfca.2011.1003.1013). We showed that vegetables appeared as the best source of lipotropes on a 100 kcal-basis compared to legumes, cereals, fruits and nuts. The main objective of this second study was to quantify the effect of processing on LD and LC of raw PBF based on lipotrope contents collected in a USDA (United State Department of Agriculture) database and the literature, i.e. betaine, choline, myo-inositol, methionine, magnesium, niacin, pantothenic acid and folate contents. Choline and betaine densities were not significantly affected by processing while methionine and lipotropic micronutrient densities were significantly decreased, especially for magnesium, pantothenate and folates. Myo-inositol density decreases were insignificant due to lower product number resulting from limited literature data. Lipotropic micronutrient densities were more affected by processing than other densities. Fermentations increased betaine (median change of +32%) and choline (+34%) densities. Canning and boiling vegetables increased choline densities (+26%). Globally, processing significantly reduced LC by 20%, fermentations being less drastic (median change of −5%) than refining (−33%) and thermal treatments (−16%). More specifically, canning increased LC of beetroot (536 vs 390%) and common bean (40 vs 36%) as fermentation towards LC grape (14 vs 7% for wine). Results were then mainly discussed based on percentages of lipotrope content changes on a dry-weight basis. Results of this study also showed that the LC is quite a relevant index to estimate effect of processing on lipotropic potential of PBF.

Fardet, A., J.F. Martin, and J.M. Chardigny, Thermal and refining processes, not fermentation, tend to reduce lipotropic capacity of plant-based foods. Food Funct, 2011. 2(8): p. 483-504.

The regulation of non-coding RNA expression in the liver of mice fed DDC

Mallory–Denk bodies (MDBs) are found in the liver of patients with alcoholic and chronic nonalcoholic liver disease, and hepatocellular carcinoma (HCC). Diethyl 1,4-dihydro-2,4,6,-trimethyl-3,5-pyridinedicarboxylate (DDC) is used as a model to induce the formation of MDBs in mouse liver. Previous studies in this laboratory showed that DDC induced epigenetic modifications in DNA and histones. The combination of these modifications changes the phenotype of the MDB forming hepatocytes, as indicated by the marker FAT10. These epigenetic modifications are partially prevented by adding to the diet S-adenosylmethionine (SAMe) or betaine, both methyl donors. The expression of three imprinted ncRNA genes was found to change in MDB forming hepatocytes, which is the subject of this report. NcRNA expression was quantitated by real-time PCR and RNA FISH in liver sections. Microarray analysis showed that the expression of three ncRNAs was regulated by DDC: up regulation of H19, antisense Igf2r (AIR), and down regulation of GTL2 (also called MEG3). S-adenosylmethionine (SAMe) feeding prevented these changes. Betaine, another methyl group donor, prevented only H19 and AIR up regulation induced by DDC, on microarrays. The results of the SAMe and betaine groups were confirmed by real-time PCR, except for AIR expression. After 1 month of drug withdrawal, the expression of the three ncRNAs tended toward control levels of expression. Liver tumors that developed also showed up regulation of H19 and AIR. The RNA FISH approach showed that the MDB forming cells' phenotype changed the level of expression of AIR, H19 and GTL2, compared to the surrounding cells. Furthermore, over expression of H19 and AIR was demonstrated in tumors formed in mice withdrawn for 9 months. The dysregulation of ncRNA in MDB forming liver cells has been observed for the first time in drug-primed mice associated with liver preneoplastic foci and tumors.

Oliva, J., et al., The regulation of non-coding RNA expression in the liver of mice fed DDC. Experimental and Molecular Pathology, 2009. 87(1): p. 12-19.

Maternal intake of methyl-donor nutrients and child cognition

Methyl-donor nutrients are substrates for methylation reactions involved in neurodevelopment processes. The role of maternal intake of these nutrients on cognitive performance of the offspring is poorly understood. We examined the associations of maternal intake of folate, vitamin B12, choline, betaine and methionine during the first and second trimesters of pregnancy, with tests of cognitive performance in the offspring at 3 years of age using data from 1210 participants in Project Viva, a prospective pre-birth cohort study in Massachusetts. We assessed nutrient intake with the use of food frequency questionnaires. Children's cognition at age 3 years was evaluated with the Peabody Picture Vocabulary Test III (PPVT-III) and visual-motor skills with the Wide Range Assessment of Visual Motor Abilities test. In multivariable models adjusting for potential sociobehavioural and nutritional confounders, for each 600 microg/day increment in total folate intake during the first trimester, PPVT-III score at age 3 years was 1.6 points [95% confidence interval (CI) 0.1, 3.1; P = 0.04] higher. There was a weak inverse association between vitamin B12 intake during the second trimester and PPVT-III scores [-0.4 points per 2.6 microg/day; 95% CI -0.8, -0.1; P = 0.01]. We did not find associations between choline, betaine or methionine and cognitive outcomes at this age. Results of this study suggest that higher intake of folate in early pregnancy is associated with higher scores on the PPVT-III, a test of receptive language that predicts overall intelligence, at age 3 years.

In unadjusted analyses, intake of folate and betaine during the first or second trimester was directly related to PPVT-III scores. After adjustment for potential socio-economic, educational and dietary confounders, however, the associations with both nutrients were attenuated and only the relationship between folate intake during the first trimester and PPVT-III scores remained statistically significant.

Villamor, E., et al., Maternal intake of methyl-donor nutrients and child cognition at 3 years of age. Paediatr Perinat Epidemiol, 2012. 26(4): p. 328-35.

Dietary choline and betaine intakes and risk of cardiovascular diseases: review of epidemiological evidence

BACKGROUND: Cardiovascular diseases (CVD) are the most important causes of human mortality in the world. Higher intakes of choline and betaine have been shown to be associated with lower plasma homocysteine levels (the putative CVD risk factor). This study aimed to review the evidence on the association between dietary intakes of choline and betaine and traditional/novel CVD risk factors.

METHODS: We searched in PubMed website from 1990 to 2009, with the use of following keywords: "dietary choline and betaine, cardiovascular diseases, metabolic syndrome, inflammation". The cross-sectional and prospective studies as well as the clinical trials were recruited in this investigation.

RESULTS: Dietary intakes of “choline”/“choline and betaine” were not significantly associated with CVD risk; however, the higher intakes of choline and betaine were associated with higher serum concentrations of CRP, IL-6 and TNF-α. Individuals with high plasma choline levels were obese and had elevated plasma triglycerides, HDL and non-HDL cholesterol levels; whereas high plasma betaine levels were inversely associated with these biochemical markers. Both choline and betaine supplementation resulted in increased blood lipid profiles.

CONCLUSION: Although dietary intakes of choline and betaine were not significantly associated with CVD incidence, the long-term consumption of these nutrients have been shown to prevent CVD mortality by decreasing inflammation and other risk factors.

Rajaie, S. and A. Esmaillzadeh, Dietary choline and betaine intakes and risk of cardiovascular diseases: review of epidemiological evidence. ARYA Atheroscler, 2011. 7(2): p. 78-86

Application of NMR-based metabonomics suggests a relationship between betaine absorption and elevated creatine plasma concentrations in catheterised sows

The objective of the present explorative study was to determine the absorption dynamics when feeding diets varying in types and levels of dietary fibre in a catheterised animal model. A total of six sows were fed a diet low in fibre (LF), a diet high in soluble fibre and a diet high in insoluble fibre in a repeated 3 x 3 cross-over design. Plasma samples were collected from the mesenteric artery and the portal vein to determine different absorption phases by 1H NMR spectroscopy-based metabonomics. Time profiles were determined for plasma levels of specific metabolites and for the absorption of these metabolites from the small intestine. The LF diet resulted in a higher betaine concentration in the blood than the two high-fibre diets (P = 0.008). This leads to higher plasma concentrations of methionine (P = 0.0028) and creatine (P = 0.020) of endogenous origin. In conclusion, the use of NMR spectroscopy for measuring nutrient uptake in the present study elucidated the relationship between betaine uptake and elevated creatine plasma concentrations.

Betaine attenuates hepatic steatosis and preserves mitochondial function

Introduction. Mitochondrial damage and disruption in oxidative phosphorylation contributes to the pathogenesis of alcoholic liver injury. Herein, we tested the hypothesis that the hepatoprotective actions of betaine against alcoholic liver injury occur at the level of the mitochondrial proteome.
Methods. Male Wister rats were pair-fed control or ethanol-containing liquid diets supplemented with or without betaine (10 mg/mL) for 4-5 wks. Liver was examined for triglyceride accumulation, levels of methionine cycle metabolites, and alterations in mitochondrial proteins.
Results. Chronic ethanol ingestion resulted in triglyceride accumulation which was attenuated in the ethanol plus betaine group. Blue native gel electrophoresis (BN-PAGE) revealed significant decreases in the content of the intact oxidative phosphorylation complexes in mitochondria from ethanol-fed animals. The alcohol-dependent loss in many of the low molecular weight oxidative phosphorylation proteins was prevented by betaine supplementation. This protection by betaine was associated with normalization of SAM : S-adenosylhomocysteine (SAH) ratios and the attenuation of the ethanol-induced increase in inducible nitric oxide synthase and nitric oxide generation in the liver.
Discussion/Conclusion. In summary, betaine attenuates alcoholic steatosis and alterations to the oxidative phosphorylation system. Therefore, preservation of mitochondrial function may be another key molecular mechanism responsible for betaine hepatoprotection.

Kharbanda, K.K., et al., Betaine treatment attenuates chronic ethanol-induced hepatic steatosis and alterations to the mitochondrial respiratory chain proteome. Int J Hepatol, 2012: p. 962183.

Non-targeted analyses of animal plasma: betaine and choline represent the nutritional and metabolic status

Simple liquid chromatography–mass spectrometry (LC-MS) was applied to non-targeted metabolic analyses to discover new metabolic markers in animal plasma. Principle component analysis (PCA) and partial least squares–discriminate analysis (PLS-DA) were used to analyse LC-MS multivariate data. PCA clearly generated two separate clusters for artificially induced diabetic mice and healthy control mice. PLS-DA of time-course changes in plasma metabolites of chicks after feeding generated three clusters (pre- and immediately after feeding, 0.5–3 h after feeding and 4 h after feeding). Two separate clusters were also generated for plasma metabolites of pregnant Angus heifers with differing live-weight change profiles (gaining or losing). The accompanying PLS-DA loading plot detailed the metabolites that contribute the most to the cluster separation. In each case, the same highly hydrophilic metabolite was strongly correlated to the group separation. The metabolite was identified as betaine by LC-MS/MS. This result indicates that betaine and its metabolic precursor, choline, may be useful biomarkers to evaluate the nutritional and metabolic status of animals.

Katayama, K., et al., Non-targeted analyses of animal plasma: betaine and choline represent the nutritional and metabolic status. J Anim Physiol Anim Nutr (Berl), 2011. 5 Nov.

Macromolecular crowding regulates assembly of mRNA stress granules after osmotic stress: new role for compatible osmolytes

The massive uptake of compatible osmolytes such as betaine, taurine and myo-inositol is a protective response shared by all eukaryotes exposed to hypertonic stress. Their accumulation results mostly from the expression of specific transporters triggered by the transcriptional factor NFAT5/TonEBP. This allows the recovery of the cell volume without increasing intracellular ionic strength. In this study, we consider the assembly and dissociation of mRNA stress granules (SGs) in hypertonic-stressed cells and the role of compatible osmolytes. In agreement with in vitro results obtained on isolated mRNAs, both macromolecular crowding and a high ionic strength favor the assembly of SGs in normal rat kidney epithelial cells. However, after hours of constant hypertonicity, the slow accumulation in the cytoplasm of compatible osmolytes via specific transporters both reduces macromolecular crowding and the ionic strength, thus leading to the progressive dissociation of SGs. In line with this, when cells are exposed to hypertonicity in order to accumulate large amount of compatible osmolytes, the formation of SGs is severely impaired and cells increase their chances of survival to another hypertonic episode. Altogether, these results indicate that the impact of compatible osmolytes on the mRNA-associated machineries and especially that associated with SGs may play an important role in the cell resistance and adaption to hyperosmolarity in many tissues like kidney and liver.

Bounedjah, O., et al., Macromolecular crowding regulates assembly of mRNA stress granules after osmotic stress: new role for compatible osmolytes. J Biol Chem, 2012. 287(4): p. 2446-58

Betaine excretion correlates with plasma homocysteine when plasma lipids are elevated

OBJECTIVES: To reconcile observing a positive correlation of betaine excretion with homocysteine in lipid disorder patients but not other study groups.
DESIGN AND METHODS: Correlations were estimated in subgroups of a control group and the lipid disorder patients.
RESULTS: Plasma non high-density lipoprotein (non-HDL) cholesterol differed between the groups. The correlation increased with the median plasma non-HDL cholesterol in subgroups.
CONCLUSIONS: This correlation is associated with patients with elevated plasma lipids.

Lever, M., et al., Betaine excretion correlates with plasma homocysteine when plasma lipids are elevated. Clin Biochem, 2012. 45(1-2): p. 154-6

Tuesday, December 25, 2012

Antioxidant effect of betaine on adipose tissue when added to a high fat diet

Although well-established, the underlying mechanisms involved in obesity-related plasma adiponectin decline remain elusive. Oxidative stress is associated with obesity and insulin resistance and considered to contribute to the progression toward obesity-related metabolic disorders. In this study, we investigated the effects of 4-hydroxynonenal (4-HNE), the most abundant lipid peroxidation end product, on adiponectin production and its potential implication in obesity-related adiponectin decrease. Long-term high-fat diet feeding led to obesity in mouse, accompanied by decreased plasma adiponectin and increased adipose tissue 4-HNE content. Exposure of adipocytes to exogenous 4-HNE resulted in decreased adiponectin secretion in a dose-dependent manner, which was consistent with significantly decreased intracellular adiponectin protein abundance. In contrast, adiponectin gene expression was significantly elevated by 4-HNE treatment, which was concomitant with increased peroxisome proliferator-activated receptor gamma (PPAR-γ) gene expression and transactivity. The effect was abolished by T0070907, a PPAR-γ antagonist, suggesting that PPAR-γ activation plays a critical role in this process. To gain insight into mechanisms involved in adiponectin protein decrease, we examined the effects of 4-HNE on adiponectin protein degradation. Cycloheximide (CHX)-chase assay revealed that 4-HNE exposure accelerated adiponectin protein degradation, which was prevented by MG132, a potent proteasome inhibitor. Immunoprecipitation assay showed that 4-HNE exposure increased ubiquitinated adiponectin protein levels. These data altogether indicated that 4-HNE enhanced adiponectin protein degradation via ubiquitin–proteasome system. Finally, we demonstrated that supplementation of HF diet with betaine, an antioxidant and methyl donor, alleviated high-fat-induced adipose tissue 4-HNE increase and attenuated plasma adiponectin decline. Taken together, our findings suggest that the lipid peroxidation product 4-HNE can differentially regulates adiponectin gene expression and protein abundance and may play a mechanistic role in obesity-related plasma adiponectin decline.

Wang, Z., et al., 4-Hydroxynonenal differentially regulates adiponectin gene expression and secretion via activating PPARgamma and accelerating ubiquitin-proteasome degradation. Mol Cell Endocrinol, 2011. 349(2): p. 222-31.

The effects of chronic betaine supplementation on exercise performance, skeletal muscle oxygen saturation and associated biochemical parameters in resistance trained men

We examined the effects of chronic betaine supplementation on exercise performance and associated parameters in resistance trained men. Men were randomly assigned in a double-blind manner using a crossover design to consume betaine (2.5 g of betaine mixed in 500 ml of Gatorade(R)) or a placebo (500 ml of Gatorade(R)) for 14 days, with a 21-day washout period. Before and after each treatment period, tests of lower- and upper-body muscular power and isometric force were conducted, including a test of upper-body muscular endurance (10 sets of bench press exercise to failure). Muscle tissue oxygen saturation (StO2) during the bench press protocol was measured via near infrared spectroscopy. Blood samples were collected before and after the exercise test protocol for analysis of lactate, nitrate/nitrite (NOx), and malondialdehyde (MDA). When analyzed using a repeated measures analysis of variance, no significant differences were noted between conditions for exercise performance variables (p > 0.05). However, an increase in total repetitions (p = 0.01) and total volume load (p = 0.02) in the 10-set bench press protocol was noted with betaine supplementation (paired t-tests), with values increasing approximately 6.5% from preintervention to postintervention. Although not of statistical significance (p = 0.14), postexercise blood lactate increased to a lesser extent with betaine supplementation (210%) compared with placebo administration (270%). NOx was lower postintervention as compared with preintervention (p = 0.06), and MDA was relatively unchanged. The decrease in StO2 during the bench press protocol was greater with betaine vs. placebo (p = 0.01), possibly suggesting enhanced muscle oxygen consumption. These findings indicate that betaine supplementation results in a moderate increase in total repetitions and volume load in the bench press exercise, without favorably impacting other performance measures.

Trepanowski, J.F., et al., The effects of chronic betaine supplementation on exercise performance, skeletal muscle oxygen saturation and associated biochemical parameters in resistance trained men. J Strength Cond Res, 2011. 25(12): p. 3461-71.

Effects of betaine on lipopolysaccharide-induced memory impairment in mice and the involvement of GABA transporter 2

BACKGROUND: Betaine (glycine betaine or trimethylglycine) plays important roles as an osmolyte and a methyl donor in animals. While betaine is reported to suppress expression of proinflammatory molecules and reduce oxidative stress in aged rat kidney, the effects of betaine on the central nervous system are not well known. In this study, we investigated the effects of betaine on lipopolysaccharide (LPS)-induced memory impairment and on mRNA expression levels of proinflammatory molecules, glial markers, and GABA transporter 2 (GAT2), a betaine/GABA transporter.

METHODS: Mice were continuously treated with betaine for 13 days starting 1 day before they were injected with LPS, or received subacute or acute administration of betaine shortly before or after LPS injection. Then, their memory function was evaluated using Y-maze and novel object recognition tests 7 and 10-12 days after LPS injection (30 ug/mouse, i.c.v.), respectively. In addition, mRNA expression levels in hippocampus were measured by real-time RT-PCR at different time points.

RESULTS: Repeated administration of betaine (0.163 mmol/kg, s.c.) prevented LPS-induced memory impairment. GAT2 mRNA levels were significantly increased in hippocampus 24 hr after LPS injection, and administration of betaine blocked this increase. However, betaine did not affect LPS-induced increases in levels of mRNA related to inflammatory responses. Both subacute administration (1 hr before, and 1 and 24 hr after LPS injection) and acute administration (1 hr after LPS injection) of betaine also prevented LPS-induced memory impairment in the Y-maze test.

CONCLUSIONS: These data suggest that betaine has protective effects against LPS-induced memory impairment and that prevention of LPS-induced changes in GAT2 mRNA expression is crucial to this ameliorating effect.

Miwa, M., et al., Effects of betaine on lipopolysaccharide-induced memory impairment in mice and the involvement of GABA transporter 2. J Neuroinflammation. 8(1): p. 153.

A therapeutic trial of pro-methylation dietary supplements in Angelman syndrome

Angelman syndrome (AS) is due to deficient ubiquitin protein ligase 3a, the gene for which (UBE3A) maps to chromosome 15q11-q13 and is imprinted such that only the maternally inherited gene is expressed. The paternally inherited UBE3A gene is silenced, a process mediated by an antisense transcript. We conducted a trial using methylation-promoting dietary supplements (betaine, metafolin, creatine, and vitamin B(12) ) in an attempt to reduce antisense transcript production, increase UBE3A expression, and ameliorate the symptoms of AS. Neuropsychological evaluations, biochemical testing, and assessment of DNA methylation were performed at the beginning and at the end of 1 year of supplementation. The primary outcome measures were changes in the level of developmental function (cognitive, motor, and language) as measured using standardized instruments. The secondary outcomes measures were changes in biochemical parameters and global DNA methylation. These data were compared to those of a control group from a previous randomized double-blind trial using folic acid and betaine. There were no statistically significant changes in the developmental performance of children treated with supplements. There were no unexpected changes in biochemical parameters and no change in site-specific DNA methylation when comparing samples from before and after treatment. There were 10 adverse events that resulted in study withdrawal of 7 participants (worsening of seizures, onset, or worsening of sleep problems, constipation, and anorexia). Supplementation with betaine, metafolin, creatine, and vitamin B(12) appears safe but ineffective in decreasing the severity of AS.

Bird, L.M., et al., A therapeutic trial of pro-methylation dietary supplements in Angelman syndrome. American Journal of Medical Genetics Part A, 2011. 155(12): p. 2956-2963

Metabolomics reveals the metabolic shifts following an intervention with rye bread in postmenopausal women- a randomized control trial

Prostate cancer (PC) is the most common cancer in the Western world and the second most important cancer causing male deaths, after lung cancer, in the United States and Britain. Lifestyle and dietary changes are recommended for men diagnosed with early-stage PC. It has been shown that a diet rich in whole grain (WG) rye reduces the progression of early-stage PC, but the underlying mechanism is not clear. This study sought to identify changes in the metabolic signature of plasma in patients with early-stage PC following intervention with a diet rich in WG rye and rye bran product (RP) compared with refined white wheat product (WP) as a tool for mechanistic investigation of the beneficial health effects of RP on PC progression. Seventeen PC patients received 485 g RP or WP in a randomized, controlled, crossover design during a period of 6 wk with a 2-wk washout period. At the end of each intervention period, fasting plasma was collected and used for (1)H NMR-based metabolomics. Multilevel partial least squares discriminant analysis was used for paired comparisons of multivariate data. A metabolomics analysis of plasma showed an increase in 5 metabolites, including 3-hydroxybutyric acid, acetone, betaine, N,N-dimethylglycine, and dimethyl sulfone, after RP. To understand these metabolic changes, fasting plasma homocysteine, leptin, adiponectin, and glucagon were measured separately. The plasma homocysteine concentration was lower (P = 0.07) and that of leptin tended to be lower (P = 0.07) after RP intake compared to WP intake. The increase in plasma 3-hydroxybutyric acid and acetone after RP suggests a shift in energy metabolism from anabolic to catabolic status, which could explain some of the beneficial health effects of WG rye, i.e., reduction in prostate-specific antigen and reduced 24-h insulin secretion. In addition, the increase in betaine and N,N-dimethylglycine and the decrease in homocysteine show a favorable shift in homocysteine metabolism after RP intake.

Moazzami, A.A., et al., Metabolomics reveals the metabolic shifts following an intervention with rye bread in postmenopausal women- a randomized control trial. Nutr J, 2012. 11: p. 88

Gene polymorphisms and low dietary intake of micronutrients in coronary artery disease


Background/Aims: Coronary artery disease (CAD) is a complex disorder involving genetic and non-genetic factors. Food is an important component of the latter. We examined if DNA polymorphisms in genes encoding enzymes of one-carbon metabolism coupled with low consumption of micronutrients such as folate, vitamins B(6) and B(12) might increase the risk of CAD. Methods: A case-control study consisting of 252 CAD patients and 252 controls were included. Three single nucleotide polymorphisms (SNP), 2 insertion/deletion and 1 repeat polymorphism were typed. The micronutrient intake was estimated from a standard 24-hour dietary recall coupled to a food frequency questionnaire. Results: The results suggest an association of 'early-onset CAD' with betaine homocysteine S-methyl transferase (BHMT) 742G-->A SNP (odds ratio = 1.52; 95% confidence interval, 0.96-2.41; p = 0.04). No association was observed for all age of onset, but more patients than controls whose micronutrient intake was in the lowest quintile also carried the minor allele (50% patients vs. 37% controls; p = 0.042). Furthermore, dietary intake of folate micronutrients below the recommended daily allowance was observed in a larger percent of patients than controls with the minor BHMT allele (51% patients vs. 44% controls; p = 0.021). Conclusions: In the presence of the minor BHMT allele, a decreased consumption of folate micronutrients might increase the risk of CAD.

Singh, P. R., S. S. Lele, et al. (2011). "Gene Polymorphisms and Low Dietary Intake of Micronutrients in Coronary Artery Disease." J Nutrigenet Nutrigenomics 4(4): 203-209.

Impact of high-fat and high-carbohydrate diets on liver metabolism studied in a rat model with a systems biology approach

The aim of the present study was to investigate the use of an integrated metabolomics and proteomics approach in the elucidation of diet-induced effects on hepatic metabolism in a rat model. Nuclear magnetic resonance (NMR)-based metabolomics of liver extracts revealed a pronounced effect of a high-fat diet on the hepatic betaine content, whereas a carbohydrate-rich diet induced increases in hepatic glucose. In addition, the metabolomic investigations revealed that the high-fat diet was associated with increased hepatic lipid levels, which was not evident with the carbohydrate-rich diet. The proteomic investigations revealed strong high-fat diet effects on the expression of 186 proteins in the liver including malate dehydrogenase. Comparison of malate dehydrogenase expression determined by proteomics and NMR metabolite profiles revealed correlations between malate dehydrogenase and lactate, glucose, and glutamine/glutamate signals, thereby demonstrating a diet-induced regulation that was evident at both proteomic and metabolomic levels.

Bertram, H.C., et al., Impact of High-Fat and High-Carbohydrate Diets on Liver Metabolism Studied in a Rat Model with a Systems Biology Approach. J. Agric. Food Chem., 2011. 60(2): p. 676-684.

Betaine and secondary events in an acute coronary syndrome cohort.

Background - Betaine insufficiency is associated with unfavourable vascular risk profiles in metabolic syndrome patients. We investigated associations between betaine insufficiency and secondary events in acute coronary syndrome patients.

Methods - Plasma (531) and urine (415) samples were collected four months after discharge following an acute coronary event. Death (34), secondary acute myocardial infarction (MI) (70) and hospital admission for heart failure (45) events were recorded over a median follow-up of 832 days.

Principal Findings - The highest and lowest quintiles of urinary betaine excretion associated with risk of heart failure (p = 0.0046, p = 0.013 compared with middle 60%) but not with subsequent acute MI. The lowest quintile of plasma betaine was associated with subsequent acute MI (p = 0.014), and the top quintile plasma betaine with heart failure (p = 0.043), especially in patients with diabetes. Top quintile plasma concentrations of dimethylglycine (betaine metabolite) and top quintile plasma homocysteine both associated with all three outcomes, acute MI, heart failure  and survival. High homocysteine was associated with high or low betaine excretion in >60% of these subjects (p=0.017). Median NT-proBNP concentrations were lowest in the middle quintile of plasma betaine concentration (p = 0.002).

Conclusions - Betaine insufficiency indicates increased risk of secondary heart failure and acute MI. Its association with elevated homocysteine may partly explain the disappointing results of folate supplementation. In some patients, especially with diabetes, elevated plasma betaine also indicates increased risk.

Lever, M., et al., Betaine and secondary events in an acute coronary syndrome cohort. PLoS One, 2012. 7(5): p. e37883