Margreet R. Olthof

A Trial of Sugar-free or Sugar-Sweetened Beverages and Body Weight in Children

BACKGROUND The consumption of beverages that contain sugar is associated with overweight, possibly because liquid sugars do not lead to a sense of satiety, so the consumption of other foods is not reduced. However, data are lacking to show that the replacement of sugar-containing beverages with noncaloric beverages diminishes weight gain. METHODS We conducted an 18-month trial involving 641 primarily normal-weight children from 4 years 10 months to 11 years 11 months of age. Participants were randomly assigned to receive 250 ml (8 oz) per day of a sugar-free, artificially sweetened beverage (sugar-free group) or a similar sugar-containing beverage that provided 104 kcal (sugar group). Beverages were distributed through schools. At 18 months, 26% of the children had stopped consuming the beverages; the data from children who did not complete the study were imputed. RESULTS The z score for the body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) increased on average by 0.02 SD units in the sugar-free group and by 0.15 SD units in the sugar group; the 95% confidence interval (CI) of the difference was -0.21 to -0.05. Weight increased by 6.35 kg in the sugar-free group as compared with 7.37 kg in the sugar group (95% CI for the difference, -1.54 to -0.48). The skinfold-thickness measurements, waist-to-height ratio, and fat mass also increased significantly less in the sugar-free group. Adverse events were minor. When we combined measurements at 18 months in 136 children who had discontinued the study with those in 477 children who completed the study, the BMI z score increased by 0.06 SD units in the sugar-free group and by 0.12 SD units in the sugar group (P=0.06). CONCLUSIONS Masked replacement of sugar-containing beverages with noncaloric beverages reduced weight gain and fat accumulation in normal-weight children. (Funded by the Netherlands Organization for Health Research and Development and others; DRINK ClinicalTrials.gov number, NCT00893529.).

Acute Effects Of Decaffeinated Coffee And The Major Coffee Components Chlorogenic Acid And Trigonelline On Glucose Tolerance

OBJECTIVE Coffee consumption has been associated with lower risk of type 2 diabetes. We evaluated the acute effects of decaffeinated coffee and the major coffee components chlorogenic acid and trigonelline on glucose tolerance. RESEARCH DESIGN AND METHODS We conducted a randomized crossover trial of the effects of 12 g decaffeinated coffee, 1 g chlorogenic acid, 500 mg trigonelline, and placebo (1 g mannitol) on glucose and insulin concentrations during a 2-h oral glucose tolerance test (OGTT) in 15 overweight men. RESULTS Chlorogenic acid and trigonelline ingestion significantly reduced glucose (−0.7 mmol/l, P = 0.007, and −0.5 mmol/l, P = 0.024, respectively) and insulin (−73 pmol/l, P = 0.038, and −117 pmol/l, P = 0.007) concentrations 15 min following an OGTT compared with placebo. None of the treatments affected insulin or glucose area under the curve values during the OGTT compared with placebo. CONCLUSIONS Chlorogenic acid and trigonelline reduced early glucose and insulin responses during an OGTT.

Effects of Betaine Intake on Plasma Homocysteine Concentrations and Consequences for Health

High plasma concentrations of homocysteine may increase risk of cardiovascular disease. Folic acid lowers plasma homocysteine by 25% maximally, because 5-methyltetrahydrofolate is a methyl donor in the remethylation of homocysteine to methionine. Betaine (trimethylglycine) is also a methyl donor in homocysteine remethylation, but effects on homocysteine have been less thoroughly investigated. Betaine in high doses (6 g/d and higher) is used as homocysteine-lowering therapy for people with hyperhomocysteinemia due to inborn errors in the homocysteine metabolism. Betaine intake from foods is estimated at 0.5-2 g/d. Betaine can also be synthesized endogenously from its precursor choline. Studies in healthy volunteers with plasma homocysteine concentrations in the normal range show that betaine supplementation lowers plasma fasting homocysteine dose-dependently to up to 20% for a dose of 6 g/d of betaine. Moreover, betaine acutely reduces the increase in homocysteine after methionine loading by up to 50%, whereas folic acid has no effect. Betaine doses in the range of dietary intake also lower homocysteine. This implies that betaine can be an important food component that attenuates homocysteine rises after meals. If homocysteine plays a causal role in the development of cardiovascular disease, a diet rich in betaine or choline might benefit cardiovascular health through its homocysteine-lowering effects. However betaine and choline may adversely affect serum lipid concentrations, which can of course increase risk of cardiovascular disease. However, whether the potential beneficial health effects of betaine and choline outweigh the possible adverse effects on serum lipids is as yet unclear.

Prospective study on dietary intakes of folate, betaine, and choline and cardiovascular disease risk in women

Objective:To investigate the association between dietary intakes of folate, betaine and choline and the risk of cardiovascular disease (CVD).Design:Prospective cohort study.Subjects:A total of 16 165 women aged 49–70 years without prior CVD. Subjects were breast cancer screening participants in the PROSPECT–EPIC cohort, which is 1 of the 2 Dutch contributions to the European Prospective Investigation into Cancer and Nutrition (EPIC).Methods:Each participant completed a validated food frequency questionnaire. Folate intake was calculated with the Dutch National Food Database. Betaine and choline intakes were calculated with the USDA database containing choline and betaine contents of common US foods. Data on coronary heart disease (CHD) events and cerebrovascular accident (CVA) events morbidity data were obtained from the Dutch Centre for Health Care Information.Results:During a median follow-up period of 97 months, 717 women were diagnosed with CVD. After adjustment, neither folate, nor betaine, nor choline intakes were associated with CVD (hazard ratios for highest versus lowest quartile were 1.23 (95% confidence interval 0.75; 2.01), 0.90 (0.69; 1.17), 1.04 (0.71; 1.53), respectively). In a subsample of the population, high folate and choline intakes were statistically significantly associated with lower homocysteine levels. High betaine intake was associated with slightly lower high-density lipoprotein (HDL)-cholesterol concentrations.Conclusion:Regular dietary intakes of folate, betaine and choline were not associated with CVD risk in post-menopausal Dutch women. However, the effect of doses of betaine and choline beyond regular dietary intake – for example, via supplementation or fortification – remains unknown.

Effect of Homocysteine-Lowering Nutrients on Blood Lipids: Results from Four Randomised, Placebo-Controlled Studies in Healthy Humans

Background Betaine (trimethylglycine) lowers plasma homocysteine, a possible risk factor for cardiovascular disease. However, studies in renal patients and in obese individuals who are on a weight-loss diet suggest that betaine supplementation raises blood cholesterol; data in healthy individuals are lacking. Such an effect on cholesterol would counteract any favourable effect on homocysteine. We therefore investigated the effect of betaine, of its precursor choline in the form of phosphatidylcholine, and of the classical homocysteine-lowering vitamin folic acid on blood lipid concentrations in healthy humans. Methods and Findings We measured blood lipids in four placebo-controlled, randomised intervention studies that examined the effect of betaine (three studies, n = 151), folic acid (two studies, n = 75), and phosphatidylcholine (one study, n = 26) on plasma homocysteine concentrations. We combined blood lipid data from the individual studies and calculated a weighted mean change in blood lipid concentrations relative to placebo. Betaine supplementation (6 g/d) for 6 wk increased blood LDL cholesterol concentrations by 0.36 mmol/l (95% confidence interval: 0.25–0.46), and triacylglycerol concentrations by 0.14 mmol/l (0.04–0.23) relative to placebo. The ratio of total to HDL cholesterol increased by 0.23 (0.14–0.32). Concentrations of HDL cholesterol were not affected. Doses of betaine lower than 6 g/d also raised LDL cholesterol, but these changes were not statistically significant. Further, the effect of betaine on LDL cholesterol was already evident after 2 wk of intervention. Phosphatidylcholine supplementation (providing approximately 2.6 g/d of choline) for 2 wk increased triacylglycerol concentrations by 0.14 mmol/l (0.06–0.21), but did not affect cholesterol concentrations. Folic acid supplementation (0.8 mg/d) had no effect on lipid concentrations. Conclusions Betaine supplementation increased blood LDL cholesterol and triacylglycerol concentrations in healthy humans, which agrees with the limited previous data. The adverse effects on blood lipids may undo the potential benefits for cardiovascular health of betaine supplementation through homocysteine lowering. In our study phosphatidylcholine supplementation slightly increased triacylglycerol concentrations in healthy humans. Previous studies of phosphatidylcholine and blood lipids showed no clear effect. Thus the effect of phosphatidylcholine supplementation on blood lipids remains inconclusive, but is probably not large. Folic acid supplementation does not seem to affect blood lipids and therefore remains the preferred treatment for lowering of blood homocysteine concentrations.

Acute effects of decaffeinated coffee and the major coffee components chlorogenic acid and trigonelline on incretin hormones

Coffee consumption is associated with a lower risk of type 2 diabetes. We tested the hypothesis that this is mediated by incretin hormones by measuring the acute effects of decaffeinated coffee and coffee components on GLP-1 and GIP concentrations. A randomized cross-over trial of the effects of 12 g decaffeinated coffee, 1 g chlorogenic acid, 500 mg trigonelline, and placebo on total and intact GLP-1 and GIP concentrations during an oral glucose tolerance test took place in fifteen overweight men. No treatment significantly affected the overall GLP-1 or GIP secretion pattern following an OGTT relative to placebo. Decaffeinated coffee slightly increased total GLP-1 concentration 30 minutes after ingestion (before the OGTT) relative to placebo (2.7 pmol/L, p = 0.03), but this change did not correspond with changes in glucose or insulin secretion. These findings do not support the hypothesis that coffee acutely improves glucose tolerance through effects on the secretion of incretin hormones. Chronic effects of coffee and its major components still need to be investigated.

Association between global leukocyte DNA methylation, renal function, carotid intima-media thickness and plasma homocysteine in patients with stage 2–4 chronic kidney disease

BACKGROUND Patients with chronic kidney disease (CKD) have an increased risk of cardiovascular disease (CVD). Preliminary evidence suggests a role for global DNA hypomethylation in the pathogenesis of atherosclerotic complications in CKD. The aims of this study in patients with stage 2-4 CKD were (1) to assess the association between renal function and DNA methylation, (2) to assess the association between DNA methylation and two markers of atherosclerosis [common carotid intima-media thickness (CCA-IMT)] and brachial artery endothelium-dependent, flow-mediated dilatation (BA-FMD) and (3) to examine the effect of a multi-step treatment strategy on DNA methylation. METHODS In the Anti-Oxidant Therapy In Chronic Renal Insufficiency study (ATIC-study), 93 patients with stage 2-4 CKD were included. In a randomized, double-blind, placebo-controlled design, the treatment group received pravastatin to which vitamin E was added after 6 months and homocysteine-lowering B-vitamin therapy after another 6 months. DNA methylation was assessed using tandem mass spectrometry. CCA-IMT and BA-FMD were assessed using B-mode ultrasonography. RESULTS At baseline, global DNA methylation was not associated with the estimated glomerular filtration rate (P = 0.32) or with CCA-IMT (P = 0.62) or BA-FMD (P = 0.51). No effect of the treatment strategy including B-vitamin on global DNA methylation was found either in the total study group or within separate strata of homocysteine concentration and renal function. CONCLUSION In patients with stage 2-4 CKD, global DNA methylation is not associated with renal function or with CCA-IMT or BA-FMD. A treatment strategy that includes B-vitamins did not alter global DNA methylation in these patients. These data do not support the role of DNA hypomethylation in CKD-associated vascular disease in patients with stage 2-4 CKD.

The Effect of Sugar-Free Versus Sugar-Sweetened Beverages on Satiety, Liking and Wanting: An 18 Month Randomized Double-Blind Trial in Children

Background Substituting sugar-free for sugar-sweetened beverages reduces weight gain. A possible explanation is that sugar-containing and sugar-free beverages cause the same degree of satiety. However, this has not been tested in long-term trials. Methods We randomized 203 children aged 7-11 years to receive 250 mL per day of an artificially sweetened sugar-free beverage or a similarly looking and tasting sugar-sweetened beverage. We measured satiety on a 5-point scale by questionnaire at 0, 6, 12 and 18 months. We calculated the change in satiety from before intake to 1 minute after intake and 15 minutes after intake. We then calculated the odds ratio that satiety increased by 1 point in the sugar-group versus the sugar-free group. We also investigated how much the children liked and wanted the beverages. Results 146 children or 72% completed the study. We found no statistically significant difference in satiety between the sugar-free and sugar-sweetened group; the adjusted odds ratio for a 1 point increase in satiety in the sugar group versus the sugar-free group was 0.77 at 1 minute (95% confidence interval, 0.46 to 1.29), and 1.44 at 15 minutes after intake (95% CI, 0.86 to 2.40). The sugar-group liked and wanted their beverage slightly more than the sugar-free group, adjusted odds ratio 1.63 (95% CI 1.05 to 2.54) and 1.65 (95% CI 1.07 to 2.55), respectively. Conclusions Sugar-sweetened and sugar-free beverages produced similar satiety. Therefore when children are given sugar-free instead of sugar-containing drinks they might not make up the missing calories from other sources. This may explain our previous observation that children in the sugar-free group accumulated less body fat than those in the sugar group. Trial Registration ClinicalTrials.gov NCT00893529 http://clinicaltrials.gov/show/NCT00893529

Effect of folic acid and betaine supplementation on flow-mediated dilation: a randomized, controlled study in healthy volunteers.

Objectives: We investigated whether lowering of fasting homocysteine concentrations, either with folic acid or with betaine supplementation, differentially affects vascular function, a surrogate marker for risk of cardiovascular disease, in healthy volunteers. As yet, it remains uncertain whether a high concentration of homocysteine itself or whether a low folate status—its main determinant—is involved in the pathogenesis of cardiovascular disease. To shed light on this issue, we performed this study. Design: This was a randomized, placebo-controlled, double-blind, crossover study. Setting: The study was performed at Wageningen University in Wageningen, the Netherlands. Participants: Participants were 39 apparently healthy men and women, aged 50–70 y. Interventions: Participants ingested 0.8 mg/d of folic acid, 6 g/d of betaine, and placebo for 6 wk each, with 6-wk washout in between. Outcome Measures: At the end of each supplementation period, plasma homocysteine concentrations and flow-mediated dilation (FMD) of the brachial artery were measured in duplicate. Results: Folic acid supplementation lowered fasting homocysteine by 20% (−2.0 μmol/l, 95% confidence interval [CI]: −2.3; −1.6), and betaine supplementation lowered fasting plasma homocysteine by 12% (−1.2 μmol/l; −1.6; −0.8) relative to placebo. Mean (± SD) FMD after placebo supplementation was 2.8 (± 1.8) FMD%. Supplementation with betaine or folic acid did not affect FMD relative to placebo; differences relative to placebo were −0.4 FMD% (95%CI, −1.2; 0.4) and −0.1 FMD% (−0.9; 0.7), respectively. Conclusions: Folic acid and betaine supplementation both did not improve vascular function in healthy volunteers, despite evident homocysteine lowering. This is in agreement with other studies in healthy participants, the majority of which also fail to find improved vascular function upon folic acid treatment. However, homocysteine or folate might of course affect cardiovascular disease risk through other mechanisms.

Randomized Placebo-Controlled Trial Assessing a Treatment Strategy Consisting of Pravastatin, Vitamin E, and Homocysteine Lowering on Plasma Asymmetric Dimethylarginine Concentration in Mild to Moderate CKD

BACKGROUND Chronic kidney disease (CKD) is associated with an increased incidence of cardiovascular disease (CVD). The Anti-oxidant Therapy In Chronic Renal Insufficiency (ATIC) Study showed that a multistep treatment strategy improved carotid intima-media thickness, endothelial function, and microalbuminuria in patients with stages 2 to 4 CKD. Increased plasma concentrations of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, have been linked to greater CVD risk in patients with CKD. The aim of this study is to assess effects of the multistep intervention on plasma ADMA concentrations in the ATIC Study. STUDY DESIGN Secondary analysis of a randomized double-blind placebo-controlled trial. SETTING & PARTICIPANTS 93 patients with creatinine clearance of 15 to 70 mL/min/1.73 m(2) (according to the Cockcroft-Gault equation) from 7 outpatient clinics in Amsterdam, The Netherlands. INTERVENTION The treatment group received sequential treatment consisting of pravastatin, 40 mg/d. After 6 months, vitamin E, 300 mg/d, was added, and after another 6 months, homocysteine-lowering therapy (folic acid, 5 mg/d; pyridoxine, 100 mg/d; and vitamin B(12), 1 mg/d, all in 1 tablet) were added and continued for another year. The control group received matching placebos. OUTCOME & MEASURES Plasma ADMA levels. RESULTS 36 participants (77%) in the treatment group and 38 (83%) in the placebo group completed the study. Mean ADMA and symmetric dimethylarginine concentrations in the total study population were 0.53 +/- 0.07 (SD) and 1.14 +/- 0.46 mumol/L, respectively. After 24 months, there was no overall effect of the treatment strategy on ADMA concentrations (beta = -0.006; P = 0.27). Analysis of separate treatment effects suggested that vitamin E significantly decreased ADMA levels by 4% in the treatment group compared with the placebo group (multiple adjusted P = 0.02). LIMITATIONS The study was a secondary analysis, power calculation was based on the primary end point of carotid intima-media thickness, mean plasma ADMA levels were relatively low. CONCLUSION Overall, a multistep treatment strategy consisting of pravastatin, vitamin E, and B vitamins had no effect on plasma ADMA levels in a stage 2 to 4 CKD population. This suggests that the beneficial effects of the intervention were not mediated by changes in ADMA levels. Possible ADMA-lowering effects of vitamin E deserve further attention.