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

Insight in modulation of inflammation in response to diclofenac intervention: a human intervention study

Background. Chronic systemic low-grade inflammation in obese subjects is associated with health complications including cardiovascular diseases, insulin resistance and diabetes. Reducing inflammatory responses may reduce these risks. However, available markers of inflammatory status inadequately describe the complexity of metabolic responses to mild anti-inflammatory therapy. Methods. To address this limitation, we used an integrative omics approach to characterize modulation of inflammation in overweight men during an intervention with the non-steroidal anti-inflammatory drug diclofenac. Measured parameters included 80 plasma proteins, >300 plasma metabolites (lipids, free fatty acids, oxylipids and polar compounds) and an array of peripheral blood mononuclear cells (PBMC) gene expression products. These measures were submitted to multivariate and correlation analysis and were used for construction of biological response networks. Results. A panel of genes, proteins and metabolites, including PGE2 and TNF-alpha, were identified that describe a diclofenac-response network (68 genes in PBMC, 1 plasma protein and 4 plasma metabolites). Novel candidate markers of inflammatory modulation included PBMC expression of annexin A1 and caspase 8, and the arachidonic acid metabolite 5,6-DHET. Conclusion. In this study the integrated analysis of a wide range of parameters allowed the development of a network of markers responding to inflammatory modulation, thereby providing insight into the complex process of inflammation and ways to assess changes in inflammatory status associated with obesity. Trial registration. The study is registered as NCT00221052 in clinicaltrials.gov database. © 2010 van Erk et al; licensee BioMed Central Ltd

A high-protein diet increases postprandial but not fasting plasma total homocysteine concentrations: A dietary controlled, crossover trial in healthy volunteers

Background: A high plasma concentration of total homocysteine (tHcy) is associated with increased risk of cardiovascular disease. A high protein intake and hence a high intake of methionine-the sole dietary precursor of homocysteine-may raise plasma tHcy concentrations. Objectives: We studied whether high intake of protein increases plasma concentrations of tHcy in the fasting state and throughout the day. Design: We conducted a randomized, dietary controlled, crossover trial in 20 healthy men aged 18-44 y. For 8 d, men consumed a controlled low-protein diet enriched with either a protein supplement [high-protein diet (21% of energy as protein)] or an isocaloric amount of short-chain glucose polymers [low-protein diet (9% of energy as protein)]. After a 13-d washout period, treatments were reversed. On days 1 and 8 of each treatment period, blood was sampled before breakfast (fasting) and throughout the day. Results: Fasting tHcy concentrations did not differ significantly after the 1-wk high-protein and the 1-wk low-protein diets. The high-protein diet resulted in a significantly higher area under the 24-h homocysteine-by-time curves compared with the low-protein diet, both on day 1 (difference: 45.1 h · μmol/L; 95% CI: 35.3, 54.8 h · μmol/L; P < 0.0001) and on day 8 (difference: 24.7 h · μmol/L; 95% CI: 15.0, 34.5 h · μmol/L; P < 0.0001). Conclusions: A high-protein diet increases tHcy concentrations throughout the day but does not increase fasting tHcy concentrations. As previously shown, the extent of the tHcy increase is modified by the amino acid composition of the protein diet. The clinical relevance of this finding depends on whether high concentrations of tHcy-particularly postprandially-cause cardiovascular disease

Attitudes and values among the Swedish general public to using human embryonic stem cells for medical treatment

Background: The use of human embryonic stem cells (ES cells) for the development of medical therapies is surrounded with moral concerns. The aim of this study was to assess the public's attitudes toward the use of ES cells for treatment of Parkinson's disease (PD) and other diseases, what factors are most important to consider when using ES cells for drug development, and if there is an association between religious beliefs and attitudes toward using ES cells for medical treatment. Methods: A randomly selected sample of the Swedish public, aged 18-87-years-old, completed an online survey (n = 467). The survey assessed socio-demographics, religious views, perceived moral status of the embryo, and attitudes toward using ES cells for medical treatment of PD and other diseases. Adjusted odds ratios (ORs) and 95% confidence intervals (CI) for positive vs. negative attitude toward using ES cells for drug development were computed using logistic regression. Results: The respondents were positive about using ES for treatment; specifically, 70% totally agreed that it is acceptable to use ES cells for treatment of PD, while 40% totally agreed that it is acceptable to use ES cells for treatment but induced pluripotent cells is just as efficient. Religion being of little importance in one's life was associated with a positive attitude toward using ES cells for treatment of PD (adjusted OR 6.39, 95% CI 2.78-14.71). The importance of being able "to access new, effective treatments against diseases that do not have any treatment available " was ranked as the most important factor to consider when using ES cells for drug development. Conclusion: Most respondents are positive about using ES cells for drug development, and making effective treatments accessible to those who do not have any. However, these attitudes are influenced by the specific disorder that the drug development is intended for, as well as the religious views and perceived moral status of the early embryo

Patients' views on using human embryonic stem cells to treat Parkinson's disease : an interview study

Background: Human embryonic stem cells (hESC) as a source for the development of advanced therapy medicinal products are considered for treatment of Parkinson's disease (PD). Research has shown promising results and opened an avenue of great importance for patients who currently lack a disease modifying therapy. The use of hESC has given rise to moral concerns and been the focus of often heated debates on the moral status of human embryos. Approval for marketing is still pending. Objective: To Investigate the perspectives and concerns of patients with PD, patients being the directly concerned stakeholders in the ethical discussion. Methods: Qualitative semi-structured interviews related to this new therapy in seventeen patients from two Swedish cities. Results: The participants expressed various interests related to the use of human embryos for development of medicinal therapies; however, overall, they were positive towards the use of hESC for treatment of PD. It was deemed important that the donating woman or couple made the choice to donate embryos voluntarily. Furthermore, there were concerns that the industry does not always prioritise the patient over profit; thus, transparency was seen as important

Flow Diagram of Participant Progress through Study 2

<p>Flow Diagram of Participant Progress through Study 2</p

Flow Diagram of Participant Progress through Study 3

<p>Flow Diagram of Participant Progress through Study 3</p

Flow Diagram of Participant Progress through Study 4

<p>Flow Diagram of Participant Progress through Study 4</p