Taurine Supplements Help Reduce Risk Factors for Metabolic Syndrome

In a recent study published in Nutrition & Diabetes, researchers conducted a meta-analysis of randomized clinical trials (RCTs) to evaluate the effects of taurine supplementation on parameters associated with metabolic syndrome (MetS).

Metabolic syndrome is an international health problem defined by abdominal obesity, hypertension, hyperglycemia, hypertriglyceridemia and low high-density lipoprotein (HDL) values. This condition increases the risk of cardiovascular disease, type 2 diabetesand stroke. Research points to taurine as a possible treatment for MetS due to its involvement in mitochondrial function, osmoregulation, cell membrane integrity, antioxidant defense, and regulation of cation balance. However, conflicting results make it difficult to assess whether taurine reduces the risk of MetS.

About the study

In this meta-analysis, the researchers conducted meta-regressions to evaluate the effect of taurine on MetS parameters, indicating its effectiveness in reducing risk factors in the general population.

The researchers searched PubMed, Embase, Cochrane CENTRAL, ClinicalTrials.gov and Web of Science databases for records published before December 1, 2023. The study focused on known diagnostic criteria for metabolic syndrome such as diastolic blood pressure (DBP), systolic blood pressure (SBP), fasting blood glucose (FBG), HDL and triglycerides.

The researchers used meta-regressions to examine dose-dependent associations based on total taurine dose over the course of treatment. Secondary outcomes included body composition parameters [weight and body mass index (BMI)], glycemic control [glycated hemoglobin (HbA1c), fasting insulin and homeostasis model assessment (HOMA)], lipid profile [total cholesterol (TC) and low-density lipoprotein ( LDL)] and side effects.

The researchers compared taurine supplementation with other treatments and assessed parameters associated with the diagnosis of MetS in people, providing data before and after the intervention. They excluded random clinical trials, short follow-up periods, herbal remedies with unknown active ingredients, studies without data on intermediate and endpoints before and after the intervention, studies that did not examine the outcomes of interest, and those that tested the immediate effects of energy drinks.

Two researchers first assessed the titles and abstracts of identified records to determine eligibility, then conducted a full text review. They manually searched other databases and reviewed reference lists for relevant meta-analyses. They used the Cochrane Risk of Bias (RoB 2) tool for RCTs to assess the methodological quality of included studies and examined adherence to the intervention using per-protocol methodology.

For continuous outcomes, researchers estimated weighted mean differences (WMDs), and for categorical outcomes they used odds ratios (ORs). The study used the I2 statistic to assess between-study heterogeneity, conducted a sensitivity analysis when removing one study to determine whether deleting a study significantly changed the effect size, and visually examined the distribution of effect sizes in the funnel plot to assess publication bias.

Results and discussion

The researchers initially identified 2,517 records, excluding 2,476 after title and abstract screening and 13 records after full-text screening. After applying eligibility criteria, they analyzed 1,024 people included in 25 studies. Among the records, 18 were at risk of bias due to missing allocation concealment information, seven were at low risk, and none were at high risk. Funnel plot examination for all outcomes revealed no evidence of publication bias, and the distribution of effect sizes was symmetrical, as confirmed by Egger's regression test.

Taurine doses in studies ranged from 0.5 grams to 6.0 grams per day, with follow-up periods ranging from 5 to 365 days. Taurine supplementation significantly reduced SBP (WMD, −4.0 mmHg), diastolic blood pressure (WMD 1.5 mmHg), fasting blood glucose (WMD 5.9 mg/dL), triglycerides (WMD 18.3 mg/dL) but not HDL (WMD 0.6 mg/dL) compared with control groups. Meta-regressions showed dose-dependent reductions in diastolic blood pressure (rate -0.01 mmHg per gram) and fasting blood glucose (rate -0.05 mg/dL per gram). No significant adverse effects were observed compared to the control. A meta-analysis of the incidence of treatment-related side effects found no significant difference between the taurine and control groups (OR 1.5).

Taurine significantly reduced serum and diastolic blood pressure compared to control groups, which is associated with increased nitric oxide availability and hydrogen sulfide generation, which promote dilation of blood flow. Taurine also reduces fasting blood glucose, potentially improving glycemic control through mechanisms such as reducing hepatic glucose synthesis, suppressing glucagon activity, increasing levels of thermogenesis-enhancing protein-1, improving insulin clearance, and supporting pancreatic beta cell health. It may also increase adiponectin mRNA expression, which improves insulin sensitivity and overall metabolic health. Taurine also lowers total cholesterol by promoting bile acid synthesis and enhancing the activation of LDL receptors.

The study found that taurine supplementation could significantly reduce metabolic syndrome (MetS) risk factors such as high blood pressure, high blood glucose and high total cholesterol. These findings indicate that taurine supplementation may be used as an adjunctive treatment for MetS, providing a multidimensional approach to glycemic control and cardiovascular health. Future clinical trials should focus on finding the appropriate dose of taurine and duration of therapy, especially in MetS-prone groups. Further research may help fill knowledge gaps and support clinical recommendations for the use of taurine as a nutraceutical for the prevention and treatment of MetS.