High thiamine diphosphate level as a protective factor for Alzheimer's disease

Dietary Vitamin B Complex: Orchestration in Human Nutrition throughout Life with Sex Differences

The importance of B complex vitamins starts early in the human life cycle and continues across its different stages. At the same time, numerous reports have emphasized the critical role of adequate B complex intake. Most studies examined such issues concerning a specific vitamin B or life stage, with the majority reporting the effect of either excess or deficiency. Deep insight into the orchestration of the eight different B vitamins requirements is reviewed across the human life cycle, beginning from fertility and pregnancy and reaching adulthood and senility, emphasizing interactions among them and underlying action mechanisms. The effect of sex is also reviewed for each vitamin at each life stage to highlight the different daily requirements and/or outcomes. Thiamine, riboflavin, niacin, pyridoxine, and folic acid are crucial for maternal and fetal health. During infancy and childhood, B vitamins are integrated with physical and psychological development that have a pivotal impact on one’s overall health in adolescence and adulthood. A higher intake of B vitamins in the elderly is also associated with preventing some aging problems, especially those related to inflammation. All supplementation should be carefully monitored to avoid toxicity and hypervitaminosis. More research should be invested in studying each vitamin individually concerning nutritional disparities in each life stage, with extensive attention paid to cultural differences and lifestyles.

Thiamine Demonstrates Bio-Preservative and Anti-Microbial Effects in Minced Beef Meat Storage and Lipopolysaccharide (LPS)-Stimulated RAW 264.7 Macrophages

This study assessed the anti-inflammatory effect of thiamine (TA) in lipopolysaccharide-stimulated RAW264.7 cells and also assessed the preservative properties of TA in minced beef. TA demonstrated a concentration-dependent antimicrobial effect on microbial contaminants. Inhibition zones and MIC from the effect of TA on the tested bacterial strains were respectively within the ranges 15−20 mm and 62.5−700 µg/mL. TA significantly (p < 0.05) decreased all the pro-inflammatory factors [(nitric oxide (NO), prostaglandin E2 (PGE2), TNF-α, IL-6, IL-1β, and nuclear factor-κB (NF-κB)] monitored relative to LPS-stimulated RAW264.7 cells. TA inhibited the expression of both iNOS and COX-2. In minced beef flesh, the growth of Listeria monocytogenes was inhibited by TA. TA improved physicochemical and microbiological parameters of stored minced beef meat compared to control. Principal component analyses and heat maps elucidate the quality of the tested meats.

Blood-Based Biomarkers for Alzheimer's Disease Diagnosis and Progression: An Overview

Alzheimer's Disease (AD) is a progressive neurodegenerative disease characterized by amyloid-β (Aβ) plaque deposition and neurofibrillary tangle accumulation in the brain. Although several studies have been conducted to unravel the complex and interconnected pathophysiology of AD, clinical trial failure rates have been high, and no disease-modifying therapies are presently available. Fluid biomarker discovery for AD is a rapidly expanding field of research aimed at anticipating disease diagnosis and following disease progression over time. Currently, Aβ1-42, phosphorylated tau, and total tau levels in the cerebrospinal fluid are the best-studied fluid biomarkers for AD, but the need for novel, cheap, less-invasive, easily detectable, and more-accessible markers has recently led to the search for new blood-based molecules. However, despite considerable research activity, a comprehensive and up-to-date overview of the main blood-based biomarker candidates is still lacking. In this narrative review, we discuss the role of proteins, lipids, metabolites, oxidative-stress-related molecules, and cytokines as possible disease biomarkers. Furthermore, we highlight the potential of the emerging miRNAs and long non-coding RNAs (lncRNAs) as diagnostic tools, and we briefly present the role of vitamins and gut-microbiome-related molecules as novel candidates for AD detection and monitoring, thus offering new insights into the diagnosis and progression of this devastating disease.

Serum Uric Acid and the Risk of Dementia: A Systematic Review and Meta-Analysis

Background: This meta-analysis aimed to evaluate the relationship between serum uric acid (UA) and the risk of dementia and its subtypes.

Methods: Embase, PubMed, and Web of Science were searched from inception to July 2020. Random-effect models were employed to analyze the standard mean difference (SMD) with the corresponding 95% confidence intervals (CI).

Results: Twenty-three eligible studies involving 5,575 participants were identified. The overall results showed lower levels of UA in dementia relative to non-dementia controls [SMD = −0.32 (−0.64; −0.01) p = 0.04]. The subgroup analysis of the type of dementia demonstrated a significant association of UA with Alzheimer's disease (AD) [SMD = −0.58 (−1.02; −0.15) p = 0.009] and Parkinson's disease with dementia (PDD) [SMD = −0.33 (−0.52; −0.14) p = 0.001] but not with vascular dementia (VaD). The stratification analysis of the concentrations of UA revealed that the UA quartile 1–2 was negatively correlated with dementia and neurodegenerative subtypes (p < 0.05), whereas a positive correlation of UA quartile 4 with dementia was noted (p = 0.028). Additionally, the meta-regression analysis on confounders showed that not age, body mass index, diabetes mellitus, hypertension, or smoking but education (p = 0.003) exerted an influence of the UA in the risk estimate of dementia.

Conclusions: Low concentrations of UA (< 292 μmol/L or 4.91 mg/dL) is a potential risk factor for AD and PDD but not for VaD. The mechanism of different concentrations of the UA in dementia needs to be confirmed through further investigation.

Causal association of circulating cholesterol levels with dementia: a mendelian randomization meta-analysis

Prospective studies have shown that abnormally circulating cholesterol is associated with the risk of dementia. However, whether the association is causal or not remains unclear. We attempt to infer the causal association in a MR meta-analysis by using ApoE gene polymorphisms as instrument variables. Studies with dementia risk (27 studies) or circulating lipid levels (7 studies) were included, with totally 3136 dementia patients and 3103 healthy controls. The analyses showed that carriers of ε2 allele significantly were of decreased risk of AD (OR = 0.70; 95% CI: 0.58-0.84; P < 0.01), whereas carriers of ε4 allele were of increased risk of AD (OR = 3.62; 95% CI: 3.03-4.32; P < 0.05), compared to these of ε3 allele. Circulating TC was significantly reduced in carriers of ε2 allele (WMD = - 0.29 mmol/L; 95% CI: -0.54 to -0.03; P < 0.05) and increased in carriers of ε4 allele (WMD = 0.42 mmol/l; 95% CI: 0.001-0.84; P < 0.05). In addition, carriers of ε4 allele had reduction in circulating HDL-C (WMD = - 0.04 mmol/L; 95% CI: - 0.07 to -0.001; P < 0.05). In comparing allele ε2 with ε3, the predicted OR of having AD for 1 mg/dL increment in circulating TC was 0.97 (95% CI: 0.86-0.98; P < 0.05). Comparing allele ε4 with ε3, the predicted OR for a 1 mg/dL increment in TC was 1.08 (95% CI: 1.05-17.58; P < 0.05), and reduction in HDL-C was 2.30 (95% CI: 1.51-43.99; P < 0.05). Our findings demonstrate that high circulating TC and reduced HDL-C levels might be potential risk factors of the development of AD.

The Effects of Thiamine Tetrahydrofurfuryl Disulfide on Physiological Adaption and Exercise Performance Improvement

Thiamine, named as vitamin B1, is an important cofactor for the critical enzymes regarding to glucose metabolism, like transketolase, pyruvate dehydrogenase, and alpha-ketoglutarate dehydrogenase. The thiamine tetrahydrofurfuryl disulfide (TTFD) is a derivative of thiamine with higher bioavailability and solubility than thiamine and has been widely applied to health maintenance and disease therapy. Higher physical activities are associated with higher thiamine supplements for efficient energy metabolism. Furthermore, the effective dose of TTFD, beneficial to exercise physiological adaption and performance, still be further validated and the safety evaluation were also an important issue to be considered for potential application. ICR (Institute of Cancer Research) strain mice were allocated as 0, 50, 100, and 500 mg/kg dose groups and administrated by oral gavage consecutively for 6 weeks. Physical activities including grip strength and aerobic endurance were measured. Various fatigue-associated biochemical variables such as lactate, glucose, blood urine nitrogen (BUN) or creatine kinase (CK), were also assessed. The levels of liver and muscle glycogen were measured as an indicator of energy storage at the end of the experiment. Toxicity assessments for long-term supplementation were also further evaluated for safety consideration. TTFD supplementation significantly increased the endurance and grip strength and demonstrated beneficial effects on lactate production and clearance rate after an acute exercise challenge. The TTFD supplementation significantly mitigated the BUN and CK indexes after extended exercise and elevated the glycogen content in the liver and muscle tissues. According to body composition, biochemical and histopathological data, daily administration of TTFD for over 6 weeks (subacute toxicity) also demonstrated reasonable safety results for long-term and adequate supplementation. The toxicity of TTFD were also considered as safety for long-term supplementation with indicated doses. Furthermore, the TTDF could be applied to not only the health promotion but also improvement of exercise physiological adaption and the TTFD could be further considered as potential ergogenic aids combined with different nutrient strategy.