Supplemental thiamine as a practical, potential way to prevent Alzheimer's disease from commencing

Thiamin (Vitamin B1) - A scoping review for Nordic Nutrition Recommendations 2023

Only a few studies have explored relationships between thiamine intake and function, and a few studies have examined the effects of supplements on various clinical or biochemical outcomes. None of these studies, however, makes a useful contribution to understanding requirements in healthy populations. The requirement of thiamine relates to energy and carbohydrate intake. Clinical signs of deficiency have been observed at intakes below 0.5 mg/day, which corresponds to 0.05 mg/MJ. In other studies, thiamine excretion in the urine and normalisation of enzyme activity were normalised at intakes of 0.07-0.08 mg/MJ. The lower limit of intake thus estimates at 0.05 mg/MJ. It has not been possible to set a safe upper intake level for thiamine due to a lack of data. Studies on pregnant and lactating women indicate a higher requirement as assessed by biochemical parameters. A few studies indicate that thiamine utilisation is impaired among elderly subjects.

Association Between Blood Biochemical Factors Contributing to Cognitive Decline and B Vitamins in Patients With Alzheimer's Disease

Background

Malnutrition, metabolism stress, inflammation, peripheral organs dysfunction, and B vitamins deficiency significantly contribute to the progression and mortality of Alzheimer's disease (AD). However, it is unclear which blood biochemical indicators are most closely related to cognitive decline and B vitamins deficiency (thiamine, folate, vitamin B12) in patients with AD.

Methods

This was a cross-sectional study of 206 AD patients recruited from six hospitals in China. Thiamine diphosphate (TDP), the bioactive form of thiamine, was measured by high-performance liquid chromatography fluoroscopy (HPLC) at a single center. Levels of biochemical indicators (except TDP) were measured by regular and standard laboratory tests in each hospital. Pearson's rank correlation analysis was used to assess relationships between B vitamins and biochemical indicators. T-test was used to compare the difference between ApoE ε4 and non-ApoE ε4 groups. Differences were considered statistically significant as P < 0.05.

Results

Among the biochemical results, in AD population, malnutrition indicators (erythrocyte, hemoglobin, serum albumin, and total protein) were most significantly associated with cognitive function, as was free triiodothyronine (FT3) levels which had been observed in previous study. Malnutrition and FT3 levels depend on age but not apolipoprotein E (ApoE) genotype. Meanwhile, Among the B vitamins, TDP was the most significantly associated with malnutrition indicators and FT3.

Conclusion

Our results indicated that TDP reduction could be a modifiable risk factor for malnutrition and FT3 that contributed to cognitive decline in AD patients. Correcting thiamine metabolism could serve as an optional therapy target for AD treatment.