Dementia stands as a formidable challenge globally, with no definitive treatment available. In the quest to combat cognitive decline, researchers have turned their attention to modifiable dietary and behavioral factors. Thiamine, a vital water-soluble B vitamin, has emerged as a potential ally in cognitive preservation, with studies demonstrating its cognitive-enhancing effects in specific populations. However, the relationship between dietary thiamine consumption and cognitive function among older adults remains unclear, prompting further investigation.
A recent study published in the Journal of Nutrition aimed to fill this gap by examining the association between thiamine intake and cognitive decline in a cohort of cognitively healthy older Chinese individuals. Led by a team of researchers, the study analyzed data from the China Health and Nutrition Survey (CHNS), encompassing 3,106 participants aged 55 years and above.
Over a span of five years, participants underwent repeated cognitive evaluations using a modified version of the Telephone Interview for Cognitive Status (TICS) tests. Dietary intake data were obtained through three-day diet recalls, with condiment and cooking oil consumption assessed using a food-weighed approach.
The study revealed several key findings:
J-Shape Association: A J-shaped relationship was observed between thiamine consumption and five-year composite and global cognition scores, with an inflection point of 0.7 mg/day. Individuals consuming 0.6 to 1.0 mg of thiamine daily exhibited the lowest risk of cognitive decline.
Effect on Cognitive Decline: Thiamine consumption above the inflection point was associated with a significant reduction in global and composite cognition scores over five years. Each unit increase in thiamine consumption (mg/day) correlated with declines of 4.2 points in global cognition and 0.5 units in composite cognition scores.
Impact of Covariates: Thiamine intake was influenced by various factors, including age, gender, alcohol consumption, occupation, education level, and dietary factors such as carbohydrate, fiber, fat, protein, potassium, and sodium intake.
Sensitivity Analyses: Sensitivity analyses confirmed the robustness of the findings, with the slowest cognitive decline observed among individuals consuming 0.7 to <1.0 mg/day of thiamine.
The study concluded that while thiamine consumption below 0.7 mg/day showed no significant association with cognitive decline, intake above this threshold was linked to increased cognitive deterioration, particularly among individuals with obesity, hypertension, and nonsmoking habits. Notably, the correlation was weaker among smokers, suggesting a potential mitigating effect of nicotine on the adverse consequences of excessive thiamine consumption.
These findings underscore the importance of maintaining optimal thiamine intake within the range of 0.6–1.0 mg/day for older adults to minimize the risk of cognitive decline. Further research is warranted to elucidate the underlying mechanisms and implications of thiamine consumption on cognitive function, with potential implications for dementia prevention and management strategies.