The potential of medium-chain triglyceride (MCT) to enhance athletic performance remains controversial. This study aims to explore how long-term MCT supplementation may enhance endurance and predict individual responders compared to carbohydrates (CHO), while also validating the feasibility of applying the N-of-1 trial design in the field of personalized nutrition. It consists of a series of completed 6-week, single-center, randomized, double-blind, controlled N-of-1 trials, involving a total of 9 long-distance running enthusiasts from Wuhan University (Wuhan, China). The study was divided into 3 cycles, each lasting 2 weeks. During each cycle, participants randomly consumed 400 mL of MCT as the intervention or 400 mL of CHO as the control. The 5-kilometer time trial (5KTT) results were used to assess participants’ endurance, and a Bayesian model was employed to assess individual and aggregated results. Results showed substantial variability in the intervention effect between participants, with improvements in the 5KTT on MCT relative to CHO ranging from –37.54 s (95% credible interval (CrI), –164.25 to 100.35) to 69.37 s (95% CrI, –81.14 to 215.45). The trial observed 1 CHO responder, with a posterior probability of 0.50; 2 MCT responders, with posterior probabilities of 0.57 and 0.64; and 5 non-responders, respectively. The aggregate Bayesian analysis indicated that the posterior probability of achieving a clinically meaningful intervention effect for MCT compared to CHO was only 0.37. Based on these findings, MCT did not improve participants’ running performance compared to CHO at the overall level. However, our study supports that using the N-of-1 trial design can provide more precise personalized recommendations for each participant.

Multivitamins were widely used health supplements that replenished essential nutrients in the human body. Despite their popularity, the impact of multivitamins on the cognitive function of older adults remained unclear and contentious. This study offered a comprehensive review and meta-analysis of research published until June 2024, analyzing the effects of multivitamins on various cognitive functions in individuals aged 65 and older. We included ten randomized controlled trials encompassing 13600 participants from multiple databases. These studies evaluated the impact of multivitamins on reasoning, memory, learning, visual perception, idea production, cognitive speed, psychomotor abilities, and higher cognitive functions. Our meta-analysis revealed that multivitamins significantly enhanced delayed free recall (standardized mean difference (SMD) = 0.09, 95% confidence interval (CI) : [0.05, 0.13], P < 0.0001). However, they had no substantial effects on immediate free recall (SMD = 0.85, 95% CI: [−0.18, 1.90], P = 0.11), idea production (SMD = 0.00, 95% CI: [−0.04, 0.03], P = 0.86), or cognitive speed (SMD = 0.34, 95% CI: [−0.07, 0.74], P = 0.11). Thus, while multivitamins facilitated delayed free recall, they did not significantly improve other cognitive functions in older adults.

This study investigated the association of hypertension with cognitive impairment and determined whether better adherence to plant-based diet (PBD) patterns may modify the association. We analyzed 4485 elderly individuals with normal cognition at baseline from the Chinese Longitudinal Healthy Longevity Survey (2011−2018). Cognitive function was assessed by the Mini-mental State Examination (MMSE), and cognitive impairment was defined as an MMSE score below 18 points. Diet patterns were assessed using the overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI) derived from a simplified food frequency questionnaire (FFQ). Blood pressure was measured through physical examination. Cox proportional hazard regression and restricted cubic spline were performed. Participants with hypertension had an increased risk of cognitive impairment compared with normal group. The associations between hypertension and cognitive impairment were more pronounced among participants with lower PDI than those with higher PDI, among participants with lower hPDI than those with higher hPDI, and among participants with higher uPDI than those with lower uPDI. A healthful PBD pattern may attenuate hypertension-induced cognitive impairment, while an unhealthful PBD pattern may exacerbate hypertensioninduced cognitive impairment in elderly. Adherence to healthful PBD pattern could be used to prevent or mitigate adverse neurological effects in the hypertensive population.