Cortical thickness, neurocognitive, and body composition effects of fasting during Ramadan

Abstract

Background: We aimed to study the anatomical, physiological, and cognitive function of healthy individuals practicing fasting during the month of Ramadan. Measurements were taken 1 week before and 2 weeks after Ramadan fasting. Materials and Methods: Twelve healthy male individuals (mean age ± standard error of the mean: 34.3 ± 2.9 years; body mass index: 26.26 ± 1.4 kg/m 2 ) were assessed for various parameters before and after Ramadan fasting. All the tests were performed in the morning. Body composition characteristics were assessed by bioelectrical impedance analysis using a commercially available body composition analyzer. For neurocognitive analysis, participants underwent the stop signal task (SST), pattern recognition memory task (PRM), and spatial working memory strategy (SWM) from the Cambridge Neuropsychological Test Automated Battery. T1-weighted, 1 mm-thick magnetic resonance images were also acquired. Results: Anthropometric analysis showed a significant decrease in body weight, fat-free mass (FFM), trunk FFM, and trunk predicted muscle mass, while the other body composition parameters did not exhibit any changes. The stop signal reaction time (SSRT) latency (ms) ( P > 0.05) and PRM did not show any significant difference before and after fasting. SWM task ( P < 0.05) improved significantly after fasting. Cortical thickness data of the whole brain were not significantly different after fasting at any brain location. There was a significant correlation between the left amygdala and the SWM strategy ( r 2 = 0.518) and between fat and brain segmentation volume ( r 2 = 0.375). Conclusion: Our pilot data suggest that Ramadan fasting leads to weight loss and FFM reductions and improve cognitive function.

The Implication of Physiological Ketosis on The Cognitive Brain: A Narrative Review

“…However, the cognitive tests were performed two days after fasting [ 74 ]. Iqbal et al tested cognition after two weeks of Ramadan fasting (one month) in males and found similar cognitive outcomes but significant improvements in spatial working memory [ 75 ]. For females, fasting for one month did not impact cognition even after two weeks of fasting [ 76 ].…”

“…In contrast, ketone bodies are under-reported in fasting studies, and it is hard to predict their role on cognition during fasting. IF ketosis requires long-term metabolic adaptations to appear [ 72 ]; most of the fasting studies performed on healthy and young individuals have not exceeded one month of fasting, and they mostly resemble Ramadan fasting [ 73 , 74 , 75 , 76 , 79 ]. Others tested fasting in a single-day setting [ 73 , 78 , 81 ], which could have been met with psychological difficulties that require adaptation and impact the study outcomes [ 83 ].…”

“…In a review by de Cabo and Mattson [ 84 ], which emphasized the favorable effect of IF on cognition, most of the included studies represented calorie-restricted protocols rather than IF, perhaps making the studies less comparable. The literature is heavily based on religious-fasting protocols [ 72 , 73 , 74 , 75 , 76 , 78 , 80 ]; thus, future researchers should be wary that religious fasting is not identical to the trending time-restricted fasting. Muslims are bound to abstain from any foods or drinks from dawn to sunset during the month of Ramadan, which varies between countries and is coupled with changes in sleep and circadian rhythms [ 80 , 85 ].…”