Medical Bulletin 2/June/2025

Here are the top medical news for the day:

How Your Evening Coffee Could Be Affecting Your Brain During Sleep?

A new study published in Communications Biology by researchers from Université de Montréal reveals that caffeine disrupts the brain's ability to recover during sleep by increasing neural complexity and reducing restorative brain rhythms—effects that are especially pronounced in young adults. The findings suggest that caffeine, though beneficial for alertness during the day, may impair nighttime recovery and memory consolidation, prompting researchers to call for more personalized guidelines on caffeine intake based on age and health.

Caffeine is found not only in coffee but also in tea, chocolate, soft drinks, and energy drinks, making it the most widely consumed psychoactive substance globally. While its daytime stimulating effects are well documented, its nighttime impact on the sleeping brain has remained largely underexplored.

To address this, the research studied 40 healthy adults using electroencephalography (EEG) and artificial intelligence. Each participant underwent sleep monitoring on two occasions: once after taking caffeine capsules three and one hour before bed, and once after taking a placebo.

The analysis revealed that “caffeine increased the complexity of brain signals, reflecting more dynamic and less predictable neuronal activity, especially during the non-rapid eye movement (NREM) phase of sleep that’s crucial for memory consolidation and cognitive recovery,” said Philipp Thölke, a research trainee at UdeM's Cognitive and Computational Neuroscience Laboratory. Caffeine also disrupted slow brain waves such as theta and alpha—essential for deep sleep—while increasing beta wave activity, typically linked with wakefulness.

Lab's director Karim Jerbi, a psychology professor and researcher at Mila -- Quebec AI Institute said, “These changes suggest that even during sleep, the brain remains in a more activated, less restorative state under the influence of caffeine.”

Young adults aged 20 to 27 were more affected than older participants. The researchers urge further study to guide age-specific caffeine recommendations and understand its broader effects on cognitive health.

Reference: Philipp Thölke, Maxine Arcand-Lavigne, Tarek Lajnef, Sonia Frenette, Julie Carrier, Karim Jerbi. Caffeine induces age-dependent increases in brain complexity and criticality during sleep. Communications Biology, 2025; 8 (1) DOI: 10.1038/s42003-025-08090-z

Mediterranean Diet Shows Potential for Easing Irritable Bowel Syndrome: Study

A pilot study published by Michigan Medicine researchers in the Neurogastroenterology and motility suggests that the Mediterranean diet may help alleviate symptoms of irritable bowel syndrome (IBS). While the low FODMAP diet continues to be more effective in symptom reduction, the Mediterranean diet, with its less restrictive approach, shows promising potential as an alternative. Researchers concluded that the findings warrant larger, long-term studies to explore its full effectiveness.

Irritable bowel syndrome affects between 4% and 11% of people worldwide, with many preferring dietary changes over medication for managing symptoms. The low FODMAP diet is a widely recommended intervention but is often criticized for being restrictive, time-consuming, and difficult to sustain. It also raises concerns over nutrient deficiencies and the potential for disordered eating.

To investigate a more sustainable option, researchers randomized irritable bowel syndrome patients into two groups: one following a Mediterranean diet and the other following the initial, restrictive phase of the low FODMAP diet. All participants had been diagnosed with either irritable bowel syndrome -D (diarrhea-predominant) or irritable bowel syndrome -M. Over the course of four weeks, the study measured outcomes based on an FDA-standard benchmark: a 30% reduction in abdominal pain intensity.

The results showed that 73% of participants on the Mediterranean diet met the primary endpoint, compared to 81.8% in the low FODMAP group. "Restrictive diets, such as low FODMAP, can be difficult for patients to adopt," said Prashant Singh, MBBS, lead author and Michigan Medicine gastroenterologist.

The researchers emphasized the need for future trials comparing the long-term effectiveness of both diets, especially as patients transition through more personalized dietary phases.

Reference: Prashant Singh, Gregory Dean, Sofia Iram, Westley Peng, Samuel W. Chey, Samara Rifkin, Christine Lothen‐Kline, Jane Muir, Allen A. Lee, Shanti Eswaran, William D. Chey. Efficacy of Mediterranean Diet vs. Low‐FODMAP Diet in Patients With Nonconstipated Irritable Bowel Syndrome: A Pilot Randomized Controlled Trial. Neurogastroenterology & Motility, 2025; DOI: 10.1111/nmo.70060

Intensive Blood Pressure Control Reduces Dementia Risk: Study Finds

A major study published in Nature Medicine has shown that intensive blood pressure control significantly lowers the risk of dementia and cognitive decline among hypertensive patients in rural, resource-limited communities. Conducted as part of the China Rural Hypertension Control Project Phase-3, the 48-month randomized effectiveness trial found that targeted blood pressure management reduced the risk of all-cause dementia by 15% and cognitive impairment without dementia by 16%. These findings support the broader adoption of intensive hypertension interventions as a strategy to address the global burden of dementia.

While blood pressure control is a known preventive measure for cardiovascular disease, definitive evidence linking it to dementia prevention has been limited.

To address this gap, researchers studied 33,995 individuals across 326 villages in rural China. Participants were randomly assigned to an intervention group or a usual care group. Those in the intervention group received care through a non-physician community healthcare provider-led strategy aimed at achieving systolic blood pressure below 130 mm Hg and diastolic blood pressure under 80 mm Hg.

The results were significant: the intervention group saw a 22.0 mm Hg reduction in systolic blood pressure and a 9.3 mm Hg drop in diastolic blood pressure compared to the usual care group. “These findings provide additional motivation for patients with hypertension to reduce their blood pressure—not only to prevent cardiovascular disease, but also to lower their risk of dementia,” said Yingxian Sun, professor at the First Hospital of China Medical University and lead author of the study.

The research team emphasized tMedical Bulletin 31/May/2025he need for further studies and the future integration of big data and artificial intelligence to enhance early prediction and individualized dementia prevention strategies.