Medical Bulletin 07/October/2025 - Video

A new study published in the journal Neuron reveals that high-fat, junk food diets can disrupt brain function in just a matter of days. The research shows that fatty diets impair memory by rewiring a specific group of brain cells in the hippocampus, the brain's memory hub.

This study provides a rare window into how diet affects brain health at a cellular level, particularly the role of nutrition in memory formation and cognitive function. Researchers focused on CCK interneurons, a group of brain cells in the hippocampus, which were found to become abnormally active after short-term exposure to a high-fat diet. This overactivity, triggered by reduced glucose availability in the brain, interfered with how memory is processed, well before any weight gain or metabolic conditions such as diabetes were evident.

In the study, mice were fed a high-fat diet that mimics typical Western-style junk food, including items rich in saturated fats like cheeseburgers and fries. Just four days into the diet, the researchers observed a marked disruption in the normal function of CCK interneurons.

"We knew that diet and metabolism could affect brain health, but we didn't expect to find such a specific and vulnerable group of brain cells, CCK interneurons in the hippocampus, that were directly disrupted by short-term high-fat diet exposure," said UNC School of Medicine's Juan Song, PhD, principal investigator, professor of pharmacology, who is a member of the UNC Neuroscience Center. "What surprised us most was how quickly these cells changed their activity in response to reduced glucose availability, and how this shift alone was enough to impair memory."

Importantly, the study also demonstrated that restoring glucose levels in the brain could reverse the damage. Interventions such as intermittent fasting or pharmacological treatment helped normalize neuron activity and improve memory in mice. This suggests that even after dietary damage, brain function may be recoverable with timely intervention.

With ongoing research now exploring connections to Alzheimer’s and other neurodegenerative conditions, this study emphasizes the critical role of diet in brain health and the potential of early lifestyle changes to reduce cognitive decline.

Reference: Taylor Landry, Laura Perrault, David Melville, Zhe Chen, Ya-Dong Li, Ping Dong, W. Todd Farmer, Brent Asrican, Hannah Lee, Libo Zhang, Ryan N. Sheehy, Corina Damian, Thomas Collins, Nehemiah Stewart, E.S. Anton, Juan Song. Targeting glucose-inhibited hippocampal CCK interneurons prevents cognitive impairment in diet-induced obesity. Neuron, 2025; DOI: 10.1016/j.neuron.2025.08.016

SMFM Releases New Guidelines for Managing Heart Failure in Pregnancy and Postpartum

The Society for Maternal-Fetal Medicine (SMFM) has issued new clinical guidance in its Consult Series #73, published in the American Journal of Obstetrics & Gynecology, focused on the diagnosis and management of right and left heart failure during pregnancy and postpartum. The guidance emphasizes the importance of prepregnancy counseling, multidisciplinary care teams, and referrals to specialized centers to improve maternal and newborn outcomes.

Heart disease remains a leading cause of pregnancy-related mortality in the United States, with heart failure significantly contributing to maternal deaths and complications. The burden is disproportionately high among non-Hispanic Black individuals. Heart failure, characterized by the heart's inability to effectively pump blood, can also raise the risk of premature birth, low birth weight, low Apgar scores, and maternal death.

The SMFM recommendations focus on managing heart failure with reduced ejection fraction (HFrEF) during pregnancy, a condition in which distinguishing symptoms, like shortness of breath and fatigue, may be mistaken for normal pregnancy changes. The guidance outlines specific management based on whether the heart's left, right, or both ventricles are affected, and whether the condition is acute or chronic.

The guidelines advise discontinuing several medications that may harm fetal development, including ACE inhibitors, ARBs, SGLT2 inhibitors, and ARNi, while encouraging the continuation of beta-blockers like metoprolol and carvedilol. Delivery should generally occur at term with vaginal birth preferred unless there are obstetric indications for cesarean. Postpartum care is also highlighted, noting the risk of cardiovascular deterioration after discharge, with recommendations for close monitoring and medication review for breastfeeding safety.

“Heart disease is a leading cause of maternal deaths, and it’s a growing problem,” said Dr. Arthur Jason Vaught, maternal-fetal medicine specialist at Johns Hopkins Medicine and member of the SMFM Publications Committee. “This new guidance focuses attention on heart failure in pregnancy so that we can improve both short- and long-term quality of life for our patients. Getting accurately diagnosed and treated for heart disease, either before pregnancy or early in pregnancy, is both life-prolonging and life-changing if caught early.”

Reference: Society for Maternal-Fetal Medicine (SMFM), Hameed, A.B., Licon, E., Vaught, A.J., Shree, R. and SMFM Publications Committee (2025), Society for Maternal-Fetal Medicine Consult Series #73: Diagnosis and management of right and left heart failure during pregnancy and postpartum. Pregnancy, 1: e70059. https://doi.org/10.1002/pmf2.70059

Metabolically Active Visceral Fat May be Tied to Advanced Endometrial Cancer

New research presented at the 38th Annual Congress of the European Association of Nuclear Medicine (EANM'25) suggests that the metabolic activity of visceral fat, rather than its volume alone, may be linked to more aggressive forms of endometrial cancer. The study highlights a potential shift in how clinicians may assess cancer risk and progression in obese patients.

While obesity has long been recognized as a key risk factor for endometrial cancer, the new findings suggest that it’s not just the presence of fat but how metabolically active it is that could influence disease severity. Visceral fat, the fat surrounding internal organs, has been shown in prior research to play a significant role in metabolic health and systemic inflammation.

In this study, researchers analyzed PET/CT scans from 274 women diagnosed with endometrial cancer. Using glucose uptake as a marker of metabolic activity, they specifically measured how active visceral fat tissue was in each patient. The results showed that women with higher glucose uptake in their visceral fat were more likely to present with advanced-stage disease and lymph node metastases.

“Higher metabolic activity in visceral fat was significantly associated with more advanced cancer stages and the presence of lymph node metastases,” said lead author Jostein Sæterstøl, PhD candidate and MSc. “Notably, we saw no strong correlation between the volume of visceral fat and its metabolic activity, suggesting that the link to disease aggressiveness is not merely related to the quantity of fat, but also to its biological activity.”

Sæterstøl added that chronic inflammation, insulin resistance, and adipokine signaling from visceral fat may promote tumour growth and metastasis, highlighting complex biological interactions between fat tissue and cancer cells.

Although PET/CT imaging of fat metabolism is not yet practical for routine clinical use, researchers are optimistic that advancements such as AI-based segmentation and quantitative imaging techniques could make it a valuable tool in the future.

Reference: https://eanm25.eanm.org/