Medical Bulletin 30/August/2025 - Video

A recent international study published in eBioMedicine has found that WHO-endorsed spatial repellent sheets can reduce mosquito bites by over 50%, offering a powerful new tool in the fight against mosquito-borne diseases such as malaria and dengue. The study analyzed data on 1.7 million mosquitoes collected over 25 years to evaluate the effectiveness of these repellents.

These spatial repellents, also called spatial emanators, are lightweight, paper-like sheets that release pyrethroid-based vapours to deter mosquitoes without requiring direct skin application, heat, or electricity. Roughly the size of a sheet of paper, they protect up to a year against mosquitoes that carry diseases including malaria, dengue, Zika, yellow fever, and West Nile virus.

The study’s findings showed that spatial repellents reduced mosquito bites by more than half on average, with some trials achieving up to 75% effectiveness against Anopheles arabiensis, a dangerous malaria vector. Importantly, the repellents worked both indoors and outdoors, offering more versatile protection compared to bed nets or insecticide sprays, which are often limited by location or time.

Malaria claims an estimated 608,000 lives annually worldwide, and current tools like insecticide-treated bed nets offer protection mainly indoors at night. Repellent creams and coils provide only limited or costly solutions. The long-lasting and easy-to-use spatial repellents thus represent a major breakthrough, especially for remote areas with poor electricity supply.

The vapours released are similar to those used in WHO-approved bed nets, with no new health risks detected in long-term use. "These are lightweight, affordable, and ideal for rural and urban settings," the study authors said.

Reference: Chen, Ingrid Chena, Sarah L. Millera , Daniel Msellemuc , Aidi G. Lugengec , Johnson Kyeba Swaic , Nicole Acheed , Marta Andrésc,e,f , Christopher S. Bibbsg , Theeraphap Chareonviriyaphaph , J. Derek Charlwoodi , Greg Devine; Volatile pyrethroid spatial repellents for preventing mosquito bites: a systematic review and meta-analysis; eBioMedicine, Volume 0, Issue 0, 105891; DOI: 10.1016/j.ebiom.2025.105891

New Research Reveals Diabetes May Accelerate Breast Cancer Growth

A recent study published in Communications Biology by researchers at Boston University Chobanian & Avedisian School of Medicine has revealed how type 2 diabetes alters immune responses within breast tumors, helping explain why diabetic women face more aggressive breast cancer and poorer outcomes. The study focused on microscopic particles called exosomes, which circulate in the bloodstream and influence the body’s immune system.

The researchers analyzed patient-derived breast cancer organoids—miniature tumors grown in the lab—and exposed them to blood from individuals with and without type 2 diabetes. They found that exosomes from diabetic patients weakened immune cells within tumors, reducing the body’s ability to fight cancer. In contrast, organoids exposed to non-diabetic blood maintained stronger immune defenses.

Type 2 diabetes affects more than 500 million people worldwide and is linked to a 20-30% higher risk of developing breast cancer. Women with diabetes also experience greater mortality from breast cancer compared to those without diabetes. Until now, the biological reasons behind these disparities were unclear.

Lead researchers explained that diabetes-altered exosomes reprogram immune cells inside tumors, allowing cancer cells to grow more aggressively and making treatments like immunotherapy less effective. This mechanism could also apply to other cancers that evade immune responses.

The findings suggest future possibilities such as developing drugs to block harmful exosomes, customizing immunotherapy for diabetic patients, and increasing cancer screening for women with diabetes. Meanwhile, doctors emphasize prevention through blood sugar control, healthy diet, regular exercise, and maintaining a healthy weight.

This study highlighted the complex interplay between chronic diseases, reminding us that diabetes’ impacts extend beyond sugar metabolism to shape the immune system’s fight against cancer—pointing toward more personalized treatment approaches.

Reference: Ennis, C.S., Seen, M., Chen, A. et al. Plasma exosomes from individuals with type 2 diabetes drive breast cancer aggression in patient-derived organoids. Commun Biol 8, 1276 (2025). https://doi.org/10.1038/s42003-025-08663-y

Study Links Ultra-Processed Foods to Metabolic and Reproductive Harm

A recent international study published in Cell Metabolism has revealed that ultra-processed foods can cause weight gain and disrupt reproductive health, even when calorie intake is matched with minimally processed diets. The research, led by Jessica Preston at the University of Copenhagen's NNF Center for Basic Metabolic Research, investigated the impact of food processing on metabolism and sperm quality in healthy young men.

Researchers studied 43 men aged 20 to 35, who spent three weeks on both ultra-processed and minimally processed diets, separated by a three-month washout period. Half of the participants consumed normal calorie amounts, while the other half received an additional 500 calories per day. Both diets were carefully matched for calories, protein, carbohydrates, and fats.

The findings showed that men gained around 1 kg more fat mass on the ultra-processed diet regardless of calorie intake. Additionally, several cardiovascular health markers worsened on the ultra-processed diet. Worryingly, the study also found increased levels of phthalate cxMINP, a hormone-disrupting chemical used in plastics, in men consuming ultra-processed foods. This was linked to decreases in testosterone and follicle-stimulating hormone, essential for sperm production.

“We were shocked by the extent to which ultra-processed foods disrupted body functions, even in healthy young men," said Professor Romain Barrès, senior author of the study. He emphasized the need to reevaluate nutritional guidelines to protect against chronic diseases exacerbated by ultra-processed diets.

This study highlighted that the harm caused by ultra-processed foods goes beyond excess calorie consumption, pointing to the processed nature of these foods as a fundamental risk to metabolic and reproductive health.

Reference: Preston, J. M., et al. (2025). Effect of ultra-processed food consumption on male reproductive and metabolic health. Cell Metabolism. doi.org/10.1016/j.cmet.2025.08.004