Medical Bulletin 07/September/2026 - Video

Here are the top medical news for today:

Longer Sitting Time Linked to 9% Higher Risk of Cancer Death: Study

Sitting for long, uninterrupted periods may be more harmful than simply spending a lot of time sitting, according to new research linking prolonged sitting with cancer risk.

The study, published in PLOS Medicine, included 91,292 people from the UK Biobank. Participants wore activity monitors for seven days, and researchers followed them for an average of more than 12 years.

Researchers found that every additional hour spent sitting for long periods was linked to a 9% higher risk of dying from cancer. Long periods of sitting were defined as sitting for at least 30 minutes at a time, with most of that period spent inactive.

People who spent more time in these prolonged sitting periods also had higher risks of developing cancer overall, as well as cancers linked to obesity and type 2 diabetes.

However, regularly breaking up sitting time appeared to be linked with better outcomes. Researchers estimated that replacing one hour of prolonged sitting each day with light physical activity was associated with a 12% lower risk of dying from cancer.

The findings suggest that it may not only be important how much time people spend sitting, but also how that time is spread throughout the day. Getting up regularly and moving for short periods could help reduce long stretches of inactivity.

However, the study does not prove that prolonged sitting directly causes cancer. It was an observational study, meaning researchers looked at patterns rather than testing whether reducing sitting prevents cancer.

The researchers said the findings highlight the importance of adding movement throughout the day, even for people who exercise regularly. Simple habits such as standing up, taking short walks or regularly breaking up sitting time may be helpful, although further studies are needed to confirm whether these changes can directly reduce cancer risk.

REFERENCE: Ziyi Zhou, Stewart G. et al.; Accelerometry-measured prolonged and interrupted sedentary behavior and cancer incidence and mortality: A cohort study of 91,292 UK Biobank participants. PLOS Medicine, 2026; 23 (7): e1004767 DOI: 10.1371/journal.pmed.1004767

New Injectable Therapy May Support Brain Recovery and Repair After Stroke: Study

A new injectable material may help the brain repair itself after an ischemic stroke, according to a study in mice by researchers at Duke University.

Published in Cell Biomaterials, the study looked at a special scaffold designed to fill the space left behind when a stroke destroys brain tissue. The goal was to create a better environment where the body could begin repairing the damaged area.

The researchers used a material called microporous annealed particle, or MAPS, made from tiny hydrogel particles. These particles form a sponge-like structure with spaces that cells can enter.

The researchers added extracellular vesicles, or EVs, released by brain cells called astrocytes. EVs are tiny packages that carry signals capable of changing how nearby cells behave.

The team found that combining two signalling molecules, IL-4 and C1q, helped attract immune cells to the damaged area. These included macrophages and neutrophils.

Neutrophils are usually associated with inflammation after a stroke. However, the study suggests that, at a later stage, they may also help with tissue repair when they receive the right signals. When researchers reduced these neutrophils, the formation of new blood vessels and changes in the scaffold were reduced.

The treated mice also developed more blood vessels and more axons, which are parts of nerve cells that help transmit signals. These changes were linked to better movement. After eight weeks, the treated mice performed similarly to healthy mice on a test that measured how accurately they placed their front paws while walking.

The scaffold itself appeared to be important. EVs given without the MAPS material did not produce the same level of blood-vessel repair.

However, this treatment is still at an early experimental stage. It has only been tested in mice, so researchers need to study its safety and effectiveness in larger animals before considering human trials.

REFERENCE: Shangjing Xin, et al.; IL-4/C1q activated astrocyte-derived extracellular vesicles promote stroke infarct recovery by recruiting peripheral leukocytes. Cell Biomaterials, 2026; 100543 DOI: 10.1016/j.celbio.2026.100543

Gut Microbiome Linked to Brain Aging, Study Explores the Connection

What we eat may affect more than digestion. A new review suggests that diet can change gut bacteria and the substances they produce, which may influence inflammation, brain health and cognitive ageing.

Published in Frontiers in Molecular Neuroscience, the review examined evidence linking diet, the gut microbiota and the brain. This is important as dementia cases are expected to rise from more than 55 million globally in 2020 to nearly 139 million by 2050.

As people age, changes in the gut microbiota can affect the gut lining, immune system and communication between the gut and brain. Older adults who are frail or have several health problems often have lower gut bacterial diversity. Some bacteria that produce beneficial substances, such as butyrate, may also decline.

Diet can strongly influence these bacteria. Fibre-rich foods can support beneficial gut bacteria and increase short-chain fatty acids, including butyrate. These substances help maintain the gut lining and regulate inflammation. Foods rich in polyphenols, such as fruits, berries, cocoa and tea, may also encourage healthier changes in the gut microbiota.

On the other hand, diets high in saturated fats have been linked with less diverse gut bacteria, damage to the gut barrier and increased inflammation. Omega-3 fats may have more favourable effects on gut bacteria and inflammatory responses.

Gut bacteria also produce chemicals that can communicate with the brain. These include short-chain fatty acids, tryptophan-related compounds and modified bile acids. Experimental studies suggest these substances may influence brain inflammation, brain immune cells, blood-brain barrier function and connections between nerve cells.

However, researchers caution that much of the evidence comes from animal studies or observational research. Human studies have shown mixed results, and it is not yet clear whether changing the gut microbiota can directly prevent cognitive decline.

The review calls for longer and better-designed human studies to determine how diet and gut health may influence brain ageing and dementia risk.

REFERENCE: Jarfan, M. A., Vimaleswaran, K. S., & Wijeyesekera, A. (2026). Diet–gut microbiota–immune–brain interactions in aging: Mechanistic pathways and clinical implications. Frontiers in Molecular Neuroscience. 19. DOI: 10.3389/fnmol.2026.1847644