Medical Bulletin 03/December/2025

The study involved 1,164 healthy adults (average age around 55, 52% women) from multiple sites who underwent whole-body MRI scans. These scans measured muscle mass, visceral fat (fat around internal organs), and subcutaneous fat (fat just under the skin). An advanced AI algorithm then estimated the biological age of participants’ brains based on structural imaging. Results showed a clear pattern: those with higher muscle volume tended to have younger-looking brains, while a higher ratio of visceral fat to muscle correlated with older, more aged brains. Interestingly, subcutaneous fat had no significant effect on brain age, highlighting that hidden belly fat is the major concern for brain health.

Visceral fat contributes to inflammation and metabolic stress in the body—both accelerating brain aging—whereas muscle supports metabolic resilience and hormonal balance, protecting brain structure. This combination means that having more muscle and less visceral fat creates a healthier biological environment, slowing brain aging. The study’s lead author, Dr. Cyrus Raji, emphasized that these MRI-based findings provide objective evidence linking body composition directly to brain health, beyond traditional measures like BMI.

These results have meaningful implications for public health and interventions. Programs focused on building muscle while reducing visceral fat could become valuable tools to preserve cognitive function. This is especially relevant as GLP-1 weight loss medications like Ozempic, which are effective in fat loss but may also reduce muscle, gain popularity. Future therapies might aim to selectively target visceral fat while safeguarding muscle to optimize brain health outcomes.

In summary, this groundbreaking research shows that maintaining a lean body with strong muscles and minimal hidden belly fat supports a younger, healthier brain, offering hope for combating age-related cognitive decline and dementia.

REFERENCE: Radiological Society of North America. "The body trait that helps keep your brain young." ScienceDaily. ScienceDaily, 25 November 2025.

RSV prevention in newborns may significantly reduce childhood asthma risk, study finds

Early infection with respiratory syncytial virus (RSV) in infants is strongly linked to an increased risk of developing childhood asthma, especially in those with inherited allergy or asthma predispositions.

This finding from Belgian researchers at VIB and Ghent University (UGent), working with Danish partners, was published recently in Science Immunology and highlights the potential of RSV prevention to reduce asthma rates significantly later in life.

Childhood asthma affects up to 15% of children in Europe and exacts a heavy toll on health and families. The study combined Danish nationwide health registry data from all children and their parents with controlled lab experiments to reveal how early RSV infections and genetic allergy risks interact.

Infants hospitalized with severe RSV in their first months were more likely to develop immune responses that overreact to allergens like house dust mites—an effect amplified when asthma or allergies run in the family due to allergen-specific antibodies transferred from parents to newborns.

Experimental models showed that preventing RSV infection in newborns stopped this harmful immune programming and prevented asthma development altogether. This suggests wider benefits of RSV prevention beyond merely avoiding hospitalization, potentially improving long-term respiratory health for many children.

Currently, maternal RSV vaccination during pregnancy and passive immunization with long-acting antibodies for newborns are being introduced in several countries. However, uptake varies, and these new results underscore the urgent need to increase access and acceptance of these preventative measures.

Experts emphasize combining scientific, policy, and clinical efforts to leverage RSV prevention as a powerful tool against asthma, particularly for children with genetic allergy risks.

In conclusion, this comprehensive research clarifies how early-life RSV infection shapes immune responses toward asthma, especially when paired with inherited risks. Protecting newborns from RSV offers a promising avenue to reduce asthma’s burden on children, families, and healthcare systems worldwide.

REFERENCE: Elisabeth De Leeuw, Josefine F. Justesen, Cédric Bosteels, Nincy Debeuf, Manon Vanheerswynghels, Leander Jonckheere, Caroline De Wolf, Alysia Wayenberg, Karel F.A. Van Damme, Stijn Vanhee, Manon Lesage, Kim Deswarte, Sam Dupont, Morten Dahl, Hamida Hammad, Bart N. Lambrecht. Maternal allergy and neonatal RSV infection synergize via FcR-mediated allergen uptake to promote the development of asthma in early life. Science Immunology, 2025; 10 (113) DOI: 10.1126/sciimmunol.adz4626

Overweight boys experience earlier puberty onset than normal peers: Study

Childhood obesity is reshaping puberty patterns in boys worldwide, leading to earlier sexual maturation and related physical changes.

A recent systematic review and meta-analysis published in Frontiers in Endocrinology examined data from 12 large cohort studies spanning Asia, Europe, North and South America to quantify the impact of overweight and obesity on male pubertal milestones.

The research focused on key puberty indicators driven by the hypothalamic-pituitary-gonadal axis, including testicular enlargement, pubic hair development, peak height velocity, voice change, and first ejaculation. Using standardized measures like Tanner staging and testicular volume, the team compared overweight and obese boys with their normal-weight peers.

Results showed that overweight boys had a 38% higher risk of early testicular enlargement, and obese boys had a 43% increased risk. On average, overweight boys reached this milestone about three months earlier than normal-weight boys. Central obesity, measured by waist circumference and body fat percentage, further elevated early testicular growth risk by approximately 70%.

Pubic hair development also occurred earlier in heavier boys, with overweight boys seeing a 24% increased risk and obese boys a 42% increase compared to peers. Despite these shifts in sexual maturation, peak height velocity, which reflects the speed of adolescent growth spurts, showed no significant difference between obese and normal-weight boys.

Subgroup analyses revealed regional and age-related differences, with Asian-Pacific boys and those assessed after age six showing stronger associations. Additional cohort data linked elevated prepubertal BMI to earlier first ejaculation and voice changes, reinforcing advanced puberty among boys carrying excess weight.

The study’s findings confirm childhood overweight and obesity as significant biological stressors advancing certain male puberty markers. This knowledge can guide families and clinicians in managing childhood weight to influence puberty timing and reduce long-term health risks. Further research is needed to deepen understanding and develop tailored interventions worldwide.

REFERENCE: Feng W & Ren C. (2025). The relationship between childhood obesity and male puberty development: a systematic review and meta-analysis. Front. Endocrinol. 16. DOI: 10.3389/fendo.2025.1711557. https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2025.1711557/full