Medical Bulletin 18/July/2026 - Video

Here are the top medical news for today:

WHO Issues Updated Guidelines to Help Prevent Dementia Worldwide

Nearly half of dementia cases may be preventable—and the WHO says action should start long before symptoms appear. The World Health Organization (WHO) has released updated guidelines to help reduce the risk of cognitive decline and dementia by focusing on healthy lifestyle habits and early management of risk factors throughout life.

More than 57 million people worldwide live with dementia, and nearly 10 million new cases are diagnosed every year. Alzheimer's disease accounts for about 60–70% of all dementia cases. While there is still no cure, the WHO estimates that up to 45% of dementia risk is linked to modifiable factors, meaning many cases could potentially be delayed or prevented.

The updated guidelines recommend several evidence-based measures to protect brain health. These include regular physical activity, quitting smoking, limiting alcohol intake, eating a healthy diet, staying socially active, and participating in cognitive training or mentally stimulating activities, particularly for people with normal cognition or mild cognitive impairment.

For the first time, the WHO also recommends reducing exposure to air pollution as part of dementia prevention strategies.

Managing chronic health conditions is another key recommendation. Keeping high blood pressure, diabetes, and high cholesterol under control can lower dementia risk. The guidelines also suggest that hearing aids may be offered to people with hearing loss as part of risk-reduction strategies.

However, the WHO does not recommend taking vitamin B or E supplements, omega-3 fatty acids, or multivitamins solely to prevent dementia unless a deficiency has been diagnosed, as current evidence does not show clear benefits.

The updated recommendations reflect growing scientific evidence since the WHO's 2019 guidelines and encourage countries to integrate brain health into routine care for non-communicable diseases and mental health. According to the WHO, taking preventive action early could help people live longer, healthier, and more independent lives while reducing the growing global burden of dementia.

REFERENCE: Risk reduction of cognitive decline and dementia: WHO guidelines, second edition. Geneva: World Health Organization; 2026. Licence: CC BY-NC-SA 3.0 IGO https://iris.who.int/server/api/core/bitstreams/ea44b7f6-b09f-4e6f-b8c7-2e5b0fcc9a99/content

Maternal Ultra-Processed Food Intake May Affect Children's Long-Term Health: Study

What a mother eats during pregnancy may influence her child's health for years to come, and ultra-processed foods (UPFs) are under growing scrutiny. A new review published in Nutrients suggests that eating large amounts of UPFs during pregnancy and early childhood is consistently associated with poorer maternal health and less favorable outcomes for children, although current evidence does not prove these foods directly cause these problems.

Researchers reviewed 84 published studies examining the effects of UPFs, including packaged snacks, sugary drinks, ready-made meals, processed cereals, and baked goods. They found that pregnant women who consumed more UPFs generally had poorer diet quality, with lower intake of fiber, protein, vitamins, and minerals, and higher intake of salt, unhealthy fats, and added sugars.

Higher UPF intake was linked to excessive pregnancy weight gain, obesity, gestational diabetes, preeclampsia, inflammation, and postpartum weight retention. Some studies also associated greater consumption with higher levels of stress, anxiety, and depressive symptoms during pregnancy.

The review also highlighted the role of the gut microbiome. Ingredients commonly found in UPFs, such as refined sugars, emulsifiers, artificial sweeteners, and saturated fats, may disrupt beneficial gut bacteria, increase intestinal permeability, and promote chronic low-grade inflammation. These changes could influence both maternal health and the infant's developing immune system.

Early exposure to UPFs was associated with a higher risk of childhood obesity, unfavorable cholesterol levels, chronic inflammation, food allergies, and anemia. One study also linked higher maternal UPF intake during late pregnancy with poorer verbal skills in children aged 4–5 years.

However, the authors emphasize that most evidence is observational, meaning it cannot establish cause and effect. They recommend reducing UPF consumption during pregnancy and early childhood while encouraging balanced, nutrient-rich diets and breastfeeding whenever possible.

REFERENCE: López-Yerena, A., Pinto, V., Stella, B. M., Yaşar, E., Camafort, M., Vives-Giralt, M. Q., Casanovas-Garriga, F., Ruiz-Leon, A. M., Estruch, R., & Casas, R. (2026). Unhealthy Diets, Unhealthy Futures: How Modern Eating Patterns Endanger Maternal and Offspring Health. Nutrients. 18(14). DOI: 10.3390/nu18142320.

New AI Tool Could Reduce Unnecessary Chemotherapy in Breast Cancer Care

Could artificial intelligence help some breast cancer patients avoid unnecessary chemotherapy? A new study suggests it might. Researchers from RCSI University of Medicine and Health Sciences and University College Dublin (UCD) have identified immune markers that, when analyzed using AI, may help doctors determine which women with early-stage breast cancer are unlikely to benefit from chemotherapy.

The findings, published in Nature Communications, focus on ER-positive/HER2-negative (ER+HER2-) breast cancer, the most common subtype, accounting for about 70% of breast cancer cases. Although chemotherapy can reduce the risk of cancer returning, it often causes significant side effects, and many patients receive it even when the benefit is uncertain.

Currently, treatment decisions rely heavily on genomic risk scores. However, many patients fall into an intermediate-risk category, making it difficult for doctors to decide whether chemotherapy is necessary.

To improve these decisions, researchers analyzed tumor samples from Irish patients who participated in a clinical trial comparing hormone therapy alone with hormone therapy plus chemotherapy. Using AI, they examined the tumor microenvironment, particularly the immune cells surrounding the cancer.

The study found that a high density of cytotoxic T-cells, immune cells that attack cancer, provided additional information beyond current genomic tests. Surprisingly, patients with higher levels of these T-cells had poorer outcomes after chemotherapy, suggesting this marker could help predict which patients are less likely to benefit from the treatment.

Because the approach uses standard tissue samples already collected during routine care, researchers believe it could be widely adopted if validated in larger studies.

While further research is needed, the findings move doctors closer to more personalized breast cancer treatment, helping some patients avoid unnecessary chemotherapy while ensuring others receive the treatments most likely to benefit them.

REFERENCE: Kinsella, Z., Jahangir, C.A., Nyarko, H.N. et al. Spatial analyses implicate high stromal tumour-infiltrating CD8+ lymphocytes as a negative predictive marker for chemotherapy in estrogen receptor-positive breast cancer. Nat Commun 17, 4863 (2026). https://doi.org/10.1038/s41467-026-73432-2