Health News

Older adults who received the Shingrix shingles vaccine were 24% less likely to be diagnosed with dementia over four years in a study of more than 500,000 people. Researchers estimate the difference could amount to roughly one dementia case prevented for every 17 people vaccinated.

Researchers have found a way to supercharge natural killer cells, powerful immune cells that can attack cancer, so they can penetrate solid tumors and keep fighting once inside. In mice, these specially prepared tissue-resident cells slowed the growth of several tumors, including melanoma and head and neck cancers, and worked even better when paired with the antibody drug cetuximab.

A major study found that adults with depression show disrupted production of new neurons in the hippocampus, potentially weakening the brain’s ability to separate new experiences from painful memories. The researchers also identified broad molecular changes that could open the door to new treatments tailored to different biological forms of depression.

People who reach 110 and beyond appear to have unusually large numbers of rare immune cells capable of killing abnormal cells. These CD4 cytotoxic T cells became more common with age and often expanded into large groups of nearly identical cells, suggesting the immune system was repeatedly responding to persistent threats.

Common medications may reshape the gut microbiome long after the last dose is taken. In a study of more than 2,500 people, researchers found lasting microbial changes linked not only to antibiotics, but also to antidepressants, beta-blockers, acid-reducing drugs, and benzodiazepines. Some effects were still detectable years later, suggesting past medication use may strongly influence the gut bacteria people carry today.

Backyard bird feeders could become unexpected hotspots for H5N1 as Australia’s bird flu outbreak spreads, bringing species together in ways that rarely occur naturally. Experts say stopping feeding is safest, while smaller amounts of food, no hand-feeding, and careful cleaning can reduce the danger.

Both too little and too much sleep may be linked to faster aging throughout the body. Researchers analyzing 23 biological aging clocks found the lowest aging levels among people sleeping about 6.4 to 7.8 hours per day. Short or long sleep was also associated with numerous conditions affecting the brain, heart, lungs, metabolism, and digestive system.

Gut bacteria can transform nitrate and plant-based iron from vegetables and other foods into protective molecules that may benefit the heart and metabolism. In experimental models, higher levels of these compounds were linked to lower blood pressure, better blood sugar control, healthier blood vessels, and less liver fat.

Researchers have uncovered a possible reason why the Alzheimer’s risk gene APOE4 can disrupt the brain long before memory problems begin. In mice, APOE4 increased a protein called Nell2, shrinking neurons and making memory circuits unusually active. That early hyperactivity predicted worse memory later in life. Reducing Nell2 in adult mice reversed the abnormal changes, raising hopes for a new way to intervene before Alzheimer’s progresses.

Researchers have found a way to slash the processing time for 3D-printed zirconia crowns from as much as 100 hours to under 30 minutes. The advance could eventually let dentists print strong, customized permanent crowns for patients within a single appointment.