Health News

Scientists have discovered that the aging human brain may be far less isolated from the rest of the body than once believed. Stanford researchers found that large numbers of immune cells from the blood begin entering the brain as early as middle age, where they can transform into microglia, the brain’s specialized immune cells. The finding overturns a long-standing assumption that these cells remain largely separate from the body’s immune system throughout life.

Simply choosing the stairs could have surprisingly big benefits for your heart and longevity. A large analysis involving more than 480,000 people found that regular stair climbers were 39% less likely to die from cardiovascular disease and 24% less likely to die from any cause than people who rarely took the stairs. They also had lower risks of heart attack, stroke, and heart failure.

A surprising stress-related signal may help the brain repair itself after injury. Researchers found that myelin-producing precursor cells rapidly release the stress hormone CRH near damaged brain tissue, helping control how those cells mature and rebuild protective nerve insulation. The same system also influences brain development and the thickness of myelin later in life. The findings could offer new clues about how early-life stress contributes to psychiatric disorders.

Women who used estrogen-only hormone therapy later in life were less likely to develop dementia and showed fewer signs of Alzheimer’s disease in their brains, according to a large study of more than 21,000 participants. Hormone therapy use was linked to 39% lower odds of a dementia diagnosis and 35% lower odds of Alzheimer’s-related brain changes at autopsy, including amyloid plaques and tau tangles. Biomarker tests also suggested less amyloid buildup among hormone therapy users.

A large study of more than 5,500 adults over 50 found a striking combination of risk factors: abdominal obesity paired with vitamin D deficiency was linked to a 123% higher risk of death over six years. Each condition was associated with increased risk on its own, but together they appeared to create a dangerous feedback loop, with belly fat reducing the amount of vitamin D available in the bloodstream while low vitamin D may worsen inflammation and other health problems.

Researchers have discovered that a gene linked to congenital heart disease acts like an architect for the heart cell’s DNA. Losing just one copy of TBX5 can cause the genome’s carefully folded 3D structure to unravel, disrupting the genes needed to build a healthy heart. The effects can vary from cell to cell, which may help explain why people with the same mutation develop different heart defects. The same hidden mechanism could also play a role in other birth defects.

Orange juice may have a much bigger effect on the body than scientists once realized. Drinking it regularly appears to influence genes tied to inflammation, blood pressure, metabolism, and blood sugar control, while studies have also found improvements in cholesterol and blood vessel health. Researchers suspect natural citrus compounds such as hesperidin may be partly responsible. Even the gut microbiome may benefit.

A protein inside appetite-controlling brain cells may play an important role in preventing overeating and obesity, particularly when high-fat foods are readily available. Unexpected differences between males and females could also help explain why obesity risk—and responses to weight-loss drugs—can vary.

Researchers have found a striking new way to potentially eliminate HIV soon after infection using a one-time combination of three therapies. In newborn nonhuman primates treated within three days of exposure, the regimen—standard antiretroviral drugs, broadly neutralizing antibodies, and the experimental antibody leronlimab—completely cleared the virus, even though none of the treatments could do so alone.

A single human brain cell may be far more powerful than scientists once realized. Researchers found that cortical neurons can perform remarkably complex computations, giving them capabilities more like tiny biological computers than simple on-off switches. This could help explain why the human brain supports abilities such as language, imagination, and mathematics.