Social support and memory in postmenopausal women: a careful null
A secondary analysis of the ELITE hormone-therapy trial found hints that social ties tracked with cognition, but none survived correction for multiple testing.
More greenery near home tracked with better attention in a large study of children
In nearly 12,000 US children, tree and park cover was linked to sharper directed attention and higher crystallized intelligence — and cleaner air seemed to explain part of it.
A tire chemical's toxic product dominates further from the road
Two papers landed within a week: a global map showing 6PPD-quinone taking over from its parent compound along the way to water, and the first human study linking it to cognition.
A new magnesium trial found real cognitive gains and a sleep signal too soft to call a win
Participants on Magtein scored better on memory and reaction-time tests after six weeks. On sleep — the reason most people buy it — an Oura Ring found no measurable difference at all.
Rapamycin was undetectable in spinal fluid in the first trial that looked
A ten-person phase 1 study measured whether oral rapamycin reaches the central nervous system in early Alzheimer's. It did not — and several disease biomarkers rose over eight weeks.
As New York's air got cleaner, children's cognitive scores rose. Proving it is harder
Three successive birth cohorts over 22 years show falling prenatal pollution and rising test scores together. A separate review explains why the pathway from one to the other is still poorly mapped.
Dementia in the Middle East and North Africa is projected to rise 367% by 2050
A review pooling prevalence across the region ties the projection to modifiable risks that are unusually common there — smoking, inactivity, diabetes — layered on rapid ageing.
Cognitive reserve is real. What you can do about it is a smaller, honest list.
Autopsy studies show educated brains carry the same disease but express it as dementia later. That is the concept's strength — and the reason it resists being turned into a to-do list.
The largest trial of hearing aids and cognitive decline found no overall effect
ACHIEVE randomised 977 older adults and measured three-year cognitive change. The difference between hearing aids and health education was 0.002 SD units, p=0.96. One subgroup result is doing a lot of work.
Exercise is sold as brain insurance. The trial evidence is weaker than the headlines.
Observational studies tie fitness to slower cognitive decline. When researchers randomise older adults to exercise, the cognitive payoff shrinks — in a Cochrane review of healthy people, to nothing.
Crossword-doers decline more slowly. That is not the same as crosswords working.
The link between puzzles and a sharper old age is real in the data and largely the wrong way round: the earliest changes of dementia quietly reduce the very activities that later look protective.
Multivitamins do not extend life. The one thing they may do is smaller than the pitch.
In 390,124 US adults followed up to 27 years, daily multivitamin use showed no mortality benefit. Randomised trials within COSMOS found a real but modest effect on memory, and none on physical function.
The MIND diet slowed decline in cohort studies. The randomised trial found no difference.
A diet built to protect the brain looked powerful when researchers watched who chose to eat it. When they assigned it in a three-year trial, both groups improved by almost exactly the same amount.
UK firefighters carry more PFAS in their blood than their neighbours do
A 1,224-person biomonitoring study found four compounds only in firefighter serum. A separate 65-person pilot in Texas asked whether that matters for cognition, and got a partial answer.
Five cohorts, 44 sleep measurements, no association with dementia risk
A consortium reduced overnight sleep studies to nine composites. Two tracked with better cognition. None tracked with whether a person later developed dementia.
Short naps sharpened alertness. Long habitual naps tracked with worse outcomes.
A meta-analysis of 44 cohorts covering 1,864,274 people found the risk signal attached to naps of 30 minutes or more. Below that threshold, no significant risk appeared.
Brain-training games reliably improve one thing: your score on that game
The best long-term trial found trained skills can last a decade. Whether they transfer to daily life, or hold off dementia, is where the evidence — and the FTC — parted ways with the marketing.
The Lancet's 45% dementia figure is a population estimate, not a personal promise
A standing commission estimates that eliminating 14 risk factors could prevent or delay 45% of dementia across a whole population. What that number means for one person is a different and much weaker claim.
Waist size carried a stronger cognitive signal than BMI in a Dutch cohort
In 3,873 middle-aged adults followed with repeated testing, waist-based categories of overweight and obesity showed larger effect sizes than BMI-based ones. The link to actual decline appeared only in men.
Earlier menopause, less gray matter: a Cambridge cohort finds both, and can't say why
747 postmenopausal women were tested; 182 were scanned. Gray matter volume partially mediated the link between menopause age and cognition — in a cross-sectional design that cannot establish direction.
A million women's worth of data on hormone therapy and dementia returns a flat line
Pooling ten studies, researchers found menopause hormone therapy neither raised nor lowered dementia risk. The certainty of that evidence ranged from moderate to very low.
The sleep signal tied to faster cognitive decline sits where sleep studies don't look
A small longitudinal study found reduced spindle activity over the temporal lobes in early Alzheimer's — and that lower temporal spindle density tracked with faster decline over up to seven years.
Probiotics moved older adults' cognitive scores. Half of trials never reported harms
A 21-trial meta-analysis found effects concentrated in older age groups and largely absent elsewhere. A separate safety review of the most-used strain found no excess adverse events — and a big reporting gap.