Afternoon Napping Linked To Better Mental Agility

Taking a regular afternoon nap may be linked to better mental agility, suggests research published in the online journal General Psychiatry. It seems to be associated with better locational awareness, verbal fluency, and working memory, the findings indicate. Longer life expectancy and the associated neurodegenerative changes that accompany it, raise the prospect of dementia, with around 1 in 10 people over the age of 65 affected in the developed world.

As people age, their sleep patterns change, with afternoon naps becoming more frequent. But research published to date hasn’t reached any consensus on whether afternoon naps might help to stave off cognitive decline and dementia in older people or whether they might be a symptom of dementia.

The researchers explored this further in 2214 ostensibly healthy people aged at least 60 and resident in several large cities around China, including Beijing, Shanghai, and Xian. In all, 1534 took a regular afternoon nap, while 680 didn’t. All participants underwent a series of health checks and cognitive assessments, including the Mini Mental State Exam (MMSE) to check for dementia. The average length of night time sleep was around 6.5 hours in both groups. Afternoon naps were defined as periods of at least five consecutive minutes of sleep, but no more than 2 hours, and taken after lunch. Participants were asked how often they napped during the week; this ranged from once a week to every day.

The dementia screening tests included 30 items that measured several aspects of cognitive ability, and higher function, including visuo-spatial skills, working memory, attention span, problem solving, locational awareness and verbal fluency. The MMSE cognitive performance scores were significantly higher among the nappers than they were among those who didn’t nap. And there were significant differences in locational awareness, verbal fluency, and memory.

This is an observational study, and so can’t establish cause. And there was no information on the duration or timing of the naps taken, which may be important.


Brain Metals Drive Alzheimer’s Progression

Alzheimer’s disease could be better treated, thanks to a breakthrough discovery of the properties of the metals in the brain involved in the progression of the neurodegenerative condition, by an international research collaboration including the University of Warwick.

Iron is an essential element in the brain, so it is critical to understand how its management is affected in Alzheimer’s disease. The advanced X-ray techniques that we used in this study have delivered a step-change in the level of information that we can obtain about iron chemistry in the amyloid plaques. We are excited to have these new insights into how amyloid plaque formation influences iron chemistry in the human brain, as our findings coincide with efforts by others to treat Alzheimer’s disease with iron-modifying drugs,” commented Dr Joanna Collingwood, from Warwick’s School of Engineering, who was part of a research team which characterised iron species associated with the formation of amyloid protein plaques in the human brainabnormal clusters of proteins in the brain. The formation of these plaques is associated with toxicity which causes cell and tissue death, leading to mental deterioration in Alzheimer’s patients.

They found that in brains affected by Alzheimer’s, several chemically-reduced iron species including a proliferation of a magnetic iron oxide called magnetite – which is not commonly found in the human brainoccur in the amyloid protein plaques. The team had previously shown that these minerals can form when iron and the amyloid protein interact with each other. Thanks to advanced measurement capabilities at synchrotron X-ray facilities in the UK and USA, including the Diamond Light Source I08 beamline in Oxfordshire, the team has now shown detailed evidence that these processes took place in the brains of individuals who had Alzheimer’s disease. They also made unique observations about the forms of calcium minerals present in the amyloid plaques.

The team, led by an EPSRC-funded collaboration between University of Warwick and Keele University – and which includes researchers from University of Florida and The University of Texas at San Antonio – made their discovery by extracting amyloid plaque cores from two deceased patients who had a formal diagnosis of Alzheimer’s. The researchers scanned the plaque cores using state-of-the-art X-ray microscopy at the Advanced Light Source in Berkeley, USA and at beamline I08 at the Diamond Light Source synchrotron in Oxfordshire, to determine the chemical properties of the minerals within them.