A post-mortem study of five Alzheimer's and five control brains has revealed the presence of iron-containing microglia in the subiculum of the Alzheimer's brains only. The subiculum lies within the hippocampus, a vital memory region affected early in Alzheimer's. None of the brains of those not diagnosed with Alzheimer's had the iron deposits or the microglia, in that brain region, while four of the five Alzheimer's brains contained the iron-containing microglia.
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A natural experiment involving 5,740 participants in a MOOC ( massive open online course) has found that when students were asked to assess each other's work, and the examples were exceptional, a large proportion of students dropped the course.
In the MOOC, as is not uncommon practice, course participants were asked to write an essay and then to grade a random sample of their peers' essays. Those randomly assigned to evaluate exemplary peer essays were dramatically more likely to quit the course than those assigned to read more typical essays.
In the past few months, several studies have come out showing the value of three different tests of people's sense of smell for improving the accuracy of MCI and Alzheimer's diagnosis, or pointing to increased risk. The studies also add to growing evidence that a decline in sense of smell is an early marker for mild cognitive impairment and Alzheimer’s. Indeed, it appears that this sensory loss is a very early symptom, preceding even the shrinking of the entorhinal cortex (the first brain region to show signs of atrophy).
A Finnish study involving over 1000 older adults suggests that a counselling program can prevent cognitive decline even among those with the Alzheimer’s gene.
The study involved 1,109 older adults (aged 60-77) of whom 362 were carriers of the APOE4 gene. Some of the participants received regular lifestyle counselling (general health advice), while the rest received “enhanced” lifestyle counselling, involving nutrition counselling, physical and cognitive exercises, and support in managing the risk of cardiovascular diseases.
A review of 34 longitudinal studies, involving 71,244 older adults, has concluded that depression is associated with greater cognitive decline.
The study included people who presented with symptoms of depression as well as those that were diagnosed as clinically depressed, but excluded any who were diagnosed with dementia at the start of study.
Previous research has found that depression is associated with an increased dementia risk.
A small study comparing 38 younger adults (average age 22) and 39 older adults (average age 68) found that the older adults were less able to recognize when they made errors.
The simple test involved looking away from a circle that appeared in a box on one side of a computer screen. It’s hard not to look at something that’s just appeared, and each time the participant glanced at the circle before shifting their gaze, they were asked whether they had made an error. They were then asked to rate how sure they were of their answer.
A British study following 550 adults over 30 years from 1985 has found that those who reported higher levels of alcohol consumption were more often found to have a shrunken hippocampus, with the effect greater for the right side of the brain. Such shrinkage was found in 35% of those who didn’t drink, but 65% for those who drank an average 2-3 units daily, and 77% for those who drank 30 or more units a week.
The structure of white matter was also linked to how much individuals drank.
When a group of people work together to remember an event, the group do appear to recall more than an individual working alone, but do they recall more than the sum of the memories each individual recalls?
Studies have found that "brainstorming" groups actually produce fewer ideas than groups that are groups in name only1. And in many tasks, from rope-pulling to vigilance tasks, it has been found that people contribute less when they are part of a group than when they are working alone2.
Preliminary studies have demonstrated that grape skin extract exerts a novel inhibitory activity on hyperglycemia and could be developed to aid in diabetes management.
http://www.eurekalert.org/pub_releases/2014-05/wsu--gse050814.php
Data from the very large U.S. National Health and Nutrition Examination Survey (NHANES), involving 23,168 people, has found a significant association between low dietary fiber intake and risk of metabolic syndrome, cardiovascular inflammation, and obesity.
Dietary fiber intake was also consistently below recommended intake levels: 38g per day for men aged 19-50 years, 30g per day for men 50 and over, 25g for women aged 19-50 years, and 21g per day for women over 50. Mean dietary fiber intake was only 16.2g per day across all groups.