A number of studies have come out in recent years linking age-related cognitive decline and dementia risk to inflammation and infection (put inflammation into the “Search this site” box at the top of the page and you’ll see what I mean). New research suggests one important mechanism.
The study involved 4,134 people (average age 59) who worked at the French national gas and electric company, of whom most worked at the company for their entire career. Their lifetime exposure to chlorinated solvents, petroleum solvents, benzene and non-benzene aromatic solvents was estimated, and they were given the Digit Symbol Substitution Test to assess cognitive performance. Cognitive impairment was defined as scoring below the 25th percentile. Most of the participants (88%) were retired.
Damage to the retina (retinopathy) doesn’t produce noticeable symptoms in the early stages, but a new study indicates it may be a symptom of more widespread damage. In the ten-year study, involving 511 older women (average age 69), 7.6% (39) were found to have retinopathy. These women tended to have lower cognitive performance, and brain scans revealed that they had more areas of small vascular damage within the brain — 47% more overall, and 68% more in the parietal lobe specifically. They also had more white matter damage. They did not have any more brain atrophy.
It’s estimated that 43%-70% of those with multiple sclerosis suffer from some level of cognitive impairment (yes, a very broad range! perhaps the finding of this study offers one clue why). Most commonly, this is seen in slower processing speed, impaired memory, impaired executive function, and poorer visuospatial processing. There are a number of factors that have been implicated in why some people suffer from cognitive impairment and others don’t, such as age of onset and male gender. As with dementia, depression also may be a factor, while cognitive reserve appears protective.
Women who received a once-standard type of chemotherapy regimen for breast cancer between 1976 and 1995 have been found to score worse on cognitive tests than women who never had cancer. Specifically, they tended to have lower scores on tests of immediate and delayed verbal memory, executive function, information processing speed, and psychomotor speed. The difference was comparable to some six years of age-related decline.
A study involving 130 HIV-positive people has found that memory impairment was associated with a significantly larger waistline.
Some 40% of participants (average age 46) had impaired cognition. This group had an average waist circumference of 39 inches, compared to 35 inches for those without such problems. Memory impairment was also linked to diabetes in those older than 55 (15% of those with memory problems had diabetes compared to only 3% of those without memory problems).
Data from 11,926 older twins (aged 65+) has found measurable cognitive impairment in 25% of them and subjective cognitive impairment in a further 39%, meaning that 64% of these older adults were experiencing some sort of cognitive impairment.
A ten-year study following 12,412 middle-aged and older adults (50+) has found that those who died after stroke had more severe memory loss in the years before stroke compared to those who survived stroke and those who didn't have a stroke.
Participants were tested every two years, using a standard word-recall list to measure memory loss (or caregiver assessment for those whose memory loss was too severe). During the decade of the study, 1,027 participants (8.3%) survived a stroke, 499 (4%) died after stroke, and 10,886 (87.7%) remained stroke-free over the study period.
New data from the ongoing validation study of the Alzheimer's Questionnaire (AQ), from 51 cognitively normal individuals (average age 78) and 47 aMCI individuals (average age 74), has found that the AQ is effective in identifying not only those with Alzheimer’s but also those older adults with mild cognitive impairment.
Of particular interest is that four questions were strong indicators of aMCI. These related to:
Why is diabetes associated with cognitive impairment and even dementia in older adults? New research pinpoints two molecules that trigger a cascade of events that end in poor blood flow and brain atrophy.