Looking after a spouse with dementia greatly increases your own risk of dementia

A study comparing blood serum levels of the DDT metabolite, DDE, in 86 patients with Alzheimer's disease (average age 74) and 79 controls (average age 70), has found that levels of DDE were 3.8 times higher in 74 of the 86 Alzheimer’s patients (86%). Having the Alzheimer’s gene, APOe4, plus high levels of the pesticide, produced more severe cognitive impairment.

Brain cell studies found that DDE increased production of the amyloid precursor protein (APP).

A study involving both mice and human cells adds to evidence that stress is a risk factor for Alzheimer's.

The study found that mice who were subjected to acute stress had more amyloid-beta protein in their brains than a control group. Moreover, they had more of a specific form of the protein, one that has a particularly pernicious role in the development of Alzheimer's disease.

When human neurons were treated with the stress hormone corticotrophin releasing factor (CRF), there was also a significant increase in the amyloid proteins.

Data from over 11,500 participants in the Atherosclerosis Risk in Communities (ARIC) cohort has found evidence that orthostatic hypotension in middle age may increase the risk of cognitive impairment and dementia 20 years later.

Orthostatic hypotension is the name for the experience of dizziness or light-headedness on standing up. Previous research has suggested an association between orthostatic hypotension and cognitive decline in older adults.

Poor sleep has been associated with Alzheimer's disease risk, but a new study suggests a specific aspect of sleep is important.

The study, involving 119 older adults (60+), of whom 80% were cognitively normal and the remainder very mildly impaired, found that decreased slow-wave sleep coincided with higher levels of tau in the brain and a higher tau-to-amyloid ratio in the cerebrospinal fluid.

Disrupted sleep in one's 50s, 60s raises Alzheimer's risk

A study involving 95 healthy older adults found that adults reporting a decline in sleep quality in their 40s and 50s had more amyloid-beta in their brains later in life, while those reporting poorer sleep in their 50s and 60s had more tau tangles. Those with high levels of tau protein were more likely to lack the synchronized brain waves during deep NREM sleep that are associated with a good night's sleep, and the more tau protein, the less synchronized these brain waves were.

A long-running study involving 8225 adults found that self-reported diet during midlife (mean age 50) was not significantly associated with subsequent risk for dementia.

Dietary intake was assessed in 1991-1993, 1997-1999, and 2002-2004, with follow-up for incident dementia until March 31, 2017. Diet quality was assessed using the Alternate Healthy Eating Index (AHEI), an 11-component diet quality score (score range, 0-110), with higher scores indicating a healthier diet.

Data from the large and very long-running Framingham Heart Study has revealed that people who drink sugary drinks frequently are more likely to have poorer memory, smaller overall brain volume, and a significantly smaller hippocampus. Moreover, a second study found that those who drank diet soda daily were almost three times as likely to develop stroke and dementia over a 10-year period, compared to those who didn’t – suggesting that substituting artificial sweeteners for the sugar doesn’t make matters better.