Alzheimer's & other dementias
Data from the large, long-running U.S. Health and Retirement Study found that healthy cognition characterized most of the people with at least a college education into their late 80s, while those who didn’t complete high school had good cognition up until their 70s.
Data from the Whitehall II study, tracking 10,228 participants for 30 years, found that increased social contact at age 60 is associated with a significantly lower risk of developing dementia later in life. Someone who saw friends almost daily at age 60 was 12% less likely to develop dementia than someone who only saw one or two friends every few months.
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 10-year South Korean study using data from 262,349 older adults (50+) has found that those with chronic periodontitis had a 6% higher risk for dementia than did people without periodontitis. This connection was true despite behaviors such as smoking, consuming alcohol, and remaining physically active.
https://www.eurekalert.org/pub_releases/2019-03/ags-pmr031519.php
Brain scans from over 4,000 people, across the age range (9 months to 94 years) and including 1,385 Alzheimer's patients, has revealed an early divergence between those who go on to develop Alzheimer’s and those who age normally. This divergence is seen in early atrophy of the hippocampus before age 40, and in the amygdala around age 40.
https://www.eurekalert.org/pub_releases/2019-03/c-ahd030819.php
A fruitfly study suggests that losing neurons is not necessarily a bad thing. The study used fruitflies genetically engineered to express human amyloid-beta proteins in their brains. When neuronal death was blocked, the flies developed even worse memory problems, worse motor coordination problems, died earlier and their brain degenerated faster. However, when the normal process of cell competition was enhanced, the flies showed an impressive recovery.
A specially designed mobile phone game called Sea Hero Quest has found that gaming data can distinguish between those people who are genetically at risk of developing Alzheimer's disease ond those who are not. The game is designed to test spatial navigation skills — one of the first cognitive areas affected in Alzheimer's.
A standard memory and thinking test could not distinguish between the risk and non-risk groups.
Data from the Alzheimer's Disease Neuroimaging Initiative (ADNI), involving 230 cognitively normal individuals and 394 individuals with diagnosed with MCI on the basis of one episodic test, has found that performance on two tests markedly improved the identification of those whose MCI was more serious.
MCI can be a step on the road to Alzheimer's, but it can also be a reversible condition, and it’s obviously helpful to be able to distinguish the two.
Data from the Harvard Aging Brain Study found that higher amyloid beta levels were associated with increasing anxiety symptoms in cognitively normal older adults. The results suggest that worsening anxious-depressive symptoms may be an early predictor of elevated amyloid beta levels.
The study involved 270 cognitively healthy older adults (62-90). For five years, participants were annually assessed for depression, apathy-anhedonia, dysphoria, and anxiety.
A study has shown new technology can quickly and non-invasively detect reduced blood capillaries in the back of the eye that are an early indication of Alzheimer's. It also shows that these signs can help distinguish between Alzheimer's and MCI.