Alzheimers

A long-running study following 387 Australian women found that regular exercise in middle age was the best lifestyle change they could make to prevent cognitive decline in their later years.

The women were aged 45-55 when the study began in 1992. Health and lifestyle factors were assessed at intervals over the next 20 years.

Memory was assessed using a Verbal Episodic Memory test in which they were asked to learn a list of 10 unrelated words and attempt to recall them 30 minutes later.

A large study, involving nearly 14,000 older adults (50+) participating in the 2006 Health and Retirement Study, found that weaker handgrip strength was associated with a greater risk of developing cognitive impairment, especially severe impairment, over the eight-year study period.

Moreover, there was a dose-response type relationship, with every 5-kilogram (11-pound) reduction in handgrip strength being associated with a 10% greater risk of cognitive impairment and an 18% greater risk of severe cognitive impairment.

A large, long-running Finnish study looking at the dietary habits of 2,497 men aged 42-60 has found that a high intake of dietary cholesterol was not associated with the risk of dementia or Alzheimer's disease, even among carriers of the ‘Alzheimer’s gene’ APOE4.

Previous research has found that the effect of dietary cholesterol on serum cholesterol levels is more visible in carriers of APOE4. In Finland, the prevalence of the APOE4 gene variant is exceptionally high and approximately a third of the population are carriers.

Findings from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) Study, which followed 2,802 healthy older adults for 10 years, has found that those who participated in computer training designed to improve processing speed and visual attention had a 29% lower risk of developing dementia compared to controls, with more training producing lower risk. Those who received instruction in memory or reasoning strategies showed no change in dementia risk.

A long-running study involving 454 older adults who were given physical exams and cognitive tests every year for 20 years has found that those who moved more than average maintained more of their cognitive skills than people who were less active than average, even if they have brain lesions or biomarkers linked to dementia.

Data from the English Longitudinal Study of Aging, in which nearly 4,000 older adults (60+) had their walking speed assessed on two occasions in 2002-2003 and in 2004-2005, those with a slower walking speed were more likely to develop dementia in the next 10 years. Those who experienced a faster decline in walking speed over the two-year period were also more likely to develop dementia.

https://www.eurekalert.org/pub_releases/2018-03/ags-oaw032318.php

Data from 196,383 older adults (60+; mean age 64) in the UK Biobank found that a healthy lifestyle was associated with lower dementia risk regardless of genes.

Both an unhealthy lifestyle and high genetic risk were associated with higher dementia risk.

A very long-running study, in which 800 Swedish women (aged 38-54) were followed for 44 years, found that women with a high level of mental activities in midlife were 46% less likely to develop Alzheimer's disease and 34% less likely to develop dementia overall, compared with women with the low level of mental activities. Women who were physically active were 52% less likely to develop dementia with cerebrovascular disease and 56% less likely to develop mixed dementia, compared with women who were inactive.

Various forms of dementia, including Alzheimer's, involve brain network problems. Brain regions are not coordinating as well as they should; white matter is dysfunctional, impairing communications. It has even been suggested that problems in the default mode network (the "resting state" of the brain) may be the ultimate driver of the pathological characteristics of Alzheimer's, such as amyloid plaques, tau tangles, and brain atrophy. Regardless of the order of events, it does seem that network dysfunction is one of the big problems in dementia.