In that the loss of muscle strength is common and is associated with various adverse health outcomes in old age, Patricia A. Boyle, from Rush Alzheimer's Disease Center (Illinois, USA), and colleagues studied more than 900 community-based older persons, average age 80 years, without dementia at the study’s start, measuring the subjects’ strength in 9 muscle groups in the arms, legs, and axial muscles.  During the follow-up period that averaged 3.6 years, 138 persons developed AD, with these individuals being older, having worse mental function than the rest of the study participants, and being physically weaker.  After adjusting for confounding factors, the team found that muscle strength strongly influenced the risk of Alzheimer’s Disease: subjects who ranked in the top 10% for muscle strength were 61% less likely to develop Alzheimer's (as compared to the weakest 10%).  Physically stronger participants also showed a slower decline in their mental abilities over time.  Additionally, the relationship between muscle strength and mild mental difficulties, which occurred in an additional 275 people, was similar, with the strongest 10% being at 48% lower risk (than the weakest 10%).  Stating that: “These findings suggest a link between muscle strength, AD, and cognitive decline in older persons,” the ream posits that a possible explanation for the mental function-muscle strength link is that there is something going in the body that causes both muscle weakness and loss of mental ability.