For older adults with dementia or Parkinson’s disease, staying hydrated can be more complicated than simply drinking more water.

Dehydration can occur when fluid intake is insufficient, the body loses too much fluid or both occur together. This problem is widespread. A review of studies found that about one in four older adults outside of hospital settings experience dehydration due to insufficient fluid intake.

In Canada, a study of more than 96,000 Ontario long-term care residents aged 65 and older found that approximately one in six experienced dehydration during the study period.

When an older person becomes dehydrated, the advice seems straightforward: drink more water. But people with brain disorders, including dementia and Parkinson’s disease, may need help putting that advice into action.

Drinking is partly a brain-regulated behaviour: the brain detects changes in the body’s fluid balance, generates thirst and helps translate that signal into the behaviour needed to seek and drink water. Research involving people with Alzheimer’s dementia suggests that cognitive impairment may weaken their protective thirst response, reducing their ability to recognize and respond adequately to the body’s need for water. People with dementia may also forget to drink.

Similarly, older adults with Parkinson’s........

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