Dehydration, UTIs and cognitive health: Getting enough to drink is complicated for people with brain disorders

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 disease may struggle to drink enough because of swallowing difficulties, even when they recognize thirst. Dehydration can, in turn, worsen confusion and impair thinking.

Why bladder health matters

Canadians are becoming increasingly aware of the importance of keeping their brains healthy and resilient to age well, not simply to live longer. A growing body of research shows that lifestyles that include a rich social life, frequent physical activity, eating a healthy MIND (Mediterranean-DASH Diet Intervention for Neurodegenerative Delay) diet and doing new and challenging things like cooking new recipes are important in keeping our brains healthy.

Yet, one aspect of protecting our cognitive functioning that is often neglected is maintaining our bladder and urinary tract health. Preventing urinary tract infections (UTIs) is a key part of keeping our brains healthy as we age.

How the risks of UTIs relate to brain health

While we typically think of UTIs as relatively minor infections, the health risks are not the same for all populations. UTIs are common, with more than 150 million people affected globally every year. While these infections are common in young sexually active women, seniors over the age of 65 also experience higher risk. The incidence rate then increases further after age 85.

UTIs present differently with age. UTIs are more common among the elderly, yet are often missed due to atypical symptoms.

In younger populations, the classic UTI symptom is a burning and/or painful sensation when urinating. Older adults may not show classic UTI signs. Sudden behavioural changes or changes in personality are important reasons to seek assessment. These can be indicators of UTIs in older adults, and can include mental fog, confusion, mood changes, extreme fatigue, balance problems and/or falls, loss of appetite, and new or increasing incontinence.

UTIs can cause inflammation. If unrecognized and untreated, this inflammation can impact the brain and cause cognitive decline. The risk is particularly high for those already suffering from brain disorders such as Alzheimer’s dementia and Parkinson’s disease. People with dementia are more likely to be dehydrated, and dehydration increases the risk of urinary tract infections. Risk of dehydration is high for those in long-term care.

It’s important to know that in older patients, UTIs can trigger delirium — a sudden change in attention, thinking and awareness. This delirium is often interpreted as part of dementia rather than as a symptom of a possible UTI, which can lead to delays in seeking treatment. And even more concerning, a growing body of research suggests that the impact of infection-induced delirium is not necessarily temporary. Research published in Alzheimer’s and Dementia discusses how UTI-related delirium “accelerates cognitive and functional decline.”

The study’s senior author, Dr. Shouri Lahiri, describes a “vicious cycle” in which dementia patients are at greater risk of infectious, while the delirium that accompanies infection contributes to cognitive decline.

Preventing dehydration and UTIs in seniors

Practical ways to prevent dehydration and UTIs in seniors include:

• Offering water and other drinks throughout the day, rather than waiting for them to ask.

• Paying attention to whether they’re actually drinking.

• Helping them use the toilet regularly and making it easier for them to find and reach the bathroom. Respond patiently to accidents and assist with personal care while respecting their dignity.

• Seeking prompt medical assessment for sudden, unexplained confusion or changes in alertness or behaviour. These changes can have several causes in which UTI could be one.

Caregivers play an important role in noticing sudden changes in behaviour, alertness or thinking. These changes should prompt medical assessment rather than being dismissed as aging or dementia. Nurses and doctors should investigate the cause and decide whether urine testing is needed.