Dehydration Can Lead to Cognitive Decline Among Middle Age And Older Adults: Study

Dehydration Can Lead to Cognitive Decline in Older AdultsDehydration can cause a range of issues, from minor mood changes to serious health problems. Penn State’s Department of Biobehavioral Health researchers studied how dehydration affects thinking skills.

They discovered that even being a little dehydrated can make it harder for people to focus on tasks for a long time. This highlights the importance of staying hydrated, especially as people get older.


The study showed that typical levels of dehydration from everyday activities made it harder for people to pay attention to tasks lasting over 14 minutes. However, it didn’t affect other brain functions like memory.

The findings were published in the American Journal of Human Biology.

Led by professors Asher Rosinger and Kyle Murdock, the research team evaluated 78 adults aged 47 to 70, all of whom had good access to safe drinking water three times over three months.

Rosinger noted that they chose to study middle-aged and older adults because this age group is at a higher risk for cognitive decline.

Earlier studies have raised concerns about how dehydration affects cell health, kidney function, aging, chronic diseases, and early death. These studies had mixed results on how dehydration affects thinking skills.

Unlike other studies that made participants dehydrated on purpose, this one observed natural dehydration from everyday activities. On assessment days, participants were instructed to avoid exercise, high-fat foods, and caffeine to measure their natural dehydration levels accurately.

To check hydration, the researchers measured the balance of dissolved particles like sodium and potassium in the blood, known as serum osmolality, at three different times.

In this study, people with a serum osmolality of over 300 milliosmoles per kilogram were considered dehydrated. These dehydrated individuals had more trouble maintaining attention. At each assessment, 29% to 39.1% of the participants were dehydrated.

Participants completed surveys and four brain tests that measured inhibition, memory, flexibility, and attention. The researchers found that the more dehydrated a person was, the worse they did on the attention task.

Rosinger explained that if a person drinks less water than their body needs daily, it might take them longer to complete certain long tasks with more mistakes.

The study found no significant link between dehydration and inhibition, memory, or flexibility.

Rosinger pointed out that dehydration only affected performance on tasks requiring sustained attention. This means that in daily life, when people are not dehydrated on purpose, their performance on short tasks is not affected by hydration levels.

The main finding is that dehydration impacts longer tasks and has real-life implications. Since many job duties require sustained attention without breaks, staying hydrated is crucial for proper brain function for these tasks.

Rosinger emphasized that older adults should drink water regularly to maintain attention and improve performance at work or while doing activities like reading emails or solving crosswords.

He mentioned that greater awareness of hydration could benefit older adults, as previous research showed that their sense of thirst decreases with age.

Rosinger stated that understanding hydration and cognitive performance is especially important for middle-aged and older adults because they are more prone to dehydration as they age and tend to drink less water.

The study also raised concerns about the broader impacts on people’s physical and mental health, especially those without reliable access to safe water.


Rosinger, who also studies water insecurity, noted that people without access to clean water might drink less water or switch to less healthy drinks like sugary beverages.

He plans to continue researching how hydration affects vulnerable adults and aims to improve access to clean, healthy water. His future work will look at how climate change and extreme weather affect water access and how to improve health and well-being through better water availability.

Rosinger recommended that older adults pay attention to their water intake, especially as rising temperatures will increase water needs.

Author Bio

Devon Andre has been involved in the health and dietary supplement industry for a number of years. Devon has written extensively for Bel Marra Health. He has a Bachelor of Forensic Science from the University of Windsor, and went on to complete a Juris Doctor from the University of Pittsburgh. Devon is keenly aware of trends and new developments in the area of health and wellness. He embraces an active lifestyle combining diet, exercise and healthy choices. By working to inform readers of the options available to them, he hopes to improve their health and quality of life.