Benefits of staying hydrated: why it could help you age healthily

Researchers analysed sodium levels in the blood of 15,700 adults, aged 45-66, for 25 years. Drinking water is important for maintaining normal sodium levels, so the amount of sodium in someone’s blood can be used to measure how hydrated they are. 

Findings showed that people who had the higher end of a normal range of sodium in their blood had a 39% greater chance of developing chronic illnesses. They were also 50% more likely to have biological markers of age older than their chronological age. Chronological age is the number of years you’ve been alive, while biological age refers to the physical age of your cells and tissues. 

Lesley Carter, a registered nurse and programme lead at the Malnutrition Task Force, which is supported by Age UK, agrees. She explains that not having enough fluid can cause an imbalance of electrolytes, such as sodium, which can affect your overall health. “Drink around six to eight glasses or 1.5 litres of fluid per day,” she says. Your fluid needs can vary and depend on a variety of factors, including your age, lifestyle, body size and climate. 

Authors of the study did note the need for more studies to confirm the link between hydration and ageing. 

Staying hydrated can provide many benefits for your health.  

• It can help prevent urinary tract infections – by diluting your urine and ensuring you pee often. This allows bacteria to be flushed from your urinary tract before an infection can begin.  
• It can ease constipation – drinking enough helps to keep stools soft and makes them move through the bowel and pass more easily. Carter explains this is especially important for people on certain medications that can contribute to constipation. 
• Research shows increasing water intake can reduce or prevent headache pain. 
• Boost cognitive function and mood – studies show that drinking water can have positive effects, particularly by maintaining visual attention and increasing alertness. 
• Better breathing – Carter says drinking enough fluids means your blood will be well oxygenated, which will help you to breathe well.  
• It can improve sleep – there is increasing research into the link between hydration and sleep. According to the Sleep Foundation, staying hydrated can reduce sleep disturbances. 

Carter says: “Fluid is not just about water. If you don’t like water and the thought of drinking eight cups is beyond you, you could have soup or custard.” She also suggests a cup of tea or coffee, or a stew with gravy, as alternatives. 

“Make it work for you. Have things that you enjoy and you can manage.” 

Some older people or those with chronic illnesses, such as dementia, can experience issues with drinking enough fluid. 

Carter says: “As you age, you don’t necessarily feel as thirsty or the need to drink as much as you did when you were younger. 

“Some people don’t realise how important being hydrated is.”  

Another issue, she says, is that those with a weak bladder may worry about being incontinent and choose not to drink so much because of that. But Carter explains the idea that reducing fluid intake will reduce the amount you’re peeing is a myth. 

“When you drink less, your kidneys overact, and this can make you pee even more.” 

Carter says people with dementia may have forgotten that they haven’t had a drink or that they need to drink throughout the day. “If they’re living alone and they haven’t got any reminders, they won’t drink.” 

Carter’s top takeaway? Get your equivalent of six to eight glasses of fluid per day. “If you don’t reach eight glasses one day, don’t beat yourself up. Start again tomorrow.” 

The Malnutrition Task Force has more advice on managing hydration.