Regular water intake crucial for older citizens

Older people are especially at risk of becoming dehydrated during hot weather, because their brains underestimate how much water they need to rehydrate, according to new research by Melbourne’s Howard Florey Institute.

The researchers discovered that a region in the brain called the mid cingulate cortex, predicted how much water a person needed, but that this region could malfunction in older people.

The Institute’s Dr Michael Farrell, said that two groups – one aged 65 to 74 and another aged 21 to 30 – were infused with salty water to make them thirsty, and then participants were allowed to drink as much normal water as they wanted.

Dr Farrell said that, “although all participants had the same level of thirst, the older people only drank half as much water as the younger subjects.

“Using PET imaging, we found in the older people the mid cingulated cortex was ‘turned off’ much earlier by drinking small volumes.

“This discovery helps explain why the elderly can become easily dehydrated”.

With climate change likely to lead to higher summer temperatures, Dr Farrell recommended that older people ensure they drink enough water during warmer weather.

 “Adults should drink about eight glasses of water a day to prevent dehydration, and physically active people may need to drink more”, he said.