A large study has found that adults who don’t drink enough fluids daily—six to nine cups for women or eight to 12 cups for men—were more likely to develop chronic conditions, show signs of aging, and were more likely to die at a younger age.
Published on Jan. 2, the longitudinal study evaluated 11,255 adults over a 30-year period.
“The results suggest that proper hydration may slow down aging and prolong a disease-free life,” lead author and researcher in the Laboratory of Cardiovascular Regenerative Medicine at the National Heart, Lung, and Blood Institute, Natalia Dmitrieva said.
Participants were assessed during five medical visits—the first two when they were in their 50s, the last when they were between ages 70-90.
The researchers found that underhydrated adults were more likely to show signs of advanced biological aging, in the form of metabolic and heart health, lung function, and inflammation, than well-hydrated adults.
“Decreased body water content is the most common factor that increases serum sodium, which is why the results suggest that staying well hydrated may slow down the aging process and prevent or delay chronic disease,” Dmitrieva said.
Serum sodium levels go up when fluid intake goes down. Adults with higher than normal serum sodium levels were more likely to develop chronic conditions and die at a younger age.
Study author Dr. Manfred Boehm said that people who don’t drink enough would benefit from an evaluation of their fluid intake.
“The goal is to ensure patients are taking in enough fluids while assessing factors, like medications, that may lead to fluid loss,” Dr. Boehm said.
Eight Glasses of Water for Everyone?
The experts pointed to the standard recommendation for women to consume around six to nine cups (1.5-2.2 litres) of fluids daily and for men, eight to 12 cups (2-3 litres).The researchers found that water intake needs depends on water turnover, which is a more accurate marker of how much water people’s bodies actually need.
Published in the journal Science on Nov. 24, 2022, they said that older people generally need less water than adults between 20 and 40 years old.
Water turnover was highest among young men, ages 20 to 30, whereas for women, it was relatively unchanged from age 25 to 60, but pregnancy and breastfeeding increased it.
People in hot, humid environments had higher levels of water turnover and may need more than eight glasses of water daily.
Athletes had higher water turnover than inactive people, and people who do manual labour outdoors use more water than those working indoors at a desk.
All of these factors affect the amount of water an individual needs.
