What happens to the body when you drink less water

A new study finds that people who don't drink enough water each day have a stronger biological response to stress, with significantly higher levels of the hormone cortisol - a hormone associated with stress - than people who drink enough water.

Research shows that cortisol levels are higher in people who drink less water. (Source: RTE)

Interestingly, this group did not feel more thirsty, but their bodies responded more negatively to stress.

The study was conducted by experts at Liverpool John Moores University (UK) on 32 adults, of which 16 people drank less than 1.5 liters of water/day and 16 people met the water intake recommendation.

Researchers monitored the hydration status of both groups for seven days through urine and blood samples, then invited them to take part in a stress test in the lab.

The test consisted of a surprise job interview: Each person had 10 minutes to prepare, then had to go into another room with a fake camera and answer questions in front of a “panel” of three people in white coats. Next, they were asked to do a mental math problem, subtracting numbers as quickly as possible.

It was a “truly disconcerting” experience, described by Professor Neil Walsh, School of Sport and Exercise Sciences , Liverpool John Moores University.

“We know that people who drink less than the recommended daily water intake are often dehydrated. But what we don’t know is whether their stress hormone response is greater when they are put into a controlled stressful situation,” said Professor Walsh.

To measure cortisol levels, researchers collected saliva samples before and after the test. Cortisol, also known as the stress hormone, is produced by the adrenal glands when the body is stressed and plays a role in immune response, metabolism, and blood pressure.

Results showed that the group that drank less water had higher cortisol levels.

Professor Shaw noted that external stress responses such as rapid heartbeat, sweaty palms and dry mouth were similar in both groups. “Both felt equally anxious and had similar increases in heart rate during the test. However, the group that drank less water daily had a much stronger cortisol response.”

The research results also reinforce advice from health agencies. Specifically, the European Food Safety Authority (EFSA) recommends that men should drink 2.5 liters of water per day, while women should drink 2 liters. Meanwhile, the UK's Healthy Eating Recommendation (Eatwell) also suggests that adults should drink 6-8 glasses of water per day, equivalent to 1.5-2 liters.

Experts emphasize that the need to drink water can increase when it is hot, the body is active, sick or during pregnancy and breastfeeding.

According to the research team, keeping a bottle of water next to you during stressful times not only helps you feel more comfortable mentally but also benefits your long-term health.

Source: https://baoquocte.vn/dieu-gi-xay-ra-voi-co-the-khi-uong-it-nuoc-325356.html