Drinking water
New research from the University of Connecticut shows that even mild dehydration – like that a person might have after doing physical exercise, for example – has an effect on mood, and women seem to be better at picking up on the signs than men.
"We measured five different tests of cognitive function, as well as assessing mood, body temperature, heart rate, and taking blood samples pre and post the exercise, to assess how being dehydrated affects men’s and women’s physiology and emotional state," says lead study author Professor Lawrence E Armstrong. "Despite experiencing the same level of dehydration, women were far more likely to report feelings of tension, anger, fatigue and confusion. We found it also affected memory recall and decision making."
One of the possible reasons for this gender difference is that women showed a slightly greater change in blood concentration when compared to the men’s. A change in blood concentration is part of the body’s response to dehydration. Usually, the kidneys work hard to ensure that blood concentration is kept at an optimum level. "One study, for example, looked at more than 23,000 people who were consuming between one and six litres of water a day," says Armstrong. "Even though these people were drinking very different amounts, the concentration of blood was maintained because the kidney releases urine in varying amounts to compensate." If, however, the kidneys are unable to maintain the balance, dehydration occurs. And, says Armstrong, this is where the differences between the genders become interesting.
"We found that although both women and men were dehydrated to the same degree – 1.5% – women’s bodies were more sensitive to it, responding differently more quickly," says Armstrong. "Women showed an ability to sense what was going on in their bodies before the men did. This may work in a woman’s favour, as it means she’s less likely to put her body at risk of dehydration perhaps because she has earlier warning to correct dehydration."
First published May 13, 2011