Mild Dehydration Affects Brain Function

As global climate change extends heat waves from days into weeks of usually high temperatures, it’s important to understand how extreme heat can affect vulnerable people.  Elderly adults can more easily become dehydrated because they may lose some of their ability to sense thirst and their kidneys may be less efficient, and recent research has found that even mild dehydration can lead to cognitive and mood changes.

If you are finding it hard to concentrate or solve problems during unusually hot weather, try drinking more water, research has found that even mild dehydration can impact cognitive abilities. 

According to a recent National Public Radio report, even slight dehydration can lead to confused thinking and difficulty performing cognitive tasks such as following the rules of a complex card game.   There is also evidence from recent research that suggests excessive heat can slow down cognitive speed and hinder memory.  

High temperatures are especially dangerous when combined with high humidity; the body tries to cool itself by producing sweat but if perspiration can’t evaporate, the skin is not being cooled.  That’s why fans are ineffective in cooling a person down on a hot, humid day.  In fact, blowing hot air directly at someone on a very hot and humid day can heat a person up faster.  

Drinking water regularly throughout the day can help prevent the negative effects high temperature can have on the body and the brain.  How much water, including water from other beverages, fruits and vegetables, should the average adult consume?  According to the Food and Nutrition Board for Americans and Canadians, it is recommended that women consume 91 ounces of water and men 125 ounces of water from all sources each day.  Heat exposure and prolonged physical activity will increase water loss and may require adults to increase their daily fluid intake. 

Learn more about how heat stress can affect thinking by following this link to a recent article by Dr. David Benton of the University of Wales Swansea, published online in the journal Nutrients.