Suddenly it’s summer again and I’m already noticing more patients coming in with diarrhea and the typical “gastro” symptoms that spike every summer. It’s usually not a big deal for adults, but I worry mostly about babies and toddlers, who can quickly dehydrate after a couple of days of severe diarrhea. That’s why my top priority in talking with the parents is to help their child stay hydrated. The basics include continuing to eat normal foods if possible, and certainly continue breast-feeding. As for fluid supplements, the best treatment remains the official WHO-approved Oral Rehydration Salts, which are sold OTC in all pharmacies worldwide. In America, the most common version is called Pedialyte. Pure water, by the way, is not the best treatment — it’s critical that sodium salts and sugar are included in it as well, in very specific amounts. That’s because you need glucose and sodium specifically to work together on a special molecule in our cells which helps to rehydrate.

So the first choice is to try to continue normal eating habits and get some official ORS packets or pre-made solutions (Pedialyte) at your local pharmacy or clinic. But what about all those sports drinks, sodas or juice? After all, don’t the Gatorade-type brands specifically advertise they can replenish your essential nutrients? What’s the actual data showing if these are helpful — or harmful?

The general consensus is that none of the above options are ideal. Juice, especially apple juice, also can make diarrhea worse. This is because there’s so much sugar and other ingredients in many of these drinks that their osmolality is much higher than a normal body can handle, and this higher osmolality actually pulls more liquid from your cells — making your dehydration and watery diarrhea worse, not better. Here’s a neat table from a good review article which shows the data from ORS compared to Coke, Pocari, Gatorade and other common brands:

An important column is the far right, showing osmolarity. Notice how much higher is Coke and energy drinks when compared to official ORS. Pocari Sweat is closer but still has much more glucose and much less sodium. I have another graph below from another review article which details why juices and chicken broth also are not ideal. Notice how apple juice is too concentrated, and chicken broth has too much salt:

Let’s hear from the experts

The take-home message, especially for parents, is that you should not reach for Gatorade, Coke, apple juice or many other drinks when you or your child are throwing up and having diarrhea. But don’t just take it from me; let’s hear from some experts. Here’s a nice synopsis from my Academy of Family Practice, from their article on management of acute gastroenteritis in children;

The time-honored “clear liquids” most often used by parents or recommended by physicians in the past are not appropriate for use in oral rehydration therapy. Drinks such as colas, ginger ale, apple juice and even commercial sports drinks (e.g., Gatorade) are inappropriately high in carbohydrates and osmolality(Table 7).¹¹ They can cause osmotic worsening of diarrhea, and their low sodium content may contribute to the development of hyponatremia. Tea should not be used because of its low sodium content, and chicken broth is contraindicated because of its high sodium content.^5,11 Furthermore, food should not be arbitrarily withheld because continued feeding or the early resumption of feeding improves outcome.

So you all get the idea now. As an aside, I think that sports drinks in general are a lot more hurtful than helpful, especially with childhood obesity rising so quickly. Here’s some helpful advice from the American Academy of Pediatrics:

Specific AAP recommendations regarding use of sports drinks and energy drinks in children and adolescents include the following:

• Pediatricians should educate patients and their parents regarding the potential health risks of energy drinks and sports drinks and explain the significant differences between these types of drinks. The terms should not be used interchangeably.
• Energy drinks should never be consumed by children or adolescents, because the stimulants they contain pose potential health risks.
• Children and adolescents should avoid and restrict routine consumption of carbohydrate-containing sports drinks, which can increase the risk for overweight, obesity, and dental erosion.
• For pediatric athletes, sports drinks should be consumed in combination with water during prolonged, vigorous physical activity, when rapid replenishment of carbohydrates and/or electrolytes is needed.
• For children and adolescents, water, not sports drinks, should be the principal source of hydration.