The Triathlete's Teeth - acidity in sport drinks

Some time ago, Active.com posted an article titled "Do Sports Drinks Cause Cavities?"  Working from a perspective of dental hygiene the article touched on something many athletes are somewhat aware of but often ignore --- ph levels in sport drinks.  I soon discovered that many who write about the subject only touch on a single aspect at a time and the lack of knowledge in some areas was startling.  In this case the focus was on how the combination of sugar and acid common in most sports drinks is a ripe environment for tooth decay.  The solution they proposed?  Rinse your mouth with water after workouts and take care of your teeth outside the sports arena.  Ground breaking stuff, huh?  Still, my curiosity was peaked especially since Gatorade was the only sport drink used as a reference ..... not exactly comprehensive.

For those new to the subject of pH balance, here's a quick primer.  The pH scale goes from 0 (acid) to 14 (base) with water being in the middle at 7.  Our blood is slightly alkaline at 7.5 and stomach acid is a 2.  Where does Gatorade fall?  A 2.73, the same as a Coca-Cola.  Yikes!  (NOTE: I didn't single these two products out.  They happen to be the most tested as they lead their respective markets.)

One of my first actions was to find information for my sport drink of choice:  Hammer Heed (melon flavor).  I scoured the Hammer Nutrition site which has tons of nutritional info but not one mention of pH levels.  I emailed their support and got a fairly quick reply with a copy of a response from their Senior Technical Advisor to a similar question in the past.  Here were the key points in the email:

1. Heed tested at a pH of 7.04, slightly above neutral (towards alkaline).
2. They believe it tests more neutral due to the lack of refined sugars (Heed favors complex carbs).
3. They also believe the inclusion of Xylitol plays a role.  What is Xylitol?  The short answer is it severely reduces the likeliness of an acid attack on the tooth enamel as it is not fermented in the metabolism of the offending bacteria.  In fact, when not in an acidic environment it can actually harden the soft, calcium-deficient enamel sites.

Naturally I was glad to find that my drink of choice wasn't acidic but one thing still bothered me ..... they "believe that HEED has a more-neutral pH is because of the lack of refined sugars".  The word "believe" isn't very definitive.  It looks like I'd need to dig deeper into this subject matter.

Ben Greenfield, an Ironman and 2008 Personal Trainer of the Year, has written extensively on this subject.  Most of his writings deal with the extremely common condition of an overly-acidic body during training and competition.  Some of the more interesting quotes:

“An over-acidic body reduces the amount of oxygen entering the cells, which accelerates free-radical damage and speeds lactic acid buildup. joint pain and muscle ache An over- acidic body leaches vital acidic-buffering minerals such as magnesium and calcium from bones. These minerals are forced to be redeployed into the blood in an attempt to balance the pH of the body by increasing alkalinity. The depletion of these minerals affects a myriad of body functions that are vital to athletes, including energy, endurance and recovery.”

“Every living organism on the planet relies upon a pH-balanced state, which is why fish die in acidic water and plants do not grow properly in excessively acidic soil. Athletes and all people are no different—they rely upon a net alkaline state to function properly.”

Wow!  All of a sudden we're talking about a lot more than tooth decay.  Drinking acidic, sugary sports drinks leads to depletion of minerals as our bodies attempt a balancing act.  Two minerals are mentioned specifically:  calcium and magnesium.  Turns out there's more than meets the eye when it comes to this pair of minerals.  The typical Western diet puts an emphasis on dairy consumption and calcium supplements yet other cultures with lower calcium intakes have fewer fractures and less prevalent osteoporosis.  Why?  Because the Western diet neglects magnesium and the two are out of balance.  Magnesium is crucial to calcium absorption and utilization.  It also has a big impact on sleep, hydration, metabolic efficiency, oxygen consumption, muscle function, and even heart rate.  In fact, Greenfield calls magnesium "the single most important mineral in sports nutrition."  Going back to my Hammer Heed, I was pleased to find 5% daily value of calcium balanced with 6% daily value of magnesium (coincidentally about a 2:1 ratio of calcium to magnesium).  I have yet to come across a sport drink or gel that doesn't include both minerals but the ratios vary wildly.  Where you need to be extra careful is when using supplements or other methods for getting calcium (such as Tums) as they often do NOT include the requisite magnesium for proper absorption and utilization.

In summary, watch out for too many simple sugars and imbalanced electrolytes that can lead not only to excessive tooth decay, but also a condition of over-acidity that will negatively impact your energy levels, endurance, and recovery.  What's in your sport drink, electrolyte tab, gel or chew?