Re: The truth about sports drinks
26 July 2012
The BMJ feature “The Truth About Sports Drinks” is sensational reading but contains many inaccuracies. I am repeatedly named for my supposed role in a poorly disguised conspiracy to dupe the public for personal gain. Since I was never contacted by the author, I would like to address some of the statements and innuendos. I will only comment on matters for which I have personal experience.
The BMJ feature implies that I have inappropriate “links” (i.e., conflict of interest) with the sports beverage industry because: a) I work for the U.S. military (referred to as “the biggest customer of Gatorade”); b) I receive monetary benefits (“not clear he receives funding directly”) and c) I attended exclusive Quakers Oats meetings in the 1990s. Regarding these “links”:
a) I do work for the U.S. Army, but am not aware of (or would have any role in) any contract or arrangement that the U.S. Army might have with Gatorade (or any sports beverage company). I did co-author U.S. Army guidance for sports beverage consumption during heat stress, which is contained in Technical Bulletin 507: Heat Stress Control and Heat Casualty Management (published March 2003, page 23). Briefly, that guidance recommends sports drink consumption for only specific conditions (e.g., prolonged [>4h] periods of profuse sweating if meals are not available), and only if the composition of such beverages is consistent with recommendations of the National Academy of Sciences (Fluid Replacement and Heat Stress, Institute of Medicine, 1994).
b) I do not have (nor have I ever had) any financial links with any beverage company or related entity. I have not received any monetary benefits from any beverage company, but did receive a beach towel, plastic bottle and t-shirt.
c) I did attend two meetings sponsored by Quaker Oats and both were in Hawaii (1989 and 1990). Both were high-quality meetings attended by ~25 other scientists who conducted research in the topic areas being discussed. This and all of my professional travel has always been pre-approved and in full compliance with U.S. Army Legal Policies.
The BMJ feature implies that I and others were appointed to “senior” editorial positions of influential journals (such as Journal of Applied Physiology and Medicine and Science in Sports and Exercise) due to our supposed association with the beverage industry. Since I have no such associations, these appointments were likely based on scientific merit.
The BMJ feature suggests that negative research findings, regarding hydration effects, cannot be published. That assertion is false as many hydration studies with negative findings have been published within the two targeted journals. Rather than representing a conspiracy to suppress research, an alternate explanation is that rejected papers lacked good science.
The BMJ feature suggests that Medicine and Science in Sports and Exercise (and Journal of Applied Physiology) suppressed Dr. Noakes (and scientists who supposedly were not purchased by the beverage industry) views related to hydration. I am not aware of any criteria for manuscript acceptance, besides scientific merit, being employed by these two journals. It is important to note that Dr. Noakes and I engaged in an invited Contrasting Perspective on “Does Dehydration Impair Exercise Performance” for Medicine and Science in Sports and Exercise (39:1209-1217, 2007). I believe that Dr. Noakes was given an opportunity to fully state his case without censorship. In addition, a recent publication (Shephard, R.J. British Journal of Sports Medicine 45:1238-1242, 2011) has challenged Dr. Noakes’ claims regarding suppression of several of his controversial theories by scholarly journals.
The BMJ feature twice quotes passages from an Institute of Medicine DRI report (Dietary Reference Intakes (DRI) for Water, Potassium, Chloride and Sulfate, 2005) to imply that the 2007 American College of Sports Medicine (ACSM) position statement (Medicine and Science in Sports and Exercise 39:377-390, 2007) is inconsistent with their findings. I served on that Institute of Medicine DRI Panel and am not aware of any meaningful inconsistencies between the Institute of Medicine findings and the 2007 ACSM position statement, which I chaired.
The BMJ feature advocated several positions that many scientists would disagree with. In contrast to the characterization in the BMJ feature, scientific evidence strongly supports that:
a) Dehydration can impair aerobic exercise performance during heat stress. This finding has been consistent throughout the scientific literature, well before sports beverages were invented, and continues to be better refined.
b) Dehydration “increases the risk” of heat exhaustion. Experimental studies support that dehydration will accentuate heat exhaustion and that hyperhydration is not protective.
c) Dehydration is a “risk factor” for heat stroke. This risk factor has been identified by epidemiological studies, and is supported by the observation that dehydration can mediate tissue under-perfusion which is likely an important mechanism for some heat stroke cases (Sawka et.al. Comprehensive Physiology 1:1883-1928, 2011).
The BMJ feature inaccurately describes the 2007 ACSM statement on Exercise and Fluid Replacement.
The ACSM position statement does not suggest that sports beverages have any “special” ingredients, does not indicate they should always be consumed, and does not imply they will prevent hyponatremia. The ACSM position statement recommends sports beverage composition (carbohydrate, sodium, potassium) and use that are consistent with the Institute of Medicine (1994) recommendations. The consumption of food, salted snacks, gels and energy bars are promoted as options to replace carbohydrate and electrolytes. Sports beverage consumption is promoted as one option to replace fluid under conditions where merited. Exercise hyponatremia is clearly stated as often being associated with fluid overdrinking.
The BMJ feature inaccurately suggests that the ACSM position statement recommends urine color as a measure of hydration status. In fact, the limitations of all urine indices are clearly articulated within the ACSM position statement.
The BMJ feature inaccurately suggests that that the ACSM position statement indicates that dehydration causes muscle cramps. The position stand provides a balanced presentation regarding associated factors, and it is stated that athletes experiencing muscle cramps, “have been reported to not have clinically different serum electrolyte concentrations”.
I appreciate the opportunity to share my thoughts with your readership.
Michael N. Sawka
Competing interests: None declared
Institute of Environmental Medicine, Natick MA
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