Caffeine Content in Popular Energy Drinks and Energy Shots

Transcription

1 MILITARY MEDICINE, 181, 9:1016, 2016 Caffeine Content in Popular Energy Drinks and Energy Shots Selasi Attipoe, MA; Jeffrey Leggit, MD; Patricia A. Deuster, PhD ABSTRACT The use of energy beverages is high among the general population and military personnel. Previous studies have reported discrepancies between the actual amount of caffeine in products and the amount of caffeine on stated labels. Thus, the purpose of this study was to examine the content of caffeine listed on the labels of various energy drinks and energy shots. Top-selling energy drinks (n = 9) and energy shots (n = 5) were purchased from retail stores. Three of each of the 14 products were purchased and analyzed for caffeine content by an independent laboratory. Of the 14 products tested, 5 did not provide caffeine amounts on their facts panel of those, 3 listed caffeine as an ingredient and 2 listed caffeine as part of a proprietary blend. The remaining 9 (of 14) products stated the amounts of caffeine on their labels, all of which were within 15% of the amount indicated on the label. In this study, although the energy beverages that indicated the amount of caffeine it contained had values within ±15% of the amount listed on the label, a potentially acceptable range, this finding is not acceptable with regard to current labeling regulations, which require added ingredients to total 100%. INTRODUCTION Since energy beverages (energy drinks and energy shots containing stimulants and additives) were introduced to the market a little over a decade ago, their popularity has soared. 1 The prevalence of adolescent and young adult energy beverage consumption is approximately 30 to 50%. 2 6 In 2012, the energy drink/shot market was worth more than $12.5 billion, a 60% increase from The increase in popularity of energy beverage consumption is also evident among military personnel. 8 Military personnel reportedly use these products to give them the edge, i.e., increased alertness and decreased mental fatigue, that they believe they need to complete various missions In light of these perceived benefits, the potential for overconsumption, intoxication, and adverse effects is possible, especially if the caffeine content of the beverage is higher than the amount indicated on the label. Symptoms of caffeine intoxication include anxiety, nervousness, restlessness, insomnia, gastrointestinal issues, and tachycardia and in rare cases, death. 1,12 The concern for inaccurate reporting of caffeine levels in energy beverages is warranted in light of recent scientific evidence highlighting discrepancies in caffeine amounts reported on dietary supplement labels. 13 The purpose of our study was to examine the accuracy of actual caffeine content of various energy drinks and energy shots compared to amounts listed on the labels. Findings from this study provide consumers and health policy professionals information Uniformed Services University, 4301 Jones Bridge Road, Bethesda, MD This article was presented in poster format at the Experimental Biology/ American Nutrition Society conference, San Diego, CA, April 26 30, 2014, and at Uniformed Services University Research Week, Bethesda, MD, May 14 15, The opinions and assertions expressed herein are those of the authors and should not be construed as reflecting those of the Uniformed Services University, Department of the Army, Department of the Air Force, Department of the Navy, or the U.S. Department of Defense. doi: /MILMED-D on the reliability of caffeine amounts reported on energy beverage labels. METHODS A total of 9 energy drinks and 5 energy shots were selected for analysis using consumer information from the scientific literature and Veterans Affairs. Energy beverages were purchased online and at retail stores in Maryland and Michigan in May Triplicates of each single product (from 2 or 3 different lots) were purchased and sent for independent testing according to standards for caffeine content. The quantity of caffeine for each beverage was determined by high-pressure liquid chromatography with ultraviolet absorbance after solvent extraction. When the caffeine level was below the limit of quantitation by the high-pressure liquid chromatography with ultraviolet method, liquid chromatography with tandem mass spectrometry detection was used. Actual caffeine content of all products was averaged across the triplicates and coefficients of variation were determined. For products with the caffeine content listed on the product label, laboratory values were compared to the label caffeine content. Data were analyzed using SPSS (v 20.0; IBM, Armonk, New York). Basic descriptive statistics were used for group characterization. RESULTS A total of 9 energy drinks and 5 energy shots were tested. Of these 14 products, 9 listed the amount of caffeine in the product on the label. All of these 9 products were within ±15% of the amount listed on the label. Values for the products that listed caffeine amount on their labels ranged from 75 to 240 mg for energy drinks and 31 to 270 mg for energy shots (Table I). On average, the amount of caffeine measured (151 mg) was slightly lower than what was reported on label (161 mg). The remaining 5 of 14 products did not list amounts of caffeine on the label. For these 5 products, 3 (2 energy 1016

2 Container Size TABLE I. Products That Quantified Caffeine (n = 9) Caffeine Label Claim Mean Caffeine Amount ± SEM (mg) Range (mg) Percent Difference From Caffeine Label Amount Energy Drink fl oz 80 mg/8.4 fl oz 76.3 ± fl oz 80 mg/8 fl oz 159 ± fl oz 200 mg/16 fl oz 190 ± fl oz 260 mg/16 fl oz 240 ± fl oz 100 mg/8 fl oz 177 ± fl oz 92 mg/16 fl oz 81.3 ± Pouch in 120 mg/1 Pouch in ± fl oz Water 8 fl oz Water Energy Shot 1 2 fl oz 35 mg 34 ± fl oz 300 mg ± of each product were purchased and assessed. drinks and 1 energy shot) listed caffeine as an ingredient and 2 (1 energy drink and 1 energy shot) listed caffeine as part of a proprietary blend. Table II presents the information for these 5 products. As shown, caffeine amounts ranged from 67 to 350 mg. 3 of the products had 150 mg and 1 had amounts ranging from 300 to 350 mg. Overall, for these 5 products, the average caffeine content was 178 mg. For all products, the coefficient of variation for the 3 analyses ranged from 0 to 8.7% with a mean of 3.2% and a standard deviation of 5.4 mg. 4 of the 9 energy beverages that listed the amount of caffeine on the label had a supplement facts panel, 4 had a nutrition facts panel, and 1 product line had both nutrition and supplement facts panels. 4 of the 5 energy beverages that did not list the amount of caffeine on the label had supplement facts panels; and the fifth had a nutrition facts panel. DISCUSSION The popularity of energy beverage consumption and associated adverse effects have led to scrutiny from scientific experts and attention from the media. Although energy drinks contain a variety of ingredients, the main active ingredient is caffeine; energy shots also contain B vitamins in excess of 2,000% of daily values on the basis of a 2,000 calorie diet, in addition to caffeine and other ingredients (e.g., taurine, guarana, l-glucoronolactone). In the most recent guidance for industry on substances added to foods, the Food and Drug Administration (FDA) stated that the addition of ingredients in excess of their traditional use levels is especially concerning, as it is unknown whether higher levels and new conditions of use are safe. 14 Thus, whereas the ergogenic effects of caffeine are well established, the safety and efficacy of these other added ingredients in energy beverages remain to be determined. 15 Current literature suggests that the physiological effects of energy beverages may differ from those of other caffeine-containing beverages because of additional ingredients (e.g., sugars, ginseng, guarana, taurine, B vitamins) present in energy beverages. 16,17 Our study suggests that if one plans to consume an energy beverage, it would be best to select one with a label that quantifies the actual amount of caffeine, given that products without the caffeine content listed may contain more than 300 mg. That energy beverages tend to be used in addition to, rather than replace caffeine from other sources such as coffee, is a concern. Also, some individuals consume multiple servings of these beverages in a short time, which could result in intoxication/overdose. In this study, we examined the caffeine content of selected energy drinks and shots to determine the caffeine amounts, and if the amounts indicated TABLE II. Products That Did Not Quantify Caffeine (n = 5) Container Size Caffeine Label Claim Mean Caffeine Amount ± SEM (mg) Range (mg) Energy Drink 8 16 fl oz Caffeine as part of 2,500 mg energy blend ± fl oz Caffeine listed as ingredient but not quantified 67.3 ± Energy Shot fl oz Caffeine as part of 1,870 mg energy blend ± fl oz Caffeine listed as ingredient but not quantified 150 ± fl oz Caffeine listed as ingredient but not quantified ± of each product were purchased and analyzed. 1017

3 on the label were consistent. All (9 of 9) of the energy beverages tested that listed the amount of caffeine had at least 88% of what was indicated on the label; some (6 of 9) of these amounts were comparable to or less than what is provided by an 8-ounce Starbucks brewed coffee (i.e., 180 mg). Many (4 of 5) of those that did not quantify caffeine had amounts in excess of 100 mg, with 1 containing as much as 350 mg. Findings in this study are comparable in some respects to a similar analysis conducted by Consumer Reports in December In the Consumer Reports study, caffeine content of 27 energy beverages was examined, 8 of which were also analyzed in the current study. 16 beverages reported caffeine amounts, and 60% (10 of 16) of those products had values within 20% of the actual numbers listed on the label; in our study, all the beverages met this criterion. Conversely, 30% (5 of 16) of the products in the Consumer Reports study had caffeine amounts greater than 20% above what was indicated on the label; and 1 product had caffeine amounts 70% below the labeled amount. According to the current FDA regulation, dietary ingredients that are specifically added to products must contain 100% of the volume or weight declared on the label (with the exception of a deviation that is attributable to the analytical method), whereas naturally occurring dietary ingredients must be present at 80% of the declared value. 19 Thus, a majority of the products tested by Consumer Reports and in the present study were misbranded and in violation of this guideline. 19 The findings of this study are more favorable than our findings from a previous similar study. 13 In the previous study, 45% of caffeine-containing dietary supplements that quantified caffeine on their label had within ±10% of the amounts on the label, whereas 25% varied widely from the laboratory-determined levels; 30% listed caffeine as an ingredient without quantifying the amount on the label. In the present study, all of the energy beverages that indicated caffeine amounts on their labels had actual quantities within ±15%. A study in 2007 by Andrews et al 20 also found that a majority (89%) of the supplements they tested had caffeine within ±20% of amounts indicated on labels. Thus, our findings are consistent but still do not meet the requirements of the FDA. Currently, disclosing the caffeine content is not required on beverages marketed as dietary supplements, but is required on products marketed as food if caffeine is added to the food (vs. naturally occurring). 21 This may explain in part why over half of the beverages we tested had supplement facts panels, and the remaining had nutrition facts panels. Interestingly, 1 product line had both nutrition and supplement facts panels. This is not surprising, as some companies are currently switching classification of their beverages from dietary supplement to food or vice versa. Until this market shift is complete, 1 product may be marketed as a dietary supplement or a conventional food (beverage). This lack of consistency can be confusing to the consumer. Occasional consumption of energy beverages may be acceptable for most adults. Data suggest that the safe upper limit of caffeine consumption in healthy adults is approximately 400 mg per day. 1,18,22 In pregnant women, the limit is 200 mg and for children the amount is 45 to 85 mg depending on weight. 18 In the military, moderate or optimal doses can be essential to maintain or improve cognitive function during exposure to severe stress; and it has been proposed that a dose of 200 mg appears to be optimal under such conditions. 23 On the other hand, excessive consumption of caffeine can be harmful, though significant personto-person variability exists. For example, overconsumption of caffeine can increase sleep complications and negatively affect daytime performance. 8,24 Centers for Disease Control and Prevention observed this phenomenon when they examined the relationship between energy drink consumption and self-reported effects on sleep and daytime activities in U.S. service members on deployment in Afghanistan. 8 In the study, the consumption of 3 or more energy drinks per day was associated with daytime sleepiness and sleep disturbances. Any product that markedly affects sleep and daytime activities could be detrimental in deployment and other high-stress settings. Moreover, the report 8 noted that sleep problems could substantially influence the health of an individual; thus, excessive energy drink consumption might indirectly contribute to poor health. As such, this issue has important implications for military health, readiness, and bearing. The use of energy drinks and energy shots among U.S. service members is common practice. About 30 to 50% of respondents to energy beverage surveys indicate that they consume energy beverages at least once per week or have consumed them in the past 30 days In the aforementioned Centers for Disease Control and Prevention survey of U.S. service members on deployment in Afghanistan, 45% indicated daily energy beverage consumption. 8 The wide variation in caffeine content in energy beverages available for purchase on military bases and the frequency of use raise concern, especially if consumption of these beverages is in addition to intake of other products containing caffeine such as coffee, medications, or select ration items. It is essential that physicians and health care providers are aware of the pervasive use of energy beverages and associated issues to counsel patients appropriately. For instance, energy beverages that declare caffeine on their labels but do not indicate amount could contain as much as 350 mg (energy shot) or 150 mg (energy drink) of caffeine. Also, consumers should be aware that there may be variances in the amount of caffeine in a given product compared to the amounts indicated on the label. This study presents findings on the status of labeling practices of energy drinks and energy shots. However, a few 1018

4 limitations must be noted. First, our sample size is small. Although this is a simple descriptive study, a larger sample size would enable one to generalize more broadly. Nonetheless, 3 analyses of each beverage were evaluated to allow the assessment of caffeine content variability from the multiple samples. Importantly, within-product variability was small (3.2%). In addition, products were purchased during the summer of 2013 when the energy beverage industry was under significant media and scientific scrutiny. Thus, thiscouldpossiblyhavebiasedtheresultsandtheymay not reflect practices before this period. Importantly, the current scrutiny of the issue may have altered the practices of various manufacturers, but no data are available to support these possibilities. Thus, it is possible that we may not have captured a stable market or obtained a good sampling of energy beverages. In summary, the results from this study suggest that the caffeine content of the energy beverages with caffeine amounts were within ±15%, but do not meet FDA guidelines. Beverages not listing caffeine on their labels consistently had higher amounts of caffeine ( 178 mg) than those with caffeine listed. Manufacturers should be diligent about listing the amount of caffeine on energy beverages. Consumers are advised to consume safe amounts of caffeine and avoid products that fail to list the amount of caffeine. ACKNOWLEDGMENTS We acknowledge Mr. Patrick Singly for his assistance in the initial planning phase of this study. We would also like to acknowledge Dr. Jonathan Scott for his intellectual contribution to and review of the manuscript. This work was supported by a grant from the Center Alliance for Dietary Supplement Research, NB91FD. SA and PAD designed research. SA wrote the article, conducted research, and analyzed data. PAD and JL had primary responsibility for final content. 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