By Cheryl D. Davis and Nancy A. Rice, Western Kentucky UniversityBased on a case by Merle Heidemann and Gerald Urquhart, Michigan State University

Another Can of Bull? Do Energy Drinks Really Provide a Source of Energy?

Do energy drinks really live up to their claims?

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http://abcnews.go.com/Video/playerIndex?id=2622366

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CQ#1: Which of the following best describes your use of energy drinks?

A. I have never tried an energy drink.B. I drink an energy drink occasionally.C. I drink an energy drink whenever I

need a “boost” of energy.D. I drink an energy drink almost every

day.

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CQ#2: I drink energy drinks because:

A. They do give me an energy boost.B. They taste good.C. They give me an energy boost and

they taste good.D. I don’t drink energy drinks.

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CQ#3: The average cost of a canned energy drink is:

A. $1B. $2C. $3D. $4

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The Case

The job was fantastic! Since high school, where she had excelled in cross country, Rhonda had been a consistent runner, participating in local races and those assigned to her for her job. For her last assignment, she had run in and reported about the Leadwood, South Dakota marathon, and it was a blast!

After spending several years working at the Sports Desk of the Lansing State Journal, Rhonda found the job of her dreams as a writer for Running Magazine.

Rhonda’s StoryThe day she returned, her boss Charley walked in her office with a can of Red Bull® in one hand and a list of several other energy drinks in the other. “We’ve been getting a lot of inquiries about the different energy drinks on the market. Do you know anything about them?” Charley asked.

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“I do know that people use them for various reasons,” replied Rhonda. “They’re primarily used by athletes to provide some “fuel” as they practice and compete. Other people use them more casually as a way to become more ‘energized.’ That’s about all I know.”

“For your next assignment,” Charley continued, “I want you to find out what each of the ingredients in these drinks is and what it does for a runner or for a non-athlete. You need to be very accurate in your analysis. Determine what each component really does for the body, not what the marketers want us to believe it does. Then look at the marketing claims to see if the scientific facts match up to them. Here are the marketing claims, a list of ingredients and nutrition facts provided on the cans for consumers.”

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As Charley left the office, Rhonda looked over the materials.

“Guess I’ll have to brush up on my biochemistry. No problem. I’m interested in knowing if my running would be improved by drinking this stuff.”

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Rhonda perused the marketing claims for each drink on the list.Red Bull® (from advertising materials)

• is a functional product developed especially for periods of increased mental and physical exertion.

• can be drunk in virtually any situation.• improves performance, especially during times of

increased stress or strain.• improves concentration and reaction speed.• stimulates the metabolism.

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Lo-Carb Monster Energy® (from advertising materials)

• Tear into a can of the meanest energy supplement on the planet. We went down to the lab and cooked up a double shot of our killer energy brew.

• We hacked out the carbohydrates and calories, transplanted the “wicked buzz,” and dialed in the flavor.

• Lo-Carb MONSTER energy drink still delivers twice the BUZZ of a regular energy drink, but only has a fraction of the calories.

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Sobe Adrenaline Rush® (from advertising materials)

• This maximum energy supplement delivers an energy boost with a natural passion fruit flavor. It’s lightly carbonated with a clean smooth feel.

• This maximum energy supplement delivers an energy boost with a unique blend of natural energizing elements, including d-ribose, l-carnitine and taurine. It’s pure, concentrated energy in an 8.3 fluid ounce can.

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Impulse® (from advertising materials)

• Elevate Your Performance.• Impulse® Energy Drink contains special

supplements to immediately enhance mental and physical efficiency and give you the energy boost you deserve…replenishing your strength.

• Impulse® Energy Drink gets its energy from a simple source: nutrients, minerals, and vitamins that occur naturally in the body and foods we eat. Enjoy: the wake-up power of caffeine, the alertness-inducing properties of taurine, the lift you get from vitamin B6 and B12. Combined with Impulse’s other ingredients, these are known to increase mental focus and physical well being, enhance performance, and accelerate metabolism.

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Rhonda recalled that a food’s calorie content was the simplest reflection of its energy content. Looking at Charley’s list, she saw that the different energy drinks contained the following calories per can:

– Lo-Carb Monster® 20– Red Bull® 110– Sobe Adrenaline Rush® 140– Impulse® 110

For comparison– Coca Cola® 140

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Rhonda realized that before she could start analyzing the energy drinks, she needed to know the answer to the following questions:

When we say something gives us “energy” what does that mean?

What is a biological definition of energy?

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CQ#4: Food energy is the amount of stored chemical energy in food that is available following digestion and metabolism. The most common value for expressing the amount of available energy in food is:

A. CalvinsB. JoulesC. OuncesD. Calories

How is food used for energy?A brief review of metabolism

• Adenosine triphosphate (ATP) is the primary energy molecule of organisms

• The hydrolysis of ATP provides the chemical energy that powers most cell work.

• On the flip side, making ATP takes energy; this comes from the oxidation of sugars and other reduced compounds.

• This energy is used to phosphorylate adenine diphosphate (ADP) to make ATP

+ H20

ATP

ADP + Pi

+ 7.3 kcal/mol of ATP

Energy18

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So, how do we get from food to ATP?

• Respiration and fermentation are two of the fundamental chemical reactions that power metabolism.

• Metabolism is the process by which the cells break down (or build up) glucose and produce ATP in order to provide the cell with a constant source of energy.

• Glucose is a key intermediary in cell metabolism. Cells use glucose to build fats, carbohydrates, and other compounds; and cells recover glucose by breaking down these molecules.

• Glucose is a monosaccharide (carbohydrate) that is oxidized through either cellular respiration (under aerobic conditions) or fermentation (under anaerobic conditions) to produce ATP.

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Energy use

Energy conversion Energy storage

CO2 + H2O + sunlight(Fats and carbohydrates)(Photosynthesis)

Glucose

O2 + (CH20)n

RespirationGlucose + O2 + ADP + Pi

CO2 + H2O + ATP (high yield!)

FermentationGlucose + ADP + Pi

Small organic molecules + ATP (low yield) But it is fast!

Matter conversions that accompany energy transformations / transfers

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CQ#5: ATP is used as an energy source for nearly all cellular metabolic processes. Which of the following macromolecules, if available, is used preferentially for ATP synthesis?

A. Amino acidsB. CaffeineC. ProteinsD. LipidsE. Carbohydrates

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The combination of glycolysis, the Krebs cycle, and the electron transport chain is called cellular respiration.

Glycolysis Pyruvate processing and Krebs Cycle

Electron Transport and Oxidative Phosphorylation

Glucose Pyruvate

ATP

CO2

NADH

CO2

NADH

KrebsCycle

NADHFADH2

ATP

Electron transport chain establishes a proton gradient that is used to produce ATP

O2 H20

ATP

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Processing Glucose: Glycolysis• Glycolysis, a series of ten chemical reactions that take

place in the cytoplasm of the cell, is the first step in glucose oxidation.

• In glycolysis, glucose is broken down into two molecules of pyruvate.

• Nicotinamide adenine dinucleotide (NAD+) is reduced to NADH, an electron carrier that donates electrons to more oxidized molecules.

• At the end of glycolysis, each molecule of glucose yields a net gain of 2 ATP molecules.

GLYCOLYSIS

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CQ#6: The net products of glycolysis are:

A. 2 ATP, 2 CO2 , 2 ethanol

B. 2 ATP, 2 NAD+, 2 acetateC. 2 ATP, 2 NADH, 2 pyruvateD. 38 ATP, 6 CO2, 6 H2O

E. 4 ATP, 2 FADH2, 2 pyruvate

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The Krebs Cycle• In the presence of O2, the pyruvate of most cells

enters the Krebs cycle (citric acid cycle), in which each pyruvate is oxidized to three molecules of CO2.

• 6 additional (NAD+) molecules are reduced to 6 NADH, and 2 FAD+ (a second electron carrier) are reduced to form 2 FADH2.

• 2 additional ATPs are formed as the 2 pyruvates are oxidized in the Krebs cycle.

• The Kreb’s cycle occurs in the mitochondria of eukaryotic cells.

The Krebs Cycle

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Electron TransportThe high-potential-energy electrons carried by NADH and FADH2 participate in a series of redox reactions. These electrons are passed down an electron transport chain (ETC) in the inner mitochondrial membrane of eukaryotes (and in the cell membrane of prokaryotes).

Simultaneously, protons are pumped across the inner mitochondrial membrane generating a proton gradient with high potential energy.

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ATP Synthase

• The proton gradient drives the production of ATP through the mechanical rotation of the enzyme ATP synthase.

ADP + Pi ATP

Matrix

Intermembrane space

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CQ#7: You have a friend who lost 15 pounds of fat on a diet. Where did the fat go?

A. It was released as CO2 and H2O.B. It was converted to heat and then

released.C. It was converted to ATP, which weighs

less than fat.D. It was broken down into amino acids and

eliminated from the body.E. It was converted to urine and eliminated

from the body.

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Rhonda was determined to wade through the confusing labeling of the drinks. The first thing she needed to do was sort out the various ingredients on the labels- a task that consumers rarely undertake. She decided she to determine a few things:

– What is the nature (sugar, fat, amino acid, vitamin, etc.) of each ingredient listed on the cans?

– What is the physiological role of each in the human body?

– Which ingredients actually provide energy?

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CQ#8: The most common ingredient in energy drinks is caffeine. Do you think caffeine is a source of energy?

A: YesB: No

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Rhonda started her research with Caffeine. She discovered that:– small to moderate amounts (50-300 mg) of caffeine act as a

mild stimulant. – Caffeine increases heart rate and blood pressure.– Athletes have taken advantage of the stimulant effect of

caffeine for many years.

Rhonda also discovered that individuals differ in their sensitivity to caffeine. Some are sensitive to the effects of caffeine at very small doses, and pregnancy and age can affect this sensitivity. Even in people who consume caffeine regularly, the stimulant effect is not always consistent. This suggests that we may actually become less sensitive to the effects of caffeine over time.

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Rhonda discovered that energy drinks typically contain large doses of caffeine. In fact, she learned that energy drinks may contain as much as 80 mg of caffeine, the equivalent of a cup of coffee. Compared to the 37 mg of caffeine in a Mountain Dew, or the 23 mg in a Coca-Cola Classic, that's a big punch!

She also found that many energy drinks add other legal stimulants like ephedrine, guarana, and ginseng.

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Your Task:• Research each ingredient found in one of the

energy drinks (or in Coca Cola®) using the information provided in your handout. Work in groups of two or three so that one person can record the relevant information.

• Place each ingredient for your drink under the proper heading in the table provided.

• We will summarize the information on the boards in front of the room and then discuss the results.

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CQ#9: Based upon the class analysis, which of the following “energy drinks” actually provides more energy per can than a 12oz can of Coca Cola®?

A. Red Bull®B. Impulse®

C. Lo-Carb Monster®

D. SoBe Adrenaline Rush®

E. None of the above

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Rhonda finished her research and started writing her article. She wanted her article for Running Magazine to be a real eye opener for the readers. Her overall message would be to “Know What You're Drinking.”

Charley stopped by her office to see how everything was going. “Hey Rhonda, so what about those energy drinks? Are they good for you?”

“Oh hi Charley. Well, based upon my research I don’t think they are necessarily bad for you, but they shouldn't be seen as "natural alternatives" either. Some of the marketing claims they make like "improved performance and concentration" are down right misleading.”

“Really?” Charley sounded intrigued.

“Well, I think people should think of energy drinks more as highly-caffeinated beverages. They’ll have a much more accurate picture of what they are and how they affect you.”

“These drinks are just loaded with stimulants – not true sources of energy. I mean you wouldn't use Mountain Dew as a sports drink, and you shouldn’t use most of the energy drinks as a sports drink either,” said Ronda.

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“Sounds like good work, Rhonda.” Charley said as he headed out the door.

“Oh, I forgot. I am going to include in my article some information about the growing trend of mixing energy drinks with alcohol. Apparently, a drink made with Red Bull and vodka is very much like mixing strong coffee and whiskey. Worse yet, since energy drinks are stimulants and alcohol is a depressant, the combination may be dangerous.

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“There is a nation-wide concern about the marketing of these mixed drinks. Moreover, both energy drinks and alcohol are very dehydrating (the caffeine in energy drinks is a diuretic). Dehydration hinders your body's ability to metabolize alcohol and will increase the toxicity, and therefore the hangover, the next day.” said Rhonda.

http://www.cbsnews.com/video/watch/?id=3465186n%3fsource=search_video

“Sounds like a really important thing for young people to know. You’ve done a great job, Rhonda. This will be a super story for our magazine.”

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CQ#10: Should you simply buy a soft drink rather than one of these energy drinks when you need an energy boost?

A. YesB. NoC. Still undecided

Slide CreditsSlide 1

Description: Photo of a can of Red Bull®. Author: Böhringer Source: Wikimedia Commons, http://commons.wikimedia.org/wiki/File:070506_RedBull08.JPG Clearance: Licensed in accordance with Creative Commons Attribution-Share Alike 2.5 Generic.

Slide 6 Description: Female photographer close taking pictures at marathon. Author: Wolfgang Amri Source: Dreamstime, ID: 10099451 Clearance: Copyrighted, licensed, royalty free.

Slide 7 Description: Generic energy drink can. Author: Ashestosky Source: Dreamstime, ID: 10573205 Clearance: Copyrighted, licensed, royalty free.

Slide 8 Description: Runner with paper drink cups. Author: Wolfgang Amri Source: Dreamstime, ID: 9102948 Clearance: Copyrighted, licensed, royalty free.

Slide 9Description: Line drawing of Erlenmeyer shape.Author: Danilo PSource: Wikimedia Commons, http://commons.wikimedia.org/wiki/Image:Erlenmayer_shape.svgClearance: Licensed in accordance with Creative Commons Attribution-Share Alike 3.0 Unported.

Slide 10 Description: Woman jogger with applied motion blur. Author: Ronfromyork Source: Dreamstime, ID: 1338730 Clearance: Copyrighted, licensed, royalty free.

Slide 16 Description: Drawing of lithium atom. Author: Halfdan Source: Wikimedia Commons, http://commons.wikimedia.org/wiki/File:Stylised_Lithium_Atom.png Clearance: Licensed in accordance with Creative Commons Attribution-Share Alike 3.0 Unported.

Slide 18 Description: ATP → ADP Author: Cheryl D. Davis and Nancy A. Rice, authors of this case study. Clearance: Used with permission.

Slide 20 —Top left Description: Green plant Source: Wikimedia Commons, http://commons.wikimedia.org/wiki/File:Chélidoine.JPG Clearance: Released by author into the public domain.

Slide 20 —Top right Description: Potatoes Source: Wikimedia Commons, http://commons.wikimedia.org/wiki/Image:Potatoes.jpg Clearance: This image is a work of a United States Department of Agriculture employee, taken or made during the course of the

person’s official duties. As a work of the U.S. federal government, the image is in the public domain.

Slide 20 —Bottom Description: Runners Author: Steve Gregory Source: Wikimedia Commons, http://commons.wikimedia.org/wiki/Image:Bristol_Half_Marathon.jpg Clearance: Used in accordance with Creative Commons Attribution-Share Alike 2.5 Generic license.

Slide 22 Description: Overview of cellular respiration Author: Cheryl D. Davis and Nancy A. Rice, authors of this case study. Clearance: Used with permission.

Slide 23 Description: Animal cell Author: Jomegat Source: Wikimedia Commons, http://commons.wikimedia.org/wiki/Image:Cell_parts.png Clearance: Used in accordance with Creative Commons Attribution-Share Alike 2.5 Generic license.

Slide 24 Description: Pathway of glycolysis Source: Wikimedia Commons, http://commons.wikimedia.org/wiki/Image:GlycolysisPathway.svg Clearance: Released by author into the public domain.

Slide 26 Description: Mitochondrion Author: Mariana Ruiz Villarreal LadyofHats Source: Wikimedia Commons,

http://commons.wikimedia.org/wiki/File:Animal_mitochondrion_diagram_en.svg Clearance: Released by author into the public domain.

Slide 27 Description: Krebs cycle Author: YassineMrabet Source: Wikimedia Commons, http://commons.wikimedia.org/wiki/Image:Citricacidcycle_ball.svg Clearance: Used in accordance with Creative Commons Attribution-Share Alike 3.0 Unported license.

Slide 28 Description: Electron transport chain Author: Fvasconcellos Source: Wikimedia Commons,

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Clearance: Released by author into the public domain.

Slide 29 Description: ATP Synthase Author: Modified version of PDB image by User:TimVickers. Source: Wikimedia Commons, http://commons.wikimedia.org/wiki/File:ATPsynthase_labelled.png Clearance: Used in accordance with Creative Commons Attribution-Share Alike 3.0 Unported license.

Slide 32 Description: Caffeine molecule Source: Wikimedia Commons, http://commons.wikimedia.org/wiki/File:Caffeine_molecule.png Clearance: Used in accordance with Creative Commons Attribution-Share Alike 3.0 Unported license.

Slide 34 Description: Cup of coffee Author: Julius Schorzman Source: Wikimedia Commons, http://commons.wikimedia.org/wiki/File:A_small_cup_of_coffee.JPG Clearance: Used in accordance with Creative Commons Attribution-Share Alike 2.0 Generic license.

Slide 39 Description: Skull and crossbones Source: Wikimedia Commons, http://commons.wikimedia.org/wiki/Image:Skull_and_crossbones.svg Clearance: Released by author into the public domain.