THE EFFECT OF ENERGY DRINKS ON THE HEART RATE OF DAPHNIA MAGNAOlivia Warner, Megan Levin, Rose Brusaferro and Trina SeunarineStevenson UniversityBIO 114 – Dr. Kimber

INTRODUCTION

Daphnia magna are freshwater crustaceans whose hearts can be seen clearly through a compound microscope.

Energy drink sales have increased by 55% every year since 2002.

Soda consumption has more than doubled since 1971. Previous research has focused on the link between soda

and obesity, diabetes, osteoporosis and cavities. Studies have shown that caffeine is a stimulant and

causes an increase in heart rate. What is caffeine’s effect on heart rate when combined

with other energy enhancing ingredients, as in energy drinks?

What effect do various types of soda have on heart rate?

INTRODUCTION (CONTINUED) Energy drinks with unique active ingredients

Amp Overdrive Yerba Mate

Sugar Free Rockstar Milk Thistle Extract

Lo-Carb Monster Glucose, Sodium Chloride, Glucuronolactone

Hypotheses Higher concentrations of energy drinks and

caffeinated sodas will increase the heart rate in D. magna.

Energy drinks with unique active ingredients will cause a more dramatic increase in the heart rate of D. magna than energy drinks without them.

MATERIAL AND METHODS Four different energy drinks were tested:

Amp Overdrive Lo-Carb Monster Amp Relaunch Sugar Free Rockstar

Two different sodas were tested: Caffeine-Free Pepsi Wild Cherry Pepsi

20, 10, and 5% concentrations of each drink in distilled water were administered to three D. magna per concentration

Heart rates were determined using a compound microscope and tally counter before and 2 minutes after administration

The average change in heart rates was calculated for each diluted solution

20, 10, and 5% concentrations were made using pond water from the D. magna container and distilled water as a control to rule out the possibility of distilled water affecting the heart rate.

RESULTS FOR ENERGY DRINKSEnergy Drink Dilution: 5% Dilution: 10% Dilution: 20%

Amp Overdrive

+71.1 bpm +11.65 bpm -23.3 bpm

Lo-Carb Monster

+55.6 bpm +45.6 bpm -34.5 bpm

Amp Relaunch

+10.0 bpm +16.7 bpm -58.4 bpm

Sugar Free Rockstar

+30.0 bpm +12.2 bpm -8.9 bpm

Original Pond Water

-7.8 bpm -1.1 bpm -7.9 bpm

RESULTS FOR ENERGY DRINKS

5% 10% 20%

-80

-60

-40

-20

0

20

40

60

80

Amp OverdriveLo-Carb MonsterAmp RelaunchSugar Free RockstarOriginal Pond Water

Percent Dilution

Ave

rage

Cha

nge

in H

eart

Ra

te (b

pm)

Figure 1: Average change in heart rate of D. magna based on percent dilution of given energy drinks.

RESULTS FOR PEPSI PRODUCTSPepsi Product Dilution: 5% Dilution: 10% Dilution: 20%

Caffeine-Free +48.9 bpm +51.1 bpm -16.7 bpm

Wild Cherry +76.7 bpm +23.3 bpm +33.4 bpm

Regular No data No data +6.7 bpm

Original Pond Water

-7.8 bpm -1.1 bpm -7.9 bpm

RESULTS FOR PEPSI PRODUCTS

5% 10% 20%

-40

-20

0

20

40

60

80

100

Caffeine-Free PepsiWild Cherry PepsiRegular PepsiOriginal Pond Water

Percent Dilution

Aver

age

Chan

ge in

Hea

rt R

ate

(bpm

)

Figure 2: Average change in heart rate of D. magna based on percent dilution of given Pepsi products.

OVERALL RESULTS

5% Solution 10% Solution 20% Solution

-60

-40

-20

0

20

40

60

80

AMP OverdriveLo-Carb MonsterAMP RelaunchSugar Free RockstarCaffeine-Free PepsiWild Cherry PepsiOriginal Pond Water

Percent Dilution

Aver

age

Chan

ge in

Hea

rt R

ate

(bpm

)

Figure 3: Average change in heart rate of D. magna based on percent dilution of given energy drinks and sodas

DISCUSSION Hypothesis #1 - Higher concentrations of

energy drinks and caffeinated sodas will increase the heart rate in D. magna. FALSE – Lower concentrations had the highest heart

rate, probably due to higher concentrations becoming toxic to the D. magna.

Hypothesis #2 - Energy drinks with unique active ingredients will cause a more dramatic increase in the heart rate of D. magna than energy drinks without them. TRUE – With the exception of Sugar Free Rockstar’s

milk thistle, energy drinks containing unique active ingredients caused higher heart rates in D. magna.

DISCUSSION At a 5% dilution, Amp Overdrive, Lo-Carb Monster and Wild Cherry Pepsi

averaged a high 69 bpm. At a 10% dilution, Lo-Carb Monster and Caffeine-Free Pepsi increased

heart rate higher than most of the highly sugared drinks. An anomaly is shown in the 20% dilution of Wild Cherry Pepsi. The

dilution increased the D. magna heart rate while the other dilutions and control showed a decrease in heart rate.

All of the energy drinks and soda solutions contained sugar and/or caffeine. D. magna heart rate was least affected by Sugar Free Rockstar which probably puts less strain on the heart.

Amp Overdrive had the greatest effect on D. magna heart rate, followed closely by Lo-Carb Monster- possibly due to the active ingredients yerba mate in Amp Overdrive and glucose, sodium chloride and glucuronolactone in Lo-Carb Monster.

The D. magna starting heart rates were fairly high in some of the specimens. To lessen or control stress levels of the organisms certain measures like light exposure, habitat they are kept in, and controlling the temperature of water must be taken.

Further experiments can be done to determine the effects of caffeine when combined with varying amounts of sugar on the heart rate of D. magna.