1. THE EFFECT OF ENERGY DRINKS ON
THE HEART RATE OF DAPHNIA
MAGNA
Olivia Warner, Megan Levin, Rose Brusaferro and Trina
Seunarine
Stevenson University
BIO 114 – Dr. Kimber

2. 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?

3. 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.

4. 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.

5. RESULTS FOR ENERGY DRINKS
Energy 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

6. RESULTS FOR ENERGY DRINKS
-80
-60
-40
-20
0
20
40
60
80
5% 10% 20%
AverageChangeinHeartRate
(bpm)
Percent Dilution
Amp Overdrive
Lo-Carb Monster
Amp Relaunch
Sugar Free Rockstar
Original Pond Water
Figure 1: Average change in heart rate of D. magna based on percent dilution of given
energy drinks.

7. RESULTS FOR PEPSI PRODUCTS
Pepsi 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

8. RESULTS FOR PEPSI PRODUCTS
-40
-20
0
20
40
60
80
100
5% 10% 20%
AverageChangeinHeartRate(bpm)
Percent Dilution
Caffeine-Free Pepsi
Wild Cherry Pepsi
Regular Pepsi
Original Pond Water
Figure 2: Average change in heart rate of D. magna based on percent dilution of given
Pepsi products.

9. OVERALL RESULTS
-60
-40
-20
0
20
40
60
80
5% Solution 10% Solution 20% Solution
AverageChangeinHeartRate(bpm)
Percent Dilution
AMP Overdrive
Lo-Carb Monster
AMP Relaunch
Sugar Free Rockstar
Caffeine-Free Pepsi
Wild Cherry Pepsi
Original Pond Water
Figure 3: Average change in heart rate of D. magna based on percent dilution of given
energy drinks and sodas

10. 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.

11. 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.