Transcript Sweeteners - Plant Root Genomics Consortium Project

The skinny on artificial
sweeteners and weight gain
Presented by Ann Cohen
and Jessica Kovarik
Taste: how
Groups of taste cells on papillae (bumps)
Chemical binds with taste cell
 Depolarization of nerve fibers  action
potential to brain
 Adaptation of nerve transmittion
Taste: what and why
5 tastes: salty, sour, bitter, umami, and
sweet
 No longer taste ‘zones’
Taste and survival
 Avoid bitter
 Seek out sweet
Sweetness abounds
Sugar = Carbohydrates
 Simple and complex
Main source of energy (4 calories per gram)
Occur naturally in foods and added to foods
Simple sugars:
 Sucrose = glucose + fructose
Table sugar
 Lactose = glucose + galactose
Dairy
 Maltose = glucose + glucose
Germinating grains
Sweetness abounds
Other natural sweeteners:
 Honey, molasses, maple syrup, corn syrup,
high fructose corn syrup
 Sugar alcohols or polyols, such as mannitol,
sorbitol, isomalt
Sweet energy
Nutritive sweeteners
 Contain calories
 Honey, HFCS, table sugar, maple syrup, etc.
Nonnutritive sweeteners
 Reduced or no calories
 Sugar alcohols and artificial sweeteners
Getting 1+1=1: artificial sweeteners
Low-calorie sweeteners
 Sweet taste with fewer or no calories
 Food and Drug Administration approval
Six intense, low-calorie sweeteners:
 Saccharin – Sweet’N Low/Sugar Twin
 Acesulfame potassium (Ace-K)
 Aspartame
 Neotame
 Sucralose - Splenda
 Tagatose
Getting 1+1=1: artificial sweeteners
Sucralose aka Splenda
 Heat stable = use for baking
 3 chlorine atoms instead of hydroxyl groups
 600 times sweeter than sugar
 Created from sugar, so tastes similar to sugar
Body not able to break it down
Getting 1+1=1: artificial sweeteners
Stevia
 Natural sweetener extracted from plants
 Not FDA approved, so sold as a supplement
 Body cannot metabolize, so no calories
 Studies inconclusive about safety: some show
no adverse reactions, others suggest smaller
offspring
Rumor has it sugar causes…
Cavities
 Contact time of bacteria, not type of food leads
to decay
 i.e.: bread can be worse than caramel
Hyperactivity
 No scientific research to support
 Is it the sugar or the environment?
 May have a calming affect
Rumor has it sugar causes…
Diabetes
 Important to monitor to control diabetes
Obesity
 Energy imbalance leads to weight gain
High fructose corn syrup
What is it?
 Corn starch converted to glucose
 Glucose isomerized by enzymes to 42% or
55% fructose
 Named ‘high fructose’ to distinguish from
glucose corn syrup
 Sweet taste, low cost, easy to use resulting in
wide use
Soft drinks, fruit drinks, baked goods,
processed foods, dairy products
High fructose corn syrup
Media claims HFCS causes obesity
 Increase in obesity coincides with increased
HFCS use
i.e.: added to soft drinks in early 1980s
But obesity also problematic in countries where HFCS
use is not as prevalent
High fructose corn syrup
Media claims HFCS causes obesity
 Fructose converts to fat easier than glucose
Absorbed at different site by different mechanism
Any fructose metabolized same
 HFCS vs. sucrose
Fructose metabolized differently than glucose once in
the cell
Fructose verses glucose
Insulin
 Glucose causes insulin to be released
 Fructose does not stimulate insulin release
Satiety
 Glucose used by the brain and helps sense
satiety
Fructose verses glucose
Leptin
 Increased by insulin release
 Increased leptin  decreased food intake
Controls appetite
 Glucose  insulin release increased leptin 
decreased food intake
High fructose corn syrup verdict
No evidence to support HFCS contributes
significantly to obesity
Energy imbalance leads to obesity
Sweeteners and obesity
Artificial sweeteners may cause disruption
in body’s ability to gauge caloric density
Body appears to gauge calories based on
thickness
 Semi-solid and liquid foods/beverages inhibit
body’s ability to accurately compensate
Sweeteners and obesity
Obesity has continued to rise as use of
artificial sweeteners has risen
Multi-factorial problem
 Energy balance: energy in and energy out
 Sugar = calories
Excess calories (and inactivity) = weight gain
Weight balance = energy out vs. energy in
Laboratory ideas
Tooth Decay
 Explores the effect of various liquids on
decaying teeth
Sugar composition of beverages
 Determine the sugar content of various
beverages
All the same type: such as juice or soft drinks
Compare different types: such as milk, juice, soft
drinks, water, etc.
Experiments with soft drinks
 http://www.eepybird.com/science1.html
Resources for teachers
http://science.nsta.org/enewsletter/200606/member_high.htm
http://www.free-science-fair-projects.net/
 http://www.free-science-fairprojects.net/science-fair-projects-on-toothdecay.html
http://www.splenda.com/
http://www.eepybird.com/science1.html
References
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Physiology of taste. Accessed June 12, 2006 from
http://biology.about.com/library/organs/blpathodigest2.htm
Schorin MD. (2005). High fructose corn syrups, part 1. Nutrition Today, 40(6), 248-252.
Hein GL, Lineback DR, Storey ML, & White JS. (2005). Highs and lows of high fructose
corn syrup. Nutrition Today, 40(6), 253-256.
Science fair projects on tooth decay. Accessed June 12, 2006 from http://www.freescience-fair-projects.net/science-fair-projects-on-tooth-deecary.html
Juices. Accessed May 31, 2006, from
http://www.selah.k12.wa.us/MS/SciProj98/8TH/tarrahw/JUICES.HTML
Which beverage contains the most sugar? Accessed May 31, 2006, from
http://www.selah.k12.wa.us/MS/SciProj98/6TH/Sugar/COURTNEYA.HTML
Duyff RL. (2002). Complete food and nutrition guide. 2nd ed. Hoboken, New Jersey:
Wiley.
Physiology of taste. Accessed June 13, 2006, from
http://biology.about.com/library/organs/blpathodigest2.htm
Study: artificial sweeteners may disrupt body’s ability to count calories. (2004). Purdue
News. Accessed June 13, 2006, from
http://www.purdue.edu/UNS/html4ever/2004/040629.Swithers.research.html