Transcript Carbs_Part 1_Feb 14 - 35-206-202

CARBOHYDRATES
CHAPTER 5
LEARNING OUTCOMES
• Identify the major types of carbohydrates and give
examples of food sources for each
• List alternative sweeteners that can be used to
reduce sugar intake and know how they work
• Describe recommendations for carbohydrate
intake and health risks caused by low or excessive
intakes
• List the functions of carbohydrates in the body
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LEARNING OUTCOMES
• Explain how carbohydrates are digested and
absorbed
• Identify the cause of, effects of and dietary
treatment for lactose intolerance
• Describe the regulation of blood glucose,
conditions caused by blood glucose imbalance,
types of diabetes, and dietary treatment for
diabetes
• Explain the basis of low carbohydrate diets and low
glycemic index diets and the pros and cons of
following them
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CARBOHYDRATES
• Composed of carbon,
hydrogen and oxygen
• Produced by plants via
photosynthesis
• Simple carbohydrates
• Monosaccharides and
Disaccharides
• Complex
carbohydrates
• Polysaccharides,
Glycogen and Fiber
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CARBOHYDRATES
Sources of carbohydrates in the diet: Plants
Plants use carbon and oxygen from the CO2 in the air and
hydrogen from H2O and energy from the sun to make glucose
(carbs).
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Pasta
Rice
Potatoes
Bread
Fruits
Veggies
Milk
Legumes
These foods should make up 45-65% of our daily intake
Desserts
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MONOSACCHARIDES
6 carbon, single units
• Glucose
• Blood sugar, corn syrup
• Fructose
• Fruit sugar
• Galactose
• Part of lactose
• Sugar Alcohols
• Xylitol, mannitol and sorbitol
• Pentoses (5 carbon)
• Ribose and Deoxyribose
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MONOSACCHARIDES (SIMPLE SUGAR)
Each contains
6 Carbons
12 Hydrogen
6 Oxygen atoms
but in different
configurations
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DISACCHARIDES (SIMPLE SUGAR)
Two monosaccharides linked
by a condensation reaction
(loss of H20 molecule in this case.)
• Maltose
• Glucose and Glucose-alpha
bond
• Sucrose
• Glucose and Fructose-alpha
bond
• Lactose
• Galactose and Glucosebeta bond
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DISACCHARIDES
Sucrose
Alpha bond
Maltose
Alpha bond
Lactose
Beta bond (harder to
break down)
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OLIGOSACCHARIDES
• Oligo (means “few” and is 3-10 in this case)
• Raffinose• Stachyose (found in some vegetables, grains
and beans)
• Our bodies cannot break down
oligosaccharides they get to our small intestines
where the bacteria there metabolize them and
turn them into gas.
• Beano can break down these sugars for us
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DIGESTIBLE POLYSACCHARIDES
Polysaccharides
• Contains many glucose molecules (hundreds to
thousands)
• Alpha or beta bond determine digestibility
Starch
• Amylose-straight chain
• Amylopectin-branched
Glycogen- digestible
• Storage form of glucose in human body
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DIGESTIBLE POLYSACCHARIDES
Amylose (1-4 alpha
bonds broken by
amalase)
Amylopectin (1-4
and 1-6 alpha bondsbroken by alphadextrinase)
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DIGESTIBLE POLYSACCHARIDES
Glycogen (alpha bonds)
- Storage form of
carbohydrates in animals
• The liver can store about 90
grams of CHO (360 kcals)
• The muscles can store
about 300 grams of CHO
(about 1200kcal)
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INDIGESTIBLE POLYSACCHARIDES
Fiber
• These carb bonds are not digested by humans so
they pass through the SI to the LI where they are
metabolized by our gut bacteria and produce SCFA and gas.
• S-CFA provide kcals for gut flora
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TOTAL FIBER = DIETARY FIBER (SOLUBLE +
INSOLUBLE) + FUNCTIONAL FIBER
Dietary Fiber (beta
bonds)
Soluble Fiber
• Pectins
• Some hemicellulose
• Gums and mucilages
• Dissolves in water
• Forms gel and can slow down
digestion- good for regulating
blood glucose, weight, and
can interfere with cholesterol
reabsorption.
• Used commercially to thicken
foods
• Found in oat bran, fruits, beans
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TOTAL FIBER = DIETARY FIBER (SOLUBLE +
INSOLUBLE) + FUNCTIONAL FIBER
Dietary Fiber (beta
bonds)
• Cellulose
• Hemicellulose
• Lignins
Insoluble Fiber
• Good for treating constipation
• Adds bulk to stool and
increases transit time in large
intestine
• Found in whole grains
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DIETARY FIBER
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INDIGESTIBLE POLYSACCHARIDES
• Functional fiber also called “isolated” fibers.
These are “faux” fibers added to foods for potential
health benefits and clever marketing.
• Just like dietary fiber, these fiber additives pass
undigested through the gastrointestinal tract, so
the FDA accepts them as the real deal.
• Yet no scientific studies link these artificial fibers to
the health benefits—including a lowered risk of
heart disease and obesity
Can’t turn junk food into a health food
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INDIGESTIBLE POLYSACCHARIDES
The most common isolated fibers manufacturers use to bulk up
not-so-fibrous foods include:
• Maltodextrin
• Inulin (chicory root)
• Polydextrose
• Oat fiber
• Resistant starch
• Pectin
• Gum
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WHOLE GRAINS
Whole grains, or foods
made with whole grains
contain all the essential
(an naturally occurring)
parts of the entire grain
seed.
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Amaranth
Barley
Buckwheat
Corn
Millet
Oats
Quinoa
Rice (brown)
Rye
Sorghum
Teff
Triticale
Wheat
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WHOLE GRAINS
1997
Since whole grains lose
so many nutrients, food
manufacturer must add
back iron and the B
vitamins riboflavin, niacin
thiamine (1973), and folic
acid (1998) this called
enriched flour.
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WHOLE GRAINS
16 grams of whole grains = 1 serving
• Recommend 3 servings or 48 grams daily
• Which cereals are whole grain?
(a)Total
(b)Special K
(c) corn flakes
(d)shredded wheat
(e) cream of wheat
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IS THIS A GOOD SOURCE OF WHOLE
GRAINS?
16 crackers - 2 gram fiber- 23 grams
CHO
150 kcal
Ingredients: WHOLE GRAIN WHEAT
FLOUR, UNBLEACHED ENRICHED FLOUR
(WHEAT FLOUR, NIACIN, REDUCED
IRON, THIAMINE MONONITRATE
{VITAMIN B1}, RIBOFLAVIN {VITAMIN B2},
FOLIC ACID), SOYBEAN OIL, SUGAR,
CORNSTARCH, MALT SYRUP (FROM
BARLEY AND CORN), INVERT SUGAR,
SALT, VEGETABLE COLOR (ANNATTO
EXTRACT, TURMERIC OLEORESIN). BHT
ADDED TO PACKAGING MATERIAL TO
PRESERVE FRESHNESS.
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IS THIS A GOOD SOURCE OF WHOLE
GRAINS?
2 slices of bread- 4 gram fiber- 25 grams CHO
130 kcal
Enriched Wheat Flour [Flour, Barley Malt, Ferrous
Sulfate (Iron), B Vitamins (Niacin, Thiamine
Mononitrate (B1), Riboflavin (B2), Folic Acid)],
Water, Whole Wheat Hour, High Fructose Corn
Syrup or Sugar, Yeast, Wheat Gluten, Brown Rice
Flour, Soy Fiber, Calcium Sulfate, Contains 2% or
Less or Soybean Oil, Salt, Vinegar, Cornstarch,
Wheat Starch, Soy Flour, Honey, Dough
Conditioners (Sodium Stearoyl Lactylate, DATEM,
Mono and Diglycerides, Ethoxylated Mono and
Diglycerides, Dicalcium Phosphate, Calcium
Dioxide and/or Azodicarbonamide), Yeast
Nutrients (Ammonium Sulfate, Ammonium Chloride,
Monocalcium Phosphate and/or Ammonium
Phosphate), Enrichment [Vitamin E Acetate,
Ferrous Sulfate (Iron), Zinc Oxide, Calcium Sulfate,
Niacin, Vitamin D, Pyridoxine Hydrochloride (B6),
Folic Acid, Thiamine Mononitrate (B1) and Vitamin
B-12], Calcium Propionate (to Retain Freshness),
Whey, Soy Lecithin.
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IS THIS A GOOD SOURCE OF WHOLE
GRAINS?
1 English muffin- 3 gram fiber- 23 grams
CHO 120 kcal
Whole Wheat Flour, Water, Yeast, Wheat
Gluten, Honey, Farina, Cornmeal, Salt,
Cracked Wheat, Preservatives (Calcium
Propionate, Sorbic Acid), Grain Vinegar,
Calcium Sulfate, Soybean Oil, Wheat
Starch, Mono- and Diglycerides, Datem,
Natural Flavor, Sodium Stearoyl Lactylate,
Ethoxylated Mono- and Diglycerides, Wheat
Sour, Dextrose, Calcium Carbonate, Guar
Gum, Lactic Acid, Molasses, Fumaric Acid,
Whey, Soy Flour (Trivial Amount of Soy Flour),
Caramel Color, Acetic Acid, Sucralose,
Citric Acid, Sodium Citrate, Natamycin (a
Natural Mold Inhibitor), Potassium Sorbate
(Preservative), Nonfat Milk.
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IS THIS A GOOD SOURCE OF WHOLE
GRAINS?
2 waffles- 3 gram fiber- 21 grams CHO 140 kcal
Ingredients: Water, Enriched Flour (Wheat Flour,
Niacin, Reduced Iron, Thiamin Mononitrate
[Vitamin B1], Riboflavin [Vitamin B2], Folic Acid),
Whole Wheat Flour, Wheat Bran, Egg Whites,
Sugar, Vegetable Oil (Soybean Oil, Palm Oil and
Palm Kernel Oil with TBHQ and Citric Acid for
Freshness), Contains Two Percent or Less of
Leavening (Baking Soda, Sodium Aluminum
Phosphate, Monocalcium Phosphate), Salt,
Nonfat Dry Milk, Natural Flavors, Calcium
Carbonate, Polyglycerol Esters of Fatty Acids,
Malt Flavoring, Modified Cornstarch, Whey, Soy
Lecithin, Vitamin A Palmitate, Guar Gum,
Niacinamide, Reduced Iron, Thiamin
Hydrochloride (Vitamin B1), Pyridoxine
Hydrochloride (Vitamin B6), Riboflavin (Vitamin
B2), Calcium Pantothenate, Folic Acid, Vitamin
B12.
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SWEET
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HIGH FRUCTOSE CORN SYRUP?
• Starts out as cornstarch, which is enzymatically degraded to
glucose and some short polymers of glucose and then again into
fructose- now similar to sucrose
• Some believe that your body reacts differently to high-fructose
corn syrup than it does to other types of sugar
• According to commercials “High-fructose corn syrup is made
from corn, has no artificial ingredients, has the same calories as
sugar and is okay to eat in moderation.”
• Can extend the shelf-life of foods
• Subsidized commodity = In almost everything
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HIGH FRUCTOSE CORN SYRUP?
HFCS
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SUGAR ALCOHOLS
• Add energy (about 1.5- 3kcal/g) sorbitol, mannitol, xylitol
• Caries
• Sugar alcohols are usually incompletely absorbed into the blood
stream from the small intestine which generally results in a smaller
change in blood glucose than "regular" sugar (sucrose).
• Popular sweeteners among diabetics and people on low-carbohydrate
diets.
• Like many other incompletely digestible substances, overconsumption
of sugar alcohols can lead to bloating, diarrhea and flatulence because
they are not absorbed in the small intestine
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NON-NUTRITIVE SWEETENERS
(ALTERNATIVE, ARTIFICIAL)
Yield no energy so are used to provide sweetness to a lot of
products
• Saccharin
• Cyclamate
• Aspartame
• Neotame
• Sucralose
• Acesulfame-K
• Tagatose
• Stevia
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ALTERNATIVE SWEETENERS
Saccharin
Oldest alternative sweetener
Cannot be used in cooking
300 times sweeter than sugar
Used to be thought to cause cancer in large
amounts (bladder cancer in rats)
• ADI (Acceptible daily intake: 5mg/kg (154#, 70
kg person this is three, 12 ounce cans of soda,
or 9 packets)
• Some fountain beverages
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ALTERNATIVE SWEETENERS
Aspartame (Equal)
In diet sods
Contains phenyalanine (PKU)
Cannot be used in cooking,
Very sweet (180-200 times sweeter than sucrose) so
only small amountsneeded (does provide 4kcal/g)
• ADI for adult is 50mg/kg (18 cans of soda or 80
packets)
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ALTERNATIVE SWEETENERS
ACE-K
• Sunette
• 200 times sweeter than sucrose
• 0kcal/kg
• Can be used in baking
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ALTERNATIVE SWEETENERS
Sucralose (Splenda)
• 600 times sweeter than sucrose
• Made from sucrose-can be used in cooking
• Substitutes Chlorine for hydroxyl groups
• Body cannot use it for energy
• Can be used for cooking
• Passed all safety tests
• Splenda same ADI as sacharrin 3 x 12 oz diet
sodas or 7 packets/day
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ALTERNATIVE SWEETENERS
Stevia
• From a shrub in S. America, 100-300x sweeter than
sugar
• Herbal supplement- only specific highly refined
and purified extracts of stevia have been
approved for use in food products.
• Concern it may cause infertility
• ADI is 4mg/kg
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NON-NUTRITIVE SWEETENERS
(ALTERNATIVE, ARTIFICIAL)
Are they safe?
• Determined by the FDA
• ADI are set at 100 x less than the
level at which no harmful effects
were seen in animals
• Personal preference especially
during pregnancy
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Non-nutritive sweeteners
Are they safe?
Saccharin
• Many studies on animals have shown that saccharin can
cause cancer of the urinary bladder.
• In other rodent studies, saccharin has caused cancer of
the uterus, ovaries, skin, blood vessels, and other organs.
• Other studies have shown that saccharin increases the
potency of other cancer-causing chemicals. And the best
epidemiology study (done by the National Cancer
Institute) found that the use of artificial sweeteners
(saccharin and cyclamate) was associated with a higher
incidence of bladder cancer.
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NON-NUTRITIVE SWEETENERS
ARE THEY SAFE?
Aspartame (Equal, NutraSweet)
• Might cause cancer or neurological problems such
as dizziness or hallucinations.
• A 1970s study suggested that aspartame caused
brain tumors in rats. However, the Food and Drug
Administration persuaded an independent review
panel to reverse its conclusion that aspartame was
unsafe.
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NON-NUTRITIVE SWEETENERS
ARE THEY SAFE?
• The California Environmental Protection Agency
and others have urged that independent scientists
conduct new animal studies to resolve the cancer
question.
• In 2005, researchers at the Ramazzini Foundation in
Bologna, Italy, conducted the first such study. It
indicated that rats first exposed to aspartame at
eight weeks of age caused lymphomas and
leukemias in females. However, the European Food
Safety Authority reviewed the study and concluded
that the tumors probably occurred just by chance.
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NON-NUTRITIVE SWEETENERS
ARE THEY SAFE?
In 2007, the same Italian researchers published a follow-up study
that began exposing rats to aspartame in utero. This study found
that aspartame caused leukemias/lymphomas and mammary
(breast) cancer. It is likely that the new studies found problems
that earlier company-sponsored studies did not because the
Italian researchers monitored the rats for three years instead of
two. The Italian tests remain controversial, with the industry
contending that they were flawed in several ways and with the
FDA stating its scientists couldn't evaluate the studies because
the researchers refused to provide their original data.
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