DEN 209 EXAM #1- UNIT 3

Carbohydrates:

• Ideal fuel; easy to grow; can be stored at room temp, chief fuel for the brain and the CNS

  • Largest component of most diets (other than water)

  • MAJOR source of energy

  • 4 cal/gm

  • 45-65% of daily caloric intake should be from carbs

  • Organic: Produced by plants during photosynthesis when carbon combines with water and releases oxygen

Understand that good carbs are good: No established RDA for carbs

• Reasonable intake: 45-65% of daily calories

• Approx. 130g of digestible carbs per day

• DVs for total carbs are about 300 g, with fiber contributing 25-30 g

• 4 cal/g

• The body converts excess glucose to fat

  • at 4 cal/g the same number of carb calories are less fattening than the same number of fat calories plus they are used up quicker

Carbs are comprised of

• Carbon

• Hydrogen

• Oxygen

Simple sugars

• Absorbed without further digestion; monosaccharides

  • Glucose (dextrose): best-transported and used product of digestion (breakdown) of di- and polysaccharides; main brain fuel (grapes, oranges, corn)

  • Fructose (levulose): Sweetest of all, product of digestion of sucrose (fruits, honey, corn syrup)

  • Galactose: From lactose (milk sugar) digestion

Sugar alcohols: monosaccarides

• Formed from or converted from sugar (when a monosaccharide is reduced)

• They can occur naturally or they can be added by manufacturers

• Incomplete absorption of sugar alcohols can produce a laxative effect on the body due to the drawing in of water into the GI tract

• Xylitol, Sorbitol, Mannitol

Simple sugars composed of 2 monosaccarides

• Sucrose = glucose + fructose (table sugar)

• Lactose = glucose + galactose (Sugar in milk)

• Maltose = glucose = glucose (beer, malt)

Polysaccharide: Complex carbs: a chain made up of MANY monosaccharides (more than 10)

• The body’s best source of time-released long-term energy

• Starch: Storage form of glucose in plants; most important carb; most complex carbs are in the form of starch - cereals, grains, legumes, rice, potatoes, pasta

• Amount of starch in plants increases as they ripen; amount of starch in fruits decreases as they ripen

• Glycogen: storage form of starch (excess glucose) in animals and humans

• Stored in muscles & liver

• When the liver if filled, the excess is stored in adipose tissue

• When the body needs glucose, it pulls from the liver storage area (not from adipose tissue, and once it is there, it stays there)

• This is not a food source

• Glycogen can be rapidly degraded to glucose when energy is needed

What do carbs do?

• Provide energy (too much sugar, in excess of need can be converted to fat & stored)

• Helps with fat metabolism (oxidation)

• Spares protein and helps with its metabolism

• Contributes to structural elements of the body

• Provides palatability of food

• Energy source for oral and intestinal bacteria

• Furnish vitamins and minerals

• Furnish dietary fiber for GI motility (helps prevent colon cancer)

• Brain fuel- Needed for RBCs and WBCs

Understand the following about starch digestion

• Starch (and complex carbs) are broken down into dextrin molecules and continue breaking down until the end product … which is glucose (the smallest unit)

• Glucose is absorbed and used

• Starch is insoluble in cold water due to the cell wall surrounding it (cellulose encases the starch granule) ; only can be digested if cooked so the cell wall ruptures

Understand the following about fiber

• Fiber: not digestible, passes through the digestive tract unchanged

• Functional (water-soluble) (added) (Viscous); fruits, grains, corn, beans

• Pectins: polysaccharides that form a gel with water; they are things like gums that are added during manufacturing

• Soluble fibers: soluble; dissolve in water; soluble fiber changes as it goes through the digestive tract, where it is fermented by bacteria

  • Soluble fiber foods : Beans (kidney, pinto); Brussels sprouts, broccoli, spinach, zucchini, raw fruit, grains, whole wheat bread

Diety fiber (water soluble)

• does not dissolve in water, cellulose is the most plentiful and abundant polysaccharide (indigestible)

  • Insoluble fiber: goes through the digestive tract without changing form; traps water and adds bulk to the stool (help with regularity of bowel movements)

  • Common sources: bran, seed coverings of plants (skins), fruits, vegetables, legumes

  • Helps with intestinal motility by drawing the water into the intestinal tract

  • Insoluble fiber sources: vegetables (especially dark green leafy), root vegetables, skin (potatoes, carrots, onions) nuts, seeds, bran

Fiber recommendations

• 20-25-20-35 g per day

• good sources provide 2.5g/serving

• Excellent sources provide 5g/serving

• Veggies, wheat, bran, celery, apples, whole grain bread

Benefits of fiber

• Fills you up with fewer calories

• Prevents hemorrhoids, constipation, and colon cancer

• The best sources are from your diet, not supplements

• Supplements often have a chelating agent, which promotes binding and takes it out of your body things like calcium, zinc, iron

Consequences of too much fiber

• Gas, bloating

• limitations of mineral absorption (intestinal motility is too fast)

• IBS

• Dehydration (fiber drawing in too much water)

• High fiber means the need to increase water intake

Extracellular polysaccharides

• The bacteria in the mouth form these

• Sucrose forms dextrans, levan, and some fructose and acid (fermentable carbs)

• Dextran (glucan): 95% - energy source for bacteria that cause caries S. mutans

• Levan (fructan): 5% - storage medium that allows the carb to remain on the tooth and increases acid production time up to 20 mins (like glue)

Know that types of hypoglycemia

• Reactive (postprandial): drop in blood glucose following a meal, usually has stress accompanying it and the pancreas over-secretes insulin

• Fasting: when no food is ingested for a long period of time - symptoms like headache, fatigue, etc

Define:

• Cariostatic: keeps caries at “bay” puts up a roadblock to acid attacks

• Acidogenic bacteria: capable of promoting decay ( reduces ph of saliva)

• Fermentable carbs: carbs are metabolized by plaque bacteria, resulting in acid formation (extracellular polysaccharides)

• Fuel for bacteria (biofilm) : sugars, cooked starches - combo of sugar and cooked starch is most damaging

• Trigger foods: foods containing fermentable carbs

Describe millers caries theory

• 1890: most widely accepted theory

• main points:

  • Fermentable carbs are the dietary substances that, when mixed with saliva, are largely responsible for tooth demineralization

  • Bacteria in close contact with teeth are the culprits in the initiation of caries

Host person

• 1. resistance due to genetics, immune system; developmental factors - nutrition in utero like calcium phosphorus vitamin A, C,D; fluoride

• Salivary gland function: consistency, how much (xerostomia) - function of saliva is to neutralize the acid and act as a buffer

• 2. tooth - fluoride content and organic content (enamel thickness, so morphology)

Time

• Frequency of trigger food ingestion produces a much longer acid attack every time a trigger food is eaten

Plaque/biofilm

• Largest bacterial content in nature - 400 million bacteria S. mutans is the main culprit (attaches readily makes acid) - the more you have, the more acid you have and acid increases as carb intake increases

Diet - substrate (what the bacteria work on)

• Sucrose- fermentable carbs

• Any amount of sucrose will cause acid production

• Any food causing enough acid to lower pH to 5.5 or below will cause tooth demineralization, especially if prolonged or frequent

• TO bacteria, all sugar is the same (even honey)

• Dental erosion occurs when an acidic environment is present for a long time gradually removed minerals from enamel

When discussing caries risk

• the amount of sugar is not as important as form and frequency

protective measures

• Raising PH of the mouth (inhibits acid production)

• Consuming protein (casein, the principal protein in milk), phosphorus, calcium

• Consuming hard cheese, meats, raw veggies, nuts, green and black teas (min acidogenic potential)

• Consuming licorice (anti-cariogenic properties)

• Consuming Xylitol (Anit - cariogenic because the oral bacterial lacks enzyme to ferment it)

Understand the basics of food and biofilm

• Sugars and cooked starches are cariogenic

• A combination of sugar and cooked starch is the worst

• Acid is produced within 20-30 seconds, and production continues for a minimum o 20 mins

• Close relationship between caries and fermentable carbs is well documented

Relevence to RDH

• Frequency is most important (mealtime or in between)

• Duration of exposure

• infants/toddlers - bottle with sugary drinks

• CAMBRA - assessing caries risk

• Eliminate or reduce fermentable carbs in diet

• Decrease eating frequency of fermentable carbs

• Decrease intake of added sugars

• OSC to remove bacteria; protective measures like fluoride, sealants

• * based on pt need