Discussions Flashcards
Mechanisms to Increase Blood Glucose
- Glycogen in liver gets broken down into glucose
- Gluconeogenesis - make new glucose from amino acids
- Regulated by 2 hormones
- glucagon
- epinephrine
Mechansims to Decrease Blood Glucose
- Regulated by the hormone INSULIN
- causes cells to uptake glucose from the bloodstream
- Excess glucose stored as glycogen or fat
Glycogen in where gets broken down to glucose?
- LIVER
Gluconeogenesis
- Make new glucose from amino acids
- regulated by 2 hormones:
- glucagon
- epinephrine
2 Blood Glucose Disorders
- Hypoglycemia
- Hyperglycemia
Hypoglycemia
- Low blood sugar
- usually feel hungry
Reactive Hypoglycemia
- Excessive production of insulin
- Large sugary meals may induce larger insulin response
Hyperclycemia
- Elevated blood sugar
- 2 types
- Type 1 diabetes
- Type II diabetes
Type I diabetes
- “autoimmune”
- Cause: Pancreas doesn’t secrete any or enough insulin
- Symptoms: Excessive hunger, thirst and urination; fatal without treatment
- Treatment: insulin therapy
Type II Diabetes
- Cause: Cells are insulin resistant; related to obesity
- Symptoms: gradual weakness; kidney failure, vision loss, infections and amputations
- Treatment: weight loss
Glycemic Effect
- How much a food will affect blood sugar
- High glycemic foods are rapidly abosrbed (simple sugars)
- Low glycemic foods are absorbed slowly (starch)
Juice
Refined Grains
Low - fiber and other nutrients
*fortifying/enriching adds back some nutrients
Refined sugar
- Lowers nutrient density of food
- Contributes to dental caries
- Source of Calories; large contribution to weight gain
The active ingredient in alcohol:
ethanol
Alcohol is denoted with a(n):
OH
Congeners
- impurities in beverages produced during fermentation
Congeners of beer
- hops
- malt
- asbestos
- yeast
- cobalt
Congeners of Wine
resveratrol
congeners of hard liquor
asbestos
Variations in enzymes:
- ADH: fast version in African Americans; slow version in Native Americans (prolongs ethanol action so increased addiction)
- ALDH: slow version in Asians (results in flushing, more product is acetaldehyde)
Ethanol ->
Acetaldehyde -> Acetic Acid
ADH then ALDH
More alcohol from each drink reaches the blod in women than men because:
- Women make lower levels of enzymes
- Women weigh less, generally
- Women typically have less lean mass
Absorption of alcohol is:
- very efficient
- 95% of alcohol in women gets abosrbed
- 75% of alcohol in men gets abosrbed
1 drink =
15 g EtOH (ethanol)
- Beer: 12 oz
- Wine: 5 oz
- Hard Liquor: 1 oz
True or False: there are health benefits of consuming more than 1-2 drinks per day
False - there are NO health benefits of more
Liver has enzymes called
- Microsomal ethanol oxidative system
- cytochrome P450 system
Enzymes of the liver metabolize ethanol, but also:
- Make free radicals - damage liver
- metabolizes other drugs
- Increases risk of cancer by making carcinogens
Ethanol is stored as:
- fat
- contains 7 kcal/g
> 2-5 drinks per week
- Benefit: None
- Consequence: Raise BP; Increase HR and stroke risk
3-9 drinks per week
- Benefit: Reduce CVD risk by rasing HDL
- Consequence: None if stay at this level
4-6 drinks per sitting
- Benefit: None
- Consequence: Decrease fat burning by 33%; “Holiday Heart”
Polyphenols
- Benefit: Reduce blood clotting so reduce heart attack and stroke risk
- Consequence: None
Ethanol’s bad effects:
- Mutagenic - causes mutations in DNA
- Increase cancer risk
- stomach, pancreas, liver, colorectal, breast, prostate
- Displacement of protective nutrients with alcohol calories
- Beverage content is unregulated
Fetal Alcohol Syndrome
- the largest known cause of mental retardation
- Symptoms: attention deficit, impulsive, inability to tell cause-and-effect
Drinking during pregnancy?
NEVER - never safe to drink during pregnancy
What does Alcohol target?
- Alcohol targets brain receptors that control rewards and pleasure
Alcoholism
- Caused by:
- 50% Genes
- 50% environmental causes
Nutrient
An essential substance to the body that we cannot synthesize or live without
Where does toxicity usually come from?
Concentrated supplements
Recommended Dietary Allowance (RDA)
- A level of recommended intake set at two standard deviations from the Estimated Average Requirement
- designed to meet the needs of about 97% of the population
Food Components to reduce:
- Salt (sodium) - leads to high blood presure
- < 2300 mg a day
- Saturated fat (animal fats) - leads to heart disease
- < 10% sat. fat a day
- Cholesterol (animal products) - leads to heart disease
- < 300 mg a day
- Trans fats
- Refined grains
- Alcohol
Food components to increase:
- Vegetables and fruits - dark green, orange and yellow, legumes
- Make half your gains whole - increased fiber, vitamins/minerals
- fat-free or low-fat milk products - calcium
- Variety of proteins - focus on low fat, lean meats (poultry, fish)
Digestion Summary:
Mouth
Esophogus
Stomach
Small Intestine
Large Intestine / Colon
Rectum
4 Digestive functions:
- motility
- secretion
- digestions
- absorption
Two types of motility
- Peristalsis - rhythmic contraction of muscles surrounding gut to move food through
- Segmentation - random contraction that serves to break up and mix food
Mouth
- Function: Chewing (mechanical breakdown/mixing)
- Secretions: mouth releases 1st digestive secretions
- saliva - moisten food, contains amylase
- Enzymes: Amylase (works on amylose, or starch)
Esophogus
- Function: Peristalsis (rhythmic contractions to move food to stomach) begins
Stomach
(Reservoir for slow release of food into intestine)
Functions of the Stomach:
- Churning (grinding & mixing)
- Begin some protein breakdown, little digestion happens in the stomach
- Reservoir for slow release of food into the small intestine
- A little absorption (20% of alcohol)
Secretions of the stomach:
- Acid - helps sterilize food, start chemical breakdown of (denaturing) proteins
- Protease - starts protein digestion (breakdown of protein)
- Mucus - protests walls of stomach; ulcers - thin lining of mucus
Enzymes of the Stomach
- Protease acts on proteins
3 Parts of the Small Intestine:
- Duodenum
- Jejunum
- Ileum
Functions of the Small Intestine:
- Motility - peristalsis and segmentation
- Major chemical breakdown of food
- Majority of absorption of nutrients - large surface area created by bili
Aborption of nutrients in Small Intestine
- Nutrients: glucose, fat, amino acids, water soluble vitamins, B-12, Calcium, Magnesium, Iron, Sodium, Potassium, Free water, 80% of total alcohol, bile
- Blood vessels / capillaries - water soluble nutrients
- Lymphatic system vessels - fat soluble nutrients (lipids and some vitamins)
Secretions in the Small Intestine
- Enzymes secreted via the common bile duct
- Amylase
- Protease
- Lipase
- Sodium bicarbonate
- Bile
- Disaccharidases
Enzymes of the Small Intestine
- Amylase
- Protease
- Lipase
- Disaccharidase
Amylase
- Made in pancreas, breaks down starch
Protease
- Made in pancreas, breaks down protein
Lipase
- Made pancreas, breaks down lipids/fats
Sodium bicarbonate
- Secreted by pancreas
- helps neutralize acid in intestines
Bile
- Made in liver
- stored in gallbladder
- emulsifier (mix fat & water)
Disaccharidases
- Made in small intestines/mucosa
- breaks down double sugars (di-) into single sugars (mono-)
Large Intestine (Colon)
- Major function: water re-absorption (from foods)
- some nutrient absorption, not the main job
- Large Bacteria population - Such as E. coli
- Fiber affects movement of food through the colon, shortens the transit time
Secretions and Enzymes in the Large Intestine (colon)
None
Function of Rectum
- Reservoir for elimination
Carbohydrates (CHO)
- 4 kcal/gram
- produced by photosynthesis
- Sources: grains, fruits, vegetables, beans, some in nuts and dairy
- chemical formula: CnH2nOn
Monosaccharides
- Glucose - 6 sided ring; brain only burns glucose
- Galactose - 6 sided ring
- Fructose - 5 sided ring
Disaccharides
- Sucrose
- glucose + fructose; table sugar (cane, beets)
- Maltose
- glucose + glucose; barley malt syrup
- Lactose
- glucose + galactose; milk & dairy (ONLY)
Oligosaccharides
- Not nutritionally significant
- Hard to digest, but bacteria in colon causes gas & discomfort
- In beans, onions, legumes, and some vegetables
- Raffinose
- Stachyose
Polysaccharides
- Starch
- many glucose units, amylose (straight), amylopectin (branched
- Grains: wheat, oats, rice, corn, and barley
- Legumes: beans, lentils, and peas
- Dextrins (malodextrins)
- intermediate of starch digestion
- shorter = sweater; often in sports drinks
- Glycogen
- storage form of glucose in the body (liver & muscles): important in blood sugar maintence and exercise
- Dietary Fiber
- structural material in plants only
- indigestible polysaccharide
Insoluble Dietary Fiber
- Cellulose
- Hemicellulose
- Lignin
Cellulose
- can’t be digested by humans
Hemicellulose
- digested by ruminant animals
Lignin
- woody part of plants; not a polysaccharide
Soluble Dietary Fibers
- Pectin
- Gums & Mucilages
Pectin
- forms gel (jams & jellies)
Gums & Mucilages
- Thickens food
- gives creaminess to food
- Note: soluble, but still not digestible
Insoluble Dietary Fiber functions:
- Abosrbs water and add bulk feces
- Stimulates peristalis and decreases transit time
- Prevents/treats constipation
Soluble Dietary Fiber
- Reduce cholestorol reabsorption; helps lower blood cholesterol
- Slows CHO absorption; helps lower blood sugar
Sources of Insoluble Dietary Fiber
- Whole grains
- vegetables
- fruits
- bran
- oatmeal
Sources of Soluble Dietary Fiber
- Oats
- barley
- legumes (beans)
- rice
- fruits
CHO digestion of Starches
Starches ————–>maltose——->glucose
Salivary & pancreative amylase - between starches and maltose
CHO digestion of Disaccharides
Disaccharides ————————>monosaccharides
Enzymes in the intestinal mucosa
i.e of monosaccharides = lactase enzyme
Lactose intolerance
- Comes from a deficiency in lactase enzyme
- Bacteria in gut utilize lactose creating GI distress
- Substitute cultured milk products: yogurt, cheese, keefer, buttermilk
- May be dose dependent with only slight defiency in enzyme
Glucagon
- mobilizes glycogen to raise blood sugar
Glycogen
- storage form of glucose
The form of CHO that most other forms of CHO are changed to before being used for energy:
Glucose
In what condition is an excessive amount of insulin produced when a normal amount of available CHO has been consumed?
reactive hypoclycemia
What does a Type I (juvenile-onset) diabetic fail to produce?
Insulin
Gluconeogenesis is the…
Synthesis of glucose from amino acids
Type I diabetes facts
- the pancreas does not produce insulin
- symptoms include sugar in the urine
Glycogen is formed and stored in the liver and muscle when…
Excessive glucose is present in the blood
The major site of alcohol removal is the…
liver
Congeners
- are substances other than alcohol found in alcoholic beverages
- like alcohol, may also have effects on the body
Enrichment process for grain products
- Some of the micronutrients lost in processing have been restored
Typical response of the body to blood glucose:
- Excessive fall in blood glucose triggers the release of glucagon
A person with Type I diabetes is most likely to receive
Insulin by insulin injection
When blood glucose levels start dropping to the low-normal range, which substance is produced in larger amounts to promote the breakdown of stored carbohydrate to glucose?
Glucagon
What has the greatest impact in terms of person’s ability to handle alcohol?
Lean body mass and total body water
