1. THE CARIBBEAN HEALTHWORKSPROJECT
Digestion & Nutrition

2. Digestive System

Digestion

Absorption

Digestive Organs

Enzymes & Hormones

Common Digestive Disorders

3. Digestive System

Digestion: breaking food into components small enough to be absorbed by the body.

Digestion occurs before entry of nutrients into circulation.

Absorption: movement of nutrients, including water and electrolytes across intestinal wall and into blood and lymph.

Digestive System: including the mouth, pharynx, esophagus, stomach, pancreas, gallbladder, liver, small/large intestines.

4. Whole Body System

Digestive system does not act alone.

Endocrine system: stimulates hormones.

Nervous system: send signals that control passage of food, control hunger, etc.

Cardiovascular system: transports nutrients to cells.

Urinary and Integumentarysystem: eliminate waste.

6. Gastrointestinal (GI) Tract

Long hollow tube about 30 feet in length that runs from the mouth to the anus.

Transit time = 24 to 72 Hours

Transit time affected by composition of diet, physical activity, emotions, medications and illnesses.

7. Secretions

Mucus –moistens, lubricates, protects

Enzymes -protein molecules secreted by the pancreas that aid in digestion.

Hormones –chemical messengers that are secreted into the blood by one organ to regulate bodily function elsewhere.

8. Immune System

70% of the immune system is located in or around the digestive tract

Underneath the mucosal lining of the stomach is lymphatic tissue

Constantly assessing good vs. bad

SecretoryIgAantibodies are present in gut mucosa

9. Digestion Begins in the Mouth

Just the smell of food starts saliva flowing

Chewing increases the surface area of food and allows for the mixing of saliva.

Saliva: 99.5% water and amylase –Moistens food and carries dissolved food molecules to taste buds

Salivary amylase: breaks starches into sugars.

10. Pharynx

Shared by the digestive tract and the respiratory tract

Funnel shaped opening the connects the nasal passages and mouth to respiratory passages and esophagus

Common passageway for air and food and is responsible for swallowing.

11. Esophagus/Peristalsis

Tube extending from mouth to stomach

Peristalsis: wave like flow to move food toward stomach

Esophageal sphincter protects food once in the stomach from moving back to the esophagus

Reflux is caused by weakening of the sphincter

12. The Stomach

Temporary storage place for food

While in the stomach food mixes with HCL

Only some water, alcohol, and a few drugs like Tylenol are digested here

Food exits through P.S.

13. Gastric Juices

The stomach contains gastric glands

HCL kills most bacteria

HCL stops action of salivary amylase

HCL starts the digestion of protein by activation of the enzyme pepsin

HCL drops the pH of the stomach from 3.5 –4 to 1- 2 (only acidic environment in the body)

14. Ulcers

Stomach lining protected by mucus

Ulcers form when acid/pepsin penetrate mucus

Typically caused by poor diet and bacterial infection (Heliobacterpylori or H Pylori)

15. Gastric Triggers

Churning and acid production is regulated by signals from hormones and nerves

These signals come from the brain, stomach and small intestine

The thought and sight of food causes the brain to tell the stomach to release gastric juices

Food local nerve signals brain to release gastin(hormone that triggers HCL release/stomach motility)

16. Gastric Triggers

Food small intestines hormonal and nervous signals decrease stomach motility/secretions

A hormone CCK signals the release of leptin–a hormone that tells the brain to signal fullness

Once empty another hormone –ghrelinis produced that tells the brain to send a signal of hunger

17. Stomach Emptying

Stomach empties in 2-6 hours

Determined by the size and composition of the meal

To move into the small intestines food passes through the pyloric sphincter

Food composition affects transit time

Emotions affect transit time

18. Transit Time

Large meal moves slower than small one

Solid meal moves slower than a liquid one

Mixed meal takes 4 hours

Higher fat slows transit

Protein alone moves faster than with fat

Carbohydrates move the quickest

Sadness/fear slow movement

Aggression/anger speed movement

19. Small Intestines

Narrow tube –20 feet in length
-Duodenum: 1st12 inches
-Jejunum: Next 8 feet
-Illeum: Last 11 feet

The small intestine is the main site for digestion and absorption of water, vitamins, minerals, CHO, fat, and protein

Accessory organs (pancreas/gallbladder) aid in digestion

20. The Pancreas: Exocrine Tissue

Secretes pancreatic juices

Bicarbonate: brings pH up

Enzymes: Amylase, Trypsin/Chymotrypsinand Lipase

21. Digestive Enzymes

Protein molecules that aid in the breakdown of food for absorption

Food needs to be broken down into smallest molecules before they can be absorbed

Lipasebreaks fats into fatty acids and glycerol

Amylasesplits carbohydrates into simple sugars

Proteasebreaks proteins into single amino acids

22. The Pancreas: Endocrine Tissue

Produces 2 very important hormones: Insulin and Glucagon

Insulin: released when blood sugar rises allowing muscles and other tissues to take in glucose for fuel

Glucagon: released when blood sugar is low, causing liver to break down glycogen and release to the blood

23. The Gallbladder

Stores and secretes bile

Bile:produced by the liver, necessary for digestion and absorption

Secreted in the SI, mixes with fat, and breaks it into smaller globules, allowing lipases to access it

24. Diffusion

Movement of substances from one area of higher concentration to an area of lower concentration (Water)

Simple diffusion: no energy required

Facilitated diffusion: helped by carrier protein, no energy required

Active Transport: Needs both carrier protein and energy

25. Lining of the SI

Large surface area for absorption (the size of a tennis court)

Intestinal walls arranged in circular/spiral folds, Villi, Microvilli(brush border)

The villicontain one cell layer that needs to be crossed to reach the bloodstream / lymphatic system

26. Getting Nutrients to the Cells

Once absorbed nutrients have to be sent to the rest of the body

AA and sugars enter the bloodstream at the intestine and travel to the liver

Fat travels via the lymphatic system before entering the blood

27. Blood Flow

When at rest: ¼ blood goes to the GI, 1/5 to your skeletal muscles, and the rest goes to the heart, kidneys, brain, skin and other organs

Changes when you eat and exercise

When you are exercising –85% goes to the skeletal muscles to deliver oxygen

When you eat a large meal more blood flows to help digest it

28. The Liver: Gatekeeper

Amino acids, sugars, water-soluble vitamins cross the mucosal cells and end up moving to the hepatic portal vein which goes to the liver

In the liver they are processed, some stored, or sent to general circulation

The liver modifies products of protein breakdown to make them safe to get to the kidneys

29. Lymphatic System

System of vessels, organs, and tissues that drains excess fluid from the spaces between cells, transports fat-soluble substances from the digestive tract, and contributes to immune function

Functions in the absorption and transport of fat- soluble substances (cholesterol, long chain fatty acids, fat-soluble vitamins)

These substances do not go to the liver first before the bloodstream

30. Large Intestines

Anything that has not been absorbed by the SI moves into the LI

LI is –5 feet long and includes colon and rectum

Slow movement: fecal matter may stay in LI up to 24 hours which favors growth of bacteria

31. Intestinal Microflora

Permanent residents of the LI (300 –500 different species)

Bacteria in gut –10 x greater than cells in the body

Breakdown unabsorbed portion of food (fiber)

Producing nutrients for bacteria to flourish

These micronutrients synthesize some of the B vitamins and VitK, which are absorbed

This breakdown produces flatulence

32. The Colon

Colon absorbs small amounts of water and electrolytes

Material not absorbed is excreted

Feces –undigested matter, dead cells, water, bacteria

Amount of water in feces depends on fiber and water

33. The Rectum

End of the colon

Feces stored prior to excretion

Connected to the anus

Defection regulated by a sphincter that is under voluntary control

34. Common Digestive Problems

Reflux

IBS

IBD ( Crohn’sor Ulcerative Colitis)

Lactose Intolerance

Constipation/Diarrhea

Celiac Sprue

Gallstones

35. Reflux (GERD)

Acid from stomach re-enters esophagus

Often related to obesity

Dietary components include:
-Lowers LES:chocolate, caffeine, coffee, tea, peppermint, spearmint, alcohol
-Increased HCL: large portions, fatty foods, spices, tomato products, citrus

Avoid eating close to bedtime

Eating too fast and high stress play a role

Some medications cause such as Fosamax

36. Constipation

Usually caused by lack of fiber and/or fluids

Lack of exercise plays a role

Can be caused by medications such as iron supplements, calcium supplements

Increase fiber in the diet with fruits, vegetables, whole grains, legumes, flaxseeds

Magnesium

Add exercise

Probiotics

37. IBS (Irritable Bowel Syndrome)

Can cause constipation or diarrhea, bloating, gas and abdominal pain

Can be triggered by stress, food intolerance, high far, lactose intolerance, hormone imbalances, or environmental sensitivities

Low fat, high fiber, dairy free diets work best

Exercise and stress reduction helps a great deal

Some people are sensitive to fructose or mannitol

38. IBD (Inflammatory Bowel Disease)

Crohn’sDisease/Ulcerative Colitis

Inflammation of digestive tract

Can cause pain, bloody diarrhea, cramping, fever, weight loss and FTT in children

Usually sensitive to dairy and grains

On low fiber diet when in active flare-up

Probioticsand digestive enzymes work well

Specific Carbohydrate Diet (Elaine Gotschall)

39. Diarrhea

Can be caused by bacteria, virus, food intolerances (lactose intolerance), medications

Avoid high fiber foods

Add banana and white rice

Remove intolerant food

Add probiotics

Fermented foods

40. Gallstones

Most common disorder of the gallbladder

Often related to diet

Low fat, low meat, high fiver diet recommended

Limit coffee, increase water (coffee triggers CCK which stimulates the gallbladder)

Maintain healthy weight

Exercise reduces the risk

41. Celiac Disease

Gluten Intolerance: genetic/inheritable disease

Gluten: protein found in wheat, barley, rye and ?Oats

Autoimmune response that damages SI decreasing the ability to absorpnutrients and can lead to many deficiencies if left untreated

Only treatment is to avoid gluten

42. Macronutrients

Carbohydrates

Fiber

Lactose Intolerance

Proteins

Vegan Dishes

Fats

Toxins

43. Carbohydrates

Makes up the largest group of food

Found only in plant foods with the exception of lactose

All fruits, vegetables, grains, legumes, nuts and seeds

Should make up 50-60% of daily calories

Provide 4 calories/gram

44. Whole vs. Refined

Whole Grain: foods that have not been significantly altered from how they occur in nature

Refined (processed): foods that have undergone processing to remove the coarse part of their original form

46. Refining

Milling process separates the layers

White flour –milling only the endosperm

White flour is enriched (thiamin, riboflavin, niacin, and iron)

Refined sugars are added to many foods

Once sugar is removed from its plant source it no long contains fiber, vitamins or minerals Empty Calories

47. What are carbs?

Chemically they all contain carbon, hydrogen, and oxygen molecules

Classifications include:

Simple Carbohydrates

Complex carbohydrates: starches and fibers

48. Simple Carbohydrates

Monosaccharide (mono –one) simple sugar molecule

Disaccharide (Di –two) two sugar molecules linked together

Glucose, fructose, galactose

Each contain 6 contain, 12 hydrogen, and 6 oxygen but differ in arrangement

49. Simple Sugars

Glucose: most important fuel for the body –blood sugar
-Rarely found alone in nature –usually found as part of a disaccharide

Fructose: found in fruit, vegetables, honey, tastes sweeter than glucose

Galactose: rarely found alone in nature, usually part of lactose

50. Disaccharides

Maltose(glucose and glucose)
-Forms when starch is broken down, provides sweet taste when bread is chewed

Sucrose: table sugar (glucose and fructose)
-Sugar cane, sugar beets, honey, maple syrup
-Only sweetener that can be labeled as sugar

Lactose: milk sugar (glucose and galactose)
-Only sugar found naturally in animal foods

51. Glycogen and Starch

Glycogen: storage form of glucose in animals

Starch: storage form of CHO in plant
-When we eat starch we are eating stored energy
-Potatoes –starchy root
-Legumes/grain –starchy seed

Starches are thickeners when heated

52. Fiber

Cannot be digested by human enzymes

Soluble fiber: absorbs water and increases weight of feces
-Can be absorbed by bacteria in LI and cause gas
-Oats, fruit, beans, seaweed, pectin

Insoluble fiber: does not absorb water, increase bulk of stool and speeds transit time
-Wheat, rye, vegetables

53. Benefits of Fiber

Promotes healthy gut function by stimulating peristalsis –muscles of the colon work harder and get stronger

High fiber diets increase transit time

High fiber can cause constipation without enough water

Soluble fibers and oligosaccharides promotes healthy gut flora

Reduces cholesterol

54. Low Fiber Diets

Constipation

Diverticulosis

Hemmorrhoids

Some evidence of increased colon cancer risk

Obesity

Diabetes

55. Carbohydrates = Energy

Glucose: main energy source for the body

In the body glucose is broken down into carbon dioxide, water and ATP

Glucose not needed is stored: glycogen

Glucose can be made from protein

Energy can be made from fat: ketoneproductions (low CHO diets)

56. GlycemicResponse

How quickly blood sugar rises after food is consumed

Affected by the amounts and type of CHO, protein and far in the meal

Affected by how quickly food leaves the stomach

Refined CHO leaves the stomach quickly

Whole foods (fiber) leave slowly

Fat and protein leave the stomach slowly

57. Carbohydrate Digestion

Begins in mouth pancreatic enzymes absorbed by brush border

Sugars broken down in mono/disaccharides before absorption transported to the liver

Glucose stored in the liver and sent to the organs via blood

Substances not completed digested LI and are utilized by bacteria

58. Insulin’s Role

Allows cells to take in glucose

Promotes storage of glycogen by the liver

Leads to uptake of glucose for energy and synthesis of glycogen in muscle

Promotes protein synthesis in muscle

Promotes conversion of glucose to fat in fat cells

60. Lactose Intolerance

Newborns almost always produce lactase (enzyme to digest milk)

As we age lactase is produces less and less

Lactose not digested in the SI therefore moves to LI for bacteria to attack

The undigested lactose, acids and gas draws water to the LI causing diarrhea

-100% Asians/ African, -30-50% other Americans

61. Lipids (Fats)

Group of molecules most of which do not dissolve in water

Fats give food texture, flavor, aroma and calories

Lowering the fat in the diet doesn’t necessarily make it healthier

Fat should make up -30% of daily calories

9 calories/gram

62. Fats in the Body

Provide structure, regulation and energy

Stored as adipose tissue under skin and around organ

Insulates the body and protects the body from shock

Important structural part of cells

Lubricates body surfaces

Used to make hormones

63. Triglycerides

Major form of lipid in food and the body
-Contains 3 fatty acids and a glycerol backbone
-Each fatty acid is a chain of carbon atoms with an acid group on the end

The fatty acids can be either saturated or unsaturated

64. Saturated Fatty Acids

All carbon atoms in the fatty chain are saturated with hydrogen (no double bonds)

Found mostly in animal foods (meat/dairy)

Solid at room temperature with the exception of tropical oils

High intakes leads to high cholesterol, heart disease, etc.

65. Unsaturated Fatty Acids

Contain some carbons that are not saturated with hydrogen

Tend to be liquid at room temperature

Monounaturated: olive, canola, peanut oil

Polyunsaturated: linoleicacid, corn, safflower, soybean oils

66. Omega Fatty Acids (Poly)

Omega-3 fatty acids –(linolenic): flaxseed, walnuts, fatty fish
-Anti-inflammatory fat
-We need to increase our intake
Omega-6 fatty acids )linoleic): nuts, corn, safflower, and sunflower oils
-Pro-inflammatory far
-We need to decrease our intake

67. Essential Fatty Acids

Omega-6: growth, skin integrity, fertility, maintaining RBC structure

Omega-3: structure and function of the cell membranes (retina, CNS)

EFA Deficiency: scaly, dry skin, liver abnormalities, poor wound healing, impaired vision & hearing, growth failure in infants

68. Cholesterol

Needed in the body but not essential: produced by the liver

Part of the cell membranes

Part of myelin (coating on nerve cells)

Needed to synthesize vitamin D in the skin

Part of bile acids and hormone

Found in animal food only

69. Lipid Digestion

Lipids need help moving through the body because they do not mix with water

Fat absorption occurs in the SI

Bile, secreted by the gallbladder, breaks down small fat droplets which can then be broken down further by enzymes

70. Lipid Absorption

Micelles: mixture of digested fatty acids, bile, and fat-soluble vitamins

Once absorbed enters the lymph and finally blood

71. Over-consumption of Fat

Obesity

Cardiovascular disease/Atherosclerosis

Elevated cholesterol/triglycerides

Cancer

Fatty liver

Diabetes

Gallbladder disease

72. Protein (Amino Acids)

Animal food, legumes, soy, nuts, bread, rice and pasta all have protein

Animal protein: provides B vitamins and minerals such as iron, zinc and calcium but has no fiber and is often high in fat and cholesterol

Plant protein: provides fiber, iron, zinc, calcium, phytochemicals, unsaturated fats, but does not provide certain B vitamins (B12)

73. Protein

Made up of amino acids:20 total in protein (9 essential)

Amino acids are strung together in chains

Needed for the building/repair of muscles, tissues, organs etc.

Should make up –10-15% of daily calories

4 calories/gram

74. Amino Acids

EssentialNonessential
Histidine-Alanine
-Isoleucine-Arginine
-Leucine-Asparagine
-Lysine-Aspartic acid
-Methionine-Cysteine
-Phenylalanine-Glutamicacid
-Threonine-Glutamine
-Tryptophan-Glycine
-Valine-Proline
-Serine
-Tyrosine

75. Protein Digestion

Proteins must be digested to be absorbed

Digestion begins within the acidic stomach

Broken into smaller chains before entering the SI

Amino Acids compete with each other for the transport system

Move to liver and finally blood stream once past the brush border

76. Functions of Protein

Collagen: most abundant protein in body
-Holds cells together and forms framework of bones and teeth

Enzymes

Transport protein

Skin, hair, nails, muscles, organs, bones

Hormones

Regulate fluid balance

Regulates pH balance

77. Compounds Made From AA

Amino acid chains contain a nitrogen compound

Nitrogen: Non-protein compound needed to make neurotransmitters (tryptophan needed for serotonin)

DNA/RNA are also nitrogen-containing compounds

Skin pigment (melanin)

Niacin

Creatine(fuels muscle contraction)

Histamine (causes blood vessels to dilate)

78. Food Allergies

Triggered when a protein from the diet is absorbed without being completely digested

Milk, eggs, peanuts, tree nuts, wheat, soy, fish and shellfish

First time this happens, immune system is triggered

When it happens again immune system attacks causing allergic reaction

79. Excess of Protein in the Diet

Excess amino acids cannot be stored therefore they are…
-Used for energy if your body does not provide enough carbohydrate and fat
-Converted to fatty acids and contribute to weight gain

80. Dangers of High Protein Diets

Protein breakdown byproducts (urea) must be eliminated which increases water loss

Increases excretion of calcium in urine: kidney stones and bone loss

Long term excess of protein intake may lead to kidney and liver damage

Typical high protein diets are low in fruits, vegetables, fiber, and high in saturated fat

81. Protein Supplements

Often sold to promote immune function, healthier hair/nails, stimulate muscle growth

This will only happen if your diet is deficient in protein

Eating more protein does not build you more muscle (must lift weight)

Avoid taking separate amino acids

82. Micronutrients

Vitamins: A, C, D,E,K, thiamin (B1), riboflavin (B2), folic acid, niacin (B3), biotin, pantothenicacid, B6, B12

Minerals: Calcium, magnesium, Iron, Potassium, Sodium

83. Toxins

Air we breath, food we eat, and byproducts of metabolism

These can cause irritation and inflammation throughout our body

Liver is gatekeeper

We remove toxins in sweat, feces, urine etc.

Best way is to limit exposure (eat organic, avoid highly processed foods, alcohol, drugs, sugar substitutes)