Carbohydrate- & Fat-Modified Diets for Malabsorption Chapter 19

Nutrition & Diet Therapy (7 th Edition)

I. Malabsorption Syndromes

• Malabsorption disorders- most harmful to nutrition status and result in: – Nutrient deficiencies – Weight loss – Serious complications • Disorders associated with malabsorption – Genetic disorders – Pancreatic disorders – Intestinal disorders – Intestinal infections – Liver disease (bile insufficiency) – Surgeries • Rarely involves single nutrient • Treatment of malabsorption disorders (surgery and medications) may also weaken nutritional status Nutrition & Diet Therapy (7 th Edition)

Nutrition & Diet Therapy (7 th Edition)

Malabsorption Syndromes cont’d

• Fat malabsorption – Causes • Illness that interferes with production or secretion of bile (severe liver disease) or pancreatic lipase (pancreatitis, cystic fibrosis) • Damage to intestinal mucosa (inflammatory disorders or radiation treatments) • Motility disorders causing rapid gastric emptying or intestinal transit – Consequences: losses of food energy, essential fatty acids, fat-soluble vitamins, some minerals • Weight loss • Deficiencies of fat-soluble vitamins • Formation of soaps by some minerals & unabsorbed fatty acids • Bone loss from calcium deficiency • Increased risk of kidney stones (Ca oxalates) Nutrition & Diet Therapy (7 th Edition)

• Fat malabsorption (con’t) – Dietary adjustments: fat-restricted diet

• Relief of abdominal symptoms (diarrhea & flatulence) • Minimize loss of vitamins & minerals • Fats should not be restricted more than necessary • Alternative source of dietary fat: medium chain triglycerides (MCT) Nutrition & Diet Therapy (7 th Edition)

MCT

Triglycerides with fatty acids that do not require digestion; can be absorbed without lipase or bile

Malabsorption Syndromes cont’d • Bacterial overgrowth

– Gastric acid & peristalsis protect stomach & small intestine from bacterial overgrowth – When overgrowth does occur, disrupts fat digestion & absorption – Eventually results in deficiencies of fat-soluble vitamins – Bacteria compete with vitamin B 12 , impairing its absorption – Symptoms: chronic diarrhea, abdominal discomfort, bloating, weakness, weight loss Nutrition & Diet Therapy (7 th Edition)

• Bacterial overgrowth (con’t)

– Causes • Impaired intestinal motility – Some types of gastric surgery – Strictures, obstructions & diverticula in small intestine • Reduced secretion of gastric acid – Atrophic gastritis – Acid-suppressing medications – Acid-reducing surgery – Treatment • Antibiotics • Surgical correction of anatomical defects • Dietary supplements-fat soluble vitamins, Ca, vit B12 Nutrition & Diet Therapy (7 th Edition)

II. Lactose Intolerance

• High incidence: approximately 75% of population worldwide – Rarely serious – Most individuals (with lactose intolerance) can tolerate milk if consumed with other foods & limit amount consumed at one time • Cause: reduction or loss of lactase, enzyme that digests lactose in milk products • Prevalent among certain ethnic groups: Asians, African Americans, Native Americans, Ashkenazi Jews, Latinos • Dietary management – Gradually increased consumption of lactose containing products – Divide milk intake throughout the day – Consume milk with meals – Chocolate milk may be better tolerated than plain – Aged cheeses well tolerated (little lactose content) – Yogurts with live bacterial cultures that aid in lactose digestion – Low lactose or acidophilus milk?

– Addition of lactase preparation to milk or use of enzyme tablet before consumption Nutrition & Diet Therapy (7 th Edition)

III. Disorders of the Pancreas

• Maldigestive and malabsorption problems due to impaired secretion of digestive enzymes • Pancreatitis – Inflammatory disease, resulting in damage to pancreatic tissue & release of enzymes – Acute pancreatitis • Usually caused by gallstones, excessive alcohol use; also caused by high blood triglycerides, exposure to toxins • Symptoms: severe abdominal pain, nausea & vomiting, abdominal distention • Usually resolves within a week without complications • MNT: NPO>clear liquids>low fat diet or hydrolyzed TF Nutrition & Diet Therapy (7 th Edition)

• Pancreatitis (con’t) – Chronic pancreatitis may cause irreversible damage & loss of pancreatic function – Majority of cases (70%) of chronic pancreatitis caused by excessive alcohol consumption – Symptoms: severe abdominal pain; may be unrelenting & worsens when eating – Consequences • Fat maldigestion • Maldigestion of protein & carbohydrate • Steatorrhea in advanced cases • Weight loss & malnutrition due to food avoidance • Reduction in insulin & glucagon secretions, resulting in diabetes • Medical nutrition therapy – Dietary supplements to correct nutrient deficiencies – Avoidance of all alcohol – Pancreatic enzyme replacement Nutrition & Diet Therapy (7 th Edition)

Disorders of the Pancreas cont’d

• Cystic fibrosis – Genetic disorder characterized by abnormally thick exocrine secretions; often leads to respiratory illness & pancreatic insufficiency – Consequences • Major complications: involve lungs, pancreas, sweat glands • Persistent respiratory infections, causing inflammation of bronchial tissues & progressive airway obstruction • Accumulation of digestive enzymes in pancreas due to thick pancreatic secretions that obstruct pancreatic ducts • Malabsorption of protein, fat & fat-soluble vitamins • Excessive loss of salt in sweat, increasing dehydration • Chronic undernourishment, poor growth, difficulty maintaining body weight • Pancreatitis, Hyperglycemia & diabetes Nutrition & Diet Therapy (7 th Edition)

• Cystic fibrosis (con’t)

– Medical nutrition therapy • Increased energy intake (children may need 120 150% of recommended energy intake for normal growth & nutrition status) • High-kcalorie & high-fat foods • Frequent meals & snacks • Supplement meals with milk shakes or liquid dietary supplements • Supplemental tube feedings if energy intake is inadequate • Pancreatic enzyme replacement at every meal or snack • Multivitamin & fat-soluble vitamin supplements • Liberal use of table salt & salty foods Nutrition & Diet Therapy (7 th Edition)

IV. Disorders of the Small Intestine • Malabsorption common consequence when intestinal mucosa damaged due to inflammation or infection • Celiac disease

– Abnormal immune response to wheat gluten, causing severe intestinal damage & nutrient malabsorption – Also referred to as gluten-sensitive enteropathy or celiac sprue – Symptoms: GI disturbances such as diarrhea, steatorrhea & flatulence; symptoms exacerbated by milk products Nutrition & Diet Therapy (7 th Edition)

Comparison of Villi

Healthy Intestine-Villi Celiac Intestine-Villi

Nutrition & Diet Therapy (7 th Edition)

• Celiac disease (con’t)

– Consequences • Immune reaction to gluten causing changes in intestinal tissue – Reduction in mucosal surface area & digestive enzymes – May be restricted to duodenum or involve entire small intestine • Malabsorption of all nutrients, especially macronutrients, fat-soluble vitamins, electrolytes, calcium, magnesium, zinc, iron, folate, vitamin B 12 • Stunted growth in children, severe underweight • Iron-deficiency anemia • Low bone mineral density Nutrition & Diet Therapy (7 th Edition)

• Celiac disease

(con’t)

– Medical nutrition therapy • Life-long adherence to gluten-free diet • Symptom relief usually evident within weeks, but mucosal healing may take years • Avoidance of lactose containing foods if lactose intolerant • Dietary supplements Gluten-free diet • Elimination of foods containing wheat, rye, barley • Careful review of all ingredients on food labels (even small amounts of gluten can aggravate symptoms) • Use of gluten-free products Nutrition & Diet Therapy (7 th Edition)

MNT for Celiac Disease

Nutrition & Diet Therapy (7 th Edition)

Nutrition & Diet Therapy (7 th Edition)

Disorders of the S.I. cont’d • Short-bowel syndrome

– Malabsorption syndrome that follows resection of small intestine, causing insufficient absorptive capacity in remaining intestine – Surgical resection of major portion of small intestine (treatment of Crohn’s disease, small intestinal cancers, other intestinal disorders) – Results in fluid & electrolyte imbalances, multiple nutrient deficiencies – Symptoms: diarrhea, steatorrhea, dehydration, weight loss, growth impairment (in children) Nutrition & Diet Therapy (7 th Edition)

Nutrition & Diet Therapy (7 th Edition)

• Short-bowel syndrome (con’t)

– Intestinal adaptation: process of intestinal recovery, after resection, leading to improved absorptive capacity – Ileum has greater adaptive capacity than jejunum • Permanent effects on vitamin B reabsorption if ileum removed—worsens fat malabsorption & diarrhea 12 nutrition & bile acid • Removal of sphincter between ileum & cecum may result in infiltration of colonic bacteria into small intestine, causing bacterial overgrowth Nutrition & Diet Therapy (7 th Edition)

• Short-bowel syndrome (con’t)

– Medical nutrition therapy • Immediately after surgery: fluid & electrolyte replacement (intravenous) • First weeks: rehydration of diarrheal fluid losses • Total parenteral nutrition, gradually reduced as oral feeding resumes • Introduction of oral feedings as soon as possible to promote intestinal adaptation – Sips of liquid formulas, progressing to larger amounts – Solid foods, as tolerated – Small, frequent feedings – Low-fat, high-carbohydrate diet, if steatorrhea – Vitamin & mineral supplements – Low-oxalate diet to reduce risk of kidney stone development Nutrition & Diet Therapy (7 th Edition)

Nutrition in Practice— Anemia in Illness • Anemia: condition of having too few red blood cells

– Frequently first sign of another illness – May be reason for seeking medical attention – Develops when red blood cells (erythrocytes) are not produced in sufficient quantity, destroyed too quickly, lost due to bleeding – Red blood cells contain hemoglobin that carries oxygen to tissues – Produced in bone marrow (erythropoiesis) – Causes: Blood loss, malabsorption, chronic illnesses, medications Nutrition & Diet Therapy (7 th Edition)

Red Blood Cell Production

Nutrition & Diet Therapy (7 th Edition)

Nutrient Deficiencies & Anemia

Nutrient Iron Vitamin B 12 Folate & Actions

Required for hemoglobin production Maintains cell membrane integrity

Result of Deficiency

Microcytic anemia: small, hypochromic cells Macrocytic anemia: large, immature cells

Vitamin E

Role in hemoglobin production

Vitamin B Vitamin C 6

Role in hemoglobin production Supports blood vessel integrity

Protein Energy Malnutrition

Protein synthesis needed for RBC development Nutrition & Diet Therapy (7 th Edition) Hemolytic anemia: RBC breakdown Microcytic anemia Fragile, bleeding capillaries Anemia