Diet as Therapy Flashcards
examples of diet as the specific treatment for rare metabolic disorders
*phenylketonuria = decreased phenylalanine
*maple syrup urine disease = decreased branch chain amino acids
*glycogen storage disease = (+) nocturnal starch
*hereditary fructose intolerance = decreased sucrose and fructose
*galactosemia = (-) milk/dairy products
*sitosterolemia = decreased plant sterols
*adrenoleukodystrophy = decreased VLCT, increased C18:1+C22:1
*abetalipoproteinemia = decreased fat, increased MCT, increased vit A and E
abetalipoproteinemia - clinical features
*rare autosomal recessive disorder
*neonatal diarrhea, steatorrhea
*failure to thrive & poor growth
*hemolytic anemia
*retinal degeneration
*progressive neurologic dysfunction and early death in teenage years
abetalipoproteinemia - biochemical features
*very low plasma triglyceride and cholesterol
*absence of chylomicrons, VLDL, LDL, and apo B
*no post-prandial rise in triglycerides
*pre-chylomicrons absent from enterocyte golgi
*slice mutation in the MTP gene
abetalipoproteinemia - treatment
*very low-fat, high carb, high protein diet
*supplementation with MCT (medium-chain triglycerides)
*pharmacologic doses of surfactant solubilized vitamin A and vitamin E
*ALL CLINICAL FEATURES CAN BE PREVENTED
examples of diet as an adjunct to treat common diseases
*obesity = lower total caloric index
*diabetes = change percent of energy distribution
*HTN = decrease sodium
*hypercholesterolemia = decrease saturated fat and increase unsaturated fat
*osteoporosis = increase calcium and vit D
post-gastrectomy patients - clinical features
*early satiety
*dumping syndrome: pain, diarrhea, vomiting
*iron malabsorption -> iron deficiency anemia
*vitamin B12 malabsorption -> macrocytic anemia + peripheral neuropathy
iron malabsorption post-gastrectomy
*normally, stomach acid helps reduce Fe3+ to Fe2+, and Fe2+ can be absorbed by duodenal iron transporters
*post-gastrectomy, non-heme iron (iron from diet) remains in Fe3+ form, leading to poor absorption in duodenum
*therefore, we must either feed heme iron (absorption of heme iron remains intact) or give a supplement of Fe2+ iron
vitamin B12 absorption - overview
- haptocorrin (made in salivary glands) binds to vit B12 to help get it through the stomach
- pancreatic proteases digest haptocorrin away
- intrinsic factor (made by parietal cells; resistant to digestion) binds to the B12
- cubam (ileal B12 transporter) recognizes B12 bound to intrinsic factor and transports it
note - the cubam transporter is ONLY found in the terminal ileum, so B12 can only be absorbed here
vitamin B12 malabsorption post-gastrectomy
- haptocorrin (made in salivary glands) binds to vit B12
- pancreatic proteases digest haptocorrin away
- ABSENT INTRINSIC FACTOR leads to unbound vit B12
- cubam transporter cannot recognize unbound B12, leading to failure of absorption
treatment - post-gastrectomy
*multiple small, frequent meals
*moderate dietary fat restriction
*oral iron supplementation (Fe2+)
*PARENTERAL vitamin B12
examples of diet as an adjunct for diseases
*hypertriglyceridemia = increased omega-3 fatty acids
*seizure disorders = ketogenic diet
*Parkinson’s disease = time-shift protein intake (at night)
*lactase deficiency = decreased lactose
enteric hyperoxaluria (kidney stones due to increased calcium oxalate stones) - clinical & biochemical features
*terminal ileum disease or resection leads to fat and bile acid malabsorption
*fat and bile acid malabsorption leads to calcium oxalate kidney stones
enteric hyperoxaluria - treatment
*supplement calcium
*high fluid intake
*low oxalate diet (no root veggies, tea, cocoa, peanuts, bran, rhubarb)
*moderate fat restriction
examples of diet for “disease prevention”
*Mediterranean diet prevents ASCVD, diabetes, and osteoporosis
*DASH diet prevents HTN and diabetes
*MIND diet prevents cognitive decline & alzheimer’s
