Week 5 Proteins Flashcards
Protein Function Overview
- Form enzyme/hormones
- Immune functions (Ab)
- Cellular Structure building block
- Fluid balance
- N/essential AA sources
- Energy yielding
- Gluconeogenesis
AA Function
- Breakdown and uptake from diet
- Protein synthesis for cell function
- Energy production
- Non-protein N-containing compounds
- Ketone and glucose production
Dietary protein deficiency: Edema
Insufficient protein intake + loss of fluid homeostasis –> edema
> Proteins in capillaries draw fluid into blood; if not then BP exceeds counteracting force of protein, fluid remains in tissue + swelling
Dietary Protein deficiency: Immune Compromise
- Immune incompetency (anergy) –> high susceptibility (fatal meascles, Candida in mouth/throat)
> Low trp –> increased inflammation in LI - Imparied GI regeneration
Protein Amount: RDA and Typical
1. RDA: > Men: 55g > Women: 45g 2. Typical: > Men: 95-100g > Women: 65g 3. UL: 2g/kg BW > Men: 140g > Women: 115g > If too much: burden on kidney to excrete extra urea
Protein Quality
- Measure on how well they support growth and maintenance of body (PDCAAS)
- Function of abundance and ratio of essential AA
- How well digestion and assimilation goes
> Animal red meat: B12 and Fe; Diary: Ca2+
> Most plants are incomplete: grains/nuts (no lysine), beans (no methionine)
EAA requirements (cannot be made by body; must come from food)
1. Adults: > 10% of total intake > Total: 0.8g/kg; EAA: 0.09 2. Infants: > 45% of total intake > Total 1.5g/kg; EAA: 0.7
Protein Efficiency Ration (PER)
Set standards for baby food
> Compares rat BW after 10+ days eating protein standardly
> WT gained (g)/protein consumed (g)
> Protein source > 2 is COMPLETE protein
> Fish (3.6), Milk (2.5), and wheat (1.5)
Total AA Score and Chemical Score
- EAA compared to ideal standard protein
- (mg of all EAA/g)/(mg of all EAA/g of egg white)
- Chemical Score: protein quality measurement based on AA composition
> Egg white (1.0, max), fish (0.96), Milk (0.85); >= 0.85 is COMPLETE protein - Protein Digestibility Corrected AA Score:
> PDCAAS = Chem. Score x (0.9-1.0)
US Dietary Guidelines
- HHS and USDA must publish report with nutritional and dietary info for the public based on current medical knowledge
- Overall healthy dietary pattern:
> High in vegetables, fruits, whole grains, low/non-fat dairy, seafood, legumes and nuts
> Moderate in alcohol
> Low in red meat, sugar and refined grain
Prospective Longitudinal Epidemiology Study 1 (Chicago Western Electric Study)
- White employed men (40-55):
> High animal protein intake and Low vegetable protein intake (% kcal) INCREASES obesity rate - Red meat diet –> higher risk of Type II: each additional serving/day ups risk 12% for red meat and 32% for processed red meat
Study: Red Meat and Mortality (PLES 2)
- 500K people 10 years
> 30% higher risk of death from MI and CA
> Most 5 oz/d/2000kcal vs least 0.06oz.d.2000kcal
> Most at risk: women CVD (50+% in risk)
Animal and Plant Protein Intake: Mortality (Song, et al)
Prospective cohort study
> 131,342 participants from NHS via food frequency questionnaire
> Association varied by lifestyle factors (at least 1 unhealthy behavior)
> Possible contributor: meat (unsaturated fat, processing chemicals, increases IGF-1)
> Plants help with phytochemical
Gluten
Wheat, rye, barley, triticale
> Maintain food shape
> Bran (fiber); endosperm (lipids, carbs, proteins); germ (lipids, vitamins)
> Celiac Disease: AI disease (gluten ingestion damages SI due to indigestion –> stable oligopeptides cross epithelial SI barrier –> processed by transglutaminase –> resulting peptides as B cells, helper T)
NCGS: Non-coeliac gluten sensitivity
Define basis for controversy
> IBS: Irritable Bowel Syndrome (no specific cause
> People with IBS avoid FODMAPS: Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols
> When fluid drawn into bowel, these can produce diarrhea in people with IBS
