Nutrition 3 Flashcards
What dental disorders can bad nutrition cause
-abnormal appearance of structures in the mouth
-dental caries
-periodontal disease
-gingivitis
What is a primary nutritional deficiency caused by
-inadequate selection of food
-age, income, education
What is a secondary nutritional deficiency caused by
-systematic disorder interfering with, ingestion, digestion, absorption, transport, use of nutrients
What nutrients are required for dental health
Calcium, phosphorus, vitamins A,C and D, flouride
What nutrients are bad for dental health
CHO, sweet and sticky foods, sugars, carbonated drinks, fruit juices
What are the consequences of vitamin D deficiency
-preeclampsia
-childhood dental caries
-periodontitis
-autoimmune disorders
-infectious diseases ect
Why is vitamin D important in dentistry
It is relevant for mineral dentistry, it helps absorb, carry and deposit calcium in the bones that support your teeth
What are macronutrients
- carbohydrates
- proteins
- fats and oils (lipids)
What are micronutrients
- minerals
- vitamins
What does nutrition mean
Nutrition describes the processes whereby cellular organelles, cells, tissues, organs and the body as a whole obtain and use necessary substances obtained from foods (nutrients) to maintain structural and functional integrity
What are the three classifications of carbohydrates
-monosaccharides
-disaccharides
-polysaccharides
What are oligosaccharodes
3-8 sugars
What is a polysaccharide
More than 8 sugars, starch, cellulose, beta glucan, arabinoxylan
What is glucose present in
Honey, maple syrup and grape
How much sugar is recommended in the diet
The who guidelines provide that <10% of energy intake should be obtained from free sugars
What does the term free sugars mean
Includes all monosaccharides, disaccharides added to foods/beverages by the manufacturer, plus the sugars that are naturally present
What is the recommended intake of free sugars in children and adolescents aged 2 to 18
<5% of energy should be obtained from free sugars
What is a NSP
Also known as a dietary fibre (non starch polysaccharides) they can be soluble or insoluble, they absorb water in the GI tract and increase in time, they are used as fuel for bacterial metabolism
What are some common characteristics of dietary fibre
Dietary fibre is sacchraides of plant origin, resistant to digestion and absorption in the small intestine, it is fermented in the colon to produce short chain fatty acids that are absorbed and metabolised in various parts of the body
What can insulin and oligofructose be classed as
A mixture of oligo- and polysaccharides composed as fructose, they are known as fructans
Insulin and oligofructose can be known as
Prebiotics
How much dietary fibre is recommended
Daily intake of 25-35g for adults
What is hydroylisis in terms of digestion
- basic process of digestion
- major types of macronutrients in food are primarily digested by hydrolysis
R-R + H2O > R’OH + R’H
Describe how starch is digested
Starch is first digested by amylase in pancreatic secretions (and saliva) to maltose, maltotriose (and limit dextrins)
What is the function of maltase
Cleaves maltose into molecules of glucose
What is lactase
Cleaves lactose into a glucose and a galactose
What is the function of sucrase
Cleaves sucrose into a glucose and a fructose
Where are monosaccharides absorbed
The small intestine
Where are olgosaccharides digested
in the large bowel absorbed as SCFA (eg insulin)
Where are polysaccharides absorbed
Starches are digested to maltose and glucose units absorbed as glucose in small intestine
What are salivary amylase and pancreatic amylase
Secreted enzymes
What can maltase, lactase, sucrase and isomaltase be described as
Interstinal surface enzymes
Describe primary lactose intolerance
Loss of lactase at weaning, lactose is not hydrolysed, passes to the bowel, metabolised to SCFA
H2 in breath for lactose malabsorption
What is secondary lactose intolerance
Infection, illness, reduced lactate expression
What are the sugar transporters
- GLUT family
12 members, all facilitated (passive) transport - SGLT (sodium glucose transport)
Move glucose from low to high concentration
What is fat
Refers to dietary triacyglycerols (triglycerides)
What are lipids
A group of water insoluble compounds of which tricylglycerols are the major form in the diet
What are triacylglycerols or triglycerides
Glycerol + 3 fatty acids
What are phospholipids
Phosphorus + 2 fatty acids
What are sterols
Derived form fatty acids (eg cholesterol)
What are saturated fats
All C atoms are fully saturated with H atoms (no double bonds) associated with heart disease and cancer
What are unsaturated fats
Either monounsaturated (contains one C=C)
Or polyunsaturated (more than one carbon double bond)
What is a cis fat
Cis fats have a configuration of double bonds in naturally unsaturated fats
What is a trans fat
Have at least one double bond in a trans configuration, industrially produced
What are some emulsification agents
Fatty acids, bile acids, protein ect
How are micelles formed
Breakdown from bile acids with fatty acids
How are fatty acids absorbed
At brush border lower pH at mucosa reduces solubility of lipid in micelles, they are absorbed by diffusion
What is a TAG
A triglyceride
What is the composition of newly secreted chylomicrons
Core - TAG, cholesterol esters
Surface - unesterified cholestrol, phospholipids, apoprotein
How are proteins digested in the substances
Whole proteins are rarely absorbed, stomach pepsin digests 20% if proteins
Describe protein digestion in the small intestine
Hydrolysed within the lumen of the small intestine, predominantly into medium and small peptides
Name some proteases
Pepsin, trypsin ect
What are peptides
Interstinal surface enzymes
How are amino acids absorbed
Finish this later
What are the problems with fat digestion
- fats are insoluble in water
- enzymes in aqueous phase
- need to bring two together and break up fat globules
What does absorption of amino acids contribute to
Generating the osmotic gradient that drives water absorption
Describe peptide absorption
There is virtually no absorption of peptides longer than 4 amino acids, small peptides are absorbed into the small intestine
