Nutrition and Diet Flashcards
what are the NICE Guideline NG30
- “give all patients (or parents or carers) advice during dental examination based on the oral health messages in Public Health England’s ‘Delivering Better Oral Health’ evidence based toolkit (2017)
- “Ensure that advice is tailored to suit individual needs using appropriate behavioural change techniques, goals, planning monitoring and feedback”
- Tailor information to patients
why is nutrition and diet important
• Diet and general health, current dietary guidelines
• Nutrients and tooth development- in utero nutrition
• The post-eruptive affect of diet on teeth
• Diet and other oral conditions
– Diet and tooth loss
– Diet and periodontal disease
– Diet and dental erosion
• Dietary advice in dental practice
what the main nutrient classes
macronutrients
- proteins
- carbs
- fats
micronutrients
- vitamins
- minerals
- trace elements
what is energy measured in
• Energy is measured in kcal or kJ (kilocalories/ kilojoules)
how much energy is in fats carbs protein alcohol
- Fat has 9 kcal / gram consumed
- Carbohydrate has 4 kcal / gram
- Protein has 4 kcal / gram
- Alcohol has 7 kcal / gram
what is Estimated Average (Energy) Requirement (EAR)
the average dietary energy intake that is predicted to maintain energy balance in healthy, normal weight individuals of a defined age, gender, weight, height, and level of physical activity consistent with good:
• Voluntary activity
Maintenance of life
• Brain function
why is energy needed for • Maintenance of life
- Body temperature
- Breathing
- Heart beat
why is energy needed for brain function
- Growth
- Children
- Pregnancy and lactation
- Body builders- increase body mass
• In the UK a healthy Body Mass Index is between what
18.5 and 24.9 kg/m2 (calculated as weight/height 2)
what does Requirement for energy depend on
• Body size and composition- weight/ height
• Age- elderly need less
• Activity- low activity, low energy
• Basal Metabolic Rate (BMR) is estimated using equations based on metabolic studies
- the Henry equations are used to estimate BMR (Henry, 2005)
- can work out BMR
what is the Henry Equations for estimating BMR
BMR = weight coefficient x weight (kg) + height coefficient x height (m) + constant
given values (differ for male and female)
– weight coefficient
– height coefficient
– constant
how can Estimated energy requirements (EAR) be calulated using BMR
physical activity level (PAL) x BMR
The median PAL for adults is 1.63
what are some examples of Estimated Average Requirements (EAR) for different individuals
- 12 month old boy: 718 kcal
- 12 month old girl: 646 kcal
- Adult men: 2772 kcal
- Adult women: 2079 kcal
- For pregnant women in third trimester add 191kcal per day
- For lactating women for first 6 months of breastfeeding add 335kcal per day- more than this they will put weight on
what are the features of Dietary fats
- Composed of glycerol and fatty acids
- Fatty acids are saturated (single bonds) , mono-unsaturated (single bonds, one double bond) or polyunsaturated.
- Saturated (no double bonds) are mostly found in animal and dairy fats
- Monounsaturated (MUFA) (one double bond) are found in olives and nuts
- Polyunsaturated (PUFA) (several double bonds) are found in plant oils, seed oils and fish oils
what are the Functions of dietary fats
• Provision of energy- energy dense goods
• Component of membranes- lipid bilayers in plasma membranes
• Precursors of prostaglandins (inflammatory response)
• Precursor of cholesterol (digestion and absorption of fat- chylomicron)
• Absorption of fat soluble vitamins- A, D, E, K (lack of these is not good)
• Essential fatty acids- not produced in on body. MUST be consumed
– Linoleic- plant oils omega 3 (3 soluble bounds before methyl end)
what are the features of Omega 3 fatty acids
- Double bond 3 carbons from methyl end of fatty acid chain
- α-Linolenic (converts to EPA in body)
- Eicosapentanoic acid (EPA) – essential, found by consuming consuming alpha-linolenic acid from plant oil or EPA from fish oil
- Docosahexanoic acid (DHA)- omega 3 but 6 double bonds. Found in fish oil
- Form prostaglandins of the 3 series that alleviate inflammation
- Eat lots of these - Negative association with cardiovascular disease
- Possible role in preventing periodontal disease (inflammatory disease- prostagloanding involved in reducing prostaglanding)
- Oily fish are the richest source of DHA and EPA
what are Trans fatty acids
• Double bonds may be ‘cis’ or ‘trans’
• Hydrogenated oils contain trans fatty acids
- Processed oils – processed foods where we need solid fats as its much cheaper than animal sources
• Intake is strongly linked with cardiovascular disease and possible colon cancer
what the association between Dietary fats and cardiovascular disease, how can this be overcome by MUFA and PUFA
Negative associations: Accumulation of cholesterol-rich lipid in arterial walls
• Convincing evidence that saturated fat (myristic and palmitic) increase LDL cholesterol- in arterial walls it will increase CVD
• Trans fatty acids increase LDL cholesterol and decrease HDL cholesterol
• Dietary cholesterol probably increases LDL cholesterol
However
• Substituting saturated fat with PUFA (especially linoleic) decreases cholesterol
• Substituting saturated fat with MUFA has similar but lesser effect
what is • Eicosapentanoic acid (EPA) and how is it formed
Essential, found by consuming alpha-linolenic acid from plant oil or EPA from fish oil
α-Linolenic (converts to EPA in body)
• Form prostaglandins of the 3 series that alleviate inflammation
• Docosahexanoic acid (DHA)
omega 3 but 6 double bonds. Found in fish oil
• Form prostaglandins of the 3 series that alleviate inflammation
what is the link between Dietary fats and cardiovascular disease
Thrombosis: platelet aggregation at site of narrowing artery
EPA and DHA reduce aggregation
Lots of fish
what do Plant sterols do and what is an ex, where are they present
prevent cholesterol absorption and thereby lower serum LDL cholesterol
Benecol’ reduces cholesterol absorption by ~14%
Plant sterols and stanols are naturally present in low levels in fruits, vegetables, vegetable oil, nuts, seeds and cereals.
• Plant stanols work the same way
what are other food cholesterol and why
• Oat fibre reduces cholesterol absorption (beta glucan binds cholesterol in gut)
- May be due to beta glucan that will bind to cholesterol and render it un-transportable across the membrane in GI tracts
• Soya protein (soya milk, tofu etc) also reduces cholesterol absorption
what is the association between Dietary fat and cancer
- Dietary factors account for 30 % of cancers
- High fat intake (energy dense diet) is associated with obesity
- Convincing evidence that obesity is linked to some cancers
- Possible that high intake of animal fat is associated with cancers of the bowel, pancreas and prostate.
what are the different Carbohydrates
Sugars
Starches
Oligosaccharides
oGlucose polymers
oNon-digestible oligosaccharides
Fibre and non-starch polysaccharides
what are ex of sugars
• Monosaccharides (one sugar molecule) o glucose, fructose & galactose • Disaccharides (two sugar molecules) o sucrose (glucose + fructose) o maltose (glucose + glucose) o lactose (glucose + galactose)
what is an oligosaccahride
• Chains of 3+ are called oligosaccharides and are not classified as sugars but polysaccharides
what are Sugar alcohols or polyols
sorbitol, mannitol, xylitol (sweetener) & lactitol bulk sweeteners called bulk as theyre not as sweet as sugar hence need to put more in xylitol can lower dental caries risk (futile cycle)
what are sugars needed ro form and why
how much energy do they give per g consumed
• Energy 4.0 kcal /g
Glycoproteins: sugar needed to form glycoproteins. Proteins esterified to one or more oligosaccharides containing sugars. The CHO content varies 1-85% e.g. albumin, collagen, peptide hormones and enzymes, fibrinogen, immunoglobulins
Glycosaminoglycans and proteoglycans e.g. hyaluronic acid, chondroitin sulfates (in cartilage), heparin
what are Sources of sugars:
confectionery, soft drinks, table sugar, biscuits and cakes, breakfast cereals, puddings and preserves.
what are the Health effects of sugars
• Contribute to excess energy intakes – obesity and weight gain
• May cause hyperlipidemia (?) in 10-15% population
- Increase in fat
• Diabetics must restrict intake- TII
• High intake of energy dense foods high in sugars and fats contribute to obesity, diabetes and cardiovascular disease
what are free sugars
OUTSIDE THE CELL
include all sugars added by manufacturer, cook and consumer, plus sugars in syrups, honey, fresh fruit juices and fruit juice concentrates. anything that is added
Fruit isn’t classed as a free sugar / fruit juice is: sugar in fruit is intrinsic sugar (in cell)
Advised not to eat free sugar between meals
what is intrinsic sugar
INSIDE THE CELL
can be consumed as much as you want, it already exists e.g. lactose in milk and fruits (all natural)
what can Dried fruits be classified as
bit of both as drying process breaks some cells releasing intrinsic sugar
what is Starch and what the 2 major forms, what are good sources
a-glucan polysaccharides (lots of glucose molecules joined by glucan links)
Amylose (straight chain of glucose with 1,4 bonds) and amylopectin (branched)
- Good sources include bread, potatoes, pasta, rice and cereals
- No adverse general health effects
- No deficiency states
what are Glucose polymers and ex
oligosaccharides
maltodextrins and glucose syrups
how are Glucose polymers made
- Made from hydrolysis of starches
* Chains of glucose 3 units and above with some mono and di saccharides (3- oligosaccharides)
what are glucose monomers used as
• Used as energy supplements, sports drinks and infant milk/foods
- Lactose intolerant babies milk replaced with glucose polymers as they still need sugar (more cariogenic than lactose)
• Are potentially cariogenic
what are The 3 classes of non-digestible (non-glycemic) carbohydrate in dietary fibre
- Non-starch polysaccharide (NSP) - skeletal remnants of plants that resists human digestion.
- Resistant starch
- Resistant oligosaccharides
what are Non-starch Polysaccharide
- Consists of cellulose, hemicelluloses, pectins, gums and mucilages
- Not digested in upper gastrointestinal tract so passes to colon where some undergo anaerobic microbial fermentation (healthy bacteria)
- NSP adds to stool bulk and stimulates peristalsis
- Soluble NSP attenuates post-prandial increase in blood lipids and glucose so important for glucose homeostasis and lipid metabolism
- Insoluble forms are more resistant to fermentation but bind water and increase stool mass which aids peristalsis and reduces toxin concentration
- NSP increases satiety and is useful in weight loss plans
what is Resistant starch
starch that is not digested e.g. physically enclosed in cell walls or un-gelatinised starch (e.g. green bananas)
what are 3) Resistant oligosaccharides
- Naturally occurring and synthetic
- Resistant or partially resistant to digestion in upper GI tract (non-digestible oligosaccharides (NDO))
- Resistant oligosaccharides include: fructo-; isomalto-; galactosyl-; gluco-oligosaccharides can be cariogenic.
- NDO encourage growth of bifidobacteria and lactobacilli in colon which metabolise NDOs (may prevent cancer)- can ferment this bacteria in the mouth
- NDO potentially cariogenic as dental plaque contains bifidobacteria and lactobacilli
- May be labelled as dietary fibre
what is the SACN for total carbohydrate
- Total carbohydrate intake appears to be neither detrimental nor beneficial to cardio-metabolic health, colo-rectal health and oral health
- The hypothesis that diets higher in total carbohydrate cause weight gain is not supported by the evidence from randomised controlled trials
- A small number of studies suggest that higher consumption of potatoes is associated with a risk of type 2 diabetes mellitus, but it is not possible to exclude confounding by other dietary variables e.g. cooking methods for potatoes such as frying. There is insufficient evidence to draw a conclusion on the association between starch intake and weight gain
- It is recommended that the dietary reference value for total carbohydrate should be maintained at an average population intake of approximately 50% of total dietary energy (starch)
what is the SACN for free sugars
• No more than 5% of total dietary energy should come from free sugars from 2 years upwards
what literature suggests for the statement “No more than 5% of total dietary energy should come from free sugars from 2 years upwards”. refer to
- prospective cohort studies
- randomised controlled trials
- Prospective cohort studies indicate that greater consumption of sugars-sweetened beverages is associated with increased risk of type 2 diabetes mellitus
- Randomised controlled trials conducted in adults indicate that increasing or decreasing the percentage of total dietary energy as sugars when consuming an ad libitum diet leads to a corresponding increase or decrease in energy intake.
- Randomised controlled trials conducted in children and adolescents indicate that consumption of sugars-sweetened beverages, as compared with non-calorically sweetened beverages, results in greater weight gain and increases in body mass index
- With the proposed reduction in the population intake of free sugars, their contribution toward recommended total carbohydrate intake should be replaced by starches, sugars contained within the cellular structure of foods and, for those who consume dairy products, by lactose naturally present in milk and milk products
- The complete replacement of energy derived from free sugars by these carbohydrate sources would only apply to those people who are a healthy BMI and in energy balance
- In those who are overweight, the reduction of free sugars would be part of a strategy to decrease energy intake”
Are we meeting the DRVs for Free sugars?
- The National Diet and Nutrition Survey published in 2014, shows that mean intake of NMES (same as free sugar) exceeded the DVR in all age groups!
- 11-18 year olds consumed the greatest amount of NMES, getting 15.6% of energy from NMES, compared to their recommended amount of under 5%
- So if on average 11-18 year olds are getting 15.6% of their energy from NMES
- 312 calories per day 78g free sugar per day
- This means in a year that’s 28,470g of free sugar (3 times more than the recommendation!)
- (29 extra bags of sugar!!!!)
what are the Main sources of free sugars consumed by 11-18 year olds
40% of free sugars came from non-alcoholic beverages:
– Fruit juices
– Fizzy drinks
– Sports drinks
19-22% came from sugar, preserves and confectionary
– Added sugar
– Chocolate
– Biscuits
what is the SACN for fibre
• Increased intakes of total dietary fibre, and particularly cereal fibre and wholegrain are associated with a lower risk of cardio-metabolic disease and colo-rectal cancer
- Adults should get around 30g/day of fibre
- 2 to 5 years -15g/day
- 5 to 11 years 20g/day
- 11 to 16 years 25 g/day
- 16 to 18 years 30g/day
• No quantitative recommendations are made for <2 years, due to the absence of information, but from about six months of age, gradual diversification of the diet to provide increasing amounts of whole grains, pulses, fruits and vegetables is encouraged
what literature suggests for the statement “Increased intakes of total dietary fibre, and particularly cereal fibre and wholegrain are associated with a lower risk of cardio-metabolic disease and colo-rectal cancer”. refer to
- prospective cohort studies
- randomised controlled trials
- Randomised controlled trials indicate that total dietary fibre, wheat fibre and other cereal fibres increase faecal mass and decrease intestinal transit times
- Randomised controlled trials also indicate that higher intake of oat bran and isolated β-glucans leads to lower total cholesterol, LDL cholesterol and triacylglycerol concentrations and lower blood pressure
what is the function of Dietary proteins and sources
• Growth and repair
• Maintenance of muscle and other tissues
• Hormones and enzymes
• Sources include
o Animal - meat, fish & dairy products
o Vegetable - pulses, quorn, bread, nuts & quinoa
what are the Protein requirements
- The amount of protein needed to be in nitrogen balance
- Nitrogen intake = nitrogen output
- 6.25g protein = 1 g N
- Body protein is continually undergoing turnover
- Positive N-balance in growth/pregnancy
- Negative N-balance in starvation/trauma
- Guidance for intake 0.75-1.5g/kg body weight (12% calorie intake)
what are the Requirements in terms of food for proteins
• 70 kg man • 1g / kg = 70g (= 280 kcal) • Protein usually provides around 12% of kcal o 30g meat - 7g o 30g fish - 5g o 1 pint milk - 20g o 30g cheese - 7g o 1slice bread 2g
- Your patient is a 60kg woman
* What is the range of her protein requirement?
45-90g
• Your patient is a 60kg woman
Assuming she consumes the middle value from this range, what percentage of her energy would this provide if she consumed 2000 calories a day?
12% =60kg/day * 4(kcal/gram) = 240
240/2000 *100 = 12%
what is Marasmus
extreme protein energy malnutrition
• Both protein and energy are limited
• Severe muscle wasting
• Decreased insulin (anabolic): glucagon (catabolic)
• Muscle proteins used in liver to make albumin which prevents oedema
what is Kwashiorkor
- Protein is deficient, but energy intake is maintained
- High insulin: glucagon
- Reduced amino acids for albumin synthesis causes oedema
- Water babies’ or ‘sugar babies bloated even though are not fed
what is NOMA
- Increased risk of NOMA (cancrum oris) in protein-energy malnutrition
- Ulcerating stomatitis of upper gum and underlying maxilla and face and ulceration of cheeks
- Occurs in malnourished impoverished children
- Results in irreversible disfiguration can be fatal
outline DRVs (Dietary ref values )summary with ref to % of total energy from the following macronutrients
fat
free sugar
proteins
balance
fat <35% (<10% saturated)
free sugar 5%
protein 12-15%
balance- from starch, milk sugar and intrinsic sugar
what do • Carbohydrates (CHO) include
sugars, oligosaccharides, starch, glucose polymers and fibre (non-starch polysaccharides, resistant starch and resistant oligosaccharides)
what are the Dietary reference values (DRVs)
series of estimates of the amount of energy and nutrients needed by different groups of healthy people in the UK population. (not individual)
what is the reference nutrient intake (RNI)
the amount of a nutrient that is enough to ensure that the needs of nearly all the population (97.5%) are being met
If everyone consumes this much we can say 97.5 % of population will be getting enough of that nutrient
what is The Estimated Average Requirement (EARs)
an estimate of the average requirement for energy or a nutrient. Approximately 50% of the population will need less energy or the nutrient and 50% of the population will need more.
what is the Lower Reference Nutrient Intake (LRNI)
the amount of a nutrient that is enough for only the small number of people who have low requirements (2.5%). The majority of the population will need more.
Some people (2.5% population) will be okay on this however the rest will be below of what is needed for a healthy balanced life.
in summary what are the following used for :
EAR
RNI
LRNI
EAR is used for energy
RNI is often used as a reference amount for population groups.
LRNI is a useful measure of nutritional inadequacy.
what are the DRVs for fat, free sugar, protein, balance
fat <35% (<10% saturated)
free sugar (5%)
protein (12-15%)
Other 45% should comes form starch, milk sugar, fibrous foods, intrinsic sugars (sugars present naturally in fruits)
what are the practical steps PHE are providing to help people lower their sugars intake
- They have produced ‘Sugar why 5%?’ - a summary of SACN recommendations for professionals and non professionals
- Visualise in cubes and teaspoons
BUT!!! How many teaspoons? Heaped teaspoons, flat teaspoons • 7 x 4g per teaspoon = 28g flat • 7 x 6g per teaspoon = 42g heaped • 12 g per day more!
what does The Eatwell Guide outline
The Eatwell Guide does not include references to frequency of serving and recommended portion sizes, except for:
• fruit and vegetables: at least 5 portions of a variety of fruit and vegetables a day
• fish: eat 2 portions a week, 1 of which should be oily
• red and processed meat: limit to less than 70g per day if you usually consume more than 90g every day
• fluids: 6-8 glasses a day
• Limits for juices and dried fruit are also given (contain free sugar)
This is consistent with government advice and is in accordance with the available evidence.
what is the advice on Bread, rice, potatoes, pasta and other starchy foods
• Eat lots • Eat wholegrain if possible • Avoid frying (e.g. chips) • Avoid adding fat, rich sauces or dressings • This group includes: o Breakfast cereals o Pasta o Rice o Oats o Noodles o All types of bread
what is the advice on Milk and dairy foods
- Eat or drink moderate amounts
- Choose lower fat varieties wherever possible
- This groups doesn’t include butter eggs and cream
- This group includes milk, cheese, yogurt and fromage frais
what is the advice on Meat, fish, eggs, beans and other non-dairy sources of protein
• Eat moderate amounts • Choose lower fat versions if possible e.g cut skin off chicken, cook without oil, avoid fish in batter • Beans and pulses are good alternatives • This group includes o Meat o Poultry and game o Fish o Eggs o Nuts, beans and pulses o Quorn and soya
what is enamel hypoplasia
structural defect in which the enamel present is HARD but DEFICIENT in amount- caused by a defective ENAMEL MATRIX formation . This alters the shape during development; pits, grooves
what is enamel hypomineralisation
enamel matrix has been formed, but its mineralisation is suboptimal leading to opacities due to reduced mineral content and softer enamel. enamel chips post-eruptively
what are the causes of Enamel Hypoplasia and Hypomineralisation
developmental defects with many causes including dietary deficiencies and difficulty during birth (neonatal line)
what are the pre and post eruptive effects of enamel hypoplasia
pre- pits, grooves, larger areas of missing enamel
post- enamel may become stained on eruption from diet
what are the Nutrient deficiencies in the aetiology of hypoplasia
- Protein – protein energy malnutrition (PEM)
- Calcium - hypocalcaemia
- Vitamin D – deficiency
- Vitamin A – deficiency
Nutritional deficiencies usually occur in undernourished communities or due to metabolic disturbances (which don’t allow nutrient absorption)
discuss evidence for the link between protein deficiency and enamel defects
• Study of Guatemalan children (1977)
• 43% with moderate malnutrition had hypoplasia
• 73% with severe malnutrition had hypoplasia
• Later research showed that a protein supplement did not reduce the incidence of hypoplasia
• Feeding rat dams a protein deficient diet during pregnancy and lactation resulted in:
- Poor quality and quantity of milk
- Increased dental caries in pups (compared with a control group)
Protein deficiency causes developmental defects and salivary gland atrophy (saliva not produced sufficiently – xerostomia patients increased caries risk)
discuss evidence for the link between Hypocalcaemia and risk of developmental defects of enamel:
- 53 children with disturbances of calcium and phosphate metabolism were studied
- Vitamin D dependent rickets – Low Ca, low P – hypoplysia
- Hypophosphataemia – normal Ca, low P – no hypopysia
- Hypoparathyroidism – low Ca, high P – hypolysia
- Therefore, low blood calcium level is associated with developmental defects in enamel
- Hypocalcaemia is also common in malnourished children (diarrhoea)
a low serum calcium concentration during enamel formation is a specific determinant of enamel hypoplasia
Discuss the link between Vitamin A deficiency and pre eruptive effect on dental caries risk- mention why
- Rare in industrialised countries
- Often associated with PEM
- Linked (alongside PEM) with enamel defects
- In experiments in rats fed a cariogenic diet: Gp with vitamin A deficiency had higher levels of dental caries when compared with well-nourished rats…
- Deficiency of vitamin A causes salivary gland atrophy causing less/poorer quality saliva
outline the effects of vitamin D deficient on teeth that were also seen in children
- Delayed development of teeth
- Delayed eruption
- Poorly aligned
- Defects of enamel & dentine
outline evidence for The Association Between Enamel Hypoplasia and Dental Caries
everyone who had hypoplasia had caries
only 25% without hypoplasia had caries
what is the link between vitD supplements are caries
- lower initiation and spread of caries
- greater hardening of pre-carious lesions
• 2-year trial in Birmingham children’s home
deficiency is ONE OF the causative factors- dental caries is multifactorial
why were War-time diets better for teeth
- Improvement children’s teeth in the UK between 1939 and 1944 – sugar wasn’t freely available
- Cheap milk (calcium and vitamin D)
- Cod liver oil free to pregnant and breat-feeding mothers, infants and children
- Vitamins A and D were added to margarine
- Calcium carbonate was added to flour
what is the link between vitamin D deficiency and studies carried out in India - how does it show that vit D does have an effect
- Gross enamel hypoplasia - more common in India due to diarrhoea induced hypocalcaemia
- Mild enamel hypoplasia - Similar prevalence in both countries due to the sunshine in India (vitamin D) overriding the effects of a poorer diet- sun does make difference
what can Deficiency of vitamin D during the development of the teeth cause
defects in the enamel that render the tooth more susceptible to dental caries
outline the conclusions of some studies relating to the risk of dental caries with vitD deficiency
Low certainty conclusion that Vitamin D may decrease incidence of dental caries- (Hujoel, 2013)- Significant publication bias
Improving vitamin D status is an additional preventive consideration to reduce caries risk
• (Schroth et al., 2016)
what was the advice fromPublic Health England 2016 about vitD
- Adults, and children over the age of 1y should have 10 micrograms of vitamin D per day
- Many would need a supplement to achieve this
- NB: 10 micrograms is the amount in 5 sardines!
- NB: in North of England the angle of the sun in the sky between October and May is too low to enable synthesis of vitamin D via the skin
how does Under Nutrition Increases Susceptibility to Dental Caries- relate this between uk and developing countries
- UK – good diet but high sugars
* Developing countries – poor diet but low sugars = cariesUK
what does undernutrition result in
**Under nutrition = lack of energy and protein
- Under nutrition results in developmental defects rendering teeth caries prone
- Under nutrition causes salivary gland atrophy (post-eruptive effect)
what does malnutrition result in
delays eruption of teeth which affects caries- just delays the caries some would say
how does Excess Fluoride Ingestion Affects Mineralisation of Enamel:
- During enamel maturation, an excess of F- ions:
- Alters the rate at which matrix proteins (amelogenins) are enzymatically broken down
- Alters the rate at which the subsequent breakdown products are removed.
- Fluoride may also indirectly alter the action of protease via a decrease in the availability of free calcium ions in the mineralisation environment.
- Lower enamel mineralisation. Hypomineralised enamel has altered optical properties and appears opaque and lustreless relative to normal enamel.
what are the different fluorosis
very mild
mild
moderate
severe
what is teh accepted amount of water flourosis found by The Research of H Trendley Dean in the 1930s:
• Continued use of water with 1ppm F caused mild mottling in 10% of cases- anticaries effect accepted amount
Continued use of water with 1.7 ppm F caused mild mottling in 40-50% of cases
where is Artificially Fluoridated Water found
- Newcastle & area artificially fluoridated to 1ppm NaF 1969 Birmingham artificially fluoridated to 1ppm NaF since 1963
- Later research in the UK in the 1980’s showed permanent teeth:
- Birmingham – 1ppm NAF in water = 59% children no mottling
- Leeds – low F in water = 68% no mottling
does • Low plasma phosphate results in dental hypoplasia
no because:
• Vitamin D dependent rickets – Low Ca, low P – hypoplysia
• Hypophosphataemia – normal Ca, low P – no hypopysia
•
• List three ways in which malnutrition can impact of levels of dental caries at age 12
delays eruption of teeth which delays caries
developmental defects rendering teeth caries prone- hypoplasia ad hypomineralisation
salivary gland atrophy (post-eruptive effect)
what nutritional deficiencies can cause hypoplasia
calcium - hypocalcemia showed hypoplasia in study with phosphate
PEM- hypoplasia increased with protein deficiency severity, but supplement did not decrease this. also causes salivary gland atrophy
Vit A- linked alongside PEM with enamel defects
VitD- mild hypoplasia was the same in india and UK due to vitD from sun in india which balanced out the effects of poor diet
what nutritional deficiencies can cause caries
vitD- defiecny can render teeth more succeptibe to caries (hypomineralisation). vit D is preventative for caries
vitA- PRE-ERUPTIVE effect on caries- Gp with vitamin A deficiency had higher levels of dental caries when compared with well-nourished rats. linked with PEM on enamel defects
what deficiencies cause salivary gland atrophy thus increase dental caries risk
Protein deficiency
Vitamin A deficiency
what are the Sources of Fluoride Exposure
Diet
o Natural sources- black tea/ green tea, seafood/fish (seawater contains fluoride)
o Added: water, milk, salt
o Manufacturing of foods can influence how much water is in foods (processing)
Dental products o Toothpastes (topical) o Mouthwashes (topical) o May be swallowed by children so can be systemic intake of fluoride
F-supplements
o Tablets
outline Fluoride ingestion and excretion
- 90% of F is absorbed mainly in stomach as HF (passes easily across membrane)
- Rapid absorption
- 99% of F in body is in calcified tissues
- 10% excreted in urine or faeces
outline the differences in Fluoride ingestion and excretion in diifferent diets (high fat, vegetarian)
high fat diet slows digestion and reduced rate of gastric emptying to F is in stomach for longer so absorption is increased. Positive F balance (more than 90%) - dental/skeletal fluorosis
Vegetarian diet- increase pH of renal tubule so more alkali which will increase urinary excretion so more elimation of fluoride so negative F balance – potential increase in caries Trivalent cation (copper/zinc) will form complexes with other divalent cations in GI tract
outline Importance of fluoride in caries prevention
- Exposure to F is most reasonable explanation for the decline in caries
- Excess F fluorosis of enamel- results in mottling/opacities. Skeletal fluorosis – can end up with brittle bones.
- Optimising the use of F for maximum caries prevention and minimal fluorosis is crucial
outline the Action of fluoride
- Historically, thought to act by improving tooth structure (systemic effect)
- The local/intra-oral action is now considered more important
- Fluoride aids (re)mineralisation
- Fluoride inhibits anaerobic glycolysis and subsequent acid production by oral bacteria
what is the Modern Understanding of Dental Caries
The early stages of dental caries can be prevented, reversed or arrested, primary through the elimination or modification of aetiological factors (dietary, microbial) and/or by enhancing protective factors (fluoride, sealants and salivary stimulation).
Increased sugars in the diet utilized by bacteria to produce acid increasing caries risk.
Topically applying fluoride can help with remineralization thus reducing the risk of dental caries
outline acute Fluoride toxicity (what are the lethal and safe tolerated doses)
• sudden ingestion of large dose- fluoride poisoning
• causes nausea, vomiting, diarrhoea and
abdominal pain
• Certain lethal dose is ~ 32-64mg/F/kg
• Safe tolerated dose is 8-16 mg F/kg
outline chronic Fluoride toxicity
- More common
- smaller dose over long time-
- affects teeth while still forming: up to 6 years, incisors up to 3 years
- affects bone continually
what is the Optimum safe daily dose of F- for dental health benefits is
0.05-0.07 mg/kg body weight per/day in children <12 years of age
o Even If we go up to 0.1 mg/kg we will increase dental caries via fluorosis/ mottling of teeth
outline Systemic & topical Fluoride therapy
Public water fluoridation School water fluoridation Fluoridised salt (self-select, but high salt not good Fluoridised milk Fluoride drops/tablets
outline Topical Fluoride therapy
Topical application
Fluoride mouth rinse & Fluoride toothpaste
outline studies that show the Evidence of effectiveness of F
H Trendley Dean (in the 1940’s)
• 7,000, 12-14 year olds from 21 cities in US states
• Investigated relationship between F level in water and prevalence of dental decay – J shaped curve
• Showed that water fluoridation at 1 ppm was the best balance between caries and fluorosis
• Resulted in artificial fluoridation of water
• Low fluoride – high risk of caries
Weaver 1941
• Dentist in Lake District
• Reduced dental caries in those children from South shields (1.4ppmF naturally) than those in the west and North shields
• DMFT was higher in those in north shields with no water fluoridation
outline Newcastle fluoridation studies
- There has been a decrease in caries over the last few decades
- However, caries has been consistently lower in those from fluoridated areas
- This shows water fluoridation has a positive effect even when there is exposure to fluoride from other sources, eg. Toothpaste
outline Fluoridation of social class
- Occurrence of dental caries shows a social class trend with lower social classes at greatest risk
- Water fluoridation has a positive effect on caries levels in all social class groups but as the lower social classes have higher caries the effect is greatest in this group
outline Water fluoride: systematic reviews
- Systematic reviews locate, appraise and synthesize evidence from scientific literature
- No association between water fluoridation and mortality from any cancer was found
- Stopping water fluoridation ↑ caries to levels higher than non-fluoridated areas
- Water fluoridation is effective, despite exposure to fluoride from other sources
- Fluoridation of water ↓ social class trends in dental caries
what are the benefits and drawbacks of Fluoridised salt
Allows individual to control when they have fluoride- consumer choice – politically advantageous.
but
- Negative systemic effects
- Is this positive as a public health measure?? As then not everyone exposed
- Salt increases blood preassure
what are the benefits and drawbacks of Fluoridised milk
- Targeted at children when their teeth are developing
- Milk is nutritious
- Considered a good vehicle for fluoride
but
- Can cause mild fluorosis
- Binding of F to calcium or protein may ↓ topical effect
- Cessation of milk fluoridation associated with worsening dental health
- less good evidence than for water fluoridation (But not as many people exposed so less numbers)
outline Systematic reviews of effectiveness of milk fluoridation programmes
Yeung et al 2008:
• Considered RCT only
• Two RCTs – for primary dentition
Some individuals expose to fluoridated milk and some just to milk
Onlt 2 studies
one study showed a significant reduction in DMFT (31.3%) after 3 years
o One did not
• Concluded insufficient studies with good quality evidence to show effectiveness
• HOWEVER: need to look at totality of evidence
Systematic Review by Australian National Health & Medical Research Council 2007
• Is intentional milk fluoridation more efficacious that no milk fluoridation in the prevention of dental caries?
• Considered evidence from cohort and cross sectional epidemiological studies
o Milk fluoridation is beneficial – though less good evidence than for water fluoridation (But not as many people exposed so less numbers)
o Cessation of milk fluoridation associated with worsening dental health
o Milk F may lead to increased mild fluorosis – not considered to be of aesthetic concern rather than problematic
what are the benefits and drawbacks of Public water supply fluoride
Low cost per head
Free for consumers
but
- Individuals have no say (mass medication)
- Not widespread in UK
where are Fluoridadated milk schemes
• There are many fluoridated milk schemes in Thailand, Chile, UK, Bulgaria and Russia, which are primarily school-based
• Fluoridated milk studies in China, Chile, Hungary,Bulgaria and Scotland have shown F milk to be effective in reducing the incidence of dental caries in young children.
• Have used doses ranging from 0.5-1.5mg F per drink (daily drink)
o Fluoride ingestion due to swallowing toothpaste as opposed to from the milk
how can carbohydrates be classified
according to their chemistry
according to their digestion and absorption
how can carbohydrates be classified according to their chemistry and what is the issue with this
- Sugars (monosaccharides and disaccharides)
- Polyols
- Oligosaccharides (malto-oligosaccharides and non-digestible oligosaccharides)
- Polysaccharides (starch and non-starch polysaccharides).
× This classification does not allow a simple translation into nutritional effects since each class of carbohydrates has overlapping physiological properties and effects on health.
