Nutrition

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  • Created by: Bek
  • Created on: 10-04-14 14:25

Narrow Approach

Individual lifestyle determins risk of disease

Advise people to change own behaviour

Effective if disease related to behaviour

Fail if individual not motivated

Fail if cause outside of individuals control

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Broad Approach

Risk  of disease determined by culture/society

Aims to shape society to better suit health

Effective if dealing with long term/global issues

Fail if aims too bold! 

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Public Health Nutrition

Promotion of good health through prevention of nutrition-related illness

Design of nutritional interventions in the population

Apply knowledge to solve nutrient-related problems

Identify causal pathways and means of prevention

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Inadequate Intake

Results from poor access to food and follows disease

Due to:

Limited access to health sevices

Unhealth environment 

Poor food hygiene

Poor sanitation

Lack of clean water

These are all a result of politics, lack of money and lack of education

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Epidemiology

"The study of the distribution and determinants of health-related states or events in specified populations, and the applications of this study to control health problems."

Main source of information for PHN

Identifies nature of problems 

Allows monitoring of success if action taken

Relationship between exposure and outcome (simple or complex)

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Health Promotion

Process of enabling individuals of communities to increase control over factors that determine their health:

Healthy Public Policies

Supportive environments

Developing personal skills of public and professionals

Changing behaviour through:

Pursuasion

Advice

Recommendation and guidance

Community development

Legislation

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Fortification and Supplementation

Fortification -   Ensures all consumers have a good intake

Takes away choice

Broad approach

Supplementation - Requires education

Active choice

Narrow approach

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Successes in PHN

Rickets - Only identified as dietary disorder in 1916. Gave cod-liver oil to children on poor diets effective. Margerine now fortified wtih Vit D. Vit D also added to some cereals and other spreads. 

Wartime Rationing

Water Flouridation - gum disease

Development of dietary guidlines and DRV

Improvments in food labelling

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Food Labelling

England

DEFRA - Labelling and legislation

FSA - Safety based labelling and standards

DoH - Nutrition policy labelling

Scotland/Northern Ireland

FSA - All domestic labelling and standards and legislation

Wales

FSA - Labelling

Welsh Assembly Government - Nutrition legislation

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Pre-packaged foods labels

Basic labelling must include:

List of Ingredients

Address of manufacturer (Name of business)

Appropriate date mark

Place of origin or provenance of food

Storage and prepartion instructions

Weight and Volume of food

Quantative declaration

Name of the food

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New food labelling legislation

All packs with area >10cm2 require nutritional information

Must include energy, protein, carbohydrate, fat (sat fats, sugars, fibre, salt will replace sodium)

If ingredient is mentioned in name of product, % must be included

Compound ingredient ingredients must be included

14 allergens must be included

Gluten Crustations Fish

Celery Eggs         Lupin

Milk Molluscs         Nuts

Mustard Peanuts         Sesame

Soya Sulphates > 10ppm

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Health Claims

Full nutritional information must be provided on the pack if a claim is made

Content claims can only be made if on the list in the Annex to regulation 1924/2006

No nutritional claims may be made for macronutrients with levels <15% RDA per serving

Comparitive claims only made between foods of same category

European Commission will develop 'Nutrient Profiles' with regard to levels of saturated fat, sugar and sodium. Meeting this profile is a condition of making a health/nutrient claim

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Changes to legislation

Mandatory Nutrition information

Minimum font size

Date of first freezing for meats and fish

New definition of 'use by'

Country of origin/provenance

Allergens must be emphasised

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Probiotics

"Live microorganisms that when administered in adequate amounts will confer a health benefit on the host (surviving passage through the stomach)"

Newborn has sterile GIT. Innoculated with bacteria during birth and breast feeding (colostrum)

Improves Digestion

Coats the bowel

Protect from pathogens

Good intestinal health = 85% good microbes 15% bad microbes

Gut microflora affected by hospitalisation, feeding, antibiotic use

Effective probiotic must be

Non-toxic/Non-pathogenic

Remain viable through storage and use

Exert one or more beneficial effect on health

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Probiotic examples

Most strains are Lactic Acid Bacteria (LAB)

Bifidobacterium

LActobacillus

Other LAB

Sources include fermented food or specific probiotic prepared food

Cheese/Yoghurt

Sausage

Sauerkraut

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Probiotic Health Benefits

1) Regulate balance of gut microflora by decreasing pathogen adhesion as they produce antimicrobial substances

2) Improve digestion of lactose by producing Beta-Galactosidase and enhancing absorption of sugars

3) Stimulate the immune system by up-regulating (Gut-associated lymphoid tissues (GALT) are the largest intrinsic protection against infective agents)

4) Other health benefits include lowering serum cholesterol levels and promoting anticarciongenic effects

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Prebiotics

"Non-digestible food ingredients that beneficially affect the host by selectivly stimulating the growth and/or activity of one or a limited number of bacteria in the colon"

Characteristics include

Reaches the colon intact

Specific metabolism directed towards advantageous rather than adverse bacteria

Active at nutritionally feasible dose

Lack of side effects

Persistent throughout the colon

Oligosaccharides have the best prebiotic effect.

Typically found in plants, seeds and tubers (also in colostrum)

Benefits similar to probiotics and increases production of SCFAs

Improves mineral absorption and balance

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Functional Foods

"A food component which affects one or more targeted functions in the body in a positive way"

Established foods which have been shown to provide specific benefits

Targetted at any disease state:

Cardiovasular disease

Obesity

Gastrointestinal Health

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Quaker Oats

Reduce cholesterol as part of a low fat diet

Rich in soluable fibre

Soluable fibre binds bile acids increasing excretion while decreasing cholesterol absorption

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Flora

Part of a healthy diet

Reduce cholesterol

High in essential polyunsaturated fats and low in saturates

No hydrogenated oils, virtually no trans fatty acids (animals ones are fine) and rich in Vit E.

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Benecol

Contains plant stanol ester 

Unique dietary ingredient derived from natural plant components (veg oil, beans, wood)

Added to food stuffs such as yoghurt

Displaces cholesterol in micelles so most cholesterol is excreted and stanol ester is absorbed in the gut

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Olean

Proctor & Gambles brand name for Olestra

Sucrose polyester and is a non-absorbable fat

It has physical and organleptic quantities of conventional dietary fats

Reduces fat and energy intake as it replaces triacylglycerol with sucrose polyester

US FDA approved Olestra for use in fried/baked snack foods

Absorption of Vit D, A, E & K can be reduced if consumed with Olean.

Those 4 Vits added to foods to offset impact

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Neutraceuticals

"A mix of the words 'Nutrients' and 'Pharmaceuticals' to indicate a food component/nutrient which has drug-like effects on physiological functions"

Consumption of fruit/veg negativly correlates with several chronic diseases.

Green tea (reduces blood pressure), cocoa, pomegranate juice (reduces BP, LDL oxidation), red wine and liquorice (reduces blood pressure) are associated with health benefits

Resvertrol = Stilbene. Found in 72 plant species

Absorbance - 70%

Potent antioxidant

Inhibits platelet aggregation

Induces vasodilation

Extends lifespan

Regualates cell signalling and gene expression

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Global Food Security

Factors associated 

Population size

Population lifespan

Economic limitations

Food choices of population

Ability of ecosystem to sustain food production

United Nations Millennium Development Goals (Aim to acheive by 2015)

Goal 1 = Eradicate extreme poverty and hunger

Agriculture accounts for 75% fresh water withdrawal as well as a heave carbon footprint. Ruminants also produce a lot of methane

Conversion of plant into animal matter is around 10%. Solutions include fish farming, quorn or edible insects

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Basic Principles of Equine Nutrition

Hind Gut fermenters - large colon

Trickle feeds, continually grazing so small stomach. 16-18hrs low quality grazing

Cutting action with 12 insicors, 24 molars to grind. Hypsodont dentition

Owner kept in mind

Is it a working animal?

Ability to perform/produce

Usually feed the individual needs

Equine Gastric Ulcer Syndrome - EGUS = 90% racehorses in training

Stomach is empty but HCl production continuous

Concurrent decrease in fibre, increase in starch/energy rich feeds

Entirely preventable and reversible but incredibly painful

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Basic principles of Canine Nutrition

Rely on stomach to digest proteins. They are omnivorous meal feeders.

They have canines and sharpe molars to rip and chew. (Limited side to side motion)

Adapt easily to high levels of starch and can consume 10g/kgBW without side effects

Fibre fermention is low, and water is absorbed in the colon.

Diet designed with owner in mind

Healthly looking animal/nice coat

Faecal quality

Ease of feeding

Taste prefernces

Cost

Feeding the individual

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Basic Principles of Feline nutrition

Rely on stomach to digest proteins

Strict carnivores with 12-20 meals a day (high quality foodstuff)

Exibit lowers activity of the brush border enzymes

Fibre fermentation is low, and water is absorbed from the colon. 

Caecum much smaller than dogs

Diet designed with owner in mind

Looking healthy/Coat condition

Faecal quality

Ease of feeding

Taste preferences

Cost

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Basic Principles of Animal Nutrition

Natural eating behaviour is related to anatomy and physiology

Duodenum is the first stage of the SI. Bicarbonate (buffer) is there to neutralise stomach acid while pancreatic enzymes are also released.

Requirements are for Energy, Protein, Vitamins, Minerals

When choosing ingrients you must consider natural feeding behaviour

Cats arn't vegetarians because they cannot synthesise taurine which only comes from meat

They also cannot synthesise Vit A

Or convert Tryptophan to Niacin

Dogs Cannot synthesise Vit D

Obesity is a bit problem when diets are wrong! 

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Feeding Strategy

Carnivores = concentrated diet, easily digested

Omnivores = intermediate feeding system

Herbivores = poorly digested fibrous diet (use of microbes)

Types of digestive systems include;

Monogastrics

Hind-gut

Fore-gut (ruminants)

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Prehension

Grasping the food

Saliva is secreted from 4 major pairs of glands and then chewing helps break down the food

1) Parotid = watery secretion

2) Mandibular = watery and mucus secretion

3) Sublingual = mucus secretion

4) Zygomatic = Viscous mucus secretion

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Teeth

Skull shape and dentition are linked to diet

Cattle and sheep have a horny pad instead of teeth in the upper front jaw

Dogs have carnassials (cats don't)

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Oesophagus

Tube connecting mouth to the stomach. 

Peristalsis occurs to move the food down towards the stomach

Birds have a crop to store food. They swallow food whole and mucus is secreted in the crop

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Stomach

Food store and gastic juices are secreted.

Contractions help mix the secretions with the contents and break down the food

Avian digestive tract has 2 stomachs. Glandular stomach (proventriculus) secretes mucus, HCl and pepsin. The muscular stomach (gizzard) may contain stones for grinding. Feed is forced back and forth between the two. Regurgitation also occurs in some species.

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Liver and SI

Liver = largest organ with lots of functions

Produces bile salts and nutralises chyme

Small Intestine = Duodenum, jejunum, ileum

Secretes intestinal juices which contain enzymes

Mucin is also produced to protect the intestinal walls from the acidic chyme.

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Pancreas and LI

Pancreas = secretes pancreatic juice into the small intestine. 

Juice contains trypsin, lipase and amylase to digest proteins, fats and starch respectivly. This is alkaline to neutralise stomach acid

Large Intestine = Caecum, colon, rectum

Bacterial fermentation occurs and water and ions are reabsorbed.

Faeces is formed here but defication is controlled by the anal sphincter

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Rumen

—A large, anaerobic fermentation vat, containing microorganisms which ferment fibre to make:  Volatile Fatty Acids (VFA’s)  Microbial protein  Vitamins K and B-complex.  The rumen wall is lined with millions of papillae (short projections) which increase the surface area for absorption of VFAs.  Shag-pile carpet” appearance —In constant motion with—1-3 contractions per minute. —Filled with liquid, fibre mat & gas.  Contractions: mix contents and aid in eructation of gases move fluid and fermented feedstuffs onto next stage Move fibrous materials into the fibre mat for rumination  

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Reticulum

—Provides additional fermentative capacity —An extension of the rumen rather than a separate chamber —Larger food particles from the rumen are returned to the mouth to be chewed again. —Small food particles from the rumen are passed into the omasum. —Honey comb lining catches and holds hardware and heavy debris Rumen magnet to remove metal

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Omasum

—A heavy, hard organ —Lining has many folds (leaves). —Water and residual VFAs and bicarbonate are absorbed here. —Contents in this compartment are much drier than elsewhere.

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Abomasum

—The true, glandular stomach. Secretes hydrochloric acid and digestive enzymes and functions very much like the monogastric  stomach. —Unique feature is that it secretes lysozyme. Enzyme that can break down bacterial cell walls.

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Rumination

—A.k.a. “chewing the cud” —Bolus of previously eaten foodstuff carried back from the reticulum to the mouth by reverse peristalsis, chewed and re-swallowed. —~8-10hrs per day, dependant on how fibrous the ingested material is. —The cud can be chewed at least 30 times (ideally 60) before re-swallowing.

Usually occurs when cows are resting - 4 Phases;

—Regurgitation - coarse material the upper end of the rumen stimulates a bolus of feed (cud) to be returned to the mouth. —Chewing - each cud is chewed to grind it down into particles small enough to pass out of the rumen. —Salivation - chewing stimulates the secretion of buffer-containing saliva (as much as 75 litres/day) which is mixed with the cud to stabilise rumen pH. —Swallowing – once sufficiently ground down the cud is swallowed and sinks to the bottom of the rumen to pass into the reticulum.

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