W HAT IS N UTRITION ? Nutrition is All the processes involved in - - PowerPoint PPT Presentation

Myths & Legends

NUTRITION BASICS

Dr Niikee Schoendorfer – n.schoendorfer@uq.edu.au

OBJECTIVES



Appreciate the finer aspects of macronutrients and their physiological functions



Recognise the determinants of nutrient needs



Calculate water requirements and factors necessitating increased requirements



Differentiate between the good, the bad and the ugly fats



Understand glycaemic index versus glycaemic load



Appreciate the roles of dietary fibre in both gastrointestinal and systemic health



Understand issues related to micronutrition

WHAT IS NUTRITION?

 Nutrition is –



All the processes involved in taking in and utilization of food substances by which growth, repair and maintenance of activities in the body as a whole or in any

• f its parts, are accomplished.



This includes ingestion, digestion, absorption and metabolism (utilisation).



Some nutrients are capable of being stored in various forms and can be drawn upon when the food intake is not sufficient.

Thomas, C.L. (ed) 1993. Taber’s Cyclopedic Medical Dictionary, 17th ed, Davis, Philadelphia p1337

CONTRIBUTION OF NUTRIENT IMBALANCES TO DEVELOPMENT OF CHRONIC DISEASES

Environmental Pollutants UV Exposure Smoking Inactivity Stress Poor Hygiene Damaged Cell Nourishment Genetics Habitual Nutrient Intakes Functional Cell



Absorption Efficiency



Metabolic Demand



Excretion Levels

DETERMINANTS OF NUTRIENT NEEDS



Provide sufficient amounts to satisfy daily demands



Adequacy of intake



Balance and variety in food choices



Maintain adequate reserves



Habitual diet and dietary patterns



Defensive approach

OPTIMIZE CELLULAR ACTIVITY AND TISSUE/ORGAN FUNCTION

FUNCTIONS OF WATER

 Recommended Daily Intake

 2-3L/day (NHMRC 2009)



Water (L) = body weight x 0.03

• Role of water in body:

 Participates in chemical and metabolic

reactions

 Thermoregulation  Maintain blood and cell volume

(Pinna, Rolfes & Whitney 2009, p. 399)

Detailed information available – ‘Nutrition at a Glance’ ME Barasi, Blackwell Publishing 2007

PROTEIN

PROTEIN

• Greek word ‘protos’ meaning prime importance
• Second only to water in plant and animal tissues
• Constantly broken down and reassembled according to

body requirement

• Daily diet must be sufficient to replace what has been used
• Excess is either burned for energy or stored as fat

PROTEIN FUNCTIONS

• Growth and repair – DNA bases
• Structural constituent of most of the body

–

Contractile  muscles

–

Fibrous  other tissues

• Carry and store materials (transport proteins)

–

Albumin – calcium, zinc and hormones

–

Retinol binding protein (RBP) – vitamin A

–

Hemoglobin – oxygen

–

Transferrin – iron

–

Ceruloplasmin - copper

PROTEIN FUNCTIONS

• Enzymes – digestive, catalytic
• Fibrinogen – blood clotting
• Blood group proteins – blood types
• Immune system proteins –

immunoglobulins and antibodies

• Proteoglycans – everything in

between tissues

PROTEIN FUNCTIONS

• Hormones – insulin, leptin, thyroxine
• Neurotransmitters production
• Cell membrane channels and pumps
• Transport proteins – albumin and globulin

maintain fluid volume in the capillaries

• Acid-Alkaline balance

DIETARY SOURCES

Protein quality

 Digestibility  Amino acid composition

• Complete



Contain all essential amino acids



Animal sources only

• Incomplete



Lacking one or more essential amino acids



Plant sources

DIETARY SOURCES

• Complementary Proteins

 Combining a variety plant foods that together

contain all the essential amino acids

 Not necessary per meal as body maintains an

amino acid pool (Marsh 2012)

Rolfes, Pinna & Whitney 2009

EXCESSIVE PROTEIN INTAKE

• Caution with pre-existing or high risk of kidney disorders



Ingestion of a high protein diet, kidney blood flow increases 20-30% in 1-2 hours.



Need to monitor

• Mineral losses



May increase calcium excretion, esp. purified powders

• Obesity and heart disease



Animal proteins also high in saturated fat

• Cancer



High animal protein intake linked to colon cancer

(Insel 2011)

PROTEIN SUPPLEMENTS

• Protein powders –

 Commonly used to increase skeletal muscle synthesis  May only occur in response to exercise  If excess is being consumed without exercise, may be burned

for energy or stored as fat.

 If used for energy, increased nitrogen excretion can increase

the burden on the kidneys and increases fluid intake requirements

 Purified protein powders lack other nutrient components

found in foods which are needed to build muscle tissue

(Whitney 2011)

PROTEIN SUPPLEMENTS

• Amino Acid supplements –



Single amino acids do not occur naturally in nature



High concentrations and unusual combinations may be harmful



Excess single amino acids increase demand for a carrier at the expense of another amino acid  possibility of deficiency



High dose branch chain amino acids (popular with body builders) can raise plasma ammonia levels which is toxic to the brain.

(Whitney 2011)

CARBOHYDRATES

DIETARY SOURCES

• Grains – breads and cereals, including

corn

• Legumes – lentils, beans, peas
• Fruit and root vegetables
• Dairy foods – mainly milk and yoghurt
• Processed foods – sweets and hidden

TYPES AND FUNCTIONS



Based on number of sugar molecules



Simple sugars and starches



Used to provide energy



Unused → triglycerides → stored in fat cells



Fibre



Indigestible portion of plant foods



Move foods through digestive system



Absorb water, toxins and other substances



Adds bulk to stools



Increases beneficial microbiota in the intestines

WHOLE GRAINS

• Bran



“Outer shell”



Fibre, B vitamins, trace minerals

• Endosperm



Provides energy



Carbohydrate, protein

• Germ



Nourishment for the seed



Antioxidants, vitamin E, B vitamins

www.wheatfoods.org

REFINING GRAINS

(Slavin et al, 1999)

GLYCAEMIC INDEX (GI)

• Lower GI foods = difficult to digest  slower release
• f sugars
• High GI foods = easy to digest  release sugars more

rapidly  high insulin levels

• Processing of some grains can alter resistance to

digestion

• Higher fiber and higher fat foods are also more

resistant due to their complexity

EFFECTS ON BLOOD SUGAR LEVELS

(Jenkins et al, 2002)

GLYCAEMIC INDEX (GI)

(Rolfes, Pinna & Whitney 2009)

GLYCAEMIC LOAD (GL)

 What information does the glycaemic load

provide us with?

 How does it differ from the GI of a food?

http://www.mendosa.com/gilists.htm

GLYCAEMIC LOAD (GL)

Calculating the GL Carbohydrate (g) x GI /100 = GL eg. ½ cup of watermelon = 6g x 0.72 = GL of 4.3 ½ cup of cornflakes = 47g x 0.71 = GL of 33 ½ cup of white rice = 36g x 0.72 = GL of 26

LOW GLYCAEMIC/LOAD FOODS AID TO:



Reduce post prandial blood glucose levels.



Increase satiety



Increase the variety of foods that are suitable for someone with diabetes.



Reduce the frequency of overnight hypoglycaemic episodes.



Reduce fasting blood glucose levels.



Reduce the dose of oral hypoglycaemic medication.



Reduce insulin requirements.

WESTERN DIETS AND CARBOHYDRATES

Of major concern is the 40-50% of the Western Diet is carbohydrates, mainly from refined and processed nutrient poor sources.

(Australian Bureau of Statistics)

WESTERN DIETS AND CARBOHYDRATES

 Consequences  Depletion of nutrients required for

carbohydrate metabolism

 Insufficient fibre consumption  Most of carbohydrates in the Western diet

are also of a high GL

Associated with

Stroke (Oh K et al, 2005) High cholesterol (Fried,2003) Inflammation (Nakanishi, 2005) Diabetes mellitus (Liu, 2002) PCOS (Marsh and Brand-Miller, 2005) Gall bladder disease (Tsai et al, 2005)

EXCESSIVE REFINED CARBOHYDRATES

DIETARY FIBRE

 Fruits, vegetables, wholegrains and legumes are

a good source

 Adds bulk to foods, so the stomach turns off

ghrelin (hunger hormone) sooner

 Delays gastric emptying and release of sugars

from GIT which benefits satiety and blood sugar regulation

(Brown et al 1999)

 Binds to bile acids, reducing both toxin and

cholesterol resorption from the gut, the latter improving lipid profiles

(Brownlee et al. 2005)

SOLUBLE FIBRE

 Found in fruits and vegetables  Digested by intestinal bacteria

producing anti-inflammatory SCFA’s

 Soluble fibers form gels



Water holding capacity depends on pH of GI tract, size of fibre particles or degree of processing



Coarsely ground bran with large particles increases hydration capacity than finely ground.

(Ink and Hurt 1987)

SOLUBLE FIBRE



Psyllium, pectin, guar and oat gum (mainly soluble fibre) significantly reduced serum cholesterol levels



Oatbran and soy bean fibre (soluble and insoluble fibre) had intermediate effects



Corn, wheat and rice bran were found ineffective mainly being due to higher levels of insoluble fibre.



Soluble rich fibres also decrease HMG CoA reductase activity which causes a decrease in cholesterol synthesis in rats (Anderson et al 1994)

INSOLUBLE FIBRE

 Non-fermentable fibres

 Often referred to as roughage  Increase growth of beneficial bacteria in colon

which is important for detoxification and increasing stool bulk

 Increased scavenging of toxins and other

metabolic byproducts

 Provides substrates for endogenous synthesis of

vitamins such as vitamin K, B12, SCFA’s

 Decrease conversion of cancer causing

substances into carcinogens (Garrow et al, 1998)

STARCHES

• Raw and unprocessed starches



Not well digested



Heating in the presence of moisture disrupts the structure



This is a reversible process

• Resistant starches



Release their sugars over several hours after a meal



Legumes, beans and peas, whole and intact grains

(Kohlmeier, 2003)

FIBRE RECOMMENDATIONS

 The World Health Organization

recommends 12-24g of fibre per day for healthy people 25-30g/day of fibre is recommended to reduce the risk of diverticular disease, colorectal cancer, and breast cancer Australian recommendations 25g/day for women and 30g/day for men

FIBRE FOOD VALUES

Food Serving Fibre (g)

Navy beans, ckd 1 cup 19.1 100% Bran cereal 1 cup 17.6 Kidney beans, ckd 1 cup 16.4 Lentils, ckd 1 cup 15.6 Prunes 1 cup, pitted 12.1 Quinoa, ckd 1 cup 9.3 Artichoke hearts 1 cup 9.1 Raspberries 1 cup 8.0 Spinach, frozen, ckd 1 cup 7.0 Oat bran ckd 1 cup 5.7 Instant oatmeal, ckd 1 cup 3.7 Rice, long-grained brown, ckd 1 cup 3.5 Mushrooms 1 cup 3.4

(Adapted from Higdon, 2005)

FIBRE FOOD VALUES

 Generally speaking 

 Fruit and vegetables contain 1.5g / serve  Refined carbohydrates 1g / serve  Whole grains 2.5g /serve  Beans and legumes 8g/serve

FIBRE RESEARCH



Anderson JW, Allgood LD, Lawrence A, et al. 2000, “Cholesterol-lowering effects of psyllium intake adjunctive to diet therapy in men and women with hypercholesterolemia: meta-analysis of 8 controlled trials.” Am J Clin Nutr. Vol 71 Iss 2 pp 472-479.



“Psyllium supplementation significantly lowered serum total and LDL-cholesterol concentrations in subjects consuming a low-fat diet. Psyllium is well tolerated and safe when used adjunctive to a low-fat diet in individuals with mild-to-moderate hypercholesterolemia.”

FIBRE RESEARCH



AbuMweis, S Jew, S Ames, N 2010, “β-glucan from barley and its lipid-lowering capacity: a meta-analysis

• f randomized, controlled trials” European Journal of

Clinical Nutrition Vol 64, Dec pp1472-1480



“Increased consumption of barely products should be considered as a dietary approach to reduce LDL cholesterol concentrations.”

FIBRE RESEARCH



Bliss DZ et al. 2001. Supplementation with dietary fiber improves fecal incontinence, Nurs Res . Volume 50, Issue 4. pp. 203-13



“Supplementation with dietary fiber from psyllium or gum arabic was associated with a decrease in the percentage of incontinent stools and an improvement of stool consistency.”

FIBRE RESEARCH



Sherry, C Kim, S Dilger, R Bauer, L Moon, M Tapping, R Fahey, G Tappenden, K Freund, G 2010 “Sickness behavior induced by endotoxin can be mitigated by the dietary soluble fiber, pectin, through up-regulation of IL- 4 and Th2 polarization.” Brain Behavior and Immunity, Volume 24, Issue 4, May 2010, Pages 631–640



“A diet rich in soluble fiber protects mice from endotoxin-induced sickness behavior by polarizing mice Th2 when compared to a diet containing only insoluble fiber. Mice fed soluble fiber became less sick and recovered faster from endotoxin-induced sickness behaviors than mice fed insoluble fiber.”

FIBRE RESEARCH

Deficiency has been associated with:



Constipation - Most patients with chronic constipation respond to fibre supplementation (Wald, 2000)



Diverticulitis coli - Low fibre diets prolong colonic transit time and result in increased intraluminal pressure due to low- volume stools (Ye, Losada and West, 2005)



Colorectal cancer - The association with colon cancer and dietary fiber is still inconclusive (Martinez 2005)



Coronary heart disease - Among other dietary changes, wholegrain cereals and an abundance of fruit and vegetables

• ffers protection from many cardiovascular conditions (Hu and

Willet, 2002)



Diabetes mellitus - Lowering of the glycaemic load by consuming high fibre foods can reduce the risk of diabetes mellitus (Gray, 1995)

FATS

FATS

Functions –

• Energy reserve and insulation
• Hormone and vitamin D synthesis
• Important in transporting fat soluble

vitamins such as A, D, E, and K

• Essential part of the cell membranes
• A source of eicosanoid producing essential

fatty acids

TYPES OF FATS

 Triglycerides

 Saturated Fats  Trans Fats  Monounsaturated Fats  Polyunsaturated Fats  Omega 6  Omega 3

FAT IS GOOD!!

Depending on what kind….



Omega 3 fatty acids (fish oils-EPA, DHA; plant sources - ALA)



Mono-unsaturated fats (macadamia and olive oils)



SCFA’s



Decreased fat consumption since the 1960’s 



not associated with obesity epidemic



CHO intake has increased dramatically



Glycemic index/glycemic load

SATURATED FATS

• Saturation affects the physical characteristics of the

fat and its storage properties.



Stable structure

• Types:



Butyric acid: Butter and milk fat (SCFA)



Palmitic acid: Palm oil



Lauric acid: Coconut oil



Arachidic acid: Peanuts



Stearic acid: Beef, mutton, pork, cocoa butter

• WHO recommends maximum of 10% total energy intake.

FUNCTIONS

• Total cholesterol: HDL cholesterol ratio
• Lauric acid (coconut) – greatly decreased ratio
• Palmitic acid (palm) – no effect
• Steric acid (animals) - slightly increased ratio

 Replacing saturated fats with



Unsaturated fats – decreased ratio



Carbohydrates – no effect on ratio but increased fasting triglycerides

 Replacing trans fats with carbohydrates and

unsaturated fats - decreased ratio

(Mensink 2003)

HOW INTAKE OF OMEGA-3 FATTY ACIDS IS HELPFUL

 Stabilization of atherosclerotic plaques  Reduction of inflammation by moderating

prostaglandin synthesis pathways

 Improved ratio of omega-3 to omega 6 FA reduces

arachidonic acid and pro-inflammatory, pro-platelet aggregatory cytokines

 Enhances PGE1 and PGE 3 and less inflammatory

leukotrienes

Thies F, et al. Association of n-3 polyunsaturated fatty acids with stability of atherosclerotic plaque: RCT, Lancet, 2003;361:477-85 Harper, Beyond the Mediterranean Diet: the Role of Omega-3 Fatty Acids in the Prevention of CVD, Prev Cardiol, 2003;6(3):134-46

POLYUNSATURATED ESSENTIAL FATTY ACIDS

Omega 3 Omega 6 Chia seeds Corn oil Flaxseeds / linseeds Safflower oil Sardines Sunflower oil Herring Soy bean oil Mackerel Turkey Salmon Salad dressing Green lipped mussels Canola oil Sydney rock oysters Vegetable oil Walnuts Seeds Seaweeds Nuts

TRANS FATS  SATURATED FATS

 Trans-fatty acids- the hydrogen atoms are on

• pposite sides of the double bond and the carbon

chains are also on opposite sides; the effect of this is that the molecules can pack into straight line shapes just as saturated fatty acids do.

TRANS FATTY ACIDS

• Increase the risk of heart disease
• Increased risk of coronary artery disease
• Increased risk of thrombosis
• There have been no safe limits of trans fat consumption

shown



Maximum intake of 1% of daily kJ recommended by the World Health Organization (WHO)

SOURCES



Cookies, crackers, cakes, muffins, pie crusts, pizza dough, and breads such as hamburger buns



Some stick margarine and vegetable shortening



Pre-mixed cake mixes, pancake mixes, and chocolate drink mixes



Fried foods, including donuts, French fries, chicken nuggets, and hard taco shells



Snack foods, including chips, candy, and packaged or microwave popcorn



Frozen dinners

(McCarthy et al 2008)

SHORT CHAIN FATTY ACIDS



SCFA’s support health by:



Providing energy for the distal intestinal epithelia



Assisting the regulation of electrolyte absorption



Anti-inflammatory properties



Enhances production of macrophages, t-helper cells, neutrophils and antibodies, assisting immunity



Have other possible affects on the liver and other tissues



Decreases interluminal pH decreased secondary bile acid synthesis which has been shown to promote tumour generation

(Gropper and Groff 2009)

SHORT CHAIN FATTY ACIDS



Bacterial hydrolytic enzymes depolymerise the large undigested molecules, allowing microbiotica to ferment the component sugars and utilise the subsequent energy produced



Mainly acetate, propionate and butyrate.



Propionate carried by portal vein to liver for metabolism  decrease in cholesterol synthesis  converted to succinyl-CoA for glucose or energy production



Acetate  travels to peripheral tissues and is metabolised by skeletal and cardiac muscles, kidneys and brain



Butyrate provides energy for colonic an epithelial cells  Also been shown to decrease proliferation and differentiation of colon cancer cells in vitro.

(Tedelind et al 2007)

(Simopoulos 2008)

Detailed information available – ‘Nutrition at a Glance’ ME Barasi, Blackwell Publishing 2007

FACTORS CONTRIBUTING TO MICRONUTRIENT DEFICIENCIES



Chronic diseases



Chronic inflammation



Elderly



Malabsorption



Malnutrition



Substance abuse



Medications

STAGES OF MICRONUTRIENT

DEFICIENCY

• 1. Inadequate nutrient delivery
• 2. Depletion of nutrient stores
• 3. Biochemical changes
• 4. Physical manifestations of deficiency
• 5. Morbidity and mortality

VITAMINS AND MINERALS

VITAMINS AND MINERALS



Macronutrients provide structure , function and produce energy



Micronutrients are essential as cofactors for all of these processes to occur



All essential nutrients are similar in that they are vital to life and available from foods.

Both deficiencies and excesses of supplemental vitamins and minerals can affect health!

VITAMINS

 Water Soluble

 Vitamin C  B group

 Fat Soluble

 A, E, D, K

WATER SOLUBLE VITAMINS

(Adapted from Groff and Gropper, 2000)

WATER SOLUBLE VITAMINS

• Absorbed directly into blood
• Not stored long in body except vitamin B12
• Excreted in urine
• Easily destroyed during

food storage or preparation

WATER SOLUBLE VITAMINS

• The organic nature of vitamins means they

can be destroyed by exposure to light, air, cooking and storage.

• Preventative measures should be taken



Refrigeration



Cut fruits and vegetables should be stored in closed containers



Avoid high temperatures and long cooking times



Steam as opposed to boil

FAT SOLUBLE VITAMINS

• Differ from water-soluble vitamins in several significant

ways:

(Whitney & Rolfes, 2008)

FAT SOLUBLE VITAMINS

• Participate in numerous activities throughout the body:



Vitamin A – Primarily involved in eye function, skin health, nervous system, bone tissue and immune function



Vitamin D – Regulates bone metabolism and cell renewal



Vitamin E – Antioxidant



Vitamin K – Involved in blood clotting and bone mineralisation

MINERALS

 Macrominerals

 Calcium  Magnesium

 Microminerals

 Iron  Zinc

HIGH CALCIUM FOODS

• Seaweed
• Almonds, sesame seeds
• Green leafy vegetables
• Dairy products
• Tofu
• Salmon bones
• Sweet potato

CALCIUM FUNCTIONS

• Skeletal structure
• Cell to cell communication
• Muscle contraction with magnesium
• Nerve transmission
• Blood clotting with vitamin K
• Growth and repair of tissues

FACTORS INCREASING DEMAND

• Menopause



Low oestrogen increases urinary excretion and bone loss

• Elderly



Low stomach acid reduces absorption

• Vitamin D deficiency



Decreases absorption and increases urine losses

 Coffee and black tea



Decreases absorption

(Zimmerman, 2001)

FACTORS INCREASING DEMAND

• Gallbladder disease



Reduced fat absorption allows fats to bind to calcium

 Medication



Antacids, laxatives, steroids

• High sodium intakes



Increase urinary excretion

• Alcohol

(Zimmerman, 2001)

HIGH MAGNESIUM FOODS

• Wholegrains
• Nuts and seeds
• Dark green vegetables
• Legumes
• Seafood
• Potatoes
• Cocoa

FUNCTIONS

• Bone structure

 Supports bone mineralization with calcium

• Enzyme cofactor



Over 300 enzyme processes



Energy metabolism



Balancing Calcium



Competing with magnesium may be functionally important in preventing muscle cramps, increased blood pressure, and coronary vasospasms. (Kohlmeier, 2003)

FACTORS INCREASING DEMAND

 Digestive problems



Prolonged vomit and diarrhea

• Rapid growth



Pregnancy



Childhood and adolescence

• Medications



Diuretics, laxatives



Chemotherapy, cortisone

• Diabetes mellitus

(Saris et al, 2000)

FACTORS INCREASING DEMAND

• Stress
• Athletes
• Alcohol consumption
• Protein deficiency
• Kidney disorders

(Zimmerman, 2001)

HIGH ZINC FOODS

• Highest in protein rich foods
• Oysters
• Beef, turkey, crab
• Nuts and seeds
• cashews
• Legumes
• Ginger

FUNCTIONS



Manufactures heme for hemoglobin



Fatty acid, protein, carbohydrate, vitamin A and alcohol metabolism



Antioxidant



Digestion



Growth and repair



Immune function

(Prasad 2013)

FACTORS INCREASING DEMAND

• High dose calcium, folate and iron

supplementation

• Vegetarian diets
• Digestive disorders
• Alcohol consumption



Reduced absorption and decreased excretion

• Diabetes mellitus



Increased urinary losses

(Gropper 2005)

IRON

• Heme iron



Found in foods that are from the flesh of animals (meat, poultry, and fish)



Has an absorption rate of 25%

• Nonheme iron



Found in plant-derived and animal-derived foods



Has an absorption rate of 17%

• Heme iron is better absorbed but nonheme iron absorption can

be enhanced with vitamin C

FUNCTIONS

• Oxygen transport and storage
• Energy production
• Free radical metabolism

 DNA synthesis  Thyroid hormone synthesis  Vitamin A metabolism



Converts beta carotene to vitamin A

 Amino acid metabolism

FACTORS INCREASING DEMAND

• Growth periods
• Vegetarians
• Coffee and tea consumption
• Low stomach acid
• Heavy/chronic bleeding
• Athletes
• Chronic inflammation or illness
• Nutrient deficiencies – Vitamin A, B6, Copper

(Zimmerman, 2001)

TAKE HOME MESSAGES AND RECOMMENDATIONS



Stay up to date with scientific literature to provide educated

• pinions to your patients on the various ‘health fads’



Be aware of factors increasing the need for various nutrients and ensure your patients are consuming adequate levels



Recognise the need for discernment when investigating benefits of any commercial product



There are no miracle cures



You can always rely on your background understanding of physiological mechanisms and underlying biochemistry to get more of a clear picture of the facts 