Suggestion box Please e-mail me your questions about nutrition-Answers presented following week on line notes are not complete transcripts of lectures

Addition to lecture 2A- -use a lactose-free dairy product (lactose removed when lactose-free dairy product is made) e.g. some lactose-free milk products are currently available.

chicory seed-food additive -resistant carbohydrate causing decreased pH- due to short chain fatty acid production

Questions about diet/exercise records Project (or essay option)?

Lecture 4a- 26 September 2018 CARBOHYDRATES III

- sugars in health and disease - complex carbohydrates in health Overview of lecture 4A Carbohydrates - sugars in health and disease - complex carbohydrates in health and disease - where are carbohydrates found - dietary recommendations - what’s new and exciting    

Overview of lecture 4a continued Fibre Fibre structure and classification and effects Idatme of fibres Fibres in health and disease How to get higher fibre in the diet    

Overview of lecture 4a continued Recommendations for fibre intake too much fibre in the diet Fibres as food additives What is new in fibre research? Choosing carbohydrates wisely Next lecture-4b- Sicko

Carbohydrates in health-sugars Nutrient deficiencies- empty kcal Dental caries – sugar will cause caries and therefore good oral hygiene important Obesity – when consumed in excess sugars cause obesity due to conversion of sugar to fat- see next slide first point

Carbohydrates in health-sugars continued Heart disease –lots of refined sugar leads to alterations in blood lipids in carbohydrate sensitive individuals-due to increased insulin response that builds fat Misbehaviour in children and criminal behaviour in adults – myth- nothing to support scientifically these suggestions

Carbohydrates in health continued But sugars in foods are not all bad-many functional properties of carbohydrates in foods- e.g. taste, physical and chemical properties and antimicrobial purposes Weight control-foods rich in complex carbohydrate are usually low in fat and added sugars and provide -less kcal per bite -also satiety and delayed hunger due to glycemic index issue

Carbohydrates in health continued Heart disease Complex carbohydrate foods also help with Heart disease -high complex carbohydrate and low cholesterol diets reduce risk of heart disease -such high complex carbohydrate and low cholesterol diets are low in animal fat and cholesterol and high in soluble fibres and vegetable proteins

Carbohydrates in health-starches continued Cancer -lower risk with high complex carbohydrate diet that has loads of green and yellow vegetables and citrus fruit -nature of preventative effect is not clear Type 2 diabetes-lower risk with high complex carbohydrate diets-most likely due to such diets being low in fat- also likely due to lower glycemic index issue

Carbohydrates in foods Glucose- e.g. fruits, veggies, honey Fructose- e.g. fruit and honey Galactose-rarely in food -mostly in form of lactose Sucrose-minimal amounts in some fruits and veggies- e.g. beets Maltose -none naturally in food Lactose - milk and other dairy products Oligosaccharides – e.g. inulin – chicory, Jerusalem artichoke Starch- e.g. potatoes Glycogen- e.g.- meats little rapid conversion to lactic acid at slaughter

DIETARY Recommendations-DRI Carbohydrates be 45-65 % of energy or 900-1300 kcal of carbohydrate or 225-325 grams of carbohydrate per total energy intake of 2000 kcal/day -carbohydrates from a variety of sources with increases in complex carbohydrates are recommended

DIETARY Recommendations DRI- Added sugars (simple sugars)-no more than 25 % of calories- but that is 500 kcal or 125 grams (31 teaspoons) of sugars- this is too much WHO-recommendation http://www.who.int/mediacentre/news/releases/2015/sugar-guideline/en/

Carbohydrates in health-sugars continued Reducing dietary sugars https://wellness.uoguelph.ca/hpc/sites/uoguelph.ca.hpc/files/public//images/Sugar%20in%20beverages%20HPC%20June%20Newsletter_0.pdf

What is new in carbohydrates? Glycaemic index review by Health Canada Aziz, A, Dumais, L., Barber J. Health Canada's evaluation of the use of glycemic index claims on food labels. American J. Clin Nutr. 2013 Aug;98(2):269-74. doi: 10.3945/ajcn.113.061770. Epub 2013 Jun 12. Nutrition Research Division and the Nutrition Regulations and Standards Division, Bureau of Nutritional Sciences, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, Canada. alfred.aziz@hc-sc.gc.ca

What is new in carbohydrates? Aziz et al. American Journal of Clinical Nutrition 98:269-74(2013). “Health Canada's assessment identified 3 areas of concern with respect to GI labelling: 1)the GI measure has poor accuracy and precision for labelling purposes; 2) as a ratio, the GI does not vary in response to the amount of food consumed and the partial replacement of available carbohydrates with unavailable carbohydrates, whereas the glycemic response does; 3) an unintended focus on the GI for food selection could lead to food choices that are inconsistent with national dietary guidelines. Hence, Health Canada's current opinion is that the inclusion of the GI value on the label of eligible food products would be misleading and would not add value to nutrition labeling and dietary guidelines in assisting consumers to make healthier food choices. “

What is new in carbohydrates? Artificial sweeteners – linked to weight gain and to increased risk of type 2 diabetes- a number of papers Saccharin changes gut microbiota in mice which in turn contributes to glucose intolerance and hence the risk of type 2 diabetes Nature 514, 181–186 (09 October 2014)

Fibre structure and classification and effects Insoluble Cellulose-bran,vegetables Hemicellulose-bran, whole grains Lignins-fruits, mature vegetables, flax Generally-accelerate gi transit, -increase fecal weight(promotes bowel movements) -slow starch digestion, -delay glucose absorption -but can be exceptions

Fibre structure and classification and effects continued Soluble Pectins-apples, carrots, gums and mucilages- oats, legumes Generally-delay gi transit, -delay glucose absorption, -lower blood cholesterol -but can be exceptions

Other fibre functions (classifications) - water holding capacity viscosity cation exchange capacity bile binding capacity fermentability

Fibre ingestion, digestion, absorption and transport, metabolism, excretion mouth for ingestion fibre not digested in mouth or stomach or by small intestine enzymes-why? bacteria-make short chain fatty acids and gas short chain fatty acids and water absorbed at large intestine and transported by blood used for energy (fatty acid metabolism next week – lecture 5A), water can split molecules to release energy Excretion- gas exits anus, undigested fibre leaves in faeces, water excreted via faeces, urine, sweat, saliva?, and breathing)

Fibre in health and disease weight control -bulk-less appetite -soluble and insoluble fibres heart disease -soluble fibres lower cholesterol (bile issue) -fibre may displace fat in diet

Fibre in health and disease continued Cancer Lower colon cancer-fibre may help by diluting and binding and more rapid excretion of carcinogens- both soluble and insoluble fibre may help Breast cancer -secoisolariciresinol diglucoside (SDG) is a mammalian lignan pre-cursor that is found in flaxseed-SDG is not a fibre but is found in the fibre region of flaxseed -metabolites of SDG are mammalian lignans which are produced by bacteria in the large intestine- these mammalian lignans may reduce breast tumour growth in humans)

Fibre in health and disease continued Diabetes control weight-diabetes slow glucose absorption-glucose surge soluble fibres are key here

How to get higher fibre in the diet Fibre content High Medium Low 5g 2 g 0.5 g Breads cereal Rice Group Breads Whole wheat white 1 slice bread bread Cereal All Shredded Rice ½ cup bran Wheat Krispies Pasta whole macaroni ½ cup wheat pasta

How to get higher fibre in the diet continued Fibre content High Medium Low 4 g 2 g 1 g Fruit group 1 MEDIUM OR ½ CUP berries apple melon

How to get higher fibre in the diet continued Fibre content High Medium Low 4 g 2 g 1 g Vegetable Group ½ cup peas green asparagus beans

Remember that: fibre from natural sources rather than commercially prepared fibre is better because foods contain vitamins and minerals as well as the fibre

DRI recommendation for fibre intake follow DRI recommendations for carbohydrate intake and this will provide sufficient fibre DRI - 14 grams fibre/1000 kcal (roughly 25-35 grams of fibre/day) (no distinction between soluble and insoluble but variety is the key to balance)

Too much fibre in the diet gives: flatulence obstruct gi tract if greater than 50 g fibre /day top recommendation is 40 g/d for adults (who)

Too much fibre in the diet continued insoluble fibre has phytates that can bind minerals- e.g. calcium, iron, zinc and magnesium prevents enzyme contact

Too much fibre in the diet continued increases volume of food required to meet energy requirements satiety before adequate nutrition-generally only a problem if diet low in micronutrients or in small children (small stomachs)

Too much fibre in the diet continued -important to increase water intake with increases in dietary fibre -otherwise constipation but if have enough water can get diarrhea (bacterial breakdown of fibre)

Fibres as food additives pectin -common in fruits and vegetables -forms gel when sugar and acid added -commercially from citrus peels and apples -thickening agent in jams, jellies and tomato paste

Fibres as food additives continued -carbohydrate gums- used and thickeners and stabilizers because they combine with water to keep solutions from separating -used in gravies, pie fillings, jellies and puddings

Fibres as food additives continued gums derived from gum arabic, gum karaya, guar gum, locust bean gum, xanthan gum and gum tragacanth gums extracted from shrubs, trees and seed pods

Fibres as food additives continued pectins and gums are used in reduced fat products to mimic the texture and viscosity of fat

Fibres as food additives continued other thickening agents and stabilizers are from seaweeds ( e.g. agar, carrageen and alginates)

What’s new in fibre research? Oligosaccharides now considered fibre (used to be that fibre was only in polysaccharide form) Oligosaccharides (e.g. inulin which is found in chicory and Jerusalem artichoke for example, can promote growth of good (for health) bacteria in the large intestine (please note that inulin is a pre-biotic and the bacteria are called pro-biotics) Slavin, J. Nutrients 5:1417-35 (2013)

How to choose carbohydrates wisely 1)increase intakes of whole grains 2)use whole grain products such as oatmeal, brown rice and whole wheat bread 3)increase consumption of legumes such as kidney, black and pinto beans)if fresh fruits not available, choose frozen or canned fruits without added sugar

How to choose carbohydrates wisely continued 4)use whole grain flour for ¼ to ½ the amount of flour in the recipe 5)use less sugar in baking 6)use less added sugars in foods 7)eat fewer high sugar foods 8)use food labels to guide one’s choices