Lecture 3b- 24 Sept. 2018 CARBOHYDRATES II

Overview of lecture 3b Carbohydrates -blood glucose homeostasis -functions of carbohydrates essential or not? -fad diets

Overview of lecture 3b Carbohydrate content of foods -impact of diet on health and disease Functional foods in the management of health and disease Nutraceuticals in the management of health and disease Next lecture-fibre -carbohydrates in health and disease -WHATS NEW IN CARBOHYDRATE RESEARCH

BLOOD GLUCOSE HOMEOSTASIS P. 106-109 Maintaining blood glucose at normal levels is important -too low-dizzy and weak -too high-fatigued, confused and difficulty breathing Regulating hormones - insulin and glucagon Balancing in normal range - insulin and glucagon

Blood glucose homeostasis continued Falling outside normal range -diet does not regulate blood sugar-the body does -diabetes-types 1 and 2 and gestational diabetes-elevated blood glucose -type 1 diabetes -autoimmune attack on pancreatic beta cells -used to be called insulin dependent diabetes mellitus or juvenile diabetes -no cure at the moment -type 2 diabetes -insulin resistance followed by beta cell failure -used to be called-non-insulin dependent diabetes mellitus(NIDDM) or adult onset diabetes -gestational diabetes (GDM) -insulin resistance in pregnancy due to excessive weight gain -resolves with medical management -greater risk of type 2 diabetes later on for mum and post-partum child who experienced in utero GDM -hypoglycemia-low blood glucose from too much insulin or not enough to eat

-before and after type 2 diabetes, GDM and hypoglycemia sets in Blood glucose homeostasis continued Falling outside normal range continued -but dietary modifications important- -before and after type 2 diabetes, GDM and hypoglycemia sets in -for type 2 diabetes and GDM avoid uneccessary weight gain by dietary change-low fat and rich in complex carbohydrate and fibre -for hypoglycemia-get enough to eat

Blood glucose and diet p. 108-9 glycaemia-blood glucose glycaemic index of food-ability to provoke a blood glucose response - effects blood sugar rise -high glycaemic index foods (eg white bread) causes rapid rise in blood glucose followed by quicker drop in blood glucose -lower glycaemic foods (eg whole grain bread) - causes less rapid rise in blood glucose followed by slower drop in blood glucose - may reduce chances of getting or worsening type 2 diabetes -effect of food on blood glucose-if have slow absorption get modest rise in blood glucose and smooth decrease of blood glucose

Blood glucose and diet continued -blood glucose dependent on whether carbohydrate eaten alone or as part of a mixed meal -eating small meals often is same as low glycemic index-why?

Blood glucose and diet continued -however, glycemic index is controversial - inadequate science? - determined for relatively few foods - when determined it is based on average of multiple tests with a great deal of variability

Blood glucose and diet continued Fad diets -no apples or oranges but bacon and eggs alright-this is not good why?

Carbohydrates - essential or not?

yes- why? Healthy roles for carbohydrates 1) neural function 2) give structure to molecules 3) metabolically 4) impact on nutrient absorption

Carbohydrate functions- healthy Neural function brain and nerves really only set up to use glucose lipids/proteins cannot be used

Carbohydrate functions-healthy continued give structure to molecules carbohydrate e.g. glycogen disaccharides oligosaccharides non-carbohydrate e.g. some proteins (i.e. glycoproteins)

Carbohydrate functions-healthy continued metabolically -energy-heat/fuel -sparing protein -burning fat

Carbohydrate functions healthy continued metabolically continued make other compounds - glycogen - fat - protein (non-essential amino acids) - DNA/RNA

Carbohydrate functions-healthy continued Impact on nutrient handling non-absorbable oligosaccharides impair carbohydrase activity starch granules exposed to moist heat and then cooling are less dense and hence less available to enzyme action

Unhealthy roles for carbohydrate glycation (glycosylation) of proteins proteins-albumin -hemoglobin lipoproteins blood vessels

Unhealthy roles for carbohydrate glycation (glycosylation) of proteins continued albumin glycation or glycosylation can cause tissue breakdown via stimulating chemical messengers

Unhealthy roles for carbohydrate glycation (glycosylation) of proteins continued Haemoglobin may set up a chemical reaction that leads to blood vessel breakdown

Unhealthy roles for carbohydrate-glycation (glycosylation) of proteins continued Lipoproteins low good cholesterol higher bad cholesterol

glucose itself binds to protein in blood vessels-leaky Unhealthy roles for carbohydrate glycation (glycosylation) of proteins continued Blood vessels glucose itself binds to protein in blood vessels-leaky

Up next- carbohydrates in health and disease Influence of: the diet nutraceuticals functional foods

Different “regular” foods have differing levels of a variety of carbohydrates-can affect bodily function Functional foods can manage carbohydrates in the body and can affect bodily function Nutraceuticals can manage carbohydrates in the body and can affect bodily function

Foods Glycaemic index grains (includes breads and pastas) breads -wheat higher than rye pastas - lower than breads rice and pasta about the same as each other

Foods continued-glycaemic index continued Vegetables and fruits on average Glycemic index potato > yam legumes > root veggies fruits ~ legumes

Foods continued Glycemic index continued milk products ~ fruits on average why? lactose=fructose in glycemic index

Foods continued Glycemic index continued meats - very low glycemic index - but do not gorge gorge

Health Canada definition Functional foods Health Canada definition A functional food is similar in appearance to, or may be, a conventional food that is consumed as part of a usual diet, and is demonstrated to have physiological benefits and/or reduce the risk of chronic disease beyond basic nutritional functions, i.e. they contain bioactive compound.

Functional food examples fish flax canola chicory seed-contains an oligosaccharide

Functional food examples http://countryharvest.com/en/product/12-grains/ http://www.presidentschoice.ca/en_CA/products/productlisting/pc-quinoa---flax-multigrain-bread.html

Fish increase insulin sensitivity? -perhaps due to w3 fatty acids

Canola omega 3 fatty acids -may increase insulin sensitivity

Flax omega 3 fatty acids may increase insulin sensitivity

Chicory seed example of a resistant carbohydrate affect colonic pH and stool bulking ol BULKING

Nutraceuticals Health Canada definition A nutraceutical is a product isolated or purified from foods that is generally sold in medicinal forms not usually associated with foods. A nutraceutical is demonstrated to have a physiological benefit or provide protection against chronic disease.

Nutraceutical examples fish oil flax lignan complex flax oil canola oil evening primrose oil hemp oil chondroitin sulphate glucosamine

Fish oil omega 3 fatty acids – increased insulin sensitivity in some studies INCREASE?

Flax lignan complex Secoisolariciresinol diglucoside molecule metabolites decrease blood plasma glucose concentrations perhaps via insulin sensitivity increase?

Flax oil Omega 3 fatty acid may increase insulin sensitivity?

Canola oil Omega 3 fatty acid may insulin sensitivity?

Evening primrose oil -omega 6 fatty acids -reduces glucose impact on nerves in diabetes (improves nerve transmission speed)

Hemp oil mix of omega 3 and omega 6 fatty acids speculation-effects as above with omega 3 and omega 6 fatty acids

Chondroitin sulphate polysaccharide -found in joints-cartilage -reduced in arthritis

Glucosamine -polysaccharide linked to nitrogen group -found in cartilage in joints -reduced in arthritis