Note Final Exam-please check final schedule Atlantic Superstore Tour-Sydney River -21 November- 10:25 am start-10:55 am finish

Note Do sprouted wheat products (like Ezekiel bread) have gluten – yes receipts

Lecture 10 – 10 October 2018 Proteins

Proteins Comes from the Greek word protos meaning of prime importance

What are they?   -chains of amino acids -an amino acid is an organic acid with a side group and an NH2 group attached

Functions of proteins in the body -structure -hair, nails, cells   -mechanical functions motor proteins -eg contractile proteins in muscle

Functions of proteins in the body -enzymes -aid in reactions- make the reactions go faster   -hormones -signals to cells -eg insulin -antibodies -help fight infection

Functions of proteins in the body -fluid balance -osmotic influence   -acid base balance -charge on certain proteins affects pH -channels e.g.-move ions into and out of cells

Functions of proteins in the body pumps -move substances across cell membrane by use of energy -transport -eg -lipoproteins transport fat in bloodstream -carry fat soluble vitamins -source of energy and glucose -when protein is broken down it gives energy  

Functions of proteins in the body -used to make neurotransmitters

Digestion of protein -stomach acid -denatures-straightens out proteins –readies them for small intestine digestion of proteins   -small intestine- enzymes attack proteins and make them into amino acids

Absorption of protein Amino acids moved across intestinal wall into blood   Transport of protein No special needed-the amino acids are water soluble Metabolism Individual amino acids assembled into proteins humans need

How are proteins made in the body? -remember protein in is not protein out   -proteins are made from copies of DNA

Excretion Proteins are broken down into amino acids and then amino acids are further broken down- urea is one product of amino acid breakdown, urea and other components of protein breakdown are put in the urine and excreted  

Nitrogen balance -positive nitrogen balance- more protein being made than broken down –pregnant female -zero nitrogen balance- protein is being made as fast as it is being broken down-healthy person -negative nitrogen balance- protein is being broken down faster than it is being made eg illness  

Recommended intake of protein Infants 0-6 months 2.2 g/kg body weight/day Children 1-1.6 g/kg body weight/day Adults 0.8 g/kg body weight/day Seniors 0.8 g/kg body weight/day   -For all about 15-20 % of daily energy intake -Must be high quality (complete) protein  

Protein quality Complete proteins –correct balance of essential amino acids Definitions of two types of amino acids -essential and non-essential   Most animal proteins are complete Many plant proteins are incomplete- exception soybean protein

Complementarity Beans and rice Beans and corn Rice and lentils Pasta and beans Peanut butter on bread

Estimating protein intake Food labels will allow you to do this Following Canada’s food guide will allow you to estimate this  

Vegetarianism Various types of diets in vegetarianism-progressive risk of inadequate protein intake going from omnivores to fruitarians

Potential Health risks Vegans- MAY BE low in iron, calcium, zinc, vitamin D and B6 and B12 -higher intakes of oxalates   Fruitarian-limited in many essential nutrients However, the next four slides provide more context on the issue of potential deficiencies

Important to emphasise that plant-based protein is: affordable (even more than animal-based protein) nutrient-dense easily combined to form complete essential amino acid levels. Indication that vegans/vegetarians being deficient in other essential vitamins and minerals requires clarification and current information on the topic

There are growing amounts of vegan/vegetarian options being offered in grocery stores and restaurants, almost all of which are being fortified with B12, etc. buying fortified grain products (eg pastas); this is an important point: that deficiencies are not as big of a problem as they used to be, as it is becoming more and more difficult to find non-fortified vegan/vegetarian options

Following a vegan/vegetarian lifestyle is very similar to omnivorous lifestyles, as there are 'right' and 'wrong' ways to do it. Just as omnivores can be deficient in certain nutrients if they are not following a balanced, varied diet, and can be nutritionally healthy if they eat enough 'good' foods, vegans/vegetarians can do the same.

There are 'wrong' ways to follow this lifestyle, such as relying on too many processed foods and grains, and there is a 'right' way as well, if the food groups in the Guide are followed (many different fruits, veggies, legumes, whole grains, dairy and meat alternatives, etc). deficiencies are a result of not enough variety and nutrient-dense foods, not necessarily from the lack of complete proteins and dairy products.

Protein energy malnutrition (PEM) Marasmus Protein deficiencies Protein energy malnutrition (PEM) Marasmus Wasting- skin and bones look Not enough energy or protein Kwashiokor Evil spirit that affects first child when the second one is born Enough energy not enough protein Swollen belly appearance

Excess protein intake Risk of cancer, heart disease and osteoporosis and renal failure