Upload
quilla
View
34
Download
1
Embed Size (px)
DESCRIPTION
The Science of Nutrition. A Microscopic to Macroscopic Approach. Today’s Agenda. JEOPARDY Lipids Vitamins & Minerals Nutritional Density. JEOPARDY. Split into two equal teams and get out your note books. Lipids. Types of Lipids Fatty Acids Fats, and Oils - PowerPoint PPT Presentation
Citation preview
The Science of NutritionA Microscopic to Macroscopic Approach
Today’s Agenda1. JEOPARDY2. Lipids3. Vitamins & Minerals4. Nutritional Density
JEOPARDYSplit into two equal teams and get out your note books.
4
LipidsTypes of Lipids
Fatty AcidsFats, and Oils
Chemical Properties of Triglycerides
5
Types of LipidsLipids with fatty acids
WaxesFats and oils (trigycerides)PhospholipidsSphingolipids
Lipids without fatty acidsSteroids
What foods contain fat?
FatsFat refers to the class of nutrients known as lipids. The lipid family includes triglycerides (fats and oils), phospholipids, and sterols.
Every triglyceride contains one molecule of glycerol and three fatty acids.
7
Fatty AcidsFatty acids are chains of carbon atoms with hydrogen atoms attached that have an acid group (COOH) at one end and a methyl group (CH3) at the other end.
8
9
Fatty AcidsLong-chain carboxylic acidsInsoluble in waterTypically 12-18 carbon atoms (even
number)Some contain double bonds
corn oil contains 86% unsaturated fatty acids and 14% saturated fatty acids
Saturated v. Unsaturated Fatty Acids
Saturated fatty acids carry the maximum possible number of hydrogen atoms, while unsaturated fatty acids lack hydrogen atoms and have at least one double bond between carbons.
10
11
Structure of Fatty AcidsSaturated = C–C bondsUnsaturated = one or more C=C
bondsCOOH
COOH
palmitoleic acid, an unsaturated fatty acid
palmitic acid, a saturated acid
12
StructuresSaturated fatty acidsFit closely in regular pattern
Unsaturated fatty acidsCis double bonds
COOHCOOHCOOH
C CH H
COOHcis double bond
13
Properties of SaturatedFatty Acids
Contain only single C–C bondsClosely packed Strong attractions between chainsHigh melting pointsSolids at room temperature
14
Properties of UnsaturatedFatty Acids
Contain one or more double C=C bonds
Nonlinear chains do not allow molecules to pack closely
Few interactions between chainsLow melting pointsLiquids at room temperature
15
Fats in Your Diet• Try not to eat any trans fats
– Increases bad (LDL) cholesterol, lowers good (HDL) cholesterol – risk of heart disease
• Keep saturated fat consumption to a minimum
• Monounsaturated and polyunsaturated fats – between 15-30% daily caloric intake– Sources: olive oil, safflower oil, peanut oil and
corn oil• Avoid hydrogenated or partially
hydrogenated oils – added hydrogen to make it solid, preserve – check labels!
1.What foods are high in trans fat?2.What foods are high in saturated fat?3.What foods are high in unsaturated fat?4. What do you want to avoid in your diet?
17
Benefits of Dietary Fats
• Fat is an essential part of your diet• Vital for your cell membranes and some cellular functions• Insulates our body• Energy supplier• Absorption and transportation
around body of fat soluble vitamins A, D, E and K
• Fat surrounds and protects organs, including our kidneys
What do you notice?Peanut Butter Jelly
NUTRITIONAL DENSITYA Different Approach to Thinking about Nutrition
WHAT IS DESNSITY?
WHAT IS NUTRITIONAL DESNITY?Nutritional Density = Nutrients/Calorie
How much nutritional value (mass) per one calorie (volume)
Two Types of NutrientsMacronutrients Micronutrients
B Vitamins Bananas, seeds, green
vegetables, sweet potato, nuts
Folate Leafy greens
Vitamin E Almonds, seeds,
asparagus Vitamin C
Citrus, tomatoes, peppers, leafy greens
Vitamin D Vitamin K
Cauliflower, Broccoli, Brussle Sprouts, Greens
Vitamin Carrots, broccoli,mango,
cantaloupe
Vitamins Vitamins are organic substances bodies need to grow, metabolize, and develop normally. Deficiencies in vitamins can lead to disease and poor health.
Macrominerals Calcium Phosphorus Magnesium Sodium Potassium Sulfur Chloride
Trace Minerals Iron Zinc Copper Selenium Manganese
MineralsMinerals are the building blocks that make up muscles, tissues, and bones and are components of hormones, oxygen transport, and enzyme systems.
Flavonoids Glucosinolates
Cruciferous Vegetables
Keep Cancer in Check
Resveratrol Anti-Inflammatory
Ellagic Acid Berries
Carotenoids Provide fruits and
vegetables with red, yellow and orange color
PhytonutrientsPhytonutrients are natural chemicals found in plants. There are over 25,000 of them, and they help fight disease and keep the body working
Does anything surprise you?
A Final Note about Health
29
Vitamins and Minerals
30
The Nature of VitaminsVitamins are organic (carbon)
compounds needed for normal function, growth and maintenance.
Vitamins are cofactors, they don’t do anything by themselves.
They are not a source of calories.
31
The Nature of Vitamins Food processing
can preserve nutrients.
32
The Nature of Vitamins Nutritional Value lost by:
Light Heat Oxidation Bacteria Enzymes Insects (Nutritional value of
baby food must be assured.)
Effect of packaging on nutrient loss in milk.
Vitamin Requirements Daily Values (DV): standard nutrient intake
values developed by FDA Includes DRIs (Daily Recommended Intakes for
Individuals) and (DRVs) Daily Recommended Values (Proteins, etc.)
Disease prevention Best met through a consumption of a wide
variety of foods
34
Vitamin RequirementsDietary Reference Intakes (DRI):
recommendation for individuals (more accurate, but would be impossible to label)AgeGenderPregnancyLactation
35
Vitamin RequirementsDaily Reference Values (DRV):
standards established for protein and other dietary components lacking a RDA or nutrient standard
Constitute part of the Daily Values (DV) used on food labels
36
The Nature of VitaminsOrganic cofactors – what is a cofactor?Physiological role – specific metabolic
functionPrevents disease – unlike “supplements”
which may promote “some thing” or have general metabolic effect
(ex. Omega 3s, fibers)Natural = Synthetic (except Vitamin E)
Dietary Supplements $6 Billion Market
They are classified as “Nutritional Supplements” They are not foods, and not drugs.*
Supplements are “Product intended to supplement the diet and contains vitamins, minerals, botanicals, amino acids, and their extracts.”
NOT consumed as a food replacement Loosely regulated, “not evaluated by FDA”
By definition a “drug” is used to “prevent, treat or cure” disease. These terms cannot be used with supplements.
Use of some supplements is backed by scientific data.
38
Fat Soluble Vitamins A – orange, carotenoids, vision, antioxidant-
used as color and antioxidant D – we make it with sunlight, deficiency
causes rickets, in milk, regulates Ca:P ratios E – tocopherols, antioxidants, role in
preventing stroke, cancer, heart disease- used as antioxidant
K – contributes to blood clotting factorA LOW FAT DIET MAY CAUSE
MALABSORBION
39
Vitamin A
Lots of double bonds, good anti-oxidant
40
Vitamin A Carrotinoids Used in food industry as a colorant
(orange) Antioxidant Important for sight Dietary deficiency common in developing
countries Blindness, bone abnormalities, susceptibility
to viral infections such as measles and pneumonia
If you take a dietary supplement: teens 14-18 should not consume more than 2800mcg; 19+, 3000mcg
Cooking and storage do not reduce Vitamin A Carrotenosis
Vitamin A cont. SOURCESCarrot juice (450%) /raw carrots (175%)Boiled (270%)/raw (55%) spinachVegetable soup (115%)Boiled Peas (20%)Baked sweet potato with skinCantaloupe (110%)Steamed broccoliChicken (245%)/beef (545%) liver
QUICK: CARROTS
42
Vitamin D Also known as calciferol due to its role in
calcium absorption Main role is to maintain calcium and
potassium levels Part of Immune System and Nerve Signaling
It is the only fat soluble vitamin that we can make- in the presence of sunlight <1/3 of people meet dietary requirement
Can be made from cholesterol
43
Vitamin D Can be stored in fat tissues (as can all fat
soluble vitamins) We get vitamin D form fortified milk and
cereal Toxicity is very dangerous
Occurs only from excess supplementation
Can lead to calcium deposits in kidneys, heart and blood vessels
44
Vitamin E A family of eight naturally occurring compounds anti-oxidant Since aging is considered an “oxidation” reaction,
many “anti-oxidants” are used as dietary supplements
Protect skin, cell communication, from foods protects against prostate cancer and Alzheimer’s E in supplements = alpha-tocopherol; in food, gamma-
tocopherol Role is stroke, cancer, heart, and immune response Americans spend $300 million per year on vitamin
E supplements E dependent on C, B3, selenium and glutathione
Vitamin E cont. Low-fat diet may cause Vitamin E deficiency
(because Vitamin E is fat-soluble!) Common in vegetable oils
SOURCESWheat germ oilDry roasted sunflower seedsDry roasted almondsSafflower/sunflower oilDry roasted hazelnutsPeanut butter/peanutsBoiled spinach
QUICK: NUTS
Vitamin K Vital for blood clotting, protects bones Works as a cofactor for an enzyme that
makes two bone proteins Resilient to cooking/freezing Estimated daily value need is 80
microgramsSOURCES Boiled kale (1/2 cup, 660%)Boiled (1110.6%)/raw spinachRaw parsley (153%)Green leaf lettuceBoiled green beans (25%)
QUICK: GREENS
47
Water Soluble Vitamins Relatively cheap to
add to food Only Vitamin C is
used for its functionality
48
Water Soluble Vitamins B1, thiamine B2, riboflavin B6, pyridoxamine B12 Biotin Panothenic acid Niacin Folacin Vitamin C
Water Soluble Vitamins Vitamin B1
Thiamine Involved in carbohydrate metabolism Helps body metabolize glucose, affects central
nervous system
B2- riboflavin Energy metabolism
50
Water Soluble Vitamins B6 - Pyridoxamine
Neurotransmitter, co-enzyme in over 100 reactions
B12 – Development of red blood cells Lack of it makes one anemic Hard for vegans to get
Vitamin B12 cont.SOURCESCalf’s liver (689.8%)Sardines (137%)Baked/broiled snapper (66.2%)Steamed/boiled shrimp (28.2%)Baked/broiled salmon (54.2%)Beef tenderloin (48.7%)Low-fat yogurt (23%)
QUICK: FISH
52
Water Soluble Vitamins Biotin –
Involved in fatty acid synthesis Deficiency causes skin disease and hair
loss
Panthothenic acid Found in many foods Essential for metabolism of
carbohydrates, protein, alcohol and fat
53
Vitamin C High in citrus fruits, limes, (Limeys) Very inexpensive to add to food,
marketing tool. Antioxidant Anti-oxidant, helps immune system,
improve iron absorption Deficiency leads to bleeding gums,
hemorrhages In supplements as ascorbic acid – in most
multivitamins – check the label!
Vitamin C cont. Highly sensitive to air, water and
temperature! Fresh, raw form is bestSOURCESRaw bell peppers (291%)Steamed broccoli (84.8%)Boiled cauliflower (91.5%)Strawberries (136%)Romaine lettuce (44.8%)Papaya (313.1%)Grapefruit, oranges, cantaloupe, raspberries…
QUICK: ORANGE
55
Minerals Issues
AbsorptionBioavailability
56
Minerals Percent of Body weight
Calcium2%
Phosphorus 1% Potassium 0.3% Sulfur 0.2% Sodium
0.1% Chloride
0.1% Magnesium 0.05% Iron 0.04%
Sodium and Chloride Small amount is essential to live;
excessive consumption increase blood pressure (stroke, heart disease…)
Ideally, limit sodium to 1500mg a day; maximum 2300mg
Most sodium intake from processed and pre-packaged foods (food preservative, enhance taste) – check labels!
Sodium & Chloride cont.NATURALLY LOW CONTENTFruitsVegetablesFat-free or low-fat dairyFresh seafood and meat productsUn-salted anything
HIGH SODIUM CONTENTSoy sauce / ketchupSalad dressingChips/PretzlesFast food
Processed food
Potassium Reduces blood pressure, help muscle and
nerve function Kidney strictly regulates levels of
potassium Significant loses when cooked Athletes – support muscles Adults – 4700mg a day (so figure a bit
less for teens)
Potassium cont.SOURCES
Baked sweet potato (20%)Baked potato (17%)
Non-fat yogurt (17%)
Various fish
Banana (12%)
Spinach (12-20%)
QUICK: BANANA
Iron Oxygen transport in blood, regulate cell growth Two forms: heme (absorbed better)
and nonheme (most dietary iron) 14-18 men 11mg; women 15mg 19+ men 8mg, women 18mg Iron deficiency anemia (too few red
blood cells)
Iron cont.
HEME SOURCES
Chicken liber (70%)
Oysters (25%)
Turkey (8-10%)
Beef (20%)
Tuna (4%)
NONHEME SOURCES
Fortified cereal (100%)
Fortified oatmeal (60%)
Boiled soybeans (50%)
Kidney or lima beans (25%)Spinach (10-20%)
Calcium Bone health, nerve and muscle function Intake over 3000mg daily can lead to
hypercalcemia Not affected by cooking or storage Vitamin D accelerates absorption,
potassium reduces urinary excretion
Calcium cont. To improve absorption, take with meals – food
in stomach - > hydrochloric acid, which breaks down calcium carbonate
SOURCES MilkBoiled spinach (24.5%)Turnip/collard/mustard greensLow-fat yogurt (44.7%)Mozzarella cheese, part-skim (18.3%)
65
Calcium
Risk Factors- By Mayo Clinic staff Your gender. Age. Race. Frame size. Eating disorders. Low calcium intake.Excess soda consumption (Ca:P ratio). The link between osteoporosis and caffeinated sodas isn't clear, but caffeine may interfere with calcium absorption and its diuretic effect may increase mineral loss. In addition, the phosphoric acid in soda may contribute to bone loss. Bone density can be improved at any time.
67
Soda is the devil’s drink Extra calories Poor nutrient density Interferes with
calcification Replaces more
nutritious drinks
68
Minerals Sulfur
Necessary for collagen formation
Magnesium Abundant in plants
Fortification vs Enrichment Fortification - restores lost nutrients due to processing
Enrichment – adds nutritional value to meet a specific standard
Old London Restaurant Style Croutons. Seasoned Sourdough. Enriched Bread, [Enriched Flour (Flour, Niacin, Ferrous Sulfate, Thiamin Mononitrate, Riboflavin, Folic Acid),Water,Yeast,Sugar,Salt,Partially Hydrogenated Soybean Oil ,Vinegar,Ascorbic Acid] Bean Oil with BHT added as a Dextrin