chapter 8 minerals and water © 2015 pearson education, inc
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Why Is Water So Important? Most abundant nutrient in body Average healthy adult is ~ 60% water Can only survive a few days without water Water balance Intracellular fluids: inside cells Extracellular fluids: interstitial fluid outside cells and fluid in the blood Electrolytes: minerals that help maintain fluid balance © 2015 Pearson Education, Inc.TRANSCRIPT
Chapter 8 Minerals and Water 2015 Pearson Education, Inc. Why Is
Water So Important?
Most abundant nutrient in body Average healthy adult is ~ 60% water
Can only survive a few days without water Water balance
Intracellular fluids: inside cells Extracellular fluids:
interstitial fluid outside cells and fluid in the blood
Electrolytes: minerals that help maintain fluid balance 2015
Pearson Education, Inc. Your Body is Mostly Water
Figure 8.1 2015 Pearson Education, Inc. Water as Part of Body
Fluids
Figure 8.2 2015 Pearson Education, Inc. Why Is Water So
Important?
Solvent and transport Chemical reactions Transport oxygen,
nutrients, hormones to cells Transport waste products away from
cells Helps maintain body temperature Lubricant (joints, eyes),
part of mucus and saliva Protective cushion for brain, organs,
fetus 2015 Pearson Education, Inc. What Is Water Balance and How Do
You Maintain It?
Water balance: water consumed = water lost Water consumed: Water,
other beverages Food Fruits/vegetables ~95% water Meats/cheeses
~50% water Water lost: Urine, large intestine, lungs, sweat The
Concept of Water Balance: Intake Equals Output
Figure 8.4 2015 Pearson Education, Inc. Losing Too Much Water Can
Cause Dehydration
Too little water in the body Higher risk: infants, elderly Results
from: inadequate intake, too much loss (diarrhea, vomiting, high
fever, diuretics, excessive sweating) or both. Identifying:
Possible signs within one day Thirst (not most reliable) Measure
body weight before and after high physical activity Urine color
Urine Color Can Signal Dehydration
Figure 8.6 2015 Pearson Education, Inc. How Much Water Do You Need
and What Are the Best Sources?
Needs vary depending on: Physical activity Environmental factors
Diet Adults: 9-13 cups fluid/day Hyponatremia: too little sodium in
the blood too much water (endurance athletic events, strenuous
military training) Water Content of Foods BG: This will change
(MyPlate). Figure 8.8
2015 Pearson Education, Inc. The Best Way to Meet Your Daily Water
Needs
Figure 8.9 2015 Pearson Education, Inc. Tap Water or Bottled Water:
Is Bottled Better?
False assumption: bottled water is purer than tap water Tap water
is perfectly safe Monitored by Environmental Protection Agency
(EPA) Provides fluoride, helps prevent dental caries Bottled water
is very popular Most products conform to FDA requirements May
actually be tap water High cost Various "designer" waters on the
market 2015 Pearson Education, Inc. What Are Minerals and Why Do
You Need Them?
Needed in small amounts No calories Electrolytes maintain fluid
balance Part of enzymes Immune function Structural growth Work with
nutrients to enable body to function properly Absorbability depends
on bioavilability 2015 Pearson Education, Inc. What Are Minerals
and Why Do You Need Them?
Major (macrominerals):>100 mg/day Trace (microminerals): < 20
mg/day 2015 Pearson Education, Inc. Minerals Are Found Widely in
MyPlate
Figure 8.11 2015 Pearson Education, Inc. Sodium Toxicity:
Hypertension Functions:
(high blood pressure) Deficiency: Rare Functions: Fluid balance:
electrolyte outside cells Transport across cell membranes Sources:
Processed foods Sodium chloride (salt: 40% sodium, 60% chloride)
Sodium Content of Selected Natural and Processed Foods
BG: Change Figure 8.13 2015 Pearson Education, Inc. You and Your
Blood Pressure
Blood pressure: a measure of force that blood exerts on the walls
of arteries Expressed as systolic pressure (when heart beats) over
diastolic pressure (when heart is at rest) 120/>80 =
prehypertension 140/90 = hypertension 2015 Pearson Education, Inc.
You and Your Blood Pressure
Hypertension is the silent killer No symptomscheck blood pressure
regularly Contributes to atherosclerosis, heart enlarges,weakens
Increases risk of stroke, kidney failure Hypertension control:
Reduce weight, increase physical activity, healthy, balanced diet
DASH: Dietary Approaches to Stop Hypertension
Misc 8.8 2015 Pearson Education, Inc. Untable 8.3 2015 Pearson
Education, Inc. Potassium Toxicity: hyperkalemia Functions:
Irregular heartbeat, life-threatening Not caused by foods
Supplements or salt substitutes Deficiency: hypokalemia Muscle
weakness, cramps, irregular heartbeat, paralysis Vomiting and/or
diarrhea,eating disorders Functions: Fluid balance electrolyte
inside cells Muscle contractions Acid-base balance Lowers blood
pressure Decreases kidney stones Sources: Fruits, vegetables, dairy
foods, nuts, legumes Potassium Content in Selected Foods
Figure 8.15 2015 Pearson Education, Inc. Calcium Functions:
Toxicity: hypercalcemia Sources:
Most abundant mineral in body Functions: Strong bones/teeth Muscle
contraction Nerve transmission Blood clotting May help blood
pressure, colon cancer, obesity Sources: Dairy products, tofu,
broccoli, canned salmon (with bones), fortified juices/cereals
Toxicity: hypercalcemia Kidney damage, calcium deposits,
constipation, interferes with mineral absorption Deficiency:
osteoporosis Less dense, weakened, brittle bones Calcium Content in
Selected Foods
Figure 8.16 2015 Pearson Education, Inc. Bioavailability of
Calcium
Figure 8.17 2015 Pearson Education, Inc. Osteoporosis: Not Just
Your Grandmother's Problem
Bones constantly changing Peak bone mass: 20-30 years old; then
slowly more bone lost than added Bone mineral density test Low
score = osteopenia (low bone mass) Very low score = osteoporosis
Healthy Bone (left) vs Weakened Bone (right)
Figure 8.18 2015 Pearson Education, Inc. Risk Factors for
Osteoporosis:
Gender Females: estrogen loss after menopause Ethnicity Caucasian,
Asian-American Body type Smaller-boned/petite Family history of
fractures Smoking Medications Prednisone, antacids Lack of weight
bearing exercise Alcohol Inadequate calcium and vitamin D Low
levels of sex hormones Amenorrhea, menopause, men with low levels
Phosphorus Rare; muscle weakness, bone pain
Second most abundant mineral in body Toxicity: hyperphosphatemia
Only in individuals with kidney disease Tissue calcification
Deficiency: Rare; muscle weakness, bone pain Functions: Bones and
teeth Cell membranes Energy metabolism Sources: Meat, fish,
poultry, dairy, cola beverages Phosphorus Content of Selected
Foods
Figure 8.20 2015 Pearson Education, Inc. Magnesium Functions: Helps
>300 enzymes Protein synthesis Muscle function Lowers blood
pressure, reduce type 2 diabetes risk Sources: Whole grains, nuts,
vegetables, fruits, dairy, meat, eggs, chocolate Toxicity:
Supplements only; diarrhea Deficiency: Rare; muscle weakness,
seizures, fatigue, depression, irregular heart beat Magnesium
Content of Selected Foods
Figure 8.21 2015 Pearson Education, Inc. Chloride Functions: Fluid
balance
Part of hydrochloric acid in the stomach Sources: Salt (sodium
chloride) Salt substitutes (potassium chloride) Toxicity: Rare
Deficiency: Iron Toxicity: Functions: Sources: Deficiency:
Constipation Accidental poisoning deaths in children Heart, kidney,
liver damage Hemochromatosis Deficiency: Anemia Most common
nutritional deficiency in world Functions: Part of hemoglobin:
oxygen transport Brain function Sources: Meat, poultry, fish, whole
and enriched grains Normal and Anemic Blood Cells Iron Not
excreted; lost when blood lost Absorb 10-15% of iron consumed
Factors that increase absorption: Body need Vitamin C Type Heme
iron: animal sources; easily absorbed Non-heme iron: plant foods;
not easily absorbed Iron Content of Selected Foods
Figure 8.24 2015 Pearson Education, Inc. * Copper Rare Functions:
Part of enzymes & proteins Connective tissue
Blood clotting Immune system Sources: Organ meats, seafood, nuts,
seeds, bran cereals, whole-grain products, cocoa Toxicity: Stomach
cramps, nausea, diarrhea, vomiting, liver damage Deficiency: Rare *
Copper Content of Selected Foods
Figure 8.26 2015 Pearson Education, Inc. Zinc Red meat, shrimp,
milk, oysters, whole grains Functions:
Growth, development Immune system Wound-healing Healthy taste buds
Reduce age-related macular degeneration Sources: Red meat, shrimp,
milk, oysters, whole grains Toxicity: Stomach pain, diarrhea,
suppress immune system Deficiency: Impaired taste, hair loss, loss
of appetite, impaired growth and sexual maturation Zinc Deficiency
Zinc deficiency in young boys is common in the Middle East, where
unleavened bread that contains phytate is consumed. Phytate binds
to zinc and makes it unavailable for absorption. Zinc Content of
Selected Foods
Figure 8.27 2015 Pearson Education, Inc. Selenium Toxicity:
selenosis Functions: Antioxidant
Brittleness and loss of nails and hair, skin rash, garlicky breath,
fatigue, nervous system damage Deficiency: Rare in US Heart damage
Functions: Antioxidant Thyroid hormone regulation Sources: Brazil
nuts, meat, seafood, whole grains, dairy foods, fruits, vegetables
Selenium Content in Selected Foods
Figure 8.28 2015 Pearson Education, Inc. Fluoride Toxicity:
fluorosis Functions: Mottling of teeth
Deficiency: Dental caries Functions: Protects against dental caries
Strengthen bones Sources: Foods not a good source Fluoridated
water, beverages made with fluoridated water Chromium Rare in U.S.
Functions: Increases insulins effectiveness
Does not build muscle Sources: Grains, meat, fish, poultry,
broccoli, grape juice Toxicity: None known Deficiency: Rare in U.S.
Chromium Content in Selected Foods
Figure 8.31 2015 Pearson Education, Inc. Iodine Toxicity:
Functions: Impairs thyroid function Thyroid hormone
Deficiency: Goiter Cretinism Deficiency during early stages of
fetal development Functions: Thyroid hormone Sources: Iodized salt
Amount in foods depends on soil and water content Iodine Deficiency
Cretinism Goiter Iodine Content in Selected Foods
Figure 8.33 2015 Pearson Education, Inc.