Nutrition test 5

• Composed of molecules that
• move past one another freely

• Characterized by its ability
• to conform to the shape of the container that holds it

• About 50-70% of healthy
• adult body weight

• n The body fluid composition
• of tissue varies by

q Tissue type: lean tissues have higher fluid content than fat tissues

• q Gender
• : males have more lean tissue and therefore more body fluid

• q Age:
• lean tissue is lost with age and body fluid is lost with it

n Intracelluar Fluid (ICF)

• q Within the cell – 2/3 of
• body fluid

n Extracellular Fluid (ECF)

• q Outside the cell – 1/3 of
• body fluid

q Interstitial fluid flows between cells that make up a particular tissue or organ

q Intravascular fluid is the water in the blood and lymph

• q Plasma
• transports blood cells within arteries, veins, and capillaries

• n Substance that disassociates
• in solution into electrically charged particles ions

q Positive charge (cation): sodium, potassium

q Negative charge (anion): chloride, phosphorus

n Predominant electrolytes

q Extracellular fluid (ECF): sodium, chloride

q Intracellular fluid (ICF): potassium, phosphorus

• n Fluids dissolve and transport
• substances

• q Water is an excellent solvent
• because it dissolves a variety of substances

• q Blood plasma transport
• solutes in the body

• q Water soluble substances: amino acids, glucose, vitamins, minerals,
• medications

q Fat soluble substances must be attached to or surrounded by water soluble proteins

n Fluids account for blood volume

• q Appropriate fluid levels is
• essential for maintaining healthful blood volume

q Blood pressure increases when blood volume rises

q High blood pressure (hypertension) is a risk factor for heart disease and stroke

q Kidneys help to regulate blood volume and blood pressure

• n Fluids help maintain body
• temperature

• q Body temperature must be
• within a safe range

• q High heat capacity of water
• means that the temperature of our body fluids remains stable

• q Sweating releases heat as
• the evaporation of water from the skin cools the skin and blood

• n Protect and Lubricate
• Tissues

• q Cerebrospinal fluid protects
• the brain and spinal cord

• q Amniotic fluid protects the
• fetus

• q Synovial fluid lubricates
• joints

• q Digestive juice (saliva)
• moistens food for ease of swallowing and transport

• n Electrolytes help regulate
• fluid balance

• q ‘Water follows ion
• concentration’. Water follows the movement of electrolytes, moving by osmosis
• to areas where the concentration of electrolytes is high.

• q This allows for the controlled
• movement of fluids into and out of cells.

• q Osmotic pressure keeps electrolytes in
• solution from drawing liquid toward them across a semi-permeable membrane

• n Electrolytes enable nerves
• to respond to stimuli

• q Movement of Na+
• and K+ across the membranes of nerve cells changes the electrical
• charge across the membrane

• q This change in electrical
• charge carries the nerve impulse along the nerve cell.

• n Electrolytes signal muscles
• to contract

• q Influx of calcium into the
• muscle from the extracellular space stimulates contraction

• q Muscles can relax after
• contraction once the electrical signal is complete and calcium is pumped out of
• the muscle cell

• n Thirst mechanism
• (hypothalamus) prompts us to drink when it is stimulated by

• q Increased concentration of
• salt and other dissolved substances in the blood

• q A reduction in blood volume
• and blood pressure, such as during profuse sweating, vomiting, diarrhea, low
• fluid intake

• q Dryness in mouth and throat
• with low saliva

• n ADH signals the kidneys to
• retain water

n Water

q Essential for life

• q Required for fluid and
• electrolyte balance and many metabolic reactions

n Recommended intake

• q DRI: 2.7 liters for the
• adult female, 3.7 liters for the adult male

• q Varies with age, body size,
• health status, physical activity level, environment

n No RDA

n 1 ml/1kcal

q »8 cups/d

n 30 - 55ml/kg

n Infants have higher needs

• n Supplied by liquids, foods,
• metabolism

• Are You Drinking
• Enough Water?

n Dehydration

• q Insufficient H20
• intake

q Athletes, children, elderly

q Dry, loose skin

q Concentrated urine

q Labs

n Alb ­

n Na+ ­

n Glu ­






n Fluid Overload (toxicity)

• q Too much water without
• sufficient electrolytes

q Kidneys not able to handle

• q Headaches, blurred vision,
• cramps, convulsions

q Labs

n Alb ¯

• n
• Na+ ¯

n Glu ¯

q Major cation of the ECF

q Water balance

q Nerve functions

• q Associated with BP & pH
• balance

• q Assists with transport of
• glucose into body cells

• q Preservative –
• canned/package foods

q Processed foods

• q White bread, rolls, hot
• dogs, lunch meats, cheese, condiments

q Table salt





Hyponatremia

q Muscle cramps

q Nausea

q Vomiting

q Dizziness

q Over hydration

q Confusion

• n
• TOXICITY

Hypernatemia

q High blood pressure HTN

q Dehydration

Potassium K+

n FUNCTIONS

q Major cation of the ICF

• q Fluid & electrolyte
• balance

• q Nerve impulse ; muscle
• contraction

n FOODS

q Fruits & vegetables

q Meats, milk

q Legumes

• q Many salt substitutes are
• made from potassium chloride

Potassium K+

• n
• DEFICIENCY

Hyperkalemia

q Irregular heart beat

q Loss of appetite

q Muscle cramps

• q Can occur in people with
• kidney disease

q Avoid salt substitutes

• n
• TOXICITY

Hypokalemia

q Leads to heart failure

• q Seen in patients with kidney
• disease or diabetic ketoacidosis

• q Caution with certain
• diuretic meds

Chloride Cl-

n FUNCTIONS

• q Major anion of the ECF –
• maintain fluid balance

• q Helps maintain gastric
• acidity – HCl

q Nerve transmission

n FOODS

• q
• Salt = Na+Cl-

q Processed foods

Chloride Cl-

• n
• DEFICIENCY

q Rare in adults

• q Can occur in people with
• eating disorders

q Convulsion in children

• n
• TOXICITY

• q High blood pressure in salt
• sensitive individuals

Phosphorus P

• n
• FUNCTIONS

q Major ion of the ICF

• q Acid/Base balance; fluid
• balance

• q Required for bone and tooth
• strength

• q Part of various metabolic
• compounds - ATP

• n
• FOODS

• q Protein rich foods; Dairy
• products, Meats, Eggs

q Soft drinks

• q More readily absorbed from
• animal sources

• q Phytic acid prevents
• absorption from plant sources

Phosphorus

n Deficiency: Rare

n Toxicity:

• n Causes: kidney disease,
• excessive vitamin D supplementation or phosphorus-based antacids

• n S/S muscle spasms &
• convulsions

• n Disorders related to fluid
• and electrolyte imbalance include:

q Dehydration

q Heat stroke

q Water intoxication

q Hypertension

q Neuropsychiatric disorders

q Muscle disorders

Dehydration

• n Dehydration occurs when
• water loss exceeds water intake

• n Commonly due to heavy
• exercise or high environmental temperatures

• n Infants and the elderly are
• more at risk

• n Heat stroke occurs if the
• body’s temperature regulation mechanisms fail

• q Occurs in hot, humid
• environments

• q Symptoms include rapid
• pulse, hot, dry skin, high body temp, loss of consciousness

• q Has been fatal for athletes
• during exercise in extreme heat

• q Stop exercising when feeling
• dizzy, light-headed, disoriented, or nauseated

• n Hypertension is a chronic
• condition characterized by high blood pressure.

• q Systolic pressure over 140mm
• Hg

• q Diastolic pressure over 90mm
• Hg

• q May not show symptoms -
• “silent”

• q Increases a person’s risk of
• heart disease, stroke, kidney disease

Hypertension

n What causes hypertension?

• q
• The cause of 95% of hypertension cases is unknown – primary or
• essential hypertension

• q
• 5% are caused by kidney disease, sleep apnea, and salt sensitivity

• q Recommendations for reducing
• hypertension: weight loss, increased physical activity, reduced sodium intake,
• and more whole grains, fruits, vegetables, and low-fat protein sources, DASH
• diet

• n
• Electrolyte imbalances can result in seizures or muscle
• cramps

• n Electrolyte imbalances cause
• changes in nervous system function and impair cognition

• n Nervous system changes can
• alter proper muscle function

• n Compounds that protect cells
• from the damage caused by oxidation

• n Nutrients with antioxidant
• properties:

q Vitamin E

q Vitamin C

• q Vitamin A (precursor,
• beta-carotene)

q Selenium

• n The atom is the smallest
• unit of matter

n Atoms are composed of

• q Nucleus – positive charged
• center

q Electrons – negative charged

particles that surround the nucleus

• n Molecules are composed of
• atoms

• n During metabolic reactions,
• electrons can be transferred

q from the atoms of one molecule

• q to the atoms of another
• molecule

• n Oxidation is a chemical reaction in
• which atoms lose electrons

• n Reduction occurs when atoms gain a
• electron

• n Stable atoms have an even
• number of electrons (pairs) in the outer orbit

• n Electron loss during
• oxidation leaves an odd number or unpaired electron

• n Such highly unstable atoms
• are called free radicals

• n Oxygen molecule that becomes
• a free radical is called reactive oxygen species (ROS)

• What Causes Free Radicals to
• Form?

n Many metabolic processes

• q Digestion and absorption of
• food

• q Immune system fighting
• infections

n Environmental factors

q Pollution

q Excess sunlight

q Toxic substances

q Tobacco smoke

q Asbestos

Cell Damage *

• n Free radicals form within
• the phospholipid bilayers of cell membranes

• q Damaged lipid molecules are
• unable to maintain the integrity of the cell membrane

• Diseases Linked with Free
• Radicals

n Various cancers

n Heart disease

n Diabetes

n Arthritis

n Cataracts

n Kidney disease

n Alzheimer disease

n Parkinson disease

• n Antioxidants stabilize free
• radicals and repair the damage they cause

• n Antioxidant vitamins donate their electrons or
• hydrogen molecules to free radicals to stabilize them and reduce oxidation
• damage

• n Antioxidant minerals function within the enzyme
• systems that convert free radicals to less damaging substances that can be
• excreted

• How do Antioxidants
• Work? *

• How do Antioxidants
• Work?

• n Other compounds help stabilize
• free radicals and prevent damage to cells and tissues:

q Beta-carotene

q Phytochemicals

• n Nutrients with antioxidant
• properties:

q Vitamin E

q Vitamin C

• q Vitamin A ( precursor,
• beta-carotene)

q Selenium

n Functions:

• n Primary Function is to
• protect lipids from Free Radicals:
• PUFAs, Cell membranes, LDL oxidation

• n Normal nerve & Muscle
• development

n Enhances immune system

n Improves Vit A absorption

Vitamin E

n Food Sources:

• q Vegetable oils (Safflower,
• sunflower, canola, soybean)

q Nuts, seeds

q Wheat germ, soybeans

• n Vitamin E is destroyed by
• exposure to oxygen, metals, ultraviolet light, and heat

• q Little vitamin E in
• deep-fried and processed foods

• Vitamin E, too much or not
• enough?

n Toxicity uncommon

• n Interacts with
• anticoagulants (aspirin, Coumadin)

• n High doses associated with
• excessive bleeding, and possibly hemorrhagic stroke

• n True deficiency
• is uncommon

• n s/s hemolytic anemia, loss
• of muscle coordination & reflexes

n Anemia in premature infants

n In adults, caused by fat malabsorption diseases/conditions

n Functions:

• q Synthesizes collagen
• (prevents scurvy)

q Enhances immune response

• q Assists synthesis of DNA,
• Serotonin, Bile

q Helps regulate hormones

q Enhances iron absorption

• q Acts as an antioxidant:
• protects LDL cholesterol, the lungs, white blood cells, and the stomach

Vitamin C

Food Sources:

n Fresh fruits & veggies

• n Destroyed by heat &
• oxygen

n Can be leached into water

n Minimize loss by:

n steaming, microwaving & stir-frying

• Vitamin C, too much or not
• enough?

n Deficiency:

• n Scurvy: s/s bleeding gums,
• loose teeth, weakness, wounds fail to heal; anemia

• n At risk: people who eat few
• fruits & veggies; people who abuse drugs & alcohol

n Toxicity: Rare d/t water soluble – excreted in kidneys.

n Only with supplements

n MEGADOSE: 10 X RDA over long time; can cause: nausea, diarrhea, nosebleeds.

n Caution with hemochromatosis

• Provitamin – an inactive form or
• precursor, of the vitamin that must be converted to its active formof vitamin A

• Carotenoid, a
• plant pigment

• Precursor - one of
• three carotenoids that can be converted to retinol

Functions of Beta Carotene

n Weak antioxidant

• n Effective against lipid
• oxidation in cell membranes

n Enhance immune system

• n Protect skin from UV light
• damage

• n Protect eyes from damage,
• preventing or delaying age-related vision impairment

• Beta Carotene, too much or
• not enough?

• n Food Sources: Colorful fruits & veggies – red, orange,
• yellow or deep green

• n Toxicity: Not toxic but excess can turn the skin yellow
• or orange

n Deficiency: None known

• n Heating foods improves
• absorption of beta carotene

Functions:

n Antioxidant

n Essential for proper vision

• n Cell differentiation –
• process by which stem cells mature into specialized cells

n Sperm production & fertilization

n Bone growth

• n Derivatives of vitamin A are
• used to treat acne

Vitamin A

n Food sources:

• q animal (liver, eggs,
• whole-fat dairy, fortified foods)

• q plants (red, orange, yellow,
• and deep-green fruits and vegetables that are high in beta carotene can be
• converted to vitamin A)

• Vitamin A, too much or not
• enough?

• n Highly toxic at 3–4 times RDA, mainly
• from supplements

q Birth defects

q Damage to liver and eyes

• q Symptoms: loss of appetite,
• blurred vision, hair loss, skin disorders

• n
• Deficiency

• q night blindness, xerophthalmia an irreversible
• blindness hyperkeratosis

q impaired immunity, growth

n Functions:

• n Antioxidant; part of an
• enzyme system

• n Decreases free radicals,
• sparing vit E

• n Needed for thyroxine
• production – thyroid hormone

n Food Sources: organ meats, pork, seafood, nuts, wheat, rice

• n Variable in plant foods d/t
• different soil conditions

• Selenium (Se) too much or
• not enough?

n Toxicity can occur from supplements

• q Brittle hair, nails, skin
• rashes, vomiting, nauseas, weakness, cirrhosis of the liver

n Deficiency associated with

• q Keshan disease, a heart
• disease

• q Kashin-Beck disease, a
• deforming arthritis

q Impaired immunity

• n Cofactor – a compound needed for
• proper enzyme function

• n These minerals play critical
• roles in blood health and energy metabolism:

• q Copper (Cu), zinc (Zn), and
• manganese (Mn)
• are part of the superoxide dismutase enzyme antioxidant complex

• q Iron (Fe) is part of the catalase
• structure

• n Cancer is a group of
• diseases characterized by cells growing “out of control”

• n Primary steps of cancer
• development:

q Initiation

q Promotion

q Progression

Cancer Risk

n Risk factors

q Tobacco use

q Sun exposure (UV light)

q Nutrition

• q Environmental/occupational
• exposures

• q Low levels of physical
• activity

• n Antioxidants reduce cancer
• risk by

q Enhancing immune system

q Inhibit cancer cell growth

• q Prevent oxidative damage to
• cells

• n Naturally occurring
• chemicals in plants

• n May reduce risk for cancer,
• heart disease

• n Include phytoestrogen,
• lycopene, and flavonoids

• n Found in whole grains,
• fruits, vegetables, legumes, nuts, garlic, and soy products

• n Leading cause of death among
• adults in USA

• n Includes all diseases of the
• heart and blood vessels

q Coronary heart disease

• q Hypertension (high blood
• pressure)

• q Atherosclerosis (hardening
• of the arteries)

• n Primary manifestations of
• CVD:

q Heart attack

q Stroke

n Smoking

n Hypertension

• n High blood levels of low
• density lipoprotein (LDL) cholesterol

n Obesity

n Sedentary lifestyle

Other Risk Factors for CVD

• n Low blood levels of high
• density lipoprotein (HDL) cholesterol

• n Impaired glucose tolerance
• or diabetes

n Family history of CVD

q males before age 55

q females before age 65

• n Being male older than 45
• years

• n Being postmenopausal in
• women

• n Weakens plaque, makes it
• more fragile

• q Likely to burst, break away
• from lining, lodge in blood vessels of heart or brain, and close off blood
• supply resulting in a heart attack or stroke

n C-reactive protein (CRP)

• q Marker for inflammation
• (laboratory blood test)

• q Associated with high risk
• for heart attack in the presence of normal cholesterol levels

• q High CRP + high cholesterol
• = high risk for heart attack

• n Antioxidants (vitamins E and
• lycopene) reduce damage to blood vessels by

q Scavenging free radicals

• q Reducing low-grade
• inflammation

• q Reducing blood coagulation
• and clot formation

• n In fruits, vegetables, and
• whole grains

• q Dietary fiber (soluble) -
• oatmeal and oat bran

• q Folate - reduce
• homocysteine, a risk factor for CVD

q Others (flavonoids)

• n Associated with increased
• oxidative damage and reduced activity of antioxidant enzymes in most body
• tissues

• n Digestion, absorption, and
• metabolism of nutrients are impaired with age

• n What is the optimal
• antioxidant intake for older adults?

Vision Impairment

• n Diseases associated with
• aging

n Macular degeneration

q Leading cause of blindness

• q Deterioration of center
• portion of retina

• q Marked by loss or distortion
• of central vision

n Cataract

• q Damaged portion of eye’s
• lens causing cloudy vision

• n Possible role of
• antioxidants in vision impairment

• q Lack of nutrients (including
• antioxidants)

• q Free-radical damage caused
• by exposure to oxygen, UV light, and x-rays

• q Inflammation from eye
• disease

• n Current research does not
• support the use of antioxidant supplements in reversing or delaying aging