© 2007 Thomson - Wadsworth Chapter 7 Water and Minerals

© 2007 Thomson - Wadsworth

Chapter 7

Water and Minerals


Ask Yourself

1. Calcium is the most important mineral in human nutrition.

2. Milk is nature’s most nearly perfect food because it is rich in every nutrient.

3. It is generally harder for women than for men to obtain diets that are adequate in calcium.

4. Milk is necessary for children, but adults can find replacements for it.

5. Sodium is bad for the body and should be avoided.


Ask Yourself

6. When a person becomes deficient in iron, the very first symptom to appear is anemia.

7. Zinc is toxic in excess.8. Both too little and too much iodine in the diet

can cause swelling of the thyroid gland, known as goiter.

9. A diet high in salt is associated with high blood pressure in some individuals.

10. Osteoporosis is a disease that can affect men and women at any age.


Water—The Most Essential Nutrient

• Nutrient most needed by the body.

• Makes up part of every cell, tissue, and organ in the body.

• Accounts for about 60% of body weight:Bone is more than

20%Muscle is 75%Teeth are about

10%



• Water performs many tasks vital to life.



• Water in your blood—known as plasma volume, or just plasma—continually circulates throughout your body.Plasma picks up heat generated by muscles

and transports it to skin.Heat is expelled by the body primarily by

evaporation of sweat.Fluid losses must be replaced to prevent

dehydration and heat stroke.



• Heat stroke: an acute and dangerous reaction to heat buildup in the body, requiring emergency medical attention; also called sun stroke.



• Water enters the body in liquids and foods, and some water is created in the body as a by-product of metabolic processes. Most of the water we take in

comes from juice, milk, soft drinks, and other beverages, including tap water; foods also add considerable amounts of water to the diet.

This amount equals 1 1/2 to 3 quarts (1 oz. equals approximately 30 mL).



• Water leaves the body through the evaporation of sweat, in the moisture of exhaled breath, in the urine, and in the feces. Adults are advised to

consume 1.0 to 1.5 mL of water from all sources for each calorie expended.



• The makeup of water differs• Variations can have significant health

implications :Where it comes from How it is processed

• One of the most basic distinctions, hard versus soft water, is based on the concentrations of three minerals:CalciumMagnesiumSodium



• Hard water: water with a high concentration of minerals such as calcium and magnesium.

From a health standpoint, hard water seems to be the better alternative.

• Soft water: water containing a high sodium concentration. The excess sodium

adds more of the mineral to our already sodium-laden diets.

It dissolves potentially toxic substances such as lead from pipes.



• Environmental Protection Agency (EPA): arm of the government responsible for monitoring municipal water supplies.

• Water taken from the earth contains different levels of bacteria, microorganisms, and heavy metals such as lead.

• Some potential health threats are:A parasite called Cryptosporidium.The level of lead that comes out of your

faucet (one which the EPA has little control over).

• Lead-containing plumbing was banned in 1986.



• Bottled Water is not necessarily any purer or more healthful than tap water. About 25-40% of bottled

water comes from the same municipal water supplies.

Bottled water may not contain adequate amounts of fluoride.

Cost may be 250-10,000 times higher than tap water.


The Major Minerals

• Minerals: small, naturally occurring, inorganic, chemical elements; the minerals serve as structural components and in many vital processes in the body.

• Inorganic: being or composed of matter other than plant or animal.


The Major Minerals

• Major mineral: an essential mineral nutrient found in the human body in amounts greater than 5 grams.

• Trace mineral: an essential mineral nutrient found in the human body in amounts less than 5 grams.Minerals are inorganic compounds that

occur naturally in the earth’s crust. Some minerals (such as calcium) contribute

to the building of body structures (such as bone).


Good Sources of Minerals in the USDA MyPyramid






The Major MineralsCalcium• Bones store 99% of the body’s calcium,

which plays two roles: Supports and protects soft tissues. Serves as a calcium bank, providing calcium to

body’s fluids.

• Calcium serves as a cofactor for several enzymes.

Cofactor: a mineral element that, like a coenzyme, works with an enzyme to facilitate a chemical reaction.

• Calcium is essential for nerve impulses, muscle contraction, heartbeat, maintenance of blood pressure, & blood clotting.


The Major Minerals

Calcium• Needed to support the growth of teeth and

bones.• A deficit during growing years and in

adulthood can contribute to osteoporosis.• Osteoporosis (OSS-tee-oh-pore-OH-sis):

also known as adult bone loss; a disease in which the bones become porous and fragile.osteo = bonesporos = porousFluoride and vitamin D deficiency can also

cause loss of bone density.


The Major Minerals

• Milk and milk products typically contain more calcium than other food sources. Milk also contains vitamin D and lactose which can

enhance calcium absorption.

Calcium


• Some foods contain binders.• Binders: in foods, chemical

compounds that can combine with nutrients (especially minerals) to form complexes the body cannot absorb. Examples of such binders are:phytic (FIGHT-ic) acid,

renders the calcium, iron, zinc, and magnesium in certain foods less available than they might be otherwise.

oxalic (ox-AL-ic) acid, also binds calcium and iron..



The Major Minerals

• Calcium-fortified foods are available for those who cannot take milk products. Milk allergy: the most common food allergy;

caused by the protein in raw milk. Lactose intolerance: an inherited or acquired

inability to digest lactose as a result of a failure to produce the enzyme lactase.


The Major Minerals

Phosphorus• Combined with calcium

to form calcium phosphate; gives rigidity to bones and teeth.

• Part of DNA and RNA; necessary for all growth; genetic code.

• Plays major role in energy production as a component of enzymes and B vitamins.

• Transports nutrients.


The Major Minerals


The Major Minerals

Sulfur• Present in some

amino acids and all proteins.

• No recommended intake.

• No known deficiencies

Magnesium• Acts in all cells of

muscle, liver, heart and other soft tissues.

• Helps relax muscles after contraction.

• Bone magnesium is a reservoir.

• Deficiency not likely but can occur in certain conditions.


The Major Minerals


The Major Minerals

Sodium• Found naturally in many foods.• Component of sodium chloride (table salt), a

food seasoning and preservative.• The use of highly salted foods can contribute

to high blood pressure (hypertension) in those who are genetically susceptible.

• Dietary Guidelines for Americans recommend consuming little sodium and salt and staying below the upper limit of 2300 mg of sodium per day.


The Major Minerals

• Ions (EYE-ons): electrically charged particles, such as sodium (positively charged) and chloride (negatively charged).

• Electrolytes: compounds that partially dissociate in water to form ions; examples are sodium, potassium, and chloride.

• Salt: a pair of charged mineral particles, such as sodium (Na+) and chloride (Cl–), that associate together. In water, they dissociate and help to carry electric current—that is, they become electrolytes.

• Hypertension: sustained high blood pressure. hyper = too much tension = pressure


The Major Minerals

Electrolytes• Sodium, potassium, and

chloride are examples of body electrolytes.

• Potassium, which is usually found in the fluids inside the cells, carries a positive charge.

• Sodium and chloride are usually found in the fluids outside the cells. Sodium carries a

positive charge. Chloride carries a

negative charge.


The Major Minerals


The Major Minerals

• Many whole foods are low in sodiumWhole foods = < 10% of sodium in

the U.S. diet• Salt added during cooking or at the

table = 15% of the sodium• Sodium added by food

manufacturers to processed foods = 75% of sodium in the U.S. diet




The Major MineralsPotassium• As the principal positively charged ion inside body

cells, potassium plays a major role in maintaining water balance and cell integrity. Diuretics (dye-you-RET-ics): medications causing

increased water excretion.• dia = through• ouron = urine

• Critical to maintaining the heartbeat. Sudden deaths that occur due to fasting, severe diarrhea

or severe vomiting are thought to be due to heart failure due to potassium loss.

Chloride• The negative ion, helps in maintaining the acid–

base balance.



The Major Minerals


• Risk factors for high blood pressure:ObesityFamily historyRace (African

American)AgeExcess alcohol

consumptionSedentary lifestyle


• One of the characteristics of hypertension is that it has been called a “silent killer” that cannot be felt and may go undetected for years.

• That’s why it is crucial to have your blood pressure checked on a regular basis. Diagnosis of hypertension requires at least two elevated readings.

• The DASH diet and reducing the amount of sodium consumed lower blood pressure.


Dietary Approaches to Stop Hypertension (DASH)

DASH Diet Pyramid


Tips to Reduce Risk

1. Adopt an eating pattern rich in fruits, vegetables, legumes, and low-fat-dairy products—similar to the DASH diet—with reduced saturated fat content.

2. Maintain a normal weight. Lose weight if you’re overweight; even losing just a few pounds can reduce blood pressure if you’re overweight.

3. Keep your sodium intake at or below recommended levels—not more than 2,300 milligrams a day.

4. Pursue an active lifestyle: Walk briskly, swim, jog, cycle, or do other moderately paced aerobic activities. Aim for at least 30 minutes of activities daily.

5. If you drink, use moderation—no more than one drink a day for women, and no more than two drinks a day for men.

6. Don’t smoke. Cigarette smoking raises blood pressure and seriously increases risk for heart disease.


• At the Supermarket:Read the Nutrition Facts…

• At Home:Flavor foods with herbs, spices, etc…

• When Eating Out:Ask that they be prepared without

added salt…


The Trace MineralsIron• Bound into the protein hemoglobin in red

blood cells, iron helps transport oxygen from lungs to tissues. Hemoglobin (HEEM-oh-globe-in): the oxygen-

carrying protein of the blood; found in the red blood cells.

• When the iron supply is too low, iron deficiency anemia occurs. Iron-deficiency anemia: a reduction of the number

and size of red blood cells and a loss of their color because of iron deficiency.

Symptoms include: fatigue, weakness, apathy…


The Trace MineralsIron• Iron deficiency is prevalent among toddlers,

adolescent girls, and women of childbearing age. The cause is usually malnutrition caused by limited

access to food or high consumption of foods low in iron. Blood loss can also be a cause.

• Women are at greater risk of developing iron deficiency anemia due to: Limited iron stores. They typically eat less food than men, so their

intakes are lower. Menstruation causes iron loss.


The Trace Minerals• Heme (HEEM) iron: the

iron-holding part of the hemoglobin protein, found in meat, fish, and poultry. More reliably absorbed

than nonheme iron. 40% of iron in meat,

poultry and fish is bound into heme.

Meat, poultry and fish contain the MFP factor that further promotes absorption of iron.

• Nonheme iron: the iron found in plant foods.


The Trace Minerals

• Contamination iron: iron found in foods as the result of contamination by inorganic iron salts from iron cookware, iron-containing soils, and the like.

• Iron overload: a condition in which the body contains more iron than it needs or can handle; excess iron is toxic and can damage the liver. The most common cause of iron overload is the genetic disorder hemochromatosis.



The Trace Minerals

• The best heme sources are liver, red meats, poultry, fish, oysters and clams.• Whole grains, enriched and fortified breads and cereals, and dried beans are good sources of iron. Some fruits contribute iron to the diet.


The Trace Minerals

Enhance iron absorption:

• Heme iron• MFP factor• Vitamin C

Interfere with iron absorption:

• Foods containing phytic acid (occurs in some fruits, vegetables and whole grains)

• Tannins (occur in black tea, cola, coffee, chocolate, and red wine)

• Fiber—resulting in increased transit time of foods through intestines.


The Trace Minerals

Zinc• Found in every cell

of the body and present in enzymes that regulate: Cell multiplication and

growth Metabolism of protein,

carbohydrate, fat and alcohol

Disposal of free radicals


The Trace Minerals


The Trace Minerals

Iodine:• Part of thyroid hormone, which regulates body

temperature, metabolic rate, reproduction, and growth.

• Controls the rate at which cells use oxygen and energy.

• Present in soil in coastal areas of the country.• Iodized salt was introduced as a preventative

measure to prevent deficiency diseases.


The Trace Minerals

Iodine:• Goiter (GOY-ter):

enlargement of the thyroid gland caused by iodine deficiency.

• Cretinism (CREE-tin-ism): severe mental and physical retardation of an infant caused by iodine deficiency during pregnancy.


The Trace Minerals

Fluoride:• Only a trace amount is found in the body but

its continuous presence is desirable: Protects teeth from decay Makes bones of older individuals more resistant to

bone loss (osteoporosis).

• Drinking water is the usual supply of fluoride and is an effective means to prevent dental cavities.


The Trace Minerals

Fluorosis (floor-OH-sis): discoloration of the teeth from ingestion of too much fluoride during tooth development.



The Trace Minerals

• Copper: involved in making red blood cells, manufacturing collagen, healing wounds, and maintaining the sheaths around nerve fibers.

• Chromium: works closely with the hormone insulin to help the cells take up glucose and break it down for energy.

• Selenium: functions as part of an antioxidant enzyme and can substitute for vitamin E in some of that vitamin’s antioxidant activities.

• Manganese and molybdenum: both function as working parts of several enzymes.


Most major health organizations agree that healthy childrenand adults should be able to get all the nutrients they needby eating a variety of food.

If you decide to take a supplement, keep the following pointsin mind:1. Price is not an indication of quality.2. Look for a supplement that contains both vitamins and minerals, with no more than 100-152% of Daily Value.3. If you have children, buy childproof bottles.


This symbol on a dietary supplement label helps you know that…

• the supplement actually contains the listed ingredients in the declared amount,

• does not contain harmful levels of contaminants,

• will break down and release its ingredients in the body,

• and has been made under good manufacturing practices.


Healthy trabecular bone Osteoporotic bone




Peak bone mass occurs at approximately 30 years of age


Can Osteoporosis be Prevented?

•Age•Gender•Age-related decline in hormones•Estrogen deficiency•Family history•Race and ethnic background•Body build•Sedentary lifestyle•Smoking and alcohol•Medical conditions•A bone-healthy diet—calcium, vitamin D, and other nutrients



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© 2007 Thomson - Wadsworth Chapter 7 Water and Minerals