WATER Part B

Water Part B

Mans FoodWATERPart B

1Hello, we are going to finish up talking about water by discussing water part b. In this section we are going to finish up by talking about the third type of water. We are also going to talk about the health consequences associated with too much or too little water. We will then finish up by discussing water balance or how we control water in the body.Water Sources: Metabolic WaterFats + O2 CO2 + H2OProteins + O2 CO2 + H2O + N2Sugars + O2 CO2 + H2O

2Metabolic water, the third type of water which is also called the water of metabolism. I'd like to ask a question about this relationship - Life is characterized by the body taking in sugars, fat, proteins and oxygen and requiring us to give something back in return. Well according to our relationship from this slide, for sugars, we give back carbon dioxide and water, for fats we give back carbon dioxide and water, and for proteins we give back carbon dioxide, water and nitrogen. The nitrogen is a part of the proteins; therefore, we must give it back as we break the proteins down. You notice for these equations that water is on the right side as a product of these reactions. So, this is how we define metabolic water-the water produced through the metabolism of sugars, fats, and proteins is metabolic water.

What is the relationship of the macronutrients to metabolic water produced?Emergency Rations Burn Produce Grams 100 Grams Metabolic Water CHO 60 Fat 107 Protein 40

3This slide demonstrates more specifically this relationship. If you burn a hundred grams of carbohydrate (abbreviated CHO) it produces 60 g of metabolic water. If you burn 100 g of fat it produces 107 g of metabolic water, and if you burn 100 g of protein it will produce 40 g of metabolic water.

You may ask yourself how can you make more water than you start with for fat - does this notdefy the laws of thermodynamics cant make more than what you started with? Actually no - if you understand the biochemistry of fat metabolism, you can actually account for all the water that is produced. Now as the title of the slide states emergency rations would does this mean? Well I like to read about the Civil War and World War II and if you read about flyers who flew in the Pacific unfortunately at times they would get shot down. Now there was water water everywhere but they could not drink it, why? Well the salt in the water would cause you to dehydrate faster. So when you read some of these flyers Journal, they would use some extraordinary survival techniques. Since they couldn't drink the water from the ocean, once their canteen or water source ran out, guess what they drank? Yeah, you guessed it, they drank number one or their urine.

You may think it's disgusting now but until you're out there experiencing what those flyers experienced, it is hard to say what we would do. How many of you have ever read the book Alive? This was about a soccer team whose airplane crashed in the Andes. Now these people had an abundant supply of water, from the snow, but what they did not have was an abundant supply of food - what did they end up doing? They became cannibals, eating their dead comrades. The book describes vividly how they took the flesh and placed it on the airplane to sun dry forming a human jerky type of product. So you see when faced with surviving or not surviving, we have a tendency to revert back to a somewhat animal behavior. So, if it was up to the food scientist to develop a ration that could produce metabolic water, what macronutrient would you choose? I suspect that most of you chose fat. This is because it produces more water than what you start with. Unfortunately, you are not correct because what you don't know is that too high a fat diet and very little carbohydrate in the diet will cause a more significant health problem called ketosis or ketoacidosis. This will eventually cause you to dehydrate even faster.

So your next choice would be carbohydrate, and actually, this would be the correct ration that you would want. First, carbohydrates produce a clean, safe and sterile urine. Why would you not want a food containing high-protein? If you recall life is characterized by us consuming protein and oxygen and giving off something in return which was carbon dioxide, water, and nitrogen in the case of protein. This nitrogen that goes through the urea cycle is very toxic to the body. Consuming it would have a lethal effect on the body causing death more quickly than no water at all.

So by understanding the biology and biochemistry of the body, we can develop certain foods or practices that can sustain life under extreme environmental or survival conditions.Water LossesKidney:Most important systemSkin:Insensible: Lower skin layersSensible: SweatingLungs

4Let's talk a little about where this water goes in the body, so we're going to start talking about water losses or water balance. There are four to five mechanisms by which water is lost or exchanged in the body. The first and probably most important system is our kidneys. A lot of water is exchanged through the kidney and it is the major source of water loss controlled by the body.

The next type of water loss is through the skin. There are two types of water loss by this mechanism. The first is called insensible water loss. This takes place 24/7 at the lower layers of our skin. It is called insensible because we do not sense this water loss occurring. The other mechanism for water loss in the skin is sensible water loss or sweating. It is called sensible water loss because we sense or feel the water being removed as we perspire.

The third type of water loss is through the lungs. This usually occurs when one hyperventilates or is at an extreme altitude where water builds up in the lungs and can cause a kind of drowning.

Water LossesEyesIntestinal:Diarrhea

5Eyes are the fourth type of water loss, where you have tearing. This is usually not that significant unless you've lost that boyfriend or girlfriend.

The final type of water loss is intestinal or diarrhea. This usually occurs when we experience a food borne illness, intestinal flu, or some type of stomach virus. Depending on the severity of the organism responsible for the diarrhea, this can be life-threatening to various individuals. I really hate using the word diarrhea as it has such a negative and disgusting connotation. Thus, after today we will no longer be using the word diarrhea. What we will be using to define this annoying, disgusting, life-threatening symptom is a more sophisticated term - anal leakage.

So from now on when we speak of this horrific term, let us remember to use the more sophisticated way of defining this disorder. I must have eaten something bad at the restaurant because I had horrific anal leakage or liquid stools. I can see it now, mom calls up and asks what you learned today and you tell them: did you know there is no such thing as diarrhea but it's called anal leakage, I am sure mom will be impressed.TOO MUCH EDEMATOO LITTLE DEHYDRATIONWater Balance

6When we look at water balance, there are two ways in which you can go, and they are presented in this slide. Ideally, the scale should be equal in balance for optimal health and well-being. However, you can have too much water in the body and that his term edema. On the other hand, too little water or water rapidly being eliminated from the body is termed dehydration. We will look into these two problems in a little more detail.Edema: Fluid Excess >10%

7Here is a slide showing edema. Edema causes the tissues to become swollen. It is characterized by being in excess of 10% water. Notice the difference between your normal foot and the edema foot that is swollen, where the tissues are just saturated with water.

Notice how pliable your skin is normally. When you press on it, it is very elastic and bounces right back. However, tissues having edema do not bounce back and actually your fingerprint is indented in the tissue. It occurs a lot in the limbs. It also occurs a lot in females during pregnancy. You will also notice it again when we talk about protein deficiency disorders. It mostly is uncomfortable, painful, and annoying to those who suffer from it.Dehydration: Fluid LossLoss Effect1%-2% Thirst 3%Dry mouth 4% Flushed skin, impatience, apathy, nausea, emotional instability 8% Dizziness, labored breathing, indistinct speech, mental confusion 10% Heat stroke, spastic muscles 11% Circulatory insufficiency 15% DEATH

8Dehydration or fluid loss is the more severe of the two symptoms. It is also the more lethal when talking about water balance and optimal health and well-being.(Read slide)Diarrheal Diseases:Life Threatening

Cholera

9These on the other hand lead to a more life-threatening problem from water loss or dehydration. These are two pathogens that we will talk about later on when we get into the subject of food safety or foodborne illnesses. Needless to say their destructive nature or death that usually results is based on them dehydrating the body.Diarrheal Diseases

Cholera Incidence: 1997

10This slide shows diarrheal diseases around the globe. It mainly reflects cholera incidence and you can see that it is located in various hotspots around the globe. Presently we in the United States do not have a high risk for cholera or diarrheal diseases. However, there have been a number of hot spots in central and south America and the potential for moving northward is real.Help Prevent Dehydration10-15 Minutes Before Exercise:Up to 20 ounces of waterDuring Extended Exercise:4-6 ounces every 10-15 minutes

11The greatest risk of water loss or dehydration for most normal individuals ie us, is caused by exercising. How can one prevent dehydration from exercising, here are some recommendations.(Read slide).Exercise:For every 1 lb lost after exercise, drink 2 cups of fluid Help Prevent Dehydration

12Here is an additional recommendation for exercising. A good general rule of thumb is, for every 1 pound lost after exercise you should drink 2 cups of fluids. As much as we support exercise for good health and wellness, it is important to remember to maintain hydration during these regimes because dehydration has led to numerous deaths from us ignoring this forgotten nutrient.Osmotic Pressure (OP)DrinkingThe force that keeps water in its compartments OP = Solutes Solution

Decrease in OP

13The next question to ask is how do we regulate water balance. Water balance is regulated by changes in osmotic pressure. The general definition of osmotic pressure is the force that keeps water in its compartments; again, a force that keeps water in its compartments. Water balance is maintained by the force of osmotic pressure on one side and hydrostatic pressure on the opposite side.

Osmotic pressure is the ratio of concentration of solutes to the concentration of solution. If you are drinking plenty of fluids, then this ratio should decrease the osmotic pressure in the body. This is because the solute concentration will not increase that much compared to the solution of the fluid. Since the solution will increase many times more than the numerator, solutes, osmotic pressure must decrease.

This along with the next couple slides is a very important concept and probably should be remembered.Water ConservationOsmo receptors in bloodSignal to brain (hypothalamus)Signal to pituitary

14The change in osmotic pressure is picked up by Osmoreceptors found in the blood. The Osmoreceptors signal the brain, specifically the hypothalamus, which then sends a signal to the pituitary gland - what happens next?Water EliminationAntidiuretic (ADH) hormone not releasedKidney filters out waterBladder fills#1

15The pituitary gland must now determine whether to store or eliminate the water in the body. In this scenario, where we are drinking plenty of fluids, the body wishes to eliminate the water. The hormone which determines whether we save the water or remove it is called the anti-diuretic hormone (ADH). If you read this important definition on the bottom of page 17, it states ADH act's to conserve water by forcing the kidney to reabsorb it; when the body wants to eliminate water, ADH is not released by the pituitary gland and water is lost via the kidneys. So again, since we want to eliminate water as we are drinking plenty of fluids, ADH is not produced and released; thus, water is filtered through the kidneys, the bladder then fills, and eventually we go number one.

So, your job now becomes to look at water balance regulation by understanding how this pathway changes, when you do not have water coming in and you are sweating profusely. Hint, it should be the opposite of what we just presented.One liter per 1,000 calories eatenSee table page 17

Fluid Requirements

16When we talk about water balance, you can again look on page 17 in the middle table, which gives us an inference on how water comes in and out of the body. You can see that water intake, primarily comes from fluids and food, with metabolic water or water of oxidation being a small part of our intake. On the other side of balance, we have urine or kidney removing much of our water, while insensible water loss accounts for the remaining water removal system. Water through the stool is fairly insignificant. Thus this slide demonstrates that one liter for one thousand calories eaten should be consumed as fluids.What About Minerals?Antinaturetic System:Controls sodium balanceThree hormones:ReninAngiotensinAldosterone

17Finally we have been discussing water balance but we do know that sodium and potassium flow with water as the extracellular or intracellular minerals; so what about mineral regulation? The system involved with mineral regulation is called the antinaturetic system. This system primarily controls sodium balance. There are three hormones that are involved in this regulation. They are renin, angiotensin, and aldosterone. This is the system we usually look at when we have concerns about high blood pressure. Now, I do not want you to have to memorize all of these hormones, but I do want you to remember that it is the antinaturetic system that regulates sodium balance.

This concludes our discussion of water. Again if you have any questions please feel free to e-mail me. We will meet again next time to talk about the second most important nutrient which is energy or the calorie. This may have raised some eyebrows as most of us fear the calorie. So I leave you in suspense for next time as we talk about energy or the calorie.

If any of you are falling along using the supplemental book: nutrition for you: readings for man's food, we have completed unit one and unit 25 which deals with water. Remember, this is a supplemental resource book and nothing will be on the exam directly from this book.