Your Blood & The Cardiovascular System | Heart Health Program

Blood Of My Blood: What Is Blood?

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Over the last couple of months, we’ve been working through a series of newsletters that address the anatomy, physiology, and problems associated with the cardiovascular system. In this issue, we bring it full circle. If you think about it, everything that we’ve talked about so far culminates here. The heart, the arteries, the veins—what is their purpose? When all is said and done, they are merely a support system, a transportation system if you will, for blood. The cardiovascular system has only one purpose—to move blood through the body. By definition that makes blood pretty important, and as befits its importance, it is a vast topic that we’re merely going to touch on in the next couple of newsletters. To give you an idea of how vast, medical school courses focused on just the clotting mechanisms of blood can run an entire year. As I said, vast!

Throughout history, blood has both fascinated and awed us. It is central to many religious ceremonies, and early myths about blood have been used as the basis for everything from human sacrificial ceremonies to medical practice, and even poetry.

Blue-blooded, a term denoting royalty, was originally used by nobles of Castile who could see the “blue-blood” through their veins. In early England, red coverings were put on beds to treat smallpox, and strips of red cloth were used as cures for scarlet fever. Even today, many pills and medications are colored red, although this coloration has no medicinal value.

And let us not forget the vampire, the creature that lives on the blood of the living and keeps coming back from the dead to reappear in movie after movie after movie.

what does blood do?

So what exactly is blood?

A big surprise for most people is that your blood is actually an organ, like your liver and kidneys. In other words, it is a “group of tissues of different kinds” that functions as one system and that performs a “specific” function or group of functions. With that in mind, let’s take a look at this organ, at its composition and functions to better understand its importance and what can go wrong.

Now you might think that it would make sense to first explore what blood is made of before we explore what it does, but, in fact, the opposite is true. By first understanding the roles blood plays in our bodies, it will make it much easier to understand “why” blood is made the way it is. So, with that in mind, let’s begin today’s newsletter with a discussion of the specific functions that blood plays in our bodies.

Why we have blood

Blood serves three primary functions in the human body:

  1. Transportation
  2. Protection
  3. Balance—what doctors call homeostasis

1. Transportation

Even when it comes to transportation, blood is not so simple. It actually transports four distinct categories of things: (1) gases, (2) nutrients, (3) waste, and (4) chemical messengers.

  1. Gases: When most people think of blood, they think of the role blood plays in transporting oxygen to the various cells of the body. Correspondingly, most people are also aware that blood transports carbon dioxide (the gaseous waste from cellular metabolism) away from the body’s tissues and back to the lungs where it can be exchanged for fresh oxygen. For most people, a complete exchange of gases for your entire blood supply happens approximately every single minute of every single day of your life. It’s actually quite astounding, and for a trained athlete is even more amazing. For example, there’s Lance Armstrong. Dr. Edward Coyle, director of the Human Performance Laboratory at the University of Texas in Austin measured and studied Armstrong’s physiology for more than seven years. He found that Lance Armstrong’s heart can pump nine gallons of blood per minute working at its hardest. That’s twice the capacity of the normal person. He found that Lance’s lungs can get almost double the amount of oxygen out of every breath compared to a normal healthy 20-year-old. And he found that Lance has more red blood cells to deliver oxygen to his body, which allows it to recover at an incredible rate. “An average person when going to exhaustion would have to stay stopped or wouldn’t be able to move for 10-15 minutes and Armstrong is able to go right back to maximum in 1 to 2 minutes,” says Coyle.

what is blood's function

As you can see, the capacity of blood to perform even the simple function of exchanging gases is widely variable. At the end of this newsletter, we will explore some of the things you can do to improve the ability of blood to perform this function—as well as all its other functions.

A note on carbon monoxide: When talking about gas exchange in blood, it’s important to remember that blood cells actually prefer carbon monoxide to oxygen. Once a red blood cell grabs onto carbon monoxide, it becomes very reluctant to let go of it—either to exchange for oxygen in the lungs or carbon dioxide at the cellular level. That’s why doctors usually treat carbon monoxide poisoning by forcing pure oxygen into the lungs to force the blood cells to swap out the carbon monoxide.

  1. Nutrients: After digestion has broken food down to its fundamental components, those components—including sugars, proteins, fats, cholesterol, vitamins, and antioxidants—are circulated by the blood to fuel the body, nourish it, and provide the building blocks to rebuild it.
  2. Glucose is the primary energy fuel which is “burnt” by the “metabolic fire” in each cell. The total amount of glucose in the blood is in the range of 3-7 g for a normal adult—with levels at their lowest in the morning and rising after meals. It should be noted that glucose is not the only sugar found in the blood. Other sugars such as fructose and galactose are also transported in the blood, but only glucose levels are regulated by insulin and glucagon.
  3. Protein is the primary building block of the body for repairing organs and building muscle. Protein molecules, however, have to be broken down sufficiently to be used by the body. Large protein molecules that make their way into the bloodstream are not particularly useful to the body’s cells and are, in fact, treated as allergens by the body.
  4. Cholesterol, despite its bad reputation, is required to build and maintain cell membranes and as raw material for the production of all hormones. Cholesterol is insoluble in blood, but is transported in the circulatory system bound to lipoproteins, spherical particles which have an exterior composed mainly of water-soluble proteins. The type of cholesterol, HDL or LDL, is determined by the particular lipoprotein the cholesterol is bound to: LDL (low-density lipoprotein) and HDL (high-density lipoprotein).
  5. Vitamins that make their way into the bloodstream need to be in a form that is useable by the cells of the body. Since the cells of the body do not have receptor sites for most vitamins, most supplemental vitamin isolates are actually toxic to the body and need to be bound to carbohydrates and proteins in the liver (conjugated) so that they are useable in the body.
  6. Antioxidants need to be optimized in the blood not only to protect the arterial walls but to allow the blood to perform its function of bringing the antioxidants to every cell and organ in the body. If they’re not in your blood because they weren’t present in your food to begin with, then the blood can’t bring them where they are needed.
  7. Waste removal: It’s not just gases such as carbon dioxide that need to be removed. Blood is also filled with a great deal of “waste” that also requires removal. When we refer to nutrients being “burnt” by the “metabolic fire” in each cell, it is also an apt analogy when it comes to waste. Cellular burning produces “waste ash” not unlike an actual fire. This waste needs to be removed from each cell and transported out of the body. Also, waste produced by the immune system’s battle with invading bacteria and viruses needs to be removed, as do Circulating Immune Complexes, and used up cells (such as old blood cells), etc. All of this waste is transported about by the lymph and blood on its way out of the body.
  8. Hormones are the body’s chemical messengers. They tell the body what to do and when. Adrenaline, for example, is produced in the adrenal glands, but serves to tell the heart to speed up and the blood vessels to narrow in times of stress. HGH, on the other hand is produced in the pituitary gland. It is released in a series of 9-24 microscopic “pulses” throughout the day (mostly in the evening). Its release signals a number of body functions relative to aging and the production of other hormones such as DHEA and melatonin and various parts of the endocrine system, including the hypothalamus (considered to be the master gland). It is the role of blood to serve as the transportation system that carries hormones (and other chemical messengers) from where they are manufactured to where they are needed.

2. Protection

In addition to transportation, blood also plays several “protective” roles in the body.

  • Controls bleeding: Whenever there is damage to the body, either internal or external, clotting factors in the blood work to seal off the damage, prevent further bleeding, and promote the repair of the damaged area.
  • Fights infection and repels invaders: Many immune cells work hand in hand with your blood to fight infection by invading bacteria, viruses, and funguses.
  • Controls allergies: Again, working with the immune system, your blood works to identify and remove allergens and Circulating Immune Complexes that compromise the integrity of the body.
  • Aberrant cells: Works with the immune system to identify and eliminate cancerous cells.

3. Balance, or homeostasis

Your body depends on a very careful balance of a number of systems, and those systems operate within very narrow parameters. Fall outside those parameters by even a little and very serious illness or death can result. Some key systems that your blood keeps in balance include temperature, pH, and hydration.

  • Temperature: Healthy body temperature operates within a very narrow range of about 97 to 100 degrees Fahrenheit or 36.1 to 37.8 degrees Celsius. Go much over 100 degrees for very long and brain damage and death result. Go much lower than 97 degrees for any length of time and hypothermia sets in. Depending on the level of hypothermia, the effects can be anywhere from shivering, to loss of motor control, to death. In order to prevent extremes of temperature, your brain is constantly monitoring blood temperature. In situations of high temperature, your brain will move blood to the skin to promote the passing of heat off into the air. In cases of hypothermia, your brain will cause capillary networks to shut down and shut blood away from the skin into the brain and body core. An interesting note is that alcohol (think St. Bernard rescue dogs and brandy), which is often used to “warm people up” is potentially deadly. As a blood vessel dilator, it creates a false sense of warmth by opening up the shut capillaries and forcing blood out from the core back to the skin. This creates a sense of warmth in the skin but does so by shunting blood away from the internal organs and brain, thus potentially leading to severe hypothermia and killing you. Can you say, “Bad doggy?” Note: Your body also uses hormones transported in the blood to ramp up or slow down metabolic fires to help regulate temperature.
  • pH (your body’s acid alkaline balance): Our bodies function in a very narrow range of acid/alkaline balance (pH). Our blood, in particular, is very sensitive to these changes. Ideally, blood pH should be slightly alkaline at about 7.45. If it varies by even as little as a few tenths of a point, severe illness and death may result. Unfortunately, most of the food we eat is highly acidic (meat, dairy, sodas, alcohol, cooked grains). In the end, it becomes too much for our bodies to handle. If we don’t correct the problem by “alkalinizing” the body, disease, sickness, and death are the inevitable result. In addition to being highly sensitive to pH changes itself, your blood plays a key role in helping to monitor and effect pH changes throughout the body. For more on what pH effects and how to balance the alkalinity in the body see Chapter 14 of Lessons from the Miracle Doctors. The importance of pH really boils down to two things:
    • Enzymes. We’ve already discussed the importance of enzymes. They control every single metabolic function in our bodies, and they are integral to our immune system. As it says in Anatomy and Physiology by Anthony and Thibodeau, “Enzymes function optimally at a specific pH and become inactive if this deviates beyond narrow limits.”
    • Oxygen. Every cell in our body requires oxygen for life—and to maintain optimum health. To put it simply, the more acid the blood, the less oxygen is available for use by the cells. Without going into a discussion of the chemistry involved, just understand that it’s the same mechanism involved when acid rain “kills” a lake. The fish literally suffocate to death because the acid in the lake “binds up” all of the available oxygen. It’s not that the oxygen has gone anywhere; it’s just no longer available. Conversely, if you raise the pH of the lake, oxygen is now available and the lake comes back to life. Incidentally, it’s worth noting that cancer is related to an acid environment (lack of oxygen). The higher the pH (the more oxygen present in the cells of the body), the harder it is for cancer to thrive.

The bottom line is that a balanced pH is vital. An extended pH imbalance of any kind threatens our well-being—threatens, in fact, our very lives. Managing the pH balance of all of our bodily fluids, tissues, and organs is so important that our bodies have developed systems to monitor and balance acid-alkaline levels in every cell and biosystem. And our blood plays a key role in maintaining that balance.

  • Hydration: You can drink all the water that you want, but it has to make its way to the individual cells where it’s needed. That happens in the blood. Blood has mechanisms that we’ll learn about in the next newsletter for controlling osmotic pressure and moving water in and out of cells—if it’s available. The kidneys may regulate the amount of water in the blood, but the blood regulates the amount of water in the cells. Proper hydration is imperative, not only for maintaining proper fluid balance in the cells themselves, but for maintaining proper hydration levels in the blood itself. Too much water can wash important nutrients out of the blood and even prove toxic to the body. Too little water can lead to clumping of the blood cells, high blood pressure, and even edema, or swelling of the extremities. Yes, I know that doctors treat high blood pressure and edema as a condition of too much water and treat them with diuretics—and they are half correct. The problem is not so much “too much water” but “too much water in the wrong place.”

the function of blood in the cardiovascular system

Things to do

Even though we have merely overviewed the primary functions of blood in your body, we have enough information to start thinking about ways we can improve the ability of blood to perform those functions.


  • Exercise: We’ve already seen how exercise transformed the gas exchange capabilities of Lance Armstrong’s body. If you can accomplish just 10% of that increase in your own body, it will be transforming.
  • pH balance: Change your diet to use more fresh vegetables, which are alkalinizing and less meat, dairy, sugars, and cooked grains, which are acid forming.
  • Carbon monoxide: As much as possible avoid excessive exposure to carbon monoxide. That means:
    • Don’t smoke.
    • Avoid secondhand smoke.
    • Don’t hang around running cars in closed environments.
    • Don’t use charcoal grills in closed environments.
  • Digestive enzymes play a major role in breaking down the foods we eat into forms that are easily transported in our blood and that are easily utilized by our cells.
  • Proteolytic enzymes eliminate circulating immune complexes from the blood and quickly optimize the quality of the blood.
  • Sugar metabolic enhancers prevent glycemic swings and help maintain proper sugar levels in the blood.
  • Blood cleansing optimizes the performance of the blood.
  • Liver cleanses to balance cholesterol: We will talk more about this in a subsequent newsletter, but for now…cholesterol levels are primarily regulated by the liver. Keeping the liver clean and balanced is essential to maintaining proper cholesterol levels in the blood.
  • Kidney flushing helps the kidneys regulate blood fluid levels.


  • Supplementation: Every single blood cell in your body is replaced every 120 days. You cannot build the same quality blood cells out of pepperoni pizza, beer, and Ding Dongs that you can out of real food. The ability of blood to clot properly is dependent on having the proper vitamins and minerals (such as vitamin K) present in the diet. If they’re not present in the diet, then you must supplement.
  • Immune enhancers and pathogen destroyers help control bacteria and viruses in the blood that tax the immune system.
  • Proteolytic enzymes help eliminate circulating immune complexes, which significantly relieves the allergic burden on your body, thus taking a great deal of burden off of your blood in accomplishing that objective.


  • pH balance: Our bodies have developed a system for maintaining pH balance in all of our body fluids. To understand this system better, we need to take a look at what changes pH (usually making us more acid), and how our bodies respond to that change. When they are metabolized, carbohydrates, proteins, and fats produce various acids in our bodies. Proteins produce sulfuric acid and phosphoric acid. Carbohydrates and fats produce acetic acid and lactic acid. Since these acids are poisonous to the body, they must be eliminated. Unfortunately, they can’t be eliminated as acids through the kidneys or large intestine as they would damage these organs. How Can We Help?
    • Change your diet. Follow the guideline laid out in Chapters 6 and 7 of Lessons from the Miracle Doctors.
    • In addition, there are several special alkalinizing agents available.
    • Your health food store has alkalinizing teas or drops available.
    • There are machines from Japan that will “micronize” your water. What it actually does is take your tap water and divide it in two. One stream is acidic and can be used for washing and cleaning. The other steam is alkaline and is used for drinking. It works really well. Unfortunately, it’s really expensive—about $900-1,200.
    • One of the best alternatives is to simply magnetize your water. Applying a magnetic field to a pitcher of water for a short period of time will make it more alkaline, depending on its mineral content. It also offers the added advantage of lessening the surface tension of the water, which makes the water wetter and more usable by the cells of your body.
  • Hydration: As stated earlier, one of the primary roles of blood is to maintain proper hydration. When you start to dehydrate, your body starts trying to store water in order to survive. Instead of passing the water out through the kidneys, it starts to stockpile it in the bloodstream. It is this stockpiling resulting from dehydration that often leads to higher blood pressure. That means that in many cases the more fundamental solution to higher blood pressure lies not in using diuretics to flush out excess water but in addressing the underlying problem of dehydration. It might seem counterintuitive, but you need to drink more water to alleviate the dehydration, which then allows the body to eliminate the excess water it was storing as a response. Bottom line: you want to properly hydrate…and you want to cut down on excessive use of diuretic drinks such as coffee,  tea, and many sodas.


As we’ve seen, just by exploring some of the basic functions that blood performs, it opens the door to exploring how much we can influence the performance of those functions by our dietary and lifestyle choices. In the next newsletter, we will explore in some detail the actual composition of the blood. This actually takes you into your doctor’s world since most blood tests actually are designed to measure the amounts of key components. Understanding these components and your doctor’s tests will open up choices to you that your doctor might not otherwise present.

Read more about Cardiovascular Health