Date: Fri Aug 5 14:47:23 2005 Posted By: Steve Mack, Post-doc/Fellow, Molecular and Cell Biology Area of science: Biochemistry ID: 1121225635.Bc Message: Hi Mark,
The idea that most if not all of the atoms in your body turn over on average every seven years has been around for quite a while. I've spent the last several weeks trying to track down its origin, but it has been tossed around rather casually (i.e., no primary references cited) for more than 80 years. I found a reference to this idea in a book that was written in 1922, the original edition of which was written in the 19th century.

I'm not positive yet, but it seems likely that the idea of a turnover of the atoms in the human body every seven years is the result of experiments observing the turnover of radioisotopes in animals. The figure of seven years is probably an extrapolation from small animals to humans. I'm still doing legwork on this, so I will update this page when I am able to track down more information.

So, while I can't yet identify the origin of this concept, I think that I can back-up the claim with contemporary evidence. A very nice paper was published in Cell last month, in which the authors (KL Spalding, RD Bhardwaj, BA Buchholz, H Druid, and J Frisen) determined the age of specific human tissues and cell types and compared those ages to the age of the person in question. Spalding et al found that most cell and tissue types in the human body are much younger than the person in which they are found, and that very few cells live for the entire life of the person.

They determined this by looking at the presence of the radioactive carbon 14 isotope (14C) in the DNA of different cell types and tissues. Atmospheric levels of 14C increased dramatically after the above-ground atomic tests of the mid-1950s and have been dropping since the last above-ground tests in 1963 (due to equilibration between the oceans and the atmosphere). Atmospheric 14C enters the biosphere when it combines with oxygen to form CO2, which is then fixed by plants. Because we eat plants and plant-eating animals, the 14C levels in our bodies are proportional to the level in the atmosphere (after accounting for growing seasons and harvest times); as the level of 14C in the atmosphere decreases, so does the 14C available to us in our food.

In their paper, Spalding et al note that "Most molecules in a cell are in constant flux, with the unique exception of genomic DNA, which is not exchanged after a cell has gone through its last division." So they used the level of 14C in the genomic DNA of particular tissues to date the time of the birth of the cells in that tissue, through comparison to the decreasing level of 14C in the atmosphere over the last ~40 years.

They found the average age of intestinal tissue to be about 11 years, and after accounting for epithelial cells (which have short lifespans of only 5 days) found the average age of non-epithelial intestinal tissue to be 15.9 years. Skeletal muscle tissue was found to have an average age of 15.1 years. In the brain, tissues appear to be much older. The average age of the cerebellum's gray-matter was only 2.9 years younger than the person, and the average age of occipital-cortex gray matter was about 10 years younger than the person, but the age of occipital-cortex neurons was found to be the same as the age of the person.

So, even though we think of our bodies as being permanent structures, most of our tissues (outside of our brains) are continually being turned over, renewed in a balance between the constant death of old cells (likely through the process of apoptosis) and the constant birth of new cells. In last week's New York Times article about this paper, Dr. Frisen (the senior author) suggested that the average age of the cells in an adult human may be as low as seven to ten years. Remember, this is an average value. As shown by Spalding et al, the value varies by tissue.

Spalding et al used genomic DNA as the measure of a tissue's age because genomic DNA has the lowest turnover rate of all of the molecules in the cell, and because the levels of 14C in that DNA reflected the atmospheric levels of 14C at the time when the cell was born. This tells us that the molecules that make-up new cells are recruited from outisde the body, and are not simply recycled from cells that just died. It also tells us that an average age of seven to ten years is an upper limit for most of the atoms in the body. Even the neuronal cells of the occipital-cortex are constantly making new proteins and RNA molecules, and are constantly consuming carbohydrates and lipids. So, it seems quite plausible to me that the average time for the turnover of the atoms in your body could be around seven years.

Spalding et al conclude that "The possibility to determine the age of cells can give us a map of the human body from a cell-renewal perspective." So, there is certainly much more information to come from future studies of this sort, and I am looking forward to seeing where they lead.

... from internet

Submitted Aug 22, 2003   Updated Apr 9, 2006
By Ray Foster, rf@mt-rushmore.net

 

The most common cause of chronic disability in the developed countries is knee pain. Did you know that 100,000 people in the USA cannot independently get from their bed to their bathroom!

Rather than focus on how widespread hip and knee pain is and how much suffering and loss of revenue this most common cause of chronic disability is – there are two points that we want to focus on in this hour that we will spend together. Point no 1 is – the cause of chronic hip and knee pain. And point no 2 is – what can we do about it. Is hip and knee pain inevitable if I live long enough – or is possible to grow older without knee pain?

Q. What are the three big catagories of causes associated with hip pain?

A.

· Deformities of the acetabulum—25% to 35% of cases

· Deformities of the proximal femur (ie, slipped capital femoral

epiphysis, Legg-Calvé-Perthes disease)—35% of cases

· Joint trauma—10% of cases

· Others—15% to 20% of cases

Q What are the Early x-ray findings of Hip Osteoarthritis ?

A.

Q Are there other causes of hip pain besides hip osteoarthritis?

A.

Q Could you summarize the picture about hip arthritis

A

· Osteoarthritis, the most common form of arthritis, affects more than 16

million Americans and is a major source of disability in the elderly.

· Osteoarthritis is distinguished from other forms of arthritis primarily by the lack of a prominent inflammatory component, which has implications for selection of therapy.

· Although the pathogenesis of osteoarthritis is not precisely known, it may be related to either abnormal mechanics or biologic failure (ie, insufficient cellular capacity to respond to stress), or both.

· Age is strongly correlated with osteoarthritis, with increased incidence occurring exponentially after age 50. Women are affected more frequently than men, and their disease is more severe and more often involves multiple joints.

· Currently, there is no gold standard diagnostic test; however, the diagnosis is frequently based on x-ray studies, which may be very nonspecific. The ACR classification criteria for osteoarthritis of the hip and knee are based on a combination of clinical and laboratory criteria, clinical, laboratory, and radiological criteria, or clinical features alone (see Tables 3 and 4).

In summary:The differential diagnosis of hip pain includes rheumatoid arthritis. However, although a pattern of symmetrical peripheral joint involvement suggests rheumatoid arthritis, osteoarthritis and rheumatoid arthritis of the hip can coexist, particularly in elderly patients. Ankylosing spondylitis typically presents with back pain, but may also present with hip pain, and thus is a diagnostic possibility, particularly in younger men. Avascular necrosis is another cause of hip pain; typically the pain is out of proportion to the x-ray findings. Pigmented villonodular synovitis is also among the differential diagnoses; this entity is characterized by specific histologic features.3, 4, 8Early xray findings include osteophyte formation and loss of articular cartilage (ie, joint space narrowing), progressing to total obliteration of the joint space in severe cases. Extensive bone cyst formation and flattening of the femoral head due to subchondral bone collapse may also be seen. The pattern of subchondral thickening and initial loss of articular cartilage may reflect the underlying biomechanical disorder. Causes of adult hip osteoarthritis have been classified as follows:

 

1. First, What is chronic knee pain?

The difference between acute and chronic knee pain is the duration of the pain. If you twist and sprain your knee and it hurts, and you have done that a thousand times before and it always gets better in a few days or weeks, that is not chronic knee pain. To qualify as being chronic knee pain, it must have been present for over 3 -6 months continuously and never go away. This is entirely different from the acute, short lived knee problems. Those are not what we are talking about today. Those short lived knee problems are not the problem that chronic knee pain is which has been constantly a problem for over 3 – 6 months.

2. So let’s get started. We have Dr. Scribner who is an internist. Do you see patients with knee pain, Dr. Scribner?

   Yes. Arthrits is and knee pain is one of the common complaints that doctors see.

   What we are talking about is osteoarthritis. It is osteoarthritis that is the cause of the chronic knee pain that is the cause of the greatest amount of chronic disability in the developed countries. In my experience what I see in this country compared to what I have seen in 30 years in Africa I would say that it is diet and lifestyle that accounts for the difference.

   We should have and we think we do because we can choose to eat and drink virtually anything we want to. Our tastes and appetites are perverted. What we think is the best is not the best from a physiologic, scientific standpoint. Americans generally eat about three times as much protein as the body needs. We get far too much salt in our diet. We drink brown liquids that dehydrate us instead of water that hydrates our body cells. Most of us do this in the certain idea that it may not be best, but it is not significantly harmful. The reality is that habitually eating too much protein, habitually dehydrating the body does weaken the body and pave the way for the degenerative diseases of excess that we suffer from in these United States. Our refined foods and meat and dairy-based meals also contribute to arthritis and inflammation of the joints.

   In young children chronic knee pain used to be called, "growing pains". Today "growing pains" is not an accepted diagnosis but "knee pain" is! Both the long thigh bone, the femur, and the long leg bone, the tibia, have the fastest growing points called the epiphysis or the physis. Whether the changes in size and the lengthening of the joint capsule and the ligaments and muscles are painful or not is debatable. But joint pains for no explanable reason are not unusual in rapidly growing young children. Chondromalacia patella is the common cause of chronic knee pain in young women. In the older age group say 40 plus years of age, early osteoarthritis is the common cause of knee pain in both men and women. In the late fifties and older than 60s more advanced osteoarthritis is the common cause of chronic knee pain.

   Chondromalacia patella and osteoarthritis are really a cartilage diseases, that later, in the end stages involve the bones of the joint as well. Dehydration is probably the commonest cause of discomfort in the function of all of our body cells. Our body is 70% or more composed of water. There are three places that water is found in the body – that is besides your urinary bladder. The three places where water is found in the body are first, inside the body cells; second outside of the body cells; and third in the blood. There are other places with body fluids like saliva and gastric juices and spinal cord fluid etc. But it is the water in the cells themselves that contributes very significantly to the cell function. Chronic dehydration means chronic poor function of every cell in the body. Chronic dehydration of the blood means thicker blood, increased blood pressure, greater tendency for the blood to move slower and clot more easily. It is the blood that suffers first and most from dehydration. The body does everything in its power to keep enough water in the cells so that they can function as close to normally as possible.

   Exactly! Dehydration, excess protein, fat, refined sugar in the diet, lack of exercise, all of these lifestyle factors contribute to the compromise of the cartilage cells to make good cartilage. Poor quality cartilage is what contributes to and causes chondromalacia of the patella and early osteoarthritis that leads to advanced osteoarthritis which is the cause for so much disability and loss of function by the time we get to retirement age.

3. Dr. Foster, why is knee pain so common in the developed countries and so uncommon in the developing countries?
4. Don’t we have the finest diet and lifestyle in the world in hometown USA?
5. What are the common causes of chronic knee pain?
6. How does dehydration and excess protein contribute to chronic knee pain?
7. So is it the cartilage cells that do not function optimally from dehydration that leads to chondromalacia?
8. Let’s ask Dr. Scribner how does excess protein, fat, and refined sugar damage the function of our cartilage cells and contribute to arthritis?

   It is the refinement (taking away the fiber, vitamins and minerals from the whole food during processessing - so that it will have a longer shelf life in the stores) of our food that causes the problem of overnutrition (too many calories) and malnutrition (not having the minerals and vitamins required by the body to process the food) to happen at the same time. Overnutrition causes high blood fat levels which aggravates arthritis because the high fat in the blood makes the blood thicker and more prone to clot and decreases the oxygen-carrying capacity of the blood. The malnutrition aggravates arthritis by not supplying the proper nutrients to the cells because they are lacking in the food (due to refinement).

9. Dr. Foster, How does lack of exercise contribute to arthritis?

   There is a very direct mechanical relationship between cartilage nutrition and exercise because of the way that cartilage cells get their nutrition. There are no blood vessels in cartilage. The reason for this is that cartilage gets such mechanical punishment that it could not stand up to the punishment that it gets if it had blood vessels in it. The blood vessels are not strong enough to take the mechanical forces that the cartilage is subjected to in normal daily activities. Cartilage is a normally stiff spongy, or rubbery substance that has a lot of sponge or rubber in it and relatively few cells. The cells that are in the cartilage are nourished from the fluid content of the cartilage. The way the fluid content in the cartilage is moved through the cartilage is by alternate compression and rest from compression. It is as the cartilage is alternately squished and pulled on that the fluid in the cartilage is circulated, and so the cartilage cells are nourished by the nourishment that is in the joint and cartilage fluid. So the less exercise a person does, the less nutrition the cartilage cells receive.

   10. That makes sense. Are there any scientific studies that document this idea?

   Some years ago a study was done in San Fransciso among the dock workers. The rate of osteoarthritis among the secretaries and other clerical workers was compared to the longshoremen working on the docks doing the hard physical work. It was shown that the sedentary office workers suffered from more arthritis than did the longshoreman doing the hard physical work.

   It is not just pressure, but intermittent pressure alternating with no pressure. Walking is the perfect exercise from the standpoint of cartilage circulation. It is true that the heavier you are the more pressure your cartilage in your knees get. And when an overweight person walks, the knee cartilages would get good circulation from the standpoint of the pressure dynamics. Overweight people usually have high blood fat levels which slows their blood flow to the synovial cells lining the knee joint which makes the articular fluid which nourishes the knee joint cartilage. Overweight people tend to have high blood cholesterol which contributes to plugging of their arteries all over the body, including the arteries that nourish the knees. There are studies that show that knee arthritis is improved by losing weight. Dr. David Felson, a professor of medicine at Boston University has studied knee osteoarthritis. He has found that losing weight can make arthritis of the knee significantly better. "Factors associated with prevalent self-reported arthritis and other rheumatic conditions—United States, 1989-1991." MMWR Morb Mortal Wkly Rep 1996 Jun 14;45(23):487-491.

   No, probably not. There are two different kinds of cartilage in the knee. The articular cartilage covers the ends of the femur, the long bone in the thigh, and the articular cartilage that covers the top of the tibia, the leg bone, are what make up the articular surfaces that meet in the knee joint. Between these two layers of cartilage that the bones are covered with, is another structure made out of cartilage called the meniscus. The articular cartilage usually does not get torn in the same way that the meniscus gets torn. The menisci are two semi-circular cartilage structures that fill in the spaces between the bone ends and contribute to the capacity of the joint to bear load. The menisci are mobile. That means that they can move with the movement of the knee. Sometimes they get caught between the ends of the bone and get stuck by being pinched between the bone ends and then they may be torn. The articular cartilage covering the ends of the bones do not move like the menisci do. The articular cartilage stays put covering the ends of the bone. It is the bones themselves that move. The articular cartilage facilitates the movement of one bone on the other in the joint. The synovial fluid answers to oil in a mechanical joint. The articular cartilage answers to the surfaces of a mechanical joint that glide or move on each other. The menisci answer to the cage that holds the ball bearings in a ball bearing joint. In terms of comparing a ball bearing mechanical joint to the knee joint, the ends of the femur would answer to the balls and the menisci to the cage that holds the balls in the mechanical joint.

   The knee joint is held together by two very strong ligaments in the center of the knee. They are called cruciate ligaments because they cross each other. The anterior or front cruciate ligament attaches to the front of the tibia below and to the back of the femur above. The posterior cruciate ligament or PCL, attaches in the opposite way. The PCL is attach behind on the tibia and in front on the femur. By crossing like that they are always tight no matter what angle your knee is bent. A torn ligament is an acute significant problem. An orthopedic surgeon that treats knees and sports injuries is skilled at replacing a torn ACL so that the knee functions very well again.

   That is certainly the bottom line question. It depends upon your age. The first thing in treating pain is to determine what the cause of the pain is and address that problem. In children, chronic knee pain may be the first sign of rheumatoid arthritis or simply "growing pains". It is important to know what the cause of the pain is in order to treat the cause. Children do not have osteoarthritis generally but they may have rheumatoid arthritis. The first step would be to have your doctor determine the cause of the pain.

   The non steroidal anti-inflammatories and pain medication work well to decrease the pain in a joint but do not address the cause of the pain. Arthritis does have a cause. Millions of people in Africa and China are of advanced age without arthritis in their knees or anywhere else in their body. And they do not take Ibprofin or tylenol!. Arthritis is not caused by a deficiency of pain or anti-inflammatory meds.

   Not really! There are two reasons for this opinion. First the anti-inflammatories work by blocking the body defense to put right the problem that the knee is experiencing. So by taking the anti-inflammatory meds, the pain may feel better but the problem that the body was trying to correct is allowed to get worse faster because the body’s repair mechanism is being blocked. The other point is that pain is our great motivator to get us to do something that we would not otherwise do. So when the knee pains on a regular basis, we need to do something to help the knee overcome its problem that it is facing. Taking pain meds blocks the motivation for us to make a change that will help the knees. Pain medication works in the head. We want something to work in the knee to help the problem.

   There are several suggestions I would have based on body physiology. The bottom line cause of pain is inflammation. The way to co-operate with the body’s inflammatory response to deal with whatever it is dealing with is to determine what the cause is and correct it if the cause can be found and it is correctable. Usually the cause is not recognized because what to look for is not known. In the absence of being able to find a cause of chronic knee pain in a child who does not have rheumatoid arthritis or any other recognisable condition would be to consider doing the following.

   1. Keep the knees warm. Blood flow is improved when the body part is kept warm. For a girl, depending on her age, this may mean long stockings or a dress or pants that cover the knees and protect them and keep them warm.
   2. Drink 6-8 8-ounce glasses of water a day. This will supplant drinking harmful drinks that dehydrate the body and make sure that the body cartilage cells are getting enough water to be healthy and that the blood is thin enough to circulate well.
   3. Exercise daily in spite of the knee pain. Cycling is good exercise or swimming in the face of knee pain. Walking is one of the best exercises. One hour a day in divided doses of 20 – 30 minutes each five days a week is a good exercise schedule.
   4. Alternate hot and cold applied to the knees if the pain is severe enough would decrease the pain by decreasing the inflammation without blocking the body’s defense mechanism.
   5. Unrefined plant food contains ecosinoids and prostaglandins that will naturally decrease excess inflammation without blocking the body defense mechanism.
   2. What treatment would you suggest for the young lady or not so young lady with chronic knee paid due to chondromalacia patella?
   3. I am over 50 or 60 and my knees are beginning to or are definitely stiff in the morning or after I sit for a long time in one position longer than 30 minutes or so. What can I do for my chronic knee pain and stiffness?

      Keeping the knees warm and alternate hot and cold will help a lot to make the knees feel better almost immediately.

      Quadriceps strengthing by the method of terminal quad sets. Bending the knee more than 20 degrees during exercise may unnecessarily increase the knee pain. Sitting on the floor or firm surface with your leg straight in front of you, place a firm padded object under your knee to give about 20 degrees of knee flexion, and then straighten the knee ten times. If this is too painful to start with, don’t start with that exercise. Simply do hot and cold and keep the knee covered and warm. Without moving the knee at all, isometric quadriceps exercises will strengthen the big muscle attached to the top of the patella called the quadriceps because it has four muscle heads that attach at the knee joint.

      Drinking water and eating unrefined plant food and getting enough sleep and getting in the sunshine as you are able and letting God carry your burdens and developing a thankful attitude for all the blessings we daily receive, good posture with good deep breathing, and using self control in all your work and play, are the other things that will help your knee.

      18 My doctor has recommended surgery. What do you think about that?

      If your orthopedic surgeon has recommended surgery, that is probably needed and will help. The success rate is enhanced by following the advice just given. If you were to do the things mentioned earlier for 6 – 9 months, your knee pain may decrease to the point that surgery would not be necessary. Chondramalacia can be aggravated by a patella that is not tracking well. Surgery is not going to make your cartilage cells any stronger. Nor is doing what I have suggested going to correct a malalignment of your patella if that is present. The malalignment of the patella is probably present in both knees and has likely been that way all of your life. These are things to consider in making a decision for surgery. Losing weight may increase the flood flow to your knees and decrease the demand on your knees to the point of being quite comfortable. In short just be aware that chondromalacia is a metabolic problem, not a mechanical problem. A mechanical problem is all that surgery can deal with. It is your nutrition and lifestyle that has the potential to correct a metabolic problem with the cartilage cells.

      There is nothing that you can do that is going to change bony changes seen on xray. However there is a lot that can be done for the chronic pain of osteoarthritis in the knees and elsewhere in the body. I would suggest five things.

      1. Sit where you can let your leg swing back and forth. Let your knees swing back and forth – just like you used to do as a child. This circulates the joint fluid and tends to increase the flood flow to the knees in a way that it not painful. Do this knee swinging 10 minutes a day once or twice a day 5 or 6 days a week.
      2. Drinking 8 or more 8-ounce glasses of water between meals will make a definite improvement in the health of your cartilage cells. Drink as much water as you can when you first get up in the morning, preferably warm. You will find out that drinking water in the morning has a fringe benefit of helping you be more regular and in time may eliminate the use of the most used over-the-counter medication sold in this country – laxatives.
      3. In addition to the leg swinging exercises, do some other exercises. If you have a lot of pain and limitations with your knees, water exercises are the best. Stationary bicycle or other exercise machine exercise for 20 minutes a day five days a week is good. Outside exercise will benefit you twice as much as inside exercise because of the ultraviolet and fresh air found in abundance outside that may be limited inside.
      4. Symptomatic treatments that will assist nature in her efforts to repair the damaged cartilage while at the same time decreasing the pain of inflammation are available and can be very helpful. Alternate hot and cold by sitting in the shower and swinging your legs at the same time can be very helpful. Using a hot pack and ice pack can be very helpful. Ten minutes of heat and 3 minutes of cold changed three times, starting with hot and ending with cold is the plan for using hot packs and ice packs. In the shower 3 minutes hot and 30 seconds cold works the best.
      5. Plant based, unrefined food really makes a big difference in just a few days. The lower your blood fats levels are, including cholesterol, the more oxygen carrying capacity your blood has. Plant foods decrease the load of toxins coming into your body and gives you the benefit of wonderful phytochemicals. More than that plant fats have chemical messengers that decrease inflammation naturally and almost immediately you feel better without interfering with the body’s clean up efforts to deal with the damaged cartilage.

       

       

    

10. Wouldn’t it logically follow that overweight people would have less arthritis if pressure on the cartilage contributes to its health because of increased circulation?
11. When you talk about the knee cartilage, is that what the doctor is talking about when I am told that I have a torn knee cartilage?
12. Thinking about the knee, what has happened to the knee if the doctor tells me that my ACL is torn? What is a torn ACL?
13. So if I have chronic knee pain what can I do about it?
14. What if the doctor tells me to take Ibprofin or Tylenol, is that the best treatment?
15. Isn’t it a good idea to take anti-inflammatories and pain meds when your joints hurt?
16. So if your child is always complaining that their knees hurt, and the doctor has checked the child and tells you that it is not rheumatoid arthritis but chronic tendonitis or muscular pains or growing pains, What is the best treatment for this?

....from internet

 What Is Articular Cartilage?

The matrix of cartilage is comprised of collagens, proteoglycans, and non-collagenous proteins. While cartilage is a highly-organized structure, about 85% of cartilage is water -- decreasing to about 70% in older people. Chondrocytes are the only cells found in cartilage. Chondrocytes produce and maintain the cartilage matrix.

Articular cartilage serves as the cushion and shock absorber within the joint as it lines the ends of the two bones that form the joint. Cartilage damage can be caused by several conditions including:

• joint injury
• avascular necrosis
• osteochondritis dissecans
• osteoarthritis
• rheumatoid arthritis

Joints affected by cartilage damage become painful, stiff, and have limited range of motion.

The enormous problem is that cartilage is unable to heal itself. Consequently, articular cartilage has become the focus of many researchers and tissue engineers who strive to be able to grow new cartilage and transplant it in place of damaged or worn cartilage.

Have Researchers Made Progress With Cartilage Regeneration?

Several techniques have been developed:

• debridement or abrasion - surgeon arthroscopically removes loose cartilage which causes bleeding at the bone surface and growth of fibrocartilage (fibrous cartilage or scar tissue) but the fibrocartilage may not be strong enough
• microfracture - surgeon arthroscopically clears the affected area and makes several perforations in the bone to stimulate bleeding and growth of fibrocartilage
• mosaicplasty or osteochondral autograft transplantation surgery - surgeon removes plug of bone with cartilage covering from healthy area of the joint and transplants it to the damaged area
• periosteal flap - surgeon removes a portion of the periosteum (connective tissue covering all bones) from shin and transplants it to the area of cartilage damage
• autologous chondrocyte implantation - surgeon arthroscopically removes small portion of cartilage from knee; tissue is sent to a lab to be cultured; second surgery required so lab-grown cells can be implanted at the site of the damaged cartilage
• osteochondral allografts - donor bone is used to repair the damaged cartilage

All of the procedures yield mixed results. There are still many questions that plague attempts at cartilage regeneration. More clinical trials are needed to find definitive answers and to develop procedures that relieve arthritis symptoms and produce a durable replacement for damaged cartilage.

What's the Latest Breakthrough for Cartilage Regeneration?

Bioengineers at Rice University have discovered that intense pressure (comparable to the pressure someone would feel more than half mile below the surface of the ocean) stimulates cartilage cells to grow new tissue -- and that new tissue possesses nearly all of the properties of natural cartilage.

The Musculoskeletal Bioengineering Laboratory at Rice University has studied cartilage for more than a decade. The combination of hydrostatic pressure and growth factors are used to produce the tissue that is strikingly similar to natural cartilage. The researchers believe this development holds promise for arthritis treatment. However, the process has only been tried with cells from cows and has not yet been tested on live animals. The lead researcher forewarns that it will be several years before the process would be ready for clinical testing in humans.

_Sources:

_{Cartilage regeneration '20,000 Leagues Under the Sea'. Rice University. June 4, 2008.
http://www.media.rice.edu/media/NewsBot.asp?MODE=VIEW&ID=11084&SnID=1357758714}

_{Cartilage Regeneration: An Overview. Hospital for Special Surgery. 6/4/2003.
http://www.hss.edu/conditions_14186.asp}

I would like to point out that the hypothesis I presented here is 100% my own.
There is not a single study known to me to support my hypothesis.
As a long time medical practitioner in cardiovascular disease and general internal medicine,
it was only natural for me to come up with this hypothesis after making the above observations.
I also want to mention that as director of cardiac catheterization laboratory for some 30 years,
cadiovascular physiology was my main interest.
Once I came up with this hypothesis years ago, I've been practicing this theory by exercizing
on my treadmill, starting with 3 MPH, increasing it by increments of 0.2 miles, all the way to 4.4 MPH,
then come back down to 3 MPH, then go back up again. I repeat this 3 to 4 times over a period of
30 minutes.
I've been instructing my patients and friends in a similar fashion and
have been observing with a great interest.
So far the results seem favorable.
So anybody who overuses their joints and back without doing a regular high level aerobic
exercises will experience varying degree of joint problems, spine problems and so on
predictably according to my theory.