Cartilage is a type of tough, flexible connective tissue that forms parts of the skeleton in many animals. Cartilage contains cells called chondrocytes, which are surrounded by collagen (a fibrous protein) and proteoglycans, which are made of protein and carbohydrate.
It was once believed that sharks, whose skeletons are made mostly from cartilage, do not develop cancer. This caused interest in cartilage as a possible treatment for cancer. Although malignant tumours are rare in sharks, cancers have been found in these animals.
A History of the Medical Use of Bovine and Shark Cartilage
- It was first reported that bovine cartilage decreased inflammation (redness, swelling, pain, and feeling of heat) in the 1960s;
- In the 1970s, it was found that bovine cartilage contains a substance that blocks angiogenesis (the forming of new blood vessels). If blood vessel growth into a tumour can be blocked, the tumour will stop growing or shrink.
- By the 1980s, laboratory and animal studies as well as clinical trials (research studies in people) testing bovine cartilage as a treatment for cancer were being conducted.
Interest in using shark cartilage grew because it was believed that shark cartilage may be more active than bovine cartilage in preventing new blood vessels from being formed. Since a shark’s skeleton is made mostly of cartilage, shark cartilage is more plentiful than bovine cartilage.
- It was first published that shark cartilage contains a substance that blocks blood vessel growth in the 1980s
- Reports of clinical trials of shark cartilage as a treatment for cancer were published between 1998 and 2005
Cartilage Therapy as a Complementary Therapy
Cartilage from cows (bovine cartilage) and sharks have been studied as a treatment for people with cancer and other medical conditions for more than 30 years.
There are three theories as to how cartilage acts against cancer: As cartilage is broken down by the body, it releases products that kill cancer cells. Cartilage increases the action of the body’s immune system to kill cancer cells.
Cartilage makes substances that block tumour angiogenesis (the growth of new blood vessels that feed a tumour and help it grow).
Laboratory and animal studies show that because cartilage does not contain blood vessels, cancer cannot easily grow in it.
It is suggested that a cancer treatment using cartilage may keep blood vessels from forming in a tumour, causing the tumour to stop growing or even to shrink.
Research on Bovine and Shark Cartilage
Several Pre-clinical Studies as well as Clinical Trials have been done with cartilage and published in scientific journals:
Preclinical (Laboratory or Animal) Studies
The following have been reported from pre-clinical studies of the effect of powdered cartilage on cancer cells in vitro (outside of the body):
In a published laboratory study, a powdered form of bovine cartilage called Catrix slowed the growth of human cancer cells by half or more.
It is not clear if Catrix had this effect only on cancer cells, because its effect the growth of normal cells was not tested. It is also not known if the dose used in the laboratory study could safely be used in people.
In a published laboratory study of powdered shark cartilage, there was no effect on the growth of human astrocytoma cells (cancer cells that begin in the brain or spinal cord).
Powdered shark cartilage given by mouth to rats decreased the growth of gliosarcomas, a type of brain cancer.
Three substances that prevent blood vessel growth were found in bovine cartilage. These substances have not shown an effect on the growth of normal cells or tumour cells.
Two substances that prevent blood vessel growth were found in shark cartilage. These substances have not shown an effect on the growth of normal cells or tumour cells.
The following have been reported from preclinical studies of liquid cartilage products:
- Several studies have shown that AE-941/Neovastat blocks the growth of new blood vessels.
- AE-941/Neovastat given by mouth to mice slowed the growth of breast cancer cells and the spread of lung cancer. In the lung cancer study, AE-941/Neovastat increased the effect of the anticancer drug cisplatin.
- A substance made from human cartilage slowed the spread of pancreatic cancer cells in an animal study and prevented blood vessel growth in both animal and laboratory studies.
Clinical Trials (Research Studies with People)
There has been one randomised clinical trial of cartilage as cancer treatment published in a peer-reviewed scientific journal. This trial compared treatment using a form of shark cartilage to treatment using a placebo (an inactive substance that looks the same as, and is given the same way as, the substance being tested). Patients also received standard care. In 83 patients having either advanced breast or advanced colon cancer, there was no difference in the quality of life or survival rate between the group that received the shark cartilage product and the group that received the placebo.
The following have been reported from clinical trials of powdered cartilage products:
Case series (a collection of detailed information about individual patients) of 31 patients who were treated with Catrix by injection and/or by mouth: The cancer went into remission (signs and symptoms of cancer went away) in 19 patients and then recurred (came back) in about half of them.
Some of these patients also received standard cancer treatment and there was no control group (a group of patients who do not receive the treatment being studied, to show if the treatment being studied makes a difference).
For these reasons, the effectiveness of cartilage as a cancer treatment is not proven by this case series.
A clinical trial of Cartilade by mouth in 60 patients with advanced cancer: All but 1 patient had been treated with standard therapy before the trial. The cancer stopped growing in 10 of the patients for 12 weeks or more and then began to grow again. The cancer did not shrink or go into remission in any of the patients.
The following have been reported from clinical trials of liquid cartilage products:
A clinical trial of Catrix in 9 patients whose cancers did not respond to radiation therapy and/or chemotherapy: Catrix was given by injection. One patient’s cancer went into remission for more than 39 weeks and the other 8 patients did not respond to treatment with Catrix.
A randomised clinical trial studied the effect of AE-941/Neovastat on blood vessel growth related to wound healing after surgery. This study reported that one of the ingredients that prevent blood vessel growth can be absorbed and used by the body when taken by mouth.
A clinical trial of oral AE-941/Neovastat in 379 patients with advanced non-small cell lung cancer reported that there was no difference in how long patients lived between the group receiving the shark cartilage product and chemoradiotherapy compared to the group receiving the placebo and chemoradiotherapy. Both kinds of treatment were well tolerated.
How is Cartilage Administered?
In studies with people, cartilage products have been given by mouth; applied to the skin; injected under the skin; or given by enema (injected as a liquid into the rectum).
The dose and length of time the cartilage treatment was given was different for each study, in part because different types of products were used.
Side Effects or Risks
The side effects of cartilage treatment are usually mild or moderate.
The most common side effects of treatment with the bovine cartilage product Catrix include the following:
- Inflammation at the injection location.
- A bad taste in the mouth.
- Feeling very tired.
- Upset stomach.
- Feeling dizzy.
- Swelling of the scrotum (the sac that contains the testicles).
The most common side effects of treatment with the shark cartilage include the following:
- Abdominal cramps and/or bloating.
- Lower than normal blood pressure.
- Higher than normal blood sugar.
- General weakness.
- A higher than normal level of calcium in the blood.
Nausea, vomiting, and upset stomach are the side effects reported most often from treatment with the shark cartilage product AE–941/Neovastat.
Please note that the Little Fighters Cancer Trust shares information regarding various types of cancer treatments on this blog merely for informational use. LFCT does not endorse or promote any specific cancer treatments – we believe that the public should be informed but that the option is theirs to take as to what treatments are to be used.
Always consult your medical practitioner prior to taking any other medication, natural or otherwise.