Running and Arthritis- Cartilage Supplements: Last month I reviewed some recent literature regarding running and arthritis.
Some of the hottest selling items in pharmacies and health food stores are
glucosamine and chondroitin sulfate. These are dietary supplements that are
touted as "chondroprotective and chondrorestorative". This means that
they may assist in the protection and repair of damaged joint cartilage. "Chondro-"
means cartilage. The gliding and sliding surfaces of the bones that make up the joints are
composed of cartilage. Cartilage is a soft and pliable, but resilient living
tissue that is like teflon. Cartilage is unique in that it is a highly
specialized material that is highly permeable, with extremely low friction.
Although there are many living cells in cartilage, called chondrocytes, there
are virtually no blood vessels, so these cells get nourishment from diffusion.
The living cells are immersed as islands of life within the cartilage substrate
that they have manufactured and extruded in the past. This substrate is like a
bridge road surface. There are long strands of "rebar" like filaments
woven amongst a sea of rubbery-plastic-like cement. It is as if the
cement-mixers that have poured the cement are stuck within their product.
Because of this architecture, highly specialized biology, and the lack of a
blood supply, traditional thought is that cartilage tissue has minimal, if any,
capacity for repair. As orthopedic surgeons, we are trained to consider that cartilage tissue has
NO INHERENT HEALING CAPACITY, unless the cartilage layer is worn or injured down
to the underlying bone, where the blood vessels are located. Conventional and
operative procedures have been designed to generate access to the blood supply,
and thus encourage healing by stimulation of reparative fibrocartilage, and
different type of "scar cartilage". Proponents of chondroitin and glucosamine nutritional supplements argue that
these natural cartilage building blocks not only help preserve this vital
tissue, but also help heal and restore joint cartilage. Claims by the producers
of these elements include: stimulation of the synthesis of cartilage cells and
joint lubricant (hyaluronic acid), inhibition of damaging enzymes, enhancement
of the blood supply of the joint tissue, and decrease in joint pain and
inflammation. Conventional medical treatment such as acetominophen and
anti-inflammatory drugs certainly cannot do all of these things. Studies based upon subjective reports of arthritic users, mostly from Europe
and Asia, have shown good pain relief and increased comfort after use of these
supplements. They are heavily marketed as anti-arthritic agents. Unfortunately,
objective data is lacking, especially in the U.S. In a recent review paper of
glucosamine sufate, the conclusion was that "there are no studies
supporting the use of this agent in the U.S. The studies published to date have
been done in small numbers of patients; adequate long-term trials examining the
safety, efficacy, and optimal dosage requirements of glucosamine sulfate are
lacking. Most of the available clinical data are difficult to interpret due to
serious deficiencies in study design."1 There is even less known about their use for patients with normal joints. The bottom line: although little objective hard evidence exists to
support the use of these cartilage supplements, it probably does not hurt to
take them. Understand that they may be effective only via a subjective placebo
effect. The only known risk at this time is to one's pocketbook. They are
expensive, and as over the counter preparations, insurance companies do not
routinely pay for them. I recommend that patients with known arthritic
conditions try them for two months without changing other management factors,
and if benefit is noted, then continue if desired. However, remember that
arthritis is at least in part a mechanical process, and as such, may benefit
from mechanical solutions as well. Reference: da Camara, C.C., Dowless, G.V. Glucosamine Sulfate for
Osteoarthritis. The Annals of Pharmacology. 1998; 32:
580-587.
Dan Wnorowski, M.D.