The basic rule underlying all muscular growth is that you must in some way apply stress to a muscle, which then adapts to that stress by getting bigger and stronger. Just as drugs have side effects, though, so does heavy and intense exercise. The side effects of exercise can vary and are often grouped under the heading of overtraining. The mere act of lifting weights heavy enough to stimulate muscle growth takes a toll on connective tissue and joint structures. It’s a cumulative process, which explains why nearly everyone who lifts weights regularly for years eventually experiences sore and inflamed joint structures.
Unlike muscle, joint structures get a poor blood supply and so don’t heal as fast as muscle. While maintaining proper exercise form goes a long way toward preventing common training injuries, certain nutritional supplements may also aid the preventive process considerably.
Glucosamine-chondroitin combinations are the most familiar supplements for joints. They’re often suggested as a natural, safe way to lessen the nagging pain of arthritis, but they and other supplements may also help prevent degenerative joint diseases like arthritis by supplying essential building blocks of joints. As we age, our bodies don’t produce the building blocks of joints and connective tissue as readily, so anything that can promote their activity should help stave off joint pain and inflammation.
While glucosamine and chondroitin get all the publicity, many other natural substances work synergistically with them. In some cases they may work for people who don’t get much benefit from glucosamine and chondroitin. Here’s a look at the newest research on how to protect your joints and connective tissue with nutritional supplements.
The body produces glucosamine naturally from the amino acid glutamine and the sugar glucose. It’s incorporated into larger molecules called glycosaminoglycans (GAGs), which, in turn, are major building blocks for bones, ligaments, tendons and the synovial fluid that lubricates joint linings. Studies that have used special tracer substances to follow the route of glucosamine in the body show that it’s preferentially incorporated into GAGs, which then stimulates proteoglycan synthesis.
Proteoglycans, which contain glucosamine, form the structural matrix of joints and connective tissue; in effect, they are the bricks that form the foundation of joint structures.
Glucosamine also exerts anti-inflammatory activity, which helps to heal injured joints and connective tissue. The majority of studies that have examined glucosamine’s efficiency show that it appears to work as advertised. One study that examined past studies on the subject concluded that while there were methodological problems with many of the studies, glucosamine did appear to have beneficial effects.1
In another recent long-term study, in which subjects took glucosamine for three years, it was effective in slowing the progression of knee arthritis in 202 patients.2 Subjects took either 2,000 milligrams of glucosamine or a placebo for 12 weeks, and those taking the glucosamine experienced less knee pain. Specifically, 88 percent of those taking the genuine glucosamine felt pain relief, while only 17 percent of those getting the inert substance expressed the same feelings.
Several controversies exist about the therapeutic use of glucosamine. For example, supplemental glucosamine is extracted from chitin, which is the cartilage of shellfish, so people who are sensitive to shellfish must use caution. On the other hand, some supplemental forms of glucosamine are entirely synthetic, which circumvents the problem.
Glucosamine supplements come in several forms, such as glucosamine sulfate and glucosamine hydrochloride. Most studies have used the sulfate form, and there’s a theory that a major benefit of glucosamine and chondroitin is that they both supply sulfate, which the body needs for connective tissue synthesis. That theory, however, seems moot to most bodybuilders, who get plenty of sulfur-containing amino acids, such as cysteine and methionine, as part of their high-protein diets.
More problematic is that glucosamine is unstable, breaking down readily even in water. That’s the reason it’s complexed with other material, such as sulfate. What’s more, glucosamine sulfate contains about 30 percent sodium, not enough to cause water retention but a possible consideration for those watching their sodium intake.
Still another problem with glucosamine is the purity and potency of supplements. A recent Consumer Reports survey showed that 90 percent of tested glucosamine supplements did match label values. Another study, however, found that glucosamine content varied from 41 percent to 108 percent of stated label values among products, with the actual glucosamine content varying from 59 to 138 percent.3 A similar scenario occurred when University of Maryland investigators analyzed 23 brands of glucosamine, finding that many didn’t match label content.
Recent alarming reports have warned about glucosamine causing insulin resistance, which has to do with the way it increases the activity of a biochemical pathway in the body called the hexosamine-phosphate pathway. But those studies used injectable forms of glucosamine, which cause far higher blood levels than is ever reached with oral versions. Animal-based studies also used excessively high doses. Nevertheless, a recent study in which human subjects received injectable glucosamine failed to show any problems with insulin sensitivity.
One thing to keep in mind about glucosamine or any joint nutrient is that they take time to work. Although glucosamine works by providing raw material the body needs to build joints, there’s still the problem of the poor blood supplies that joints and connective tissues get. Just as buildings aren’t built in a day (most, anyway), so it goes with joint structures. Poor blood supplies are also the reason that joint and connective-tissue injuries have a longer healing time. It takes at least two months for joint nutrients to affect healing.
Some recent research shows a few surprising effects of glucosamine not connected to its joint-healing powers. One found that it appeared to help alleviate the pain of migraine headaches,4 while a case study found that it may have prevented the formation of scar tissue around a woman’s breast implants, a common side effect.5 The suggested dose of glucosamine is 1,500 milligrams daily in divided doses.
Although glucosamine is often sold in combination with chondroitin, there’s no evidence that combining them offers superior results to using either supplement separately. Chondroitin sulfate (CS) works similarly to glucosamine, but it’s not nearly as absorbable. While glucosamine shows about 90 percent uptake in humans, that figure drops to a mere 0 to 13 percent for CS. It has to do with molecular size: CS is about 250 times the size of glucosamine, so it’s difficult for the body to absorb.
On the other hand, studies show that even if the chondroitin sulfate is broken down in the gut, it still supplies raw material needed for joint maintenance and repair. Newer forms of CS that are specially manipulated to have lower molecular weights are absorbed to a greater degree than the usual CS supplements. Most CS supplements are made from cow trachea.
The theory of how chondroitin sulfate works is that it may block enzymes known to degrade cartilage while also increasing the fluid contents of inner joint structures. Despite its apparent low absorption characteristics, CS may work as well or better than the more highly touted glucosamine, according to the results of a few recent studies. The usual recommended dose is 1,200 milligrams a day.
Other Joint Nutrients
Several other nutritional remedies are available for treating sore or injured joints and connective tissue. Many of them work primarily by inhibiting the formation of inflammatory substances, such as certain eicosanoids, that delay healing and promote pain. In that respect these natural substances mimic the effect of expensive prescription drugs, such as COX-2 inhibitors, which are often used to treat joint pain. The problem with such drugs, however’in addition to their exorbitant expense’is their side effects, particularly involving kidney function, and they do nothing to help heal injured joints. The natural substances may promote healing, and unlike drugs, they have few or no side effects.
The following are some capsule profiles of these lesser known but highly effective joint nutrients:
‘ S-adenosylmethionine (SAMe). SAMe provides labile methyl groups needed for the formation of cartilage proteoglycans. It functions as a building block of joints and connective tissue. SAMe has been available by prescription in Europe since 1975, where it’s used to treat a variety of ills ranging from fibromyalgia to depression to arthritis. Some studies show that SAMe is an effective pain reliever, comparable to drug versions, with fewer or no side effects.
As a methyl donor, SAMe plays a pivotal role in the synthesis of a host of vital body chemicals, including creatine, melatonin and glutathione. SAMe also offers liver protective effects. As an antidepressant, it works faster than most prescription drugs. The primary drawback is that it’s expensive, since doses used to treat joint problems are 1,200 milligrams a day.
‘Cetyl myristoleate (CM). CM is a combination of cetyl alcohol and a monounsaturated fatty acid called myristoleic acid. It was discovered when experiments with a certain type of rat showed the animal to be highly resistant to experimentally induced arthritis. The rats also produced high levels of CM. When scientists gave CM to other types of rats, they also showed a markedly decreased incidence of arthritis symptoms. A recent study involving mice confirmed those findings; in this case 20-milligrams-per-kilogram-of-bodyweight doses led to a small reduction in arthritic symptoms.6
CM’s effects on joints involve a reduction in the synthesis of various inflammatory mediators, such as prostaglandins and leukotrines. Unfortunately, CM is another expensive supplement, and there’s just not enough human-based research to prove that it works. On the other hand, we know without question that fatty acids affect the production of substances that cause inflammation in the body. For example, an excess of omega-6 fatty acids, which are found in vegetable oils, promotes the synthesis of various inflammatory substances that delay healing and cause pain. Omega-3 fatty acids, which are found in fish oils, have an opposite effect’they reduce inflammation and promote healing.
‘Boswellia. The Boswellia tree, native to India, produces a sap that’s long been used in traditional Indian medicine to treat inflammation. Effective supplements are made up of at least 65 percent boswellic acids, which are the active ingredient. The typical total daily dose is 1,200 milligrams.
Boswellia works best when combined with turmeric, a popular Indian herb. Curcumin, the active ingredient in turmeric, offers many valuable health benefits. A recent study showed that a combination of boswellia and curcumin alleviated the pain of knee osteoarthritis better than the prescription drug diclofenac.7
‘Methylsulfonylmethane (MSM). This is the oral version of a topical joint treatment popular about 25 years ago, DMSO. Unlike the latter, however, MSM doesn’t cause you to smell like garlic. MSM is a good source of sulfur, which, as noted, is vital for joint synthesis and maintenance. MSM is totally nontoxic. The suggested dose is two to five grams a day.
‘Hydrolyzed collagen. Better known as gelatin, this form of collagen is thought to work by providing amino acids used in the synthesis of collagen, the primary structural protein of connective tissue. Like other joint nutrients, hydrolyzed collagen takes at least two months to work. The usual dose is 10 grams daily.
‘Devil’s claw. Although it sounds like something out of a Stephen King novel, devil’s claw is an herb touted to treat joint pain. Its active ingredient is a substance called harpagoside. One study showed that devil’s claw had anti-inflammatory activity comparable to the potent anti-inflammatory drug phenylbutazone. Peculiarly, it appears to be especially effective for treating lower-back pain. The suggested dose range is 600 to 6,000 milligrams daily of an extract standardized for 1 to 3 percent harpagoside content.
‘Green-lipped mussel. This sea extract contains natural forms of chondroitin and other GAGs. Typical doses are 500 to 3,000 milligrams daily in divided doses. Sea cucumber works in a similar manner, with a dose range of 500 to 2,000 milligrams a day.
‘Milk protein. Some specialized supplements containing milk-powder extracts derived from hyperimmunized cows may offer some joint pain relief.8 They contain concentrated natural anti-inflammatory substances derived from milk. Preliminary studies showed that people who got 2,000 milligrams twice a day of them had less joint pain, stiffness and immobility.
‘Antioxidants. Various flavonoids and antioxidant nutrients, such as the minerals manganese and zinc, aid in joint protection and repair by blunting the inflammatory effects of free radicals in joint compartments and acting as coenzyme factors in joint repair processes. Some recent studies show that green tea, which contains potent antioxidants, may help prevent arthritis.9
‘Boron. This trace mineral was touted a few years ago as a natural way to increase testosterone. It did’in older women. For anyone else it failed in that regard, but it’s also involved in joint and bone metabolism. Studies show that in parts of the world where people get one milligram or less of boron a day, the incidence of arthritis is 20 to 70 percent. In areas where they get three to 10 milligrams a day, it’s 0 to 10 percent. It’s easy to get your daily dose of boron by eating various types of fruits. Suggested doses run from three to five milligrams a day.
Finally, although testosterone is not a nutritional tool, a recent study showed that having optimal levels of it appears to maintain knee cartilage volume in healthy men.10
1 McAlindon, T.E., et al. (2000). Glucosamine and chondroitin for treatment of osteoarthritis: a systematic quality assessment and meta-analysis. JAMA. 283:1469-75.
2 Pavelka, K., et al. (2002). Glucosamine sulfate use and delay of progression of knee arthritis. Arch Intern Med. 162:2113-2123.
3 Russell, A.S., et al. (2002). Active ingredient consistency of commercially available glucosamine sulfate products. J Rheumatol. 29:2407-09.
4 Russell, A.L., et al. (2000). Glucosamine for migraine prophylaxis. Med Hypotheses. 55:195.
5 Skillman, J.M., et al. (2002). Incidental improvement of breast capsular contracture following treatment of arthritis with glucosamine and chondroitin. Brit J Plastic Surg. 55:454.
6 Hunter, K.W., et al. (2003). Synthesis of cetyl myristoleate and evaluation of its therapeutic efficiency in a murine model of collagen-induced arthritis. Pharmaceut Res. 47:43-47.
7 Badria, F.A., et al. (2003). Boswellia-curcumin preparation for treating knee osteoarthritis. Alternative and Comp Ther Dec. 341-348.
8 Zenk, J.L., et al. (2002). The effects of milk protein concentrate on the symptoms of osteoarthritis in adults: an exploratory, randomized, double-blind, placebo-controlled study. Curr Therap Res. 63:430-442.
9 Haqqi, T.M., et al. (1999). Prevention of collagen-induced arthritis in mice by a polyphenolic fraction from green tea. Proc Natl Acad Sci USA. 96:4524-29.
10 Cicuttini, E.M., et al. (2003). Factors affecting knee cartilage in healthy men. Rheumatology. 42:258-262. IM