Dietary Supplements for OsteoarthritisWhat Does the Research Really Show?
-- By Becky Hand, Licensed & Registered Dietitian
When cartilage that cushions your joints begins to breakdown faster than your body can replace it, you develop osteoarthritis. Without this protective tissue, the bones in your joints rub together, causing pain, tenderness, swelling and stiffness. Looking for a cure (or simple pain relief), many osteoarthritis sufferers seek help from the latest nutritional supplement. But before you waste your hard earned money (or put your health and safety on the line), it's important to find out what the research actually shows about these supplements.
Keep in mind that although the Food and Drug Administration (FDA) tightly regulates medications, it does not regulate dietary supplements, which can have little or no research to prove their safety or effectiveness. Always tell your doctor if you are taking any dietary supplements or if you are thinking about combining a dietary supplement with your conventional medical treatment. Supplement use may lead to overmedication and interactions, which have serious side effects. It may not be safe to forgo your conventional medical treatment and rely on dietary supplements alone. To avoid complications, talk to your physician first.
Glucosamine sulfate is a simple molecule. Your body makes it from sugar and then uses it as a major building block of cartilage. There have been over 20 studies conducted on glucosamine sulfate and osteoarthritis. Most of the studies used a brand called Dona by Rotta Pharmaceuticals. According to these studies, glucosamine sulfate:
- Reduces arthritic knee pain by 28% to 41% and improves knee function by 21% to 46%.
- Provides similar pain relief (slower acting, but longer lasting) to analgesics like ibuprofen, piroxicam and acetaminophen.
- May reduce the risk of osteoarthritis progression by 54% (1500 mg dosage).
- Does not have a significant effect on insulin resistance or blood glucose levels, making it safe for patients with diabetes.
- Is safe for people with shellfish allergies. Even though glucosamine is derived from the exoskeletons of shrimp, lobster, and crabs, there have been no documented allergic reactions, which are caused by eating the meat (not shells) of shellfish. <pagebreak>
Chondroitin sulfate is a molecule that gives cartilage its resistance and elasticity. According to preliminary studies, chondroitin sulfate:
- May improve osteoarthritis symptoms and slow its progression.
- Appears to more effectively reduce pain and improve function when taken with analgesics or non-steroidal, anti-inflammatory drugs (than analgesics or non-steroidal, anti-inflammatory drugs alone).
- May not be better than placebos, according to a recent study.
- Does not carry "mad cow" disease. Even though chondroitin sulfate is often derived from animal (cow and pig) tracheas, bovine trachea does not seem to carry this particular disease. While the risk is small, some people prefer not to use this product in favor of marine-derived (shark) sources of chondroitin sulfate.
SAMe (s-adenosylmethionine) is a compound produced in the body. Your liver makes it from the amino acid methionine, and it plays an essential role in the formation of hormones, neurotransmitters, and phospholipids. The preferred form of SAMe is the butanedisulfonate salt, which has the highest bioavailability and is more stable than the tosylate salt. Preliminary research indicates that SAMe:
- May help increase the production of cartilage cells and thickness.
- Is just as effective as anti-inflammatory pain killers in treating osteoarthritis, but has fewer side effects.
- May require up to 30 days of treatment before noticeable relief occurs.
- May not be safe for people taking medication for bipolar or depressive disorders. These individuals must watch for drug interactions, since SAMe can affect serotonin levels.
- Beta-carotene is the precursor to vitamin A, found in red, yellow, and orange fruits and vegetables and dark-green leafy vegetables. Beta-carotene supplements do not prevent osteoarthritis, but may slow the progression of the disease. Learn more about beta carotene by reading Foods that Fight Osteoarthritis.
- Vitamin C. Consuming vitamin C from foods seemed to reduce the risk of cartilage loss and disease progression. Learn more about vitamin C by reading Foods that Fight Osteoarthritis.
- Vitamin B-3. Vitamin B-3 is made up of niacin (nicotinic acid) and its amide, niacinamide, and can be found in yeast, meat, fish, milk, eggs, green vegetables, and cereal grains. A three-gram divided dosage of niacin and niacinamide seemed to improve joint flexibility and reduce inflammation of osteoarthritis when taken daily. <pagebreak>
- Bromelain is an enzyme with anti-inflammatory properties that is found in pineapple roots and stumps. When taken in combination with rutin and trypsin (see each below), it appears to reduce pain and improve knee function in patients with osteoarthritis.
- Camphor is a waxy, white substance that comes from the wood of large, Asian evergreen trees (called Camphor laurel). A topical cream containing camphor, glucosamine sulfate and chondroitin sulfate (see above) seems to reduce the severity of osteoarthritis symptoms by about half. Researchers believe that the counter-irritant effects of the camphor (not the other ingredients) cause this relief.
- Cat’s claw is a tropical vine that grows in rainforest and jungle areas. Taking a specific type of freeze-dried cat's claw appeared to relieve knee pain related to physical activity. It did not reduce knee swelling or decrease the pain when resting, however.
- Devil’s claw is a plant native to southern Africa. Taking it (alone or with anti-inflammatory drugs) seems to help decrease osteoarthritis pain.
- MSM (methylsulfonylmethane) is a naturally-occurring compound found (in small amounts) in fresh foods—fruits, vegetables, legumes, milk, eggs, fish, and grains. As foods are processed or heated, however, MSM is destroyed. In supplement form, MSM is usually derived from sulfur-rich plant or tree fibers. Some preliminary research suggests that MSM can modestly reduce some symptoms of osteoarthritis such as pain and swelling. MSM has not been shown to significantly reduce stiffness though.
- Rutin is a phytochemical found in buckwheat, citrus fruits, noni, black tea, and apple peels. When taken in combination with bromelain (see above) and trypsin (see below), it appears to reduce pain and improve knee function in patients with osteoarthritis.
- Superoxide dismutase (SOD) is a powerful, anti-inflammatory antioxidant that repairs cells and reduces the damage done by superoxide, the most common free radical in the body. SOD is found in most green plants, including barley grass, broccoli, Brussels sprouts, cabbage, and wheatgrass. The body needs plenty of vitamin C and copper to make this natural antioxidant Receiving SOD as an injection seemed to be an effective treatment for osteoarthritis. Animal research shows that when SOD is taken orally, the digestive system destroys it before it can repair damaged joints. There is no evidence to support the use of oral SOD supplements.
- Unsaponifiable avocado. (Unsaponifiables are components of oil, fat, or wax, that are not saponifiable—a chemical term used to describe a substance that can be mixed with lye to form soap. Unsaponifiable oil fractions cannot form soap and, like other “good” fats, have special health benefits when ingested.) Taking unsaponifiable fractions of avocado (in the form of a supplement) appears to significantly reduce the pain associated with osteoarthritis and stimulate cartilage repair. It seems to be most effective for hip pain.
- Unsaponifiable soybean oil. Taking unsaponifiable (see definition above) fractions of soybean oil appears to significantly lessen the pain associated with osteoarthritis and stimulate cartilage repair. It seems to be most effective for hip pain.
- Bovine cartilage is taken from the windpipe and trachea of cows. When the cartilage was administered subcutaneously in animal studies, it helped reduce the symptoms of osteoarthritis, but additional human studies are needed to prove safety and effectiveness.
- Hyaluronic acid is an anti-inflammatory substance found in the connective tissue of the body that cushions and lubricates. The hyaluronic acid in supplements usually comes from bacterial fermentation—not animal sources. The FDA has approved an intraarticular (directly into the joints) injection for osteoarthritis treatment. Its effectiveness has varied, and long-term results are still unknown.
- Trypsin is a naturally-occurring enzyme with anti-inflammatory properties that is made by the pancreas. In supplement form, it usually comes from an animal (bovine) pancreas. When taken in combination with bromelain and rutin (see each above), it seemed to reduce pain and improve knee function in patients with osteoarthritis. <pagebreak>
- Bee venom. Although early research indicated it may possibly benefit osteoarthritis, bee venom results are conflicting and most studies show no benefit.
- Cod liver oil. Taking cod liver oil with anti-inflammatory drugs has not been shown to decrease osteoarthritis pain or inflammation.
- Vitamin E has not been proven to decrease symptoms (pain and stiffness), slow cartilage loss or reduce the risk for development of osteoarthritis.
- Glucosamine hydrochloride
- Indian frankincense
- New Zealand green-lipped mussel
- Pantothenic acid (vitamin B-5)
- Shark cartilage
- Stinging nettle
- Willow bark