Glucosamine

What is it?

Glucosamine is a naturally occurring compound formed from the addition of an amino acid to glucose. It is a substrate for the synthesis of many molecules in cartilage which are responsible for trapping and holding water within the cartilage which gives cartilage its compressible / cushioning properties.

In osteoarthritis, as cartilage cells are injured, lost or aged, they produce fewer of these molecules made from glucosamine and the overall water content decreases which reduces cartilage elasticity and renders it more susceptible to injury and abrasion.

How is it made?

Most commercial preparations are made from the exoskeletons of shellfish, so people with shellfish allergies should be cautious. A few varieties are made from insect skeletons and some mushrooms. If the preparation also contains chondroitin then this is usually made from the cartilage of bovine or calf trachea or shark cartilage.

What does it do?

Glucosamine has been reported to be of use in treating osteoarthritis by relieving joint pain and also by protecting the joint cartilage from further breakdown.

Does it work?

There have now been about 15 studies that support the benefits of glucosamine in the treatment of mild and moderate osteoarthritis. It is of less benefit in advanced osteoarthritis. It has been demonstrated to help with both pain relief and cartilage preservation in the joint as measured by joint space on x-ray. All these studies however have been sponsored by companies that make glucosamine.

What kind do I take?

All the studies have been done on glucosamine sulfate, however some preparations contain glucosamine hydrochloride. Research suggests that it does not matter whether glucosamine is bound to sulfate or hydrochloride as the active part of the molecule is the glucosamine and the molecule is broken down in the digestive tract to release the glucosamine for absorption.

There are many preparations available some of which may also contain chondroitin sulfate which is another cartilage building block. Chondroitin is less readily absorbed by the digestive tract and is more expensive. The combination has not been shown to be superior to glucosamine alone. Commercially available products include Osteoeze, Joint Formula, Joint Care etc.

How much do I take?

The recommended dose in most clinical trials is 1500mg daily. Usually this is one tablet 3 times per day with meals.

How long do I take it for?

It may take up to 6 weeks before you feel any benefit in terms of pain relief so it is recommended to trial it for at least 6-8 weeks. If it helps you then you are encouraged to think about taking it long term as it has shown cartilage preserving benefits with treatment up to 3 years.

Are there any side effects?

Overall there are very few side effects with glucosamine. Some people may experience nausea. Anyone with allergies to shellfish should avoid any preparations made from shellfish exoskeleton. Patients with diabetes should be monitored by their local doctor while taking glucosamine as it may increase blood sugar levels. If taking a preparation containing chondroitin, this may interfere with warfarin (coumarin) levels for those people taking warfarin.