( 11 June 2015 )

Glucosamine is a natural compound found in healthy cartilage. It's an amino-sugar or amino-monosaccharide, and everybody has some in their body.

We need glucosamine to keep making synovial fluid, which lubricates joints and keeps cartilage healthy. Ageing cuts down the amount of glucosamine our bodies can make.

Cartilage undergoes a constant process of breakdown and repair. Ideally glucosamine should be available to keep it healthy. If glucosamine levels fall too low, the cartilage in the weight-bearing joints (hips, knees, wrists) deteriorates. You suffer pain; movement is limited and joints may become deformed: this is osteoarthritis.

Where do you get glucosamine?

There isn’t much glucosamine in the normal diet, so if you want to increase your intake, supplements are the only answer. They are mostly made from animal tissue, usually the shells of crab, lobster or shrimp. Some is made from fungal fermentation of corn.

When taken as a supplement almost 90% of glucosamine is absorbed from the gut. The liver rapidly breaks down any not used in the cartilage repair process.

Actions of glucosamine

It is used mainly to combat the symptoms of painful joints and osteoarthritis. The basis of glucosamine’s action is that it provides more of the building blocks to repair cartilage. It keeps more moisture in, reduces inflammation, and may inhibit the enzymes involved in cartilage breakdown. Glucosamine can therefore prevent cartilage destruction.

Too little glucosamine

Lack of glucosamine is a factor in developing osteoarthritis with associated pain and movement limitation.

Too much glucosamine

Side effects may include intestinal gas and softened stools; high doses may cause nausea, diarrhoea, indigestion and heartburn. Taking glucosamine with meals seems to help overcome such problems.

No serious side effects have come to light despite the many studies done on glucosamine. However, there are several concerns that may or may not prove a problem. The first is possible allergic reactions because of its source being shellfish. If you are allergic to shellfish, you may wish to avoid it. But, the allergenic part of shellfish is usually the flesh and not the shell. Finding an alternative glucosamine source (plant-based or synthetic) would be the answer.

A second possible problem is if you have diabetes. Since glucosamine is a form of sugar (an amino-sugar related to glucose) it might affect blood sugar levels. Tests have not found any evidence that this is a practical concern. If you are concerned it may be necessary to do more frequent checks of your blood sugar levels while taking glucosamine. Talk to your doctor or health professional first.

One study has suggested glucosamine could make asthma symptoms worse but more research is needed to confirm this.

Glucosamine supplements

The only way to increase the amount of glucosamine in your body is to take a suitable supplement.

A typical dose of glucosamine is 1,500mg per day taken as a single dose or split into two or three separate doses taken through the day.

Supplements come as tablets, capsules, soluble tablets and liquid. As a rule, liquid forms are absorbed more quickly than tables or capsules and therefore will act more quickly.

There is currently no evidence to show that glucosamine can get through the skin, so avoid creams and ointments. Massaging a painful joint with oil is just as effective without the expense.

Average times for glucosamine to have its effect are at least three to four weeks and perhaps up to 12 weeks. One trial found almost 90% of patients reported some improvement after 12 weeks. Manufacturers of liquid forms claim these can be effective in as little as one or two weeks, four at most.

Supplements can be of glucosamine alone or in combination with chondroitin. Chondroitin works synergistically with glucosamine to improve damaged cartilage and improve the flow of fluid to add resilience to cartilage and improve joint flexibility. (Synergistically means they work together to give you additional benefits – better then each taken alone.)

Good quality supplements of glucosamine preparations tend to be expensive due to the costs of production. Get the best you can afford.

In some clinical trials, glucosamine has been found to be at least as effective as ibuprofen in reducing joint pain, without the side effects!

Research shows glucosamine helps reduce the pain in four out of five people suffering joint pain. Evidence continues to mount that glucosamine has a positive role in the management of osteoarthritis. It is safe and well tolerated.

Glucosamine products can also contain one or more of omega-3 fatty acids, manganese, aloe vera, vitamins C, A, and E, MSM (methyl-sulphonyl-methane) and various herbs, all of which are supposed to help improve joint pain.

The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.