Certain food supplements for joint pain should be avoided by at-risk populations

Glucosamine and chondroitin sulfate are molecules naturally present in the connective and cartilage tissues of our body, and ensure, among other things, the structure and elasticity of cartilage, tendons and skin. These two compounds are marketed in most European countries as medications and food supplements. In France, many food supplements containing glucosamine and/or chondroitin sulfate claiming to contribute to joint comfort are available on the market.

Reported adverse reactions

Adverse reactions related to the consumption of these food supplements have been reported to ANSES in the framework of its nutrivigilance system. The effects reported are highly diverse: digestive disorders, abdominal pain, skin rashes, itching, hepatitis or purpura (lesions caused by bleeding beneath the skin ).

ANSES conducted an expert assessment to identify the potential risks associated with the consumption of food supplements containing glucosamine and/or chondroitin sulfate, based on adverse reaction reports received through the nutrivigilance scheme. The experts also reviewed reports filed in other countries (Europe, Canada and the United States) and carried out an in-depth analysis of the scientific literature.

Identified at-risk populations

The expert assessment identified specific populations for whom the consumption of food supplements containing glucosamine or chondroitin sulfate presents a risk. The following population groups should not consume such products:

• diabetic or pre-diabetic individuals, as well as those who are asthmatic or are treated with vitamin K antagonists (VKA);
• people with a food allergy to crustaceans or insects (glucosamine-based food supplements only);
• people on sodium, potassium or calcium-restricted diets, as these supplements can be an important source of these elements;
• pregnant or breastfeeding women, as well as children, due to insufficient data on the safety of these products.

In addition, ANSES recommends that measures be taken by manufacturers to better inform consumers about the risks associated with the consumption of these food supplements by these specific populations.

Finally, ANSES considers it necessary that the maximum authorised daily doses of glucosamine and chondroitin sulfate in food supplements be standardised at European level based on safety data from robust safety studies - currently lacking - for these two compounds.

Moreover, ANSES wishes to reiterate its general recommendations on the consumption of food supplements and the reporting of adverse reactions. 

For consumers:

• seek the advice of a doctor when consuming food supplements;
• avoid multiple intakes of an ingredient from several sources (food supplements, medications, etc.);
• avoid the concomitant consumption of several different food supplements;
• favour the consumption of food supplements with simple formulations;
• favour supply channels monitored by public authorities;
• report your consumption of food supplements to your doctor or pharmacist.

For health professionals:

• ask patients about their consumption of food supplements, particularly if biological abnormalities or clinical manifestations of undetermined origin are detected;
• report to the nutrivigilance scheme any adverse reactions likely to be related to the consumption of food supplements of which they are aware.

For food supplement manufacturers:

• report to the nutrivigilance scheme any adverse reactions likely to be related to the consumption of food supplements of which they are aware.