Sixty percent of patients with rheumatoid arthritis in Japan have used dietary supplements or health foods

We conducted a survey on the use of dietary supplements and health foods (DS/HF) in definite rheumatoid arthritis (RA) patients treated by RA specialists. Among 296 patients (male 48, female 248), 179 patients (60.5%) had experience of DS/HF use. Prevalence of DS/HF use was significantly higher in female than in male patients (63.7% versus 43.8%). Overall, patients who have used DS/HF were significantly younger than those who have not used; it was particularly notable in female patients. The proportion of current users was significantly higher in those less than 5 years from diagnosis than those who had been diagnosed for 5 years or more. Products of herbs or algae (44.1%) and components of cartilage (40.8%) were the most popular DS/HF. Primary sources of product information were family members or friends (56.4%) and advertisements in the mass media (34.1%). Of the users, 73.7% did not disclose DS/HF use to their physicians. The users expected alleviation of the symptoms (35.2%) and improvement of health (34.6%). However, 59.2% of the users were unsure of the benefits. In conclusion, physicians should be aware of the high prevalence of DS/HF usage in patients with RA in Japan.