Vitamin C and the risk of developing inflammatory polyarthritis: prospective nested case-control study
- D J Pattison1,
- A J Silman1,
- N J Goodson1,
- M Lunt1,
- D Bunn2,
- R Luben3,
- A Welch3,
- S Bingham4,
- K-T Khaw3,
- N Day3,
- D P M Symmons1
- 1Arthritis Research Campaign (arc) Epidemiology Unit, University of Manchester, Oxford Road, Manchester M13 9PT, UK
- 2Norfolk Arthritis Register, Norfolk & Norwich University Hospital, Colney Lane, Norwich NR4 7UZ, UK
- 3Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge School of Clinical Medicine, Cambridge, UK
- 4MRC Dunn Human Nutrition Unit, Welcome Trust/MRC Building, Hills Road, Cambridge CB2 2XY, UK
- Correspondence to:
Professor D Symmons
Arthritis Research Campaign (arc) Epidemiology Unit, University of Manchester, Oxford Road, Manchester M13 9PT, UK;
- Accepted 1 December 2003
Objective: To investigate whether, there is an association between consumption of fruit and vegetables and dietary antioxidants and the risk of developing inflammatory polyarthritis (IP).
Methods: In a prospective, population based, nested case-control study of residents of Norfolk, UK, men and women aged 45–74 years were recruited, between 1993 and 1997 through general practice age-sex registers to the Norfolk arm of the European Prospective Investigation of Cancer (EPIC-Norfolk). Dietary intake was assessed at baseline using 7 day diet diaries. Seventy three participants who went on to develop IP between 1993 and 2001 and were registered by the Norfolk Arthritis Register (NOAR) were identified. Incident cases of IP, assessed by general practitioners, fulfilled the criteria of two or more swollen joints, persisting for a minimum of 4 weeks. Each case of IP was matched for age and sex with two controls free of IP.
Results: Lower intakes of fruit and vegetables, and vitamin C were associated with an increased risk of developing IP. Those in the lowest category of vitamin C intake, compared with the highest, increased their risk of developing IP more than threefold, adjusted odds ratio (OR) with 95% confidence intervals (CI) 3.3 (95% CI 1.4 to 7.9). Weak inverse associations between vitamin E and β-carotene intake and IP risk were found.
Conclusion: Patients with IP (cases) consumed less fruit and vitamin C than matched controls, which appeared to increase their risk of developing IP. The mechanism for this effect is uncertain. Thus similar studies are necessary to confirm these results.
- ACR, American College of Rheumatology
- BMI, body mass index
- EPIC-Norfolk, Norfolk arm of the European Prospective Investigation of Cancer
- IP, inflammatory polyarthritis
- NOAR, Norfolk Arthritis Register
- RA, rheumatoid arthritis
- RNI, UK Reference Nutrient Intake