These studies explore the potentially protective effect of breastfeeding on the development of rheumatoid arthritis.
Breastfeeding and risk of Rheumatoid Arthritis: A systematic Review and Metaanalysis
The aim of this study was to perform a metaanalysis to clarify the effect of breastfeeding on RA risk. This metaanalysis suggests that breastfeeding is associated with a lower risk of RA, whether breastfeeding duration is longer or shorter than 12 months.
Breastfeeding and Rheumatoid Arthritis, Pikwer 2008
A new study has suggested that women who breastfeed may reduce their risk of developing rheumatoid arthritis by half. Sweden’s Malmo University Hospital compared 136 women with the condition with 544 who did not have it. Women who had breastfed for 13 months or longer were half as likely to develop rheumatoid arthritis as those who had never breastfed. Those who breastfed for between one and 12 months had a 25 per cent decreased risk. No protective effect was noted from simply having children and not breastfeeding, or from taking oral contraceptives.
Breastfeeding and Rheumatoid Arthritis, Karlson 2004
A study of reproductive and hormonal risk factors for rheumatoid arthritis (RA) in a cohort of 121,700 women has found a strong trend for decreasing risk of RA with increasing duration of breast-feeding (P for trend = 0.001). Women who had a total lifetime history of breastfeeding of at least 24 months were half as likely to develop RA as parous women who did not breastfeed (RR=0.5 (95% CI 0.3-0.8). This effect was dose-dependent, with a significant trend toward lower risk with longer duration of breastfeeding.
Breastfedding and Rheumtoid Arthritis, Brun 1995
This study found that total time of lactation was associated with a decreased mortality of rheumatoid arthritis (RA), with an approximate dose-response relationship. The results did not support a role of parity, age at first and last birth, or age at menarche and menopause in the development of RA. The authors note that, since this protective effect of lactation on the development of RA has not previously been described, and since a definite biological explanation is lacking, the association should be confirmed in other populations.
Brun JG, Nilssen S, Kvale G (1995) Breast feeding, other reproductive factors and rheumatoid arthritis. A prospective study. Br J Rheumatol 34: 542-6 [Abstract]