Breastfeeding Shields Mom from Arthritis (cont.)
Upon analyzing the data, adjusting for variables such age and cigarette smoking, the researchers noted several interesting trends. One of the strongest was a decreasing risk of RA with increasing duration for breastfeeding. Looking at total lifetime breastfeeding, regardless of number of children, women who had breast-fed for between 13 and 23 months had a 20 percent reduction in the risk of RA compared with women who did not breastfeed. Women who had breast-fed for at least 24 months - two full years out of their childbearing years - increased their risk reduction to 50 percent. "Our data suggest breast-feeding confers long lasting protection against developing RA," Dr. Karlson states, "because the mean time since the last pregnancy among women with RA was 25 years." In addition, women who experienced irregular menstrual cycles between the ages of 20 and 35 were shown to have an increased risk of subsequent RA. Women who had begun menstruating at an early age, 10 or younger, were more likely to develop seropositive RA. The study's results did not show any association between a history of oral contraceptive use and disease risk, or any significant differences in disease risk related to a woman's number of pregnancies.
Focusing on the sample of RA patients, compared to women who did not develop RA, the researchers confirmed that the risk of RA increases with age and demonstrated a peak risk at the typical time of menopause, age 50 to 54. Because the onset of RA often coincides with menopause, some studies have linked the disease to falling estrogen levels, indicating the potential benefits of estrogen therapy. In this study, however, estrogen therapy among postmenopausal women did not protect against RA. "These findings suggest avenues for further research into the hormonal mechanisms involved in RA, because the complex relationships between RA and reproductive hormones clearly warrant further study," Dr. Karlson concludes.
Source: Wiley & Sons Press Release November 4, 2004
Last Editorial Review: 11/4/2004