This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Zhang, S. M. Articles by Hankinson, S. E. Search for Related Content PubMed PubMed Citation Articles by Zhang, S. M. Articles by Hankinson, S. E.

A Prospective Study of Plasma Total Cysteine and Risk of Breast Cancer

¹ Division of Preventive Medicine and ² Channing Laboratory, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts; Departments of ³ Epidemiology and ⁴ Nutrition, Harvard School of Public Health, Boston, Massachusetts; and ⁵ Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts

Cysteine is the precursor of glutathione, a powerful intracellular antioxidant and an important detoxifying agent of carcinogens. However, data relating plasma total cysteine to breast cancer risk are sparse. We conducted a prospective nested case-control study among 32,826 women in the Nurses’ Health Study who provided blood specimens during 1989–1990. Through 1996, a total of 712 incident breast cancer cases were identified and individually matched to 712 controls by year of birth, time of day that blood was drawn, fasting status, month of blood sampling, recent use of postmenopausal hormones at the time of blood collection, and menopausal status. Conditional logistic regression with adjustment for other risk factors for breast cancer was used to estimate the relative risks and 95% confidence intervals of breast cancer by levels of plasma total cysteine. Higher plasma total cysteine concentrations were significantly associated with a lower risk of breast cancer. For women in the highest quintile of plasma total cysteine, compared with those in the lowest quintile, the multivariate relative risk was 0.44 (95% confidence interval, 0.26–0.74). This association was dose dependent (P for trend = 0.002) and independent of plasma measures of folate, vitamin B₆, vitamin B₁₂, and total homocysteine. The inverse association between plasma total cysteine concentrations and risk of breast cancer was not significantly modified by other risk factors for breast cancer, except that a stronger association was observed among women who were leaner. The findings from this prospective study suggest that higher plasma concentrations of total cysteine predict a reduced risk of breast cancer. Cysteine or its precursors might have the potential to be chemopreventive against breast cancer.

This article has been cited by other articles:

				P. W. Parodi Dairy Product Consumption and the Risk of Breast Cancer J. Am. Coll. Nutr., December 1, 2005; 24(suppl_6): 556S - 568S. [Abstract] [Full Text] [PDF]