Smoking, cereal consumption, and supplementation affect cadmium content in breast milk

Breast milk might be a source of potentially toxic metals such as cadmium (Cd). The purpose of the present study is to provide data pertaining to the influence of maternal lifestyles on Cd concentrations in breast milk in the Austrian setting. Breast milk was obtained from 124 Austrian women. Each participant provided 10 ml of milk. A second group of eight mothers were recruited to investigate changes in their milk cadmium levels at 1, 3, 5, 7 and 9 weeks post partum. The study participants filled a questionnaire concerning nutrition, supplementation, and smoking habits. The samples were analyzed using GF-Atomic Absorption Spectrophotometer (AAS). The mean Cd content in breast milk was among the lowest in Europe (0.086 +/- 0.085 microg/l, 95% CI: 0.07-0.10; n = 124). Increased Cd levels in breast milk were found to be significantly associated with frequent cereal consumption and smoking. Smokers had a two-fold higher concentration than did non-smokers (0.15 versus 0.07 microg/l; P = 0.000). In contrast, low Cd levels in breast milk were associated with the intake of supplements containing trace elements or vitamins and trace elements (P < 0.05). This protective effect of supplements on Cd levels was only observed in non-smokers. The Cd levels registered in the present investigation were far below critical levels. We conclude that the current maternal Cd levels in Austria signify no risk for the breastfed infant of a healthy mother. Further research will have to focus on the specific effects of supplementation and smoking on Cd concentrations.