BRADFORD, ENGLAND—Julia Beaumont of the University of Bradford and a team of scientists have analyzed the carbon and nitrogen isotopes in the teeth of children and adults who died during the 1845-52 Irish famine. Teeth, which begin to grow before birth, are formed in layers. Each layer of a tooth takes about four months to grow and can be linked to a specific period in a baby’s life. Higher nitrogen levels in bones and teeth are usually associated with good health and a high-protein diet, but the study showed that the babies who had higher nitrogen isotope levels at birth didn’t survive. In fact, older subjects had lower and more stable nitrogen isotope levels throughout early childhood. “At the period we studied, it’s likely that most babies were breastfed, but only some showed the spike in nitrogen isotope levels normally associated with it. Where pregnant and breastfeeding mothers are malnourished however, they can recycle their own tissues in order for the baby to grow and then to produce milk to feed it. We believe this produces higher nitrogen isotope levels and is what we’re seeing in the samples from the nineteenth-century cemeteries. Babies born to and breastfed by malnourished mothers do not receive all the nutrients they need, and this is possibly why these babies didn’t survive,” Beaumont said in a press release. To read about early Norse settlement of the island, see "The Vikings in Ireland."