Trends for breastfeeding come and go. Right now, women are told to breastfeed exclusively for six months, while in the early 1970s, just 22 per cent of women breastfed. So it's interesting to hear that breastfeeding was also subject to swings in popularity during the 18th and 19th centuries.
We know this because researchers have analysed the bones of children buried in Spitalfields, London, using a technique called stable isotope analysis to work out their feeding habits before they died.
Isotope analysis involves looking at the relative amounts of carbon and nitrogen isotopes in bone, which relate to the types of food and drink the individual consumed when they were alive. For example, when infants are born, levels of the isotope 15N in their bones are similar to those of the mother, but as they breastfeed and effectively consume their mother's tissue, levels of this isotope rise. When they are weaned onto solid foods, levels of this isotope fall again. Changes in 13C are also known to correlate with the type of food a person consumes.
Erika Nitsch at the University of Oxford and her colleagues analysed ribs from 164 skeletons recovered from a graveyard in Spitalfields, including 92 adults and 72 children. By comparing levels of 15N in the 32 children who died before their second birthday with average levels in women, they concluded that 18 were being exclusively breastfed, while the rest were either not breastfeeding at all, or were being fed a mixture of breast milk and a nutritionally poor substitute, such as flour and water.
Because the year of death was known for a large proportion of the children, the team were also able to see that differences existed between practices in the 18th and 19th Centuries.
"Not all individuals at Spitalfields were breastfed, and there may not have been a single uniformly practiced weaning scheme," writes Nitsch. "There is, however, more evidence for prolonged breastfeeding during the 19th century than the 18th century."
One reason for this may be the onset of industrialisation in the UK during the 18th century, resulting in many more women going out to work.
"Women who were employed away from home were more likely to wean their infants earlier than previous generations, or to not breastfeed at all," writes Nitsch.
In wealthier households, wet-nurses were sometimes employed to breastfeed infants, but a variety of milk substitutes are also known to have been offered to babies at this time. These included pap, a mixture of flour or bread crumbs cooked in milk or water, a bread broth called panada, and milk flavoured with spices, sugar, or eggs.
"Artificially fed infants had higher mortality rates than breastfed infants in the first six months of life," writes Nitsch. "The mortality of infants who were dry fed from birth was estimated to be particularly high, usually above 50 per cent and sometimes reaching as high as 90 per cent, due to earlier exposure of the infant to pathogens from contaminated foods, a higher risk of malnutrition, and the loss of immunological protection."
Geddes, Linda. 2011. "Bones reveal 18th and 19th-century breastfeeding fads". New Scientist. Posted: November 3, 2011. Available online: http://www.newscientist.com/blogs/shortsharpscience/2011/11/bones-reveal-18th-and-19th-cen.html