Lower weight babies and babies who aren't breastfed or not breastfed for long are at greater risk of developing chronic inflammation and related health problems later in life, according to a new study.
"There were good reasons to hypothesize that breastfeeding was important to influencing levels of inflammation in adulthood," says Thomas McDade (Northwestern University), a CIFAR (Canadian Institute for Advanced Research) fellow in the Child & Brain Development program. "It changes the microbiome. It promotes development of the immune system. Children who are breastfed get fewer infectious diseases and are less likely to become overweight."
Connections have been made previously with both low birth weight and less breastfeeding and later poor health outcomes. The new study suggests one mechanism for the poor outcomes. It shows that both factors lead to elevated levels of C-reactive protein (CRP), which is an indicator of inflammation.
Although inflammation can be a good thing when it's in reaction to an infection, for instance, chronic inflammation is associated with risks such as heart attack, diabetes and other problems, McDade says.
McDade and his colleagues looked at a study that contained health information on 10,500 US adults, including their CRP levels, their birth weight, and whether and for how long they had been breastfed as babies. The study was especially useful because it included information for many siblings.
Trying to figure out the role of birth weight and breastfeeding in long run health outcomes is complicated because children born to parents with less income and less education are also more likely to have low birth weight and less breastfeeding. That means it's never clear if other factors are also in play.
But because of the number of siblings in the study, the researchers were able to show that even within the same family, birth weight and breastfeeding matter to inflammation in adulthood.
McDade was lead author on the paper, which is published in Proceedings of the Royal Society B.
Authors on the paper "Long-term effects of birth weight and breastfeeding" include Thomas McDade, Molly Metzger, Laura Chyu, Greg Duncan, Craig Garfield and Emma Adam.
CIFAR brings together extraordinary scholars and scientists from around the world to address questions of global importance. Based in Toronto, Canada, CIFAR is a global research organization comprising nearly 400 Fellows, Scholars and Advisors from more than 100 institutions in 16 countries. CIFAR aims to generate transformative knowledge at the frontiers of understanding, to catalyze innovation and resolution of the world's major challenges, and to advance the careers of promising young researchers. Established in 1982, CIFAR partners with the Government of Canada, provincial governments, individuals, foundations, corporations and research institutions to extend our impact in the world.
CIFAR's Child & Brain Development program explores the core question of how social experiences affect developmental biology and help set early trajectories of lifelong development and health.
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