How Breastfeeding and Co-Sleeping Reduce Stress in Babies, According to Science

Last Updated on December 15, 2020 by Jenn | The Nerd Mom

We often hear about the many nutritional and emotional benefits of breastfeeding. Co-sleeping is a bit more controversial because of the increased risk of SIDS when bed-sharing. But a 2012 study demonstrates that both contribute to better responses to stress in older babies.

For clarity, co-sleeping is when the baby sleeps in the same room as parents, and can include being in the same bed. The term bed-sharing usually refers only to sleeping in the same bed with your baby. Sleeping in the same room as your baby is recommended to reduce risk of SIDS, while bed-sharing is considered a risk factor for it. This study considered both room-sharing and bed-sharing when it examined effects of co-sleeping.

The study creators wanted to observe whether or not breastfeeding and co-sleeping affected infants responses to stressful situations later in life.

There were 193 infants and their mothers who participated. For the first six months of the babies’ lives, feeding and sleeping habits were documented. At 12-months old, the babies were subjected to a minor stressful event, and their cortisol levels were measured.

Cortisol is the hormone released by your adrenal glands in response to stress. In small amounts, it is helpful for coping, but numerous and prolonged releases of the hormone are linked to higher occurrence of anxiety, depression, and PTSD.

The study determined that the longer the babies were breastfed and co-slept, the better their brains reacted to and recovered from the cortisol release.

Both breastfeeding and co-sleeping have maternal closeness in common. This shows that having these close bonds with our babies help them cope with stress as they get older.

It also shows that having this closeness very early on (first six months of life), can already shape our babies’ ability to cope with stress.

These study findings may not be particularly surprising. Of course babies develop healthier when they have close and caring mothers. But I love how science can support this with data.

We still co-sleep with both our one- and three-year-olds. And I’m still nursing the one-year-old. As someone who has struggled with anxiety and depression, I hope these habits will build healthy mental foundations for them.