Breastfeeding, sometimes known as chestfeeding, provides many benefits for baby and their birthing parent. It may even offer some protection against childhood leukemia.

Leukemia is a cancer of the blood. It’s the most common type of cancer in children and adolescents. Most children who get leukemia have a type called acute lymphocytic leukemia (ALL). Most others get acute myeloid leukemia (AML). Chronic leukemias are rare in children.

If you’re in treatment for leukemia and want to breastfeed, there are some important things to consider first.

In this article, we’ll look at what the research says about the effect of breastfeeding on childhood leukemia risk and what someone with leukemia should know about breastfeeding.

The exact cause of leukemia isn’t clear. It may involve a combination of factors. It’s also not entirely clear why breast milk offers some protection from leukemia.

Researchers do have several theories. For example, components of breast milk:

  • contain antibodies
  • reduce the inflammatory response
  • affect the development of the immune system
  • prevent infection
  • act as a prebiotic, helping to promote a healthy gut microbiome
  • affect the pH level of the stomach and promote the protein lipid a-lactalbumin, which induces death in tumor cells

Breastfeeding for at least 6 months seems to be best.

A 2015 meta-analysis of 17 studies suggests that 14 to 20 percent of all childhood leukemia cases may be prevented by breastfeeding for 6 months or more.

Another study published in 2015 collected data from 7,399 children with ALL and 11,181 controls ages 2 to 14 years. The researchers found that breastfeeding for at least 6 months was associated with a decreased risk of ALL.

And a retrospective case-control study in China suggested that promoting breastfeeding for 7 to 9 months may help lower the incidence of childhood leukemia.

According to a 2021 systematic review and meta-analysis, breastfeeding had an association with a:

  • 23 percent lower risk of childhood leukemia versus no breastfeeding or occasional breastfeeding
  • 23 percent lower risk for longest versus shortest breastfeeding duration

Breastfed children tend to have better dental health and neurodevelopmental outcomes, per the American Academy of Pediatrics. They may also be at lower risk of conditions like:

Some research suggests that breastfeeding may also lower the risk of neuroblastoma, another type of cancer. More studies are needed to investigate this link.

Breastfeeding benefits for nursing parents

Nursing parents also get a few health benefits. This includes a decreased risk of:

Maybe. It’s a case-by-case situation, depending on your current therapy.

For example, radiation therapy near the breasts can affect your ability to produce milk, according to the Leukemia & Lymphoma Society. Radiation to other areas of your body may not affect your ability to breastfeed.

Certain drugs can pass to your baby through breast milk. This includes powerful chemotherapy drugs that could be harmful to your baby. Targeted therapies and immunotherapy drugs can also pass through breast milk.

Other situations where breastfeeding is not recommended include:

If you have leukemia and want to breastfeed, consult with your doctor. A thorough review of your health and treatment regimen will help determine if it’s safe to breastfeed.

Infant formula does not cause leukemia. But introducing formula into a baby’s diet changes the gut microbiome. Some research suggests this may affect how the immune system responds to pathogens.

A 2019 study indicates that breastfeeding for short durations or not at all may be associated with a slightly higher risk for childhood leukemia.

Another 2019 study found that linoleic acid and linolenic acid were higher in newborns who later developed childhood leukemia than those who didn’t. The researchers discovered that infant formulas have more of these essential fatty acids than breast milk.

Still, if you can’t breastfeed or chestfeed, or you prefer not to, infant formula is a safe alternative.

We don’t know exactly why some children develop leukemia. Children don’t have decades of lifestyle and environmental exposures that contribute to adult cancers.

According to the American Cancer Society, risk factors for childhood leukemia may include:

  • genetic syndromes like Down syndrome and Li-Fraumeni syndrome
  • inherited immune system disorders or having a suppressed immune system
  • having a sibling with leukemia
  • a high level of radiation exposure
  • previous treatment with chemotherapy drugs

Your doctor can help you understand if your child is at a higher-than-average risk of developing leukemia.

Overall, childhood leukemia is a rare disease.

Research indicates that breastfeeding for at least 6 months may lower the risk of childhood leukemia. Of course, breastfeeding won’t eliminate all risk.

If you’re currently in treatment for leukemia and want to breastfeed, discuss it with your doctor. Certain drugs, including chemotherapy drugs, can pass through breast milk. This is potentially harmful to your baby.

It’s well documented that breastfeeding provides many health benefits. It’s an ideal food for your baby. But health issues, obstacles to breastfeeding, and personal preference all factor in. Sometimes, it just doesn’t work out or it isn’t the best choice for you.

Fortunately, the right infant formula can provide your baby with the nutrients they need for good health. Your primary care physician or pediatrician can offer guidance on which type of formula is best for your baby.