Many studies on the association between breastfeeding and autism have identified a connection between the two.

It is clear that mothers who exclusively breastfeed for longer periods of time are more likely to have children without autism than mothers who do not breastfeed exclusively or at all, though the reason behind this link is unclear.

There are too many variables in play for researchers to draw conclusions about breastfeeding’s role in potentially preventing autism. But enough studies have repeatedly come to the same conclusion to safely make a positive correlation between breastfeeding and a reduced risk of autism.

The Connection Between Breastfeeding, Formula Feeding & Autism

Scientific studies have investigated a possible connection between breastfeeding versus bottle feeding and autism. Furthermore, studies have looked at the impact of formula on autism risk.

Connections have been made between children with autism spectrum disorder (ASD) and formula feeding. A recurring theme among studies shows that children with ASD were more likely than their neurotypical peers to have been formula fed from birth or weaned from the breast earlier in life.

Formula feeding does not cause autism. There are many variables that influence the risk of autism, and the exact causes of ASD are unknown. What scientists are comfortable concluding is that there is a correlation between formula feeding, little to no breastfeeding, and an increased risk of autism spectrum disorder.

It is important to note that even to say that formula feeding directly increases the risk of ASD is unfounded. It is, however, a relationship that researchers have observed.

Can Breastfeeding Improve Autism?

One thing that researchers widely agree on is that breastfeeding is beneficial for child development. Studies have identified breastfeeding as a protective factor against autism.

One 2017 study demonstrated that breastfeeding for at least one year is highly associated with a reduced risk of autism. Likewise, a lack of breastfeeding is a risk factor for autism development in children who are already genetically at risk for the condition.

Another recent study that investigated the association between breastfeeding, cognitive development, autistic traits, and ADHD symptoms also identified benefits of breastfeeding. The study found that after adjusting for many confounding variables, longer durations of breastfeeding were independently associated with improved cognitive development and reduced autistic traits.

The study, which was conducted across multiple centers in Spain, supports the positive connection between breastfeeding and reduced risk of autism that has been demonstrated in many other studies. A positive association remains between prolonged breastfeeding, child development, and a protective role against symptoms of autism.

Benefits of Breastfeeding

There are many well-established benefits of breastfeeding. The World Health Organization (WHO) actively supports breastfeeding as the best source of nutrition for babies and young children. It is one of the most effective ways to ensure the health and survival of children.

Benefits of breastfeeding include the following:

  • Breast milk contains all the nutrients babies need for healthy development.
  • Breast milk contains antibodies to protect the baby from common childhood illnesses.
  • For mothers, breastfeeding reduces the risk of breast and ovarian cancer, type 2 diabetes, and postpartum depression.
  • Breastfed babies are less likely to grow up to be overweight or obese, or to develop type II diabetes.
  • Children who were breastfed are likely to perform better on intelligence tests.
  • Breastfeeding supports the mother-infant bond.

Additional health benefits of breastfeeding for the infant include a lower likelihood of:

  • Asthma and respiratory infections.
  • Childhood obesity.
  • Ear infections.
  • Intestinal issues.
  • Leukemia.
  • Eczema.
  • Necrotizing enterocolitis.
  • Sudden infant death syndrome (SIDS).

Risks of Breastfeeding

Although there are many well-established benefits of breastfeeding, it does not come without some risks. If mothers do not take precautions to ensure they are supplying clean and safe milk to the baby, the baby could be put in harm’s way.

Mothers put their babies at risk if they take in certain substances while breastfeeding.

  • Smoking: Smoking while breastfeeding puts toxins in your breastmilk and exposes your baby to secondhand smoke. Both of these are harmful to babies’ development.

  • Alcohol: Alcohol quickly passes into breastmilk, so you should be cautious about nursing your baby while drinking alcohol. If you drink, feed your baby first then wait until you no longer feel the effects of the alcohol to nurse again.

  • Marijuana: Experts discourage nursing mothers from using marijuana. As with smoking cigarettes, toxins can enter breastmilk and secondhand smoke is harmful to babies. Additionally, marijuana can accumulate in babies’ fat cells.

  • Prescription medications: While most prescription medications are safe to take while breastfeeding, some drugs may cross into breastmilk and babies cannot metabolize medications like their mothers can. Make sure your doctor knows you are breastfeeding if you are prescribed any medication.

What the Research Says About Breastfeeding & Autism Risk

Many studies have investigated the connection between breastfeeding and the risk of autism. One 2012 study looked at the effects of suboptimal breastfeeding on the occurrence of autism. The researchers used a case-control format by evaluating 102 cases of autism spectrum disorder and 102 cases of healthy babies without autism.

The researchers found that certain poor breastfeeding factors indicated a higher risk of autism. The factors included:

  • Late initiation of breastfeeding.
  • Non-intake of colostrum.
  • Prelacteal feeding.
  • Bottle feeding.

The researchers also identified breastfeeding practices that were related to a decreased risk of ASD. The babies who were exclusively breastfed for continued periods of time were less likely to have autism.

A 2019 study on the association between breastfeeding and ASD also identified a connection between breastfeeding practices and rates of autism. The study found that the mothers of children with autism breastfed for shorter periods of time than the mothers of children without autism.

While this connection was clear, further research is needed to understand the reasons why mothers of children with autism breastfed for shorter periods of time than the mothers of typically developing babies.

Breastfeeding & Autism

A February 2020 study on the association between breastfeeding and the risk of autism echoes similar findings to previous studies on the topic. A meta-analysis was conducted on studies that found this association. The researchers identified the following key points:

  • A 58% decrease in the risk of autism with any breastfeeding.
  • A 76% decrease in the risk of autism with exclusive breastfeeding.
  • A 54% reduction in autism risk with breastfeeding for at least six months.

The most significant reduction in the risk of autism was associated with mothers who breastfed for 12 to 24 months. Overall, the study highlighted how breastfeeding has a protective effect against the risk of autism and that exclusive breastfeeding produces the lowest risk of autism.