There have been many studies on the association between breastfeeding and autism. While studies show a potential link between higher levels of breastfeeding and lower rates of autism, we only know that there is a correlation here.
Since studies have been unable to exclude other risk factors, they are limited in determining any potential causation association between breastfeeding or formula feeding.
It's long been established that there are many benefits to breastfeeding, but it can be a complicated matter for new mothers. Many women aren't able to breastfeed for various reasons, and others choose to formula feed for personal reasons.
There are too many variables in play for researchers to draw conclusions about breastfeeding’s role in potentially preventing autism. However, repeated studies have shown that there is a positive correlation between breastfeeding and a reduced risk of autism.
Due to the many benefits of breastfeeding, the American Academy of Pediatrics encourages breastfeeding infants exclusively for the first six months of life.
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, but again, these do not show causation. 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.
The studies into formula feeding, breastfeeding, and autism haven't been able to isolate this factor.
Various other factors are related to a mother's likelihood to breastfeed or formula feed. For example, studies have linked a mother's socioeconomic status and education level to the likelihood of breastfeeding. Without excluding these related factors, it's impossible to say whether a reduced autism risk is linked to breastfeeding, a higher socioeconomic status, or another factor.
Gestational age can influence the likelihood that a baby will be breastfed. Babies who are born premature are less likely to breastfeed due to the constraints often associated with a stay in a neonatal intensive care unit and other challenges.
Premature birth has been established as a risk factor for later autism development, but the various factors involved haven't been isolated. Studies have not concluded whether a lack of breastfeeding contributes to this risk or if the many other risk factors involved in premature birth do.
Most of the studies on breastfeeding, formula feeding, and autism have been limited in size. A relatively small number of chlidren and families have been included in them. Patterns and norms for breastfeeding vary greatly between cultures, and these factors also influence the outcome of these studies.
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 potentially 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.
- 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, the baby could be put in harm’s way.
Mothers put their babies at risk if they take in certain substances while breastfeeding.
- Cigarette smoke: 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 and 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
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.
Overall Well-Being of Mother & Baby
For some women, breastfeeding will present challenges that outweigh the potential benefits. The overall well-being of mother and baby is the most important consideration, and the decision to breastfeed should take all challenges and benefits into account.
Prenatal and post-natal nutrition is incredibly important. Talk to your doctor about how best to support your baby's development, whether you formula feed or breastfeed.
- AAP Policy on Breastfeeding. (2021). American Academy of Pediatrics.
- 7 Breast-Feeding Dangers Every New Mom Should Know. (May 2017). Fox News Live.
- 10 Facts on Breastfeeding. (August 2017). World Health Organization.
- Association Between Breastfeeding Duration and Cognitive Development, Autistic Traits, and ADHD Symptoms: A Multicenter Study in Spain. (March 2016). International Pediatric Research Foundation.
- Association Between Breastfeeding Initiation and Duration and Autism Spectrum Disorder in Preschool Children Enrolled in the Study to Explore Early Development. (May 2019). International Society for Autism Research.
- Association of Breastfeeding Status With Risk of Autism Spectrum Disorder: A Systematic Review, Dose-Response Analysis and Meta-Analysis. (February 2020). Asian Journal of Psychiatry.
- Breastfeeding and Autism Risk. (January 2013). Autism Speaks.
- Effect of Suboptimal Breast-Feeding on Occurrence of Autism: A Case-Control Study. (July 2012). National Library of Medicine.
- The Association Between Household Socioeconomic Status, Breastfeeding, and Infants' Anthropometric Indices. (October 2018). International Journal of Preventative Medicine.
- Prevalence of Autism Spectrum Disorder in Preterm Infants: A Meta-Analysis. (September 2018). Pediatrics.
- Impact of Infant Feeding Methods on the Development of Autism Spectrum Disorder. (January 2017). IntechOpen.
- Making the Decision to Breastfeed. (March 2019). U.S. Department of Health & Human Services: Office on Women’s Health.