Whether breastfed babies grow up to be healthier adults is a question that many new parents ponder. Breastfeeding provides infants with optimal nutrition and supports healthy development, leading many to believe it has lifelong health benefits. However, separating the effects of breastfeeding from other factors can be challenging. In this article, we’ll explore what the research says about the potential long-term impacts of breastfeeding.
Does breastfeeding reduce risk of obesity later in life?
Obesity has reached epidemic levels around the world. Many studies have found an association between breastfeeding and lower rates of obesity later in childhood and adulthood. For example:
- A 2013 study published in the Journal of Pediatrics looked at nearly 14,000 children in Belarus. It found that those breastfed for at least 12 months were about 30% less likely to be obese at age 11.5 years compared to those breastfed for less than 3 months.
- An analysis of 17 studies involving over 200,000 participants found that breastfed individuals were 22% less likely to be classified as overweight or obese in adulthood compared to those who were formula-fed.
However, breastfeeding duration is closely tied to factors like race, ethnicity, and socioeconomic status – all of which also independently influence obesity risk. Researchers try to account for these confounding factors, but completely isolating breastfeeding effects is impossible. Overall, however, the consistency of evidence does suggest a protective effect against obesity later in life.
What about risk for type 2 diabetes and heart disease?
Type 2 diabetes and cardiovascular disease have also reached epidemic proportions globally. These conditions often co-occur with obesity and share similar risk factors. Many studies have found an association between breastfeeding and reduced likelihood of developing both type 2 diabetes and heart disease down the road. For example:
- A 2010 meta-analysis published in JAMA found that adults who were breastfed as infants had a lower risk of both type 2 diabetes (decrease of 39%) and cardiovascular disease (decrease of 9%).
- A study of over 1,100 adults found that those breastfed for at least 3 months had cardiometabolic factors like lower blood pressure, glucose levels, and insulin resistance at age 50 compared to those breastfed for less than 3 months.
Again, confounding variables make it impossible to say breastfeeding is directly responsible for reducing disease risk. However, biologically it makes sense that the nutrients in breastmilk support metabolic and cardiovascular health over the lifespan. More research is still needed to confirm the relationships.
Does breastfeeding affect immune function and inflammation as adults?
Breastmilk provides vital antibodies and immune factors that protect babies from infection. Could this immune protection have lasting impacts? Several studies suggest it may:
- A 2010 study found young adults who were breastfed for at least 3 months had lower chronic inflammation levels compared to those breastfed for less than 3 months.
- A study in the Philippines followed over 3,000 infants into young adulthood. Those breastfed for at least 6 months had higher levels of antibodies against common viruses in adulthood compared to those breastfed for less than 6 months.
While intriguing, more research is needed to confirm lasting immune system effects and understand exactly how breastfeeding duration influences antibody levels later in life.
What about intelligence and educational attainment?
The fatty acids and nutrients in breastmilk support optimal brain development. Several studies have found positive impacts of breastfeeding on intelligence and educational outcomes:
- A study in Brazil found that adults who were breastfed for at least 12 months scored over 3 points higher on IQ tests compared to those breastfed for less than 1 month.
- In a British study, adults who were breastfed scored slightly higher on intelligence tests and were more likely to hold college degrees compared to those who were formula-fed.
However, maternal education and IQ were not considered. Overall, studies tend to find small positive associations between breastfeeding duration and cognitive development. But whether this translates into measurable intelligence gains in adulthood is less clear.
Can breastfeeding reduce risk of certain cancers later in life?
Research on whether breastfeeding impacts cancer risk has been mixed:
- A systematic review of 18 studies found that breastfeeding for 6-12 months reduced the risk of childhood leukemia by about 19%. Breastfeeding also seemed to protect against lymphoma, according to four studies.
- A review of 11 studies found breastfeeding for at least 6 months reduced the risk of childhood obesity-related cancers like liver and kidney cancer. Breastfeeding did not protect against brain or bone cancers.
- A 2019 review looked at breastfeeding and breast cancer risk. While some studies found breastfeeding protective, the overall evidence was inconclusive.
More research is needed on breastfeeding’s potential to reduce cancers later in life. Current evidence is limited but indicates it may offer some protection against certain cancers.
Can breastfeeding reduce risk factors for chronic disease?
Here is a summary of well-established risk factors for major chronic diseases and what research to date says about potential protective effects of breastfeeding:
| Disease Risk Factor | Evidence for Breastfeeding Protecting Against Risk Factor |
|---|---|
| Obesity/overweight | Strong evidence for modest protective effect |
| Hypertension | Moderate evidence for small protective effect |
| Dyslipidemia | Limited evidence for potential small protective effect |
| Insulin resistance | Moderate evidence for modest protective effect |
| Chronic inflammation | Moderate evidence for potential small protective effect |
| Endothelial dysfunction | Insufficient evidence currently |
Overall, there is fairly consistent evidence that breastfeeding may provide modest long-term protection against obesity, hypertension, insulin resistance, and inflammation. More research is still needed on other chronic disease risk factors.
How could breastfeeding impact health decades later?
There are several biological mechanisms that could help explain why breastfeeding has lifelong impacts on health:
- Gut microbiome: Breastmilk shapes the infant gut microbiome by transferring maternal microbes. This promotes healthy gut colonization and metabolism which has implications for immunity, growth, and disease risk.
- Growth trajectory: Breastfed infants self-regulate milk intake which may program healthier weight gain trajectories and lower obesity risk.
- Nutrient intake: The nutrients in breastmilk (fats, proteins, vitamins, minerals) support optimal organ development and function which lasts into adulthood.
- Epigenetics: Components in breastmilk may induce epigenetic changes. These changes alter how genes are expressed, impacting development and disease susceptibility later in life.
The combination of these developmental influences may impart long-term health advantages.
Are the benefits of breastfeeding overstated?
Despite many studies finding health advantages, some experts believe breastfeeding benefits are exaggerated or negligible for several reasons:
- Studies are observational so cannot prove cause-and-effect.
- Breastfeeding duration serves as a proxy for socioeconomic advantages.
- Parenting practices like diet tend to cluster – breastfeeders may have other healthy habits.
- Critical periods of development may be less influenced by infant feeding method.
- Protective effects, when present, tend to be modest in size.
More sibling comparison studies controlling for maternal factors are needed to better isolate the impacts of breastfeeding itself. Overall though, most experts believe a small but meaningful protective effect exists.
Do benefits outweigh any risks of formula feeding?
The majority of research suggests breastfeeding has long-term health advantages compared to formula. However, there are a few important considerations when weighing infant feeding decisions:
- Any differences tend to be small – not breastfeeding does not doom a child to poor health.
- Formula today is nutritionally complete and supports healthy development.
- For mothers unable or choosing not to breastfeed, formula is a safe, healthy alternative.
- Other aspects of parenting matter more for long-term health like diet and activity patterns.
While breastfeeding is considered ideal, formula-fed babies who are otherwise well-nourished and cared for develop just fine. Overall health should be the priority, regardless of feeding method.
Does when solid foods are introduced impact health as adults?
The timing of solid food introduction is another infant feeding consideration. Evidence suggests both very early and very late introduction may be detrimental:
- Starting solids before 4 months is associated with increased obesity risk according to several studies.
- Delaying solids beyond 6 months may increase risk of autoimmune diseases and iron deficiency anemia based on limited research.
Ideally, solids should be introduced between 4-6 months based on developmental readiness. More research is needed, but timing of solid food introduction appears important for establishing healthy eating behaviors and diet quality.
Should babies be exclusively breastfed for 6 months or longer?
Health organizations like the WHO currently recommend:
- Exclusive breastfeeding for 6 months – only breastmilk, no solids or other fluids.
- Continued breastfeeding until at least 1 year as solids are introduced.
- Breastfeeding for 2 years or longer if desired.
Studies suggest health benefits increase with longer durations of exclusive and total breastfeeding up to 2 years. However, any amount of breastfeeding is beneficial. Working with healthcare providers to set personalized feeding goals is best.
What if breastfeeding is not possible?
While breastfeeding is considered ideal, it is not always feasible or desirable for every family. Many valid medical and personal reasons exist for choosing formula. In situations where breastfeeding cannot happen, here are some tips:
- Work with your healthcare provider to ensure proper formula preparation, handling, and storage.
- Do not feel guilty. Formula today is nutritionally complete and supports healthy development.
- Focus on diet quality, activity patterns, sleep routines and other positive parenting practices.
- Introduce solids at 4-6 months and progress to a healthy, balanced diet as your infant grows.
Every feeding journey is unique. Focusing on overall health and nurturing feeding relationships is what matters most, not the milk itself.
What are infant feeding best practices?
Based on the current evidence, here are some infant feeding best practices for optimizing short- and long-term health regardless of feeding method:
- Aim to exclusively breastfeed for 6 months if possible.
- Work closely with healthcare providers to make personalized infant feeding decisions.
- Ensure proper preparation and handling of formula if breastfeeding is inadvisable or not desired.
- Introduce solids at 4-6 months and offer a variety of healthy foods.
- Respond supportively to infant hunger and fullness cues.
- Create pleasant, low-stress feeding environments.
Focusing on diet quality, activity patterns and positive parenting practices as children grow older matters most for laying lifelong health foundations.
Conclusion
Current evidence suggests breastfeeding may have small but meaningful lifelong impacts on health and disease risk. However, many confounding factors make it difficult to isolate the independent effects of breastfeeding itself. While considered ideal, formula-feeding is also a safe, nutritious option when needed or preferred. Breastfeeding decisions should be guided by family circumstances, not guilt or pressure. Regardless of milk source, focusing on nurturing feeding relationships, diet quality, activity patterns, and other positive parenting practices throughout childhood is most important for supporting lifelong health.