Breast milk has long been associated with health benefits, but recent studies are shedding new light on its possible effects on brain development, immunity, sleep, emotional regulation and maternal heart healthLiora Houbara|A growing body of research points to health benefits associated with breastfeeding for both babies and mothers. From brain development and immune protection to emotional regulation and maternal cardiovascular health, here are 12 scientific findings worth knowing.Brain-imaging studies, including research published in NeuroImage, have found an association between exclusive breastfeeding and faster development of myelin in the brain’s white matter.Your comfort should always come first(Photo: Shutterstock/ASAP Creative )Myelin helps electrical signals travel efficiently between nerve cells. Researchers have reported differences in brain regions involved in language, emotional regulation and higher cognitive functions.The large-scale Avon Longitudinal Study of Parents and Children at Bristol University, also known as the Children of the 90s project, followed more than 14,000 mothers and children from infancy through adolescence.The findings showed a clear association between longer breastfeeding duration and stronger academic outcomes, as well as improved language and social development. Children breastfed for at least six months were 39% more likely to succeed in national mathematics and English exams at ages 8 and 15 than those who were not breastfed. They also showed stronger language and social development by age 9.One of the most intriguing areas of current research is known as "metabolic programming". Breast milk contains hormones such as leptin and adiponectin, which influence how an infant’s body produces fat cells and responds to insulin.Studies have found that each additional month of exclusive breastfeeding is associated with an 11% lower risk of becoming overweight or obese during the first two years of life, with some research suggesting that this metabolic protection may persist for decades.Breast milk contains complex sugars known as human milk oligosaccharides, or HMOs. Babies cannot digest them directly. Instead, they help nourish beneficial bacteria in the gut.A large European study published in Nutrients followed about 1,200 mothers and infants from birth. It found that higher exposure to these compounds during the first months of life was associated with substantially lower rates of allergic diseases and asthma by age 5.HMOs may also act as decoys for viruses and bacteria. Rather than attaching to cells in the infant’s digestive or respiratory system, some pathogens bind to these milk components and are then removed from the body.Epidemiological studies have associated exclusive breastfeeding for at least four months with a 72% lower risk of hospitalization for lower respiratory infections during the first year of life, including illness caused by respiratory syncytial virus, or RSV. RSV is highly contagious, and most children are infected by age 2. In some infants, it can cause bronchiolitis, an inflammation of the small airways.Research suggests that a mother’s body may adjust the composition of breast milk according to the baby’s sex, potentially supporting different growth patterns. Studies, including one published in the American Journal of Human Biology, found that milk produced for boys contained about 25% more fat and energy on average, while milk produced for girls was richer in calcium, which supports bone development, and certain antibodies.Research on circadian rhythms shows that the composition of breast milk changes between day and night, helping babies adjust to the body’s natural 24-hour cycle. Milk expressed or consumed at night contains four to five times more melatonin, the hormone associated with sleep, than daytime milk. This may help infants develop their internal body clock earlier and significantly reduce nighttime awakenings.During breastfeeding, a shared hormonal response is activated in both mother and baby. The release of oxytocin, often called the love hormone, together with cholecystokinin, or CCK, which helps regulate digestion and create a sense of fullness, sharply reduces cortisol levels in the infant.The findings come from a large Australian longitudinal study published in Human Development, which followed about 2,500 mother-infant pairs. Researchers found that this early physiological calm may help shape neural pathways associated with steadier heart rates and stronger emotional regulation in stressful situations by preschool age.A large Japanese study involving more than 10,000 mothers and children examined the possible long-term relationship between breastfeeding and child behavior.After accounting for several socioeconomic variables, researchers found that breastfeeding for six to 12 months was associated with fewer behavioral difficulties, fewer tantrums and stronger social adjustment by age 5.Breast milk contains IgA antibodies that bind to proteins from foods in the mother’s diet, such as peanuts, eggs and sesame, and present them to the infant’s immune system in a controlled way.The finding is based on U.S. clinical follow-up studies involving samples from more than 1,500 mother-infant pairs. Researchers writing in The Journal of Allergy and Clinical Immunology said this process may help build immune tolerance in the gut and reduce the risk of severe childhood food allergies by up to 40%.Comprehensive scientific reviews spanning decades of comparative research, while accounting for parental education and background, have consistently linked longer breastfeeding duration with an average increase of 2.6 to 3 points in a child’s overall IQ. Researchers say this may support stronger executive function and problem-solving skills later in life.Breastfeeding benefits not only the baby but may also play an important biological role in the mother’s health. During pregnancy, the body stores additional fat and undergoes major changes in blood lipid levels. Breastfeeding may act as a metabolic “reset,” helping the body use and rebalance those stores.The conclusion is based on an international meta-analysis published by the American Heart Association that included medical data from more than 1.2 million women worldwide. Women who breastfed for a cumulative total of at least 12 months over their lifetimes had a 12% lower risk of cardiovascular disease and a 14% lower risk of coronary heart disease.Breastfeeding decisions depend on comfort, mental health, personal preference, medical circumstances and practical ability. Not every woman can breastfeed. The evidence should not be interpreted as an all-or-nothing message; partial, combined or short-term breastfeeding can still provide meaningful benefits for the baby.The writer is a clinical dietitian