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Breastfeeding – why

14/01/2026

Breastfeeding makes an important contribution to mother’s health too.

Table of Contents

Breastfeeding is not just about feeding a baby. Important processes take place in the breastfeeding mother’s body that have a positive long-term influence on her health. The Lancet 2016 https://www.thelancet.com/series/breastfeeding

As a result, breastfeeding also has many benefits for maternal health. It promotes post-partum weight loss, lowers the risk of type 2 diabetes, hypertension, cardiovascular disease, breast and ovarian cancer, helps prevent anaemia and osteoporosis, helps space births (LAM), promotes mental health and attachment by creating a strong mother-child bond.

Obesity

Breastfeeding is a protective factor against maternal obesity. Check our dedicated page on Obesity

Diabetes

  • Choi ES et al. Association between breastfeeding duration and diabetes mellitus in menopausal women: a machine-learning analysis using population-based retrospective study Int Breastfeed J. 2024 May 14;19:33. doi: 10.1186/s13006-024-00642-z

Background: Breastfeeding resets insulin resistance caused by pregnancy however, studies on the association between breastfeeding and diabetes mellitus (DM) have reported inconsistent results. Therefore, we aimed to investigate the risk of DM according to breastfeeding duration in large-scale population-based retrospective study. In addition, machine-learning prediction models for DM and hemoglobin A1c (HbA1c) were developed to further evaluate this association.
Conclusion: Women who did not breasted had a higher risk of developing DM than those who breastfed for up to 12 months.

Introduction: Breastfeeding has benefits for infant health, but also for maternal health, as lactation has a positive impact on glucose homeostasis. This can be explained by the requirements of milk production. The mammary gland needs glucose to produce lactose.
Materials and methods: Prospective study conducted in the endocrinology and diabetology department including 90 patients monitored for diabetic pregnancy.
Objective of the study: The objective of this study is to evaluate the impact of breastfeeding on glycaemic balance.
Conclusion: Our results highlight the positive impact of breastfeeding on glycaemic balance and weight loss, hence the need to systematically emphasise breastfeeding in diabetic women.

Conclusions and Relevance: This study suggests that education about the benefits of breastfeeding for prevention of diabetes and hypertension in women is a low-risk intervention that can be easily included in daily practice and may have a positive impact on cardiovascular outcomes in mothers.

Purpose of review: Breastfeeding has short- and long-term benefits for child health. In this systematic review, we updated a review on the association between breastfeeding and type 2 diabetes. Recent findings: A meta-analysis published in 2015 reported that breastfeeding protects against type 2 diabetes (pooled odds ratio, 0.65 (95% confidence interval, 0.48; 0.86)). In the present update, we identified three recently published studies. An internet-based study reported that at a mean age of 25.6 years, exclusive breastfeeding in the first 6 months protected against type 2 diabetes (odds ratio, 0.63 (95% confidence interval, 0.41; 0.95)). In a retrospective cohort, those subjects who had been breastfed before hospital discharge were less likely of presenting diabetes (odds ratio, 0.83 (95% confidence interval, 0.69; 0.99)). In a case-control study, the odds of type 2 diabetes in adolescents was lower for those exclusively breastfed at hospital discharge (odds ratio, 0.52 (95% confidence interval, 0.36; 0.74)). In the meta-analysis, the pooled odds ratio was 0.67 (95% confidence interval, 0.56; 0.80). The updated systematic review and meta-analysis suggests that breastfeeding protects from type 2 diabetes.

  • Gunderson EP et al. Lactation and Progression to Type 2 Diabetes Mellitus After Gestational Diabetes Mellitus: A Prospective Cohort Study. Observational Study. Ann Intern Med. 2015 Dec 15;163(12):889-98. https://pubmed.ncbi.nlm.nih.gov/26595611/

Background: Lactation improves glucose metabolism, but its role in preventing type 2 diabetes mellitus (DM) after gestational diabetes mellitus (GDM) remains uncertain. Participants: 1035 women diagnosed with GDM who delivered singletons at 35 weeks’ gestation or later and enrolled in the Study of Women, Infant Feeding and Type 2 Diabetes After GDM Pregnancy from 2008 to 2011. Conclusion: Higher lactation intensity and longer duration were independently associated with lower 2-year incidences of DM after GDM pregnancy. Lactation may prevent DM after GDM delivery.

Background and aims: Breastfeeding has been associated with reduced risk of maternal type 2 diabetes in some cohort studies, but the evidence from published studies have differed with regard to the strength of the association. To clarify this association we conducted a systematic review and dose–response meta-analysis of breastfeeding and maternal risk of type 2 diabetes. Method: Six cohort studies including 10,842 cases among 273,961 participants were included in the meta-analysis. Conclusion: This meta-analysis suggests that there is a statistically significant inverse association between breastfeeding and maternal risk of type 2 diabetes.

Gestational diabetes mellitus (GDM) increases the future risk of developing type 2 diabetes mellitus (T2DM). There is now a growing evidence that breastfeeding has short- and long-term health benefits for mothers with GDM. Mothers with GDM who breastfeed have improved lipid and glucose metabolic profiles for the first 3 months after birth. However, women with GDM are less likely to breastfeed and, if they do, breastfeeding is usually continued for a shorter duration compared with women without GDM. One long-term prospective study followed women with GDM from delivery for up to 19 years postpartum, and found that breastfeeding for ≥3 months reduced the risk of T2DM and delayed the development of T2DM by a further 10 years compared with breastfeeding for <3 months. However, the physiological mechanisms underlying the protective effects of breastfeeding are still unknown, even though it is important to gain a full understanding of the pathways involved in these effects. Therefore, the purpose of this review is to provide a comprehensive analysis of the recent developments in the field of GDM and breastfeeding. We reviewed data from animal experiments and human studies. We also provide insight into the molecular pathways and describe promising topics for future research.

  • Jäger S et al. Breast-feeding and maternal risk of type 2 diabetes: a prospective study and meta-analysis. Meta-Analysis Diabetologia. 2014 Jul;57(7):1355-65. https://pubmed.ncbi.nlm.nih.gov/24789344/ 

Aims/hypothesis: We aimed to examine the association between breast-feeding and maternal risk of type 2 diabetes and to investigate whether this association is mediated by anthropometric and biochemical factors. Methods: A case-cohort study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study between 1994 and 2005 including 1,262 childbearing women (1,059 in a random sub-cohort and 203 incident cases) mainly aged between 35 and 64 years at baseline was applied. Self-reported lifetime duration of breast-feeding was assessed by questionnaire. Blood samples were used for biomarker measurement (HDL-cholesterol, triacylglycerols, C-reactive protein, fetuin-A, γ-glutamyltransferase, adiponectin). A systematic literature search and meta-analysis was conducted of prospective cohort studies investigating breast-feeding and risk of type 2 diabetes. Conclusions/interpretation: Longer duration of breast-feeding may be related to a lower risk of diabetes. This potentially protective effect seems to be reflected by a more favourable metabolic profile; however, the role of body weight as a mediator or confounder remains uncertain.

Objective To evaluate the association between lactation history and incidence of type 2 diabetes. Design, Setting, and Participants Prospective observational cohort study of 83 585 parous women in the Nurses’ Health Study (NHS) and retrospective observational cohort study of 73 418 parous women in the Nurses’ Health Study II (NHS II). Conclusions Longer duration of breastfeeding was associated with reduced incidence of type 2 diabetes in 2 large US cohorts of women. Lactation may reduce risk of type 2 diabetes in young and middle-aged women by improving glucose homeostasis.

Cancer

  • Swiss Leaggue against cancer : https://www.krebsliga.ch/krebs-vorbeugen/praevention-und-frueherkennung/stillen/
  • Association between breastfeeding and ovarian cancer risk. Babic A et al. JAMA Oncol 2020. https://pubmed.ncbi.nlm.nih.gov/32239218/
  • 2018 : Histological subtypes of ovarian cancer associated with parity and breastfeeding in the prospective Million Women Study. Gaitskell K et al. Int J Cancer 2018 ; 142(2) : 281-9. https://pubmed.ncbi.nlm.nih.gov/28929490/
  • 2018 : Reproductive history, breast-feeding and risk of tripple negative breast cancer : the Breast Cancer etiology in Minorities (BEM) study. John EM et al. Int J Cancer 2018 ; 142(11) : 2273-85.
  • 2017 : Le World Cancer Research Fund et l’American Institute for Cancer Research ont émis une série de 10 grandes recommandations pour prévenir le cancer, dont une portant sur l’allaitement. La protection de l’allaitement face au risque de cancer du sein : « strong evidence ». World Cancer Research Fund/American Institute for Cancer Research. https://www.wcrf.org/int/continuous-update-project/cup-findings-reports/breast-cancer
  • 2017 : Grossesse, allaitement, ménopause et risque de cancer du sein chez des femmes coréennes. Risk reduction of breast cancer by childbirth, breastfeeding, and their interactions in Korean women : heterogeneous effects across menopausal status, hormone receptor status, and pathological subtypes. Jeong SH et al. J Prev Med Public Health 2017 ; 50 : 401-10.
  • 2016 : Allaitement et expression du Ki-67, du p54 et du BCL2 dans les cancers du seinBreastfeeding and immunohistochemical expression of Ki-67, p53 and BCL2 in infiltrating lobular breast carcinoma. Gonzalez-Sistal A et al. PloS ONE 2016 ; 11(3) : e0151093.
  • 2014 : Allaitement et prévention du cancer du sein. Breastfeeding and the prevention of breast cancer : a retrospective review of clinical history. González-Jiménez E et al. J Clin Nurs 2014
  • 2013 : Facteurs reproductifs, récepteurs hormonaux, et risque de cancer du sein. Association between chronological change of reproductive factors and breast cancer risk defined by hormone receptor status : results from the Seoul breast cancer study. Chung S et al. Breast Cancer Res Treat 2013 ; 140(3) : 557-65.
  • 2013 : Lactation et risque de cancer du sein après la ménopause. Investigating the association of lactation history and postmenopausal breast cancer risk in the Women’s Health Initiative. Stendell-Hollis NR et al. Nutr Cancer 2013 ; 65(7) : 969-81.
  • 2012 : Allaitement et réduction du risque de cancer du sein. Breastfeeding and its relationship with reduction of breast cancer : a review. Franca-Bothelho Ado C et al. Asian Pac J Cancer Prec 2012 ; 13(11) : 5327-32.
  • 2002 : Lancet. 2002 Jul 20;360(9328):187-95. Professor Valérie Beral’s team at the Oxford Cancer Research Centre has proved that prolonged breastfeeding reduces the risk of developing cancer. The researchers brought together data from 47 studies carried out in 30 different countries, involving a total of almost 150,000 women: Results of the Lancet 2002 study 1) Women with cancer breastfed less often and for shorter periods than controls. 2) The risk of cancer was reduced by 4.3% for each additional year of breastfeeding (bearing in mind that the risk was already reduced by 7% for each birth).
  • 2000 : Breastfeeding and risk of breast cancer: a meta-analysis of published studies. Bernier MO et al. Human Reproduction Update, Volume 6, Issue 4, July 2000, Pages 374–386, https://doi.org/10.1093/humupd/6.4.374

Epigenetics

see our dedicated page Epigenetics

Prolactine

What is the link between prolactin and the health of breastfeeding mothers? Prolactin appears to have a positive effect on mental health.

Prolactin may also be a marker of breast cancer. Cureus. 2024 Apr; 16(4): e58375.
Serum Prolactin Levels as a Novel, Practical Marker for Predicting Malignant Diseases of the Breast. But the study concerns only 67 cases https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11097618/

Uterus

In the immediate postpartum period, breastfeeding and skin-to-skin contact, under the effect of the oxytocin naturally released in the mother’s body, allow the uterus to involve rapidly. Muscular contractions allow the uterus (which is above all a muscle) to return to its pre-pregnancy state and limit blood loss in the post-partum period.

This study suggests that skin-to-skin contact and breastfeeding immediately after birth may be effective in reducing PPH rates in women, regardless of their level of risk of PPH primary postpartum haemorrhage. Saxton et al. 2015

See also:

Anemia

Breastfeeding helps delay the return of menstruation and, under certain conditions, acts as a natural contraceptive. It allows rapid involution of the uterus after pregnancy through muscular contractions (the uterus is above all a muscle) under the effect of oxytocin naturally released into the body during breastfeeding.

Osteoporosis

Muriel E. Babey et al. published an article on July 10, 2024 A maternal brain hormone that builds bone, https://www.nature.com/articles/s41586-024-07634-3 In lactating mothers, the high calcium (Ca2+) demand for milk production triggers significant bone loss1. Although oestrogen normally counteracts excessive bone resorption by promoting bone formation, this sex steroid drops precipitously during this postpartum period. Here we report that brain-derived cellular communication network factor 3 (CCN3) secreted from KISS1 neurons of the arcuate nucleus (ARCKISS1) fills this void and functions as a potent osteoanabolic factor to build bone in lactating females. We began by showing that our previously reported female-specific, dense bone phenotype2 originates from a humoral factor that promotes bone mass and acts on skeletal stem cells to increase their frequency and osteochondrogenic potential. This circulatory factor was then identified as CCN3, a brain-derived hormone from ARCKISS1 neurons that is able to stimulate mouse and human skeletal stem cell activity, increase bone remodelling and accelerate fracture repair in young and old mice of both sexes. The role of CCN3 in normal female physiology was revealed after detecting a burst of CCN3 expression in ARCKISS1 neurons coincident with lactation. After reducing CCN3 in ARCKISS1 neurons, lactating mothers lost bone and failed to sustain their progeny when challenged with a low-calcium diet. Our findings establish CCN3 as a potentially new therapeutic osteoanabolic hormone for both sexes and define a new maternal brain hormone for ensuring species survival in mammals.

This study joins others on the subject of breastfeeding and osteoporosis which show that breastfeeding women regain normal bone density some time after weaning. Metabolic adjustments are assumed.

  • Cooke-Hubley S et al, Spine bone mineral density increases after 6 months of exclusive lactation even in women who keep breastfeeding, Arch Osteopor 2017 ; 12(1) : 73), la densité osseuse lombaire avait augmenté de 4 % entre 6 et 12 mois, et la densité osseuse au niveau des vertèbres dorsales avait augmenté de 5 %. https://pubmed.ncbi.nlm.nih.gov/28815389/
  • Kalkwarf HJ et al., Bone mineral loss during lactation and recovery after weaning, Obstet Gynecol 1995 ; 86(1) : 26-32) https://pubmed.ncbi.nlm.nih.gov/7784018/
  • Sowers M et al., Prospective study of bone density and pregnancy after an extended period of lactation with bone loss, Obstet Gynecol 1995 ; 85 : 285-89. Même après un allaitement prolongé. https://pubmed.ncbi.nlm.nih.gov/7824246/
  • Cummings RG, Klineberg RJ, Breastfeeding and other reproductive factors and the risk of hip fractures in elderly women, International Journal of Epidemiology 1993 ; 22 : 684-691) Des études faites sur des femmes ménopausées ayant allaité plusieurs enfants ont montré que ces femmes avaient moins de fractures de la hanche que la moyenne. https://pubmed.ncbi.nlm.nih.gov/8225744/
  • Aloia JF, Cohn SH, Vaswani A, Yeh JK, Yuen K, Ellis K, Risk factors for postmenopausal : moins de fractures vertébrales que la moyenne. https://pubmed.ncbi.nlm.nih.gov/3966495/
  • osteoporosis, American Journal of Medicine 1985 ; 78 : 95-100) https://pubmed.ncbi.nlm.nih.gov/3966495/

Hypertension

Breastfeeding has a protective effect on maternal hypertension

Cardiovascular diseases

Breastfeeding is protective against cardiovascular diseases in women.

Endometriosis

Breastfeeding reduces the risk of endometriosis.

  • History of breast feeding and risk of incident endometriosis : prospective cohort study. Farland LV et al. BMJ 2017 ; 358 : 3778)

    Endometriosis is a chronic gynaecological condition affecting around 10% of women in the United States. Breastfeeding (and the lactational amenorrhoea that accompanies it) could be a modifiable risk factor for endometriosis. – The study concluded that the total duration of exclusive breastfeeding had a significant impact on the risk of endometriosis.

Breastfeeding reduces the pain associated with endometriosis

Maternal mental health

To some extent, breastfeeding also has a positive impact on maternal mental health. However, the experience of a mother who wishes to breastfeed and encounters difficulties also represents a significant stress and distress factor. This situation reinforces the idea that all women who wish to breastfeed need appropriate support.

  • McNestry C et al. Breastfeeding and later depression and anxiety in mothers in Ireland: a 10-year prospective observational study BMJ Open 2026. https://bmjopen.bmj.com/content/16/1/e097323 Breastfeeding is linked to lower depression and anxiety years later. A decade-long study following Irish mothers suggests that the mental health benefits of breastfeeding may extend well beyond the postnatal period, highlighting a possible long-term link between infant feeding and maternal well-being.
  • Yuen M et al. The effects of breastfeeding on maternal mental health : a systematic review. J Womens Health 2022 ; 31(6) : 787-807. https://pubmed.ncbi.nlm.nih.gov/35442804/ Overall, breastfeeding was associated with improved maternal mental health outcomes. However, this impact was influenced by the course of breastfeeding, the difficulties encountered, the discrepancy between maternal expectations and experience, and the importance attached to breastfeeding by the mother in her role as mother. Further research on this subject is needed.
  • Butler MS, Young SL, Tuthill EL. Perinatal depressive symptoms and breastfeeding behaviors: A systematic literature review and biosocial research agenda. J Affect Disord. 2021 Mar 15;283:441-471. doi: 10.1016/j.jad.2020.11.080
  • Yusuff et al. 2015, Breastfeeding and Postnatal Depression: A Prospective Cohort Study in Sabah, Malaysia. https://pubmed.ncbi.nlm.nih.gov/26644418/
  • Dias C et Fgueiredo B. Breastfeeding and depression: a systematic review of the literature. Journ Affect Dis 2015 https://pubmed.ncbi.nlm.nih.gov/25305429/ There is a clear link between depression and reduced breastfeeding duration based on a qualitative review of 48 studies. Help for depressed pregnant women should be delivered to enhance both breastfeeding and postpartum psychological adjustment.

Regaining normal weight after pregnancy

Exclusive breastfeeding for more than 6 months is associated with a slimmer waistline.

  • Breastfeeding Greater Than 6 Months Is Associated with Smaller Maternal Waist Circumference Up to One Decade After Delivery. GG Snyder et al. Journal of Women’s Health, Vol. 28, No. 4, 22 April 2019. https://pubmed.ncbi.nlm.nih.gov/30481097/

Contraception

The LAM method – Lactational amenorrhea method of birth control – is a contraceptive method based on lactational suppression of ovulation through breastfeeding. Prolactin, a hormone involved in the production of breast milk, is secreted when the baby sucks. One of the effects of this hormone is to prevent ovulation.

This contraception is 98% reliable, provided certain rules are followed:

  • exclusive breastfeeding, i.e. nothing other than the mother’s milk
  • the baby is less than 6 months old
  • maximum 6 hours between feeds to maintain prolactin levels
  • the mother has not returned from childbirth

Sources for information

Avoidable maternal deaths

In 2016, Bartick et al. simulated avoidable maternal deaths using Monte Carlo analysis. Five maternal diseases (breast cancer, ovarian cancer, diabetes, hypertension and myocardial infarction) served as the basis. With optimal breastfeeding, the study calculated an average of 2,619 avoidable deaths per year. It concludes: Policies aimed at increasing optimal breastfeeding could result in substantial gains in terms of public health. Breastfeeding has a greater impact on women’s health than previously thought. Bartick et al. 2016 Suboptimal breastfeeding in the United States: Maternal and pediatric health outcomes and costs. https://onlinelibrary.wiley.com/doi/ftr/10.1111/mcn.12366