Anatomy of the human breast

Anatomy of the human breast - click to enlargeThe inside of a breast looks like a bush – with the nipple being the base or stump and the milk duct 'branches' and alveoli 'leaves' fanning out inside. 

It is composed of essentially four parts: alveoli or glands, milk ducts and fat, plus connective tissue. The alveoli group together into larger units called lobes.

There will be around nine to twelve main milk lobes in each breast.  Each lobe has a main duct, leading from the nipple back into the breast to the lobe - like a main branch of the bush.  Multiple smaller ducts branch off, forming the milk lobe itself. 

The 'leaves' of this bush are the alveoli – sac-like round glands, lined with milk-producing cells, lactocytes.  It is inside each alveolus that the milk is produced, travelling down the ducts and out of the nipple.

 (Click on the image to the right for a closer look.)

How breast milk is made

The process of making breast milk (lactogenisis) is heavily dependent on two hormones - prolactin and oxytocin.  Each hormone needs an equivalent receptor located wherever the hormone’s influence is required, and must be an exact match to the hormone.  In addition, there needs to be enough receptors for the amount of hormone.  Both prolactin and oxytocin are secreted by the pituitary gland (a pea-sized gland at the base of the brain).

One

The hormone prolactin is needed for milk to be produced.  Prolactin receptors are on the walls of the lactocytes (the milk-producing cells of the alveoli). The receptors allow the prolactin in the bloodstream to move into the lactocytes and stimulate milk production.

Two

As the alveoli fill up with milk two things happen:

1. They stretch, which changes the shape of the lactocytes so they cannot absorb any more prolactin, therefore slowing the rate of milk production.

2. The breast milk itself contains a protein called Feedback Inhibitor of Laction (FIL).  When the breast is full of milk, and so there is an increased amount of FIL present, the FIL gives the message to the lactocytes to stop producing milk.

Three

The baby’s suckling stimulates the hormone to be released – oxytocin. (At the same time, the pituitary gland also releases more prolactin too.) Oxytocin causes the muscles around the alveoli to contract, squeezing the milk into the ducts, which swell behind the nipple, full of milk.  The motion of the baby’s tongue as they suck, draws the milk into their mouth – though they must have a good mouthful of breast to be able to reach the ducts and feed effectively.

Four

As the milk empties out of the alveoli, the prolactin receptors return to their normal shape, so the prolactin flows back into the lactocytes and milk production starts again.  The milk that is produced as the baby feeds is higher in fat and more satisfying.

Prolactin Receptor Theory proposes that frequent milk removal in the first several weeks of feeding increases the number of receptor sites. With more receptors, more prolactin can flow into the lactocytes, and milk production capacity increases.

Prolactin levels in the body start to rise around half-way through pregnancy, surging to their highest levels at the time of birth. However, during pregnancy high levels of progesterone, produced by the placenta,  interact with the prolactin receptors on the walls of the lactocytes to inhibit milk production. But these progesterone levels fall dramatically once the placenta is delivered, and the prolactin is able to start having an effect.

The level of prolactin drops continuously until it plateaus around three months after birth.  However the more frequent the prolactin surge, experienced during feeding, in the first several weeks, the higher the baseline for on-going milk supply levels.  The more successful breastfeeding is in the first few weeks, the more successful it is likely to be going forward.

So if you're breastfeeding and need support, it is really is key to get it in the first few weeks. For more information, please visit our Breastfeeding Support page: www.contentedcalf.com/products/recipe-book/breastfeeding-support

  • (Bonyata, 2010)
  • (Chen, 2008)
  • (Evens, 2009)
  • (Kimball, 2009)
  • (West & Marasco, 2009)

 

A lactogenic diet

There are many factors that determine a successful breastfeeding experience and sufficient milk supply for your baby. It is a complex process and there can be many unknown reasons why breastfeeding works for some and others are not so lucky. If you are having problems feeding, I would advise that you call the NHS,  NCT or La Leche League breastfeeding helplines. For more information on breastfeeding support, please visit our Breastfeeding Support page: www.contentedcalf.com/products/recipe-book/breastfeeding-support

Food is just part of the picture.  Indeed, in their book “A Breastfeeding Mother’s Guide to Making More Milk” Diana West and Lisa Marasco introduce the concept of ‘The Milk Supply Equation’, which is as follows:

   1. Sufficient glandular tissue

+ 2. Intact nerve pathways AND ducts

+ 3. Adequate hormones AND hormone receptors

+ 4. Adequately frequent, effective milk removal and stimulation

= GOOD MILK PRODUCTION [i]

 

Looking at the above equation, there’s not much we can do about points 1 and 2 - these are down to an individual's antomy. (A very small number of women can suffer from breast hypoplasia – the incomplete development of the glandular tissue in the breast.)

With regards to point 4, if a new mum has breastfeeding problems, Midwives, Health Visitors and Breastfeeding Counsellors can help support her and her baby with effective feeding, which will stimulate milk production. (See www.contentedcalf.com/products/recipe-book/breastfeeding-support for further details of support organisations.) 

But what do most new mums really know about point 3, hormones and the role diet can play in lactogenesis (the process of making milk)? It's here that a lactogenic diet can play a role, by helping to increase the levels of prolactin in the bloodstream, and therefore potentially increase the quantity of milk made, as well as help improve the quality and help the flow. A lactogenic diet, along with a correct latch and frequent feeding, is one of the tools in a whole toolbox of things to help with your breastfeeding experience. 

  • (Lieberman & Cassar-Uhl, 2011) 
  • (West & Marasco, 2009)

 

Prolactin and milk supply

As we have seen above, the major hormone involved in milk production is prolactin. Anything that helps our bodies increase the level of prolactin in our bloodstream can help increase milk supply. The information below tries to show how certain foods can help increase that level of prolactin:

Tryptophan

Tryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. As well as being one of the 10 essential amino acids that the body uses to make the proteins it needs, it also serves as a precursor for seratonin.

Why is this important? Well, seratonin is the neurotransmitter that counter-acts or suppresses dopamine. And dopamine suppresses prolactin.

So anything that keeps dopamine levels low, in turn keeps prolactin levels high. High tryptophan = high seratonin = high prolactin. The good news is that tryptophan is found in lots of foods.

Foods containing tryptophan include:

  • Fruit: apricot
  • Grains: oats, barley, wheat
  • Herbs & spices: basil, chives, black pepper, garlic
  • Leafy greens: watercress, spinach
  • Legumes: beans (black, green, kidney), chickpea, peas
  • Meat & fish: Calf liver, halibut, lamb, salmon, tuna, venison, poultry (especially turkey)
  • Natural sugars: honey, malt syrup, maple syrup
  • Nuts: almond, cashews
  • Seeds: evening primrose, pumpkin, sesame, sunflower, fenugreek
  • Vegetables: asparagus, cauliflower, fennel, celery, onion, jerusalem artichoke, lettuce, carrot, sweet potato.

 

  • (Ben-Jonathan & Hnasko, 2001)
  • (Dopamine definition, 2004)
  • (George Mateljan Foundation)

 

Sedative vegetables

There is also a small group of herbs and foods containing substances that can act as sedatives. Sedative foods serve as natural opiates, which suppress dopamine, encourage increased production of prolactin. 

Foods considered sedating include: fennel, lettuce, onion, potato.

  •  (Jacobson, 2007)

 

Polysaccharides

Foods containing polysaccharides, specifically beta glucan, are able to stimulate prolactin secretion and so raise prolactin levels in the blood. 

Foods containing polysaccharides include: barley, oats, yeast.

  • (Jacobson, 2007)
  • (Sepehri, Renard & Houdebine 1990)

 

Oxytocin and milk flow

The role of oxytocin is to squeeze the milk out of the alveoli into the ducts which lead down to the nipple, by causing the muscles around the alveoli to contract.  However, if the production of oxytocin is suppressed, the ‘milk-ejection reflex’ is inhibited.  If the milk is not fully ‘let down’ (however successful actual milk production has been), only a little amount of milk can be removed.  The breasts can then not emptied and so the message to make more milk is not sent back to the brain.

The baby’s suckling stimulates oxytocin to be released.  However, stress hormones, such as adrenaline suppress the production of oxytocin. As well as trying to keep your stress-levels low, it is also very important to eat meals and snacks throughout the day, as hunger can induce stress too.

In addition to ensuring you eat regularly throughout the day, in her book Mother Food, Hilary Jacobson provides a list of different remedies for problems with let-down or flow, originally recommended by the 1st Century AD Greek Doctor Dioscorides, which include the following foods and herbs: anise, basil, dill, fennel (garden and wild), lettuce.

  • (Jacobson, 2007)
  • (Letdown Reflex When Breastfeeding)
  • (Makina & Krasnovskaia, 1999)
  • (Whittlestone, 1954)

 

Composition of breast milk and quality

Breast milk is roughly made up in the ratios listed in the table below:

Contents  
Fat (g/100ml)
total
4.2
Protein (g/100 ml)
total
1.1
Carbohydrate (g/100 ml)
lactose
7
oligosaccharides
0.5
Minerals (g/100 ml)
calcium
0.03
phosphorus
0.014
sodium
0.015
potassium
0.055
chlorine
0.043

[ii]

Breast milk draws its make-up from the food a mother eats, so it’s essential to eat the foods that make it the best it can be.  However, if the diet is found lacking, content is obtained from mother’s bodily stores. Obviously eating a healthy, balanced diet is the most sensible way of ensuring the mother is getting everything she needs.  However, two food groups particularly worth mentioning are:

Essential Fatty Acids

DHA and other Omega 3 fatty acids are fundamental to the development of the brain in infancy and childhood. Breast milk boosts the brain growth because, provided the mother herself eats foods rich in Omega 3 fatty acids, it contains lots of DHA. Having a diet with good levels of DHA in it has also been linked to promoting a mother’s own psychological and emotional well-being, and helping fight against post-natal depression.

Essential Fatty Acids are divided into two main types: Omega 6 and Omega 3. The body cannot make these fatty acids itself, so we need to ingest them through foods and/or supplements. A Texas study from 2000 showed that taking additional DHA significantly increased the DHA content of the nursing mothers' milk.

Food sources for Omega 6 are: butter, cream, eggs, grains, meat fat, nuts, whole-fat milk.

Food sources for Omega 3 are: flaxseed oil, green leafy vegetables, legumes, organic eggs and fish, walnut oil. Sources specifically for Omega 3 derivative DHA include: algae extract, cod-liver oil, fish oil.

  • (Breastfeeding mom's diet and baby's brain development)
  • (Jacobson, 2007)
  • (Jensen, Maude, Anderson & Heird 2000)

 

Coconut Oil

Your body's anti-microbial fatty acid (monolaurin) is made from lauric acid. Monolaurin is anti-viral and anti-bacterial. If you add foods rich in lauric acid your diet, the amount in your breast milk increases substantially, which may help breastfed babies fight colds and infections. In countries where coconut oil is part of the staple diet, lauric acid levels in breast milk can be as high as 21% (normally around 3%).

  • (Hareyan, 2004)
  • (Jacobson, 2007)

 

Other areas of a lactogenic diet

Hormones

As we have seen the milk production process is very hormonally driven, so one group of foods to look at are those rich in saponins.  Some saponins can mimic the human hormones they resemble. The body can use them as precursors to make hormones, and they may influence production of hormones from the pituitary gland.  This may aid production of both prolactin and oxytocin, both of which are made in the pituitary gland. 

Foods rich in saponins include: asparagus, carrots, green beans,oats, peas, potatoes.

  • (Broadhurst & Duke PhD)
  • (Jacobson, 2007)

 

Reduction in water retention

There is a possible connection between water retention and delayed milk production – often a mother’s milk does not come in fully until any swelling experienced during the pregnancy subsides.[iii]  Therefore foods which are high in beta-carotene, antioxidants and are diuretic, and so detoxify liver and kidneys helping to relieve water retention, are considered lactogenic. 

Foods high in beta-carotene, antioxidants and diuretics include: asparagus, beetroot, carrot, dandelion, green leafy vegetables, sweet potato.

  • (Jacobson, 2007)
  • (West & Marasco, 2009)

 

Calcium

Some women who are continuing to breastfeed after they have re-started menstruating have noted that they experienced lower milk production prior to their periods.  Although this link has not formally studied, Patricia Gima (IBCLC) has reported calcium/magnesium supplements have helped several of her clients, often within 24 hours. 

Foods high in calcium include:  almonds, chicken soup, green beans, green leafy vegetables, legumes, peas, sesame seeds.

  • (West & Marasco, 2009)
  • (Jacobson, 2007)

 

Protein

Some low-supply mothers also see an increase in supply if they increase intake of protein.

  •  (Jacobson, 2007)

 

References, Endnotes & Resources

> 007 Breasts. DHA and breast milk: goodies for baby's brain. Retrieved October 13, 2010, from 007 Breasts: http://www.007b.com/breastfeeding_intelligence_diet.php

> Ben-Jonathan, N., & Hnasko, R. (2001, December). Dopamine as a prolactin (PRL) inhibitor. Retrieved October 13, 2010, from PubMed.gov: U.S. National Library of Medicine: http://www.ncbi.nlm.nih.gov/pubmed/11739329

> Beth Israel Health Care System, New York. Anatomy Of The Breast. Retrieved January 31, 2012, from Beth Israel Health Care System, New York: http://mammary.nih.gov/reviews/development/Human-breast001/index.html

> Bonyata, K. (2010, March 30). How does milk production work? Retrieved October 11, 2010, from kellymom: breastfeeding & parenting: www.kellymom.com/bf/supply/milkproduction.html

> Broadhurst, C. L., & Duke PhD, J. A. Saponin: Natural Steroid. Retrieved October 13, 2010, from The Herb Companion: www.herbcompanion.com/print-article.aspx?id=6710

> Chen, P. J. (2008, October 22). Your baby's first few weeks - Breast Milk - The Basics. Retrieved October 2010, from University of Maryland Medical Center: www.umm.edu/pregnancy/000115.htm

> Davis R N, IBCLC, Marie (2010). How the Breast Makes Milk. Retrieved January 2, 2013, from Lactation Consultant (dot) Info: www.lactationconsultant.info/how.html

>Definition of Dopamine. (2004, March 19). Definition of Dopamine. Retrieved October 13, 2010, from MedicineNet.com - We Bring Doctor's Knowledge to You: www.medterms.com/script/main/art.asp?articlekey=14345

> Evens, K. (2009). The Food of Love: your formula for successful breastfeeding. Brighton: Myriad Editions: 10

> George Mateljan Foundation. Tryptophan. Retrieved January 31, 2012 from The World's Healthiest Foods: http://www.whfoods.com/genpage.php?tname=nutrient&dbid=103

> Hareyan, A. (2004, September 26). Coconut Oil Increases Beneficial Properties in Human Breast Milk. Retrieved October 13, 2010, from EmaxHealth: http://www.emaxhealth.com/4/689.html

> Jacobson, H. (2007). Mother Food: food and herbs that promote milk production and a mother's health. Rosalind Press: 6, 24- 44, 96, 118-123, 126-136, 144-153, 160-163

> Jensen C.L., Maude M., Anderson R.E. & Heird W. C. (2000). Effect of docosahexaenoic acid supplementation of lactating women on the fatty acid composition of breast milk lipids and maternal and infant plasma phospholipids. Retrieved February 08, 2012, from PubMed.gov: U.S. National Library of Medicine: http://www.ncbi.nlm.nih.gov/pubmed/10617985

> Kimball, J. W. (2009, November 14). Hormones of the Pituitary. Retrieved October 2010, from Kimball's Biology Pages: http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Pituitary.html

> Lieberman, T. & Cassar-Uhl, D. (2011, July 25). Podcast:  When the “booby fairy” doesn’t arrive – insufficient glandular tissue/breast hypoplasia. Retrieved January 31 2012, from Motherlove Blog: http://motherloveblog.com/2011/07/25/when-the-booby-fairy-doesnt-arrive-a-podcast-interview-on-insufficient-glandular-tissuebreast-hypoplasia-with-diana-cassar-uhl

> Letdown Reflex When Breastfeeing. Letdown Reflex When Breastfeeding. Retrieved October 13, 2010, from Kid & Parent: Every Parent Should Know: http://www.kidandparent.in/babycare/feeding/letdown-reflex-when-breastfeeding

> Makina, D. M., & Krasnovskaia, I. A. (1999). Morphofunctional characteristics of rat thyroid gland under the combined effect of oxytocin and adrenaline. Retrieved October 13, 2010, from PubMed.gov: U.S. National Library of Medicine: http://www.ncbi.nlm.nih.gov/pubmed/10561851

> Prentice, A. (1996, December). Food and nutrition bulletin – Volume 17, Number 4, December 1996. Retrieved November 1, 2010, from The United Nations University Press: Food and Nutrition Bulletin: http://archive.unu.edu/unupress/food/8F174e/8F174E04.htm#Constituents of human milk

> Rountree, R., & Block, M. (2006). The New Breastfeeding Diet Plan: Breakthrough ways to reduce toxins and give your baby the best start in life. McGraw-Hill.

> Sepehri H, Renard, C & Houdebine, L.M. (1990). Beta-glucan and pectin derivatives stimulate prolactin secretion from hypophysis in vitro. Retrieved February 8, 2012, from PubMed.gov: U.S. National Library of Medicine:http://www.ncbi.nlm.nih.gov/pubmed/2356188

> Turky lmaz, C; Onal, E; Murat Hirfanoglu, I; Turan, O; Koç, E; Ergenekon, E and Atalay, Y. The Effect of Galactagogue Herbal Tea on Breast Milk Production and Short-Term
Catch-Up of Birth Weight in the First Week of Life - 17(2): 139-142.  Retrieved October 25, 2011, from The Journal of Alternative and Complementary
Medicine: http://www.liebertonline.com/doi/abs/10.1089/acm.2010.0090?journalCode=acm

> WebMD Medical Reference. (2010, February 25). Why Breakfast Is the Most Important Meal of the Day. Retrieved November 1, 2010, from WebMD Medical Reference: http://www.webmd.com/diet/guide/most-important-meal

> West, D., & Marasco, L. (2009). The Breastfeeding Mother's Guide to Making More Milk. McGraw-Hill.

> Weston, S. (2010, September 28). A third of people in Ireland skip breakfast. Retrieved October 26, 2010, from FoodBev.com: http://www.foodbev.com/report/a-third-of-people-in-ireland-skip-breakfast

> Whittlestone, W. G. (1954). The effect of adrenaline on the milk-ejection response of the sow - Whittlestone 10 (2): 167. Retrieved October 13, 2010, from Journal of Endocrinology: http://joe.endocrinology-journals.org/cgi/content/abstract/10/2/167

 


 

[i] West, D., & Marasco, L. (2009). The Breastfeeding Mother's Guide to Making More Milk. McGraw-Hill: 13

[ii] Prentice, A  (1996). Food and nutrition bulletin – Volume 17, Number 4, December 1996. The United Nations University Press: http://archive.unu.edu/unupress/food/8F174e/8F174E04.htm#Constituents of human milk

[iii] West, D., & Marasco, L. (2009). The Breastfeeding Mother's Guide to Making More Milk. McGraw-Hill: 121