The Postpartum Dance of Estrogen, Insulin, and Cortisol, for Milk Production

The Postpartum Dance of Estrogen, Insulin, and Cortisol, for Milk Production

The Postpartum Dance of Estrogen, Insulin, and Cortisol, for Milk Production


To understand common lactation difficulties, we need to investigate the sensitive dance of estrogen, insulin, and cortisol after childbirth and during lactation.

How we use Energy – It Matters

All living beings are able to absorb energy from outside sources and to use that energy to fuel their life. Plants get their energy from sunlight on leaves. The sunlight is metabolized into starch in the cells of leaves and is then used by the plant to fuel its further growth. This process is called photosynthesis.

Animals and insects eat the leaves and then use the plant’s starch for their own energy needs. These starches are changed into a form of sugar called glucose, which is transported around the body in the blood (blood glucose) and used to fuel the muscles and organs. Excess glucose is put into storage in the liver and muscles. When a burst of energy is needed, the stored glucose is mobilized for rapid use.

Animals and insects eat plants, but they also eat other animals and insects. This allows the eater to absorb types of tissues, vitamins, proteins, minerals and fats that the predator does not easily produce itself. For instance, humans do not produce vitamin C or vitamin B12 in our bodies. We depend on food sources. We also have a hard time producing important fatty-acids that are needed for the brain and the nerves. We get these fatty acids from certain leaves, seeds, nuts, and fish. Humans are less able to produce vitamin D in our body as we age and need to absorb it from food sources.

Human women store excess glucose in our fat pads for the specific use of having extra energy for pregnancy and lactation. In fact, fertility typically only turns on when there is enough stored fat to support a pregnancy.

The Dance of Postpartum Hormones     

Insulin and cortisol are hormones that orchestrate the uses of energy (calories) that we derive from food. Insulin tells the blood glucose where to go. Cortisol dictates how our stored fat will be used.

After childbirth, insulin levels sink to an all-time low and they remain that way throughout the first long phase of exclusive lactation. With these lower levels of insulin, the body does not use blood-glucose to fuel the needs of muscles or organs. Instead, the breastfeeding hormone, prolactin, makes the breast tissue highly sensitive to even these lower amounts of insulin, so that blood-glucose can be directed into the breasts and the milk.

In this dance, the priority is on milk production. At the same time that insulin levels are kept low, the hormone cortisol is kept high. Cortisol tells the mother’s body to take its energy from stored fat. The fat is now metabolized and used for a mother’s daily energy needs. This is why, after childbirth, a mother gradually loses her excess weight: higher levels of cortisol tell her body to access its calories from her stored fat pads.

Estrogen, a hormone of fertility, is the dance partner of insulin. When insulin goes low, estrogen also goes low. This is why women no longer have menstrual cycles while breastfeeding.

When, after months of exclusive breastfeeding, a baby begins eat solids and to gradually wean, the mother’s body increases her levels of insulin. Now she begins to use her own blood-glucose for energy during daily life, and no longer her fat reserves. She begins to gain weight and to build fat reserves in preparation for the next pregnancy. When her insulin levels are high enough, and she has gained enough weight to support another pregnancy, her estrogen levels also increase. This turns on her menstrual cycle. She is ready to conceive.  

Scroll down past the summary and the science extract to read how our present-day blood-sugar and insulin imbalances interfere with the hormonal dance of lactation, leading to the many lactation difficulties that are widely experienced.

Summary of the Hormone Dance

This, then, is the unique dance of hormones that is supposed to occur after childbirth. 

Insulin low, estrogen low, cortisol high.

But the mammary cells are particularly sensitive to even low levels of insulin. This allows the breasts to be fully active.

We see this postpartum pattern in studies on animals and primates (gorillas, chimpanzees and orangutans). This pattern also emerges in a set of studies from the 2000s, in which postpartum insulin levels were measured in Toba women who lived a Paleolithic lifestyle in the forests of Argentina.[1] 

The Problem of Insulin Resistance

Most people today have some degree of a condition called “Insulin Resistance.” It typically develops throughout our formative years in response to a diet with foods that are high on the glycemic index, such as French fries, potato chips, bread, packaged breakfast cereal, candy, cookies, ice-cream, soda, pizza and so on. On this diet, the hormone insulin is constantly in demand. It becomes so active and “loud,” so “nagging,” that the cells of the body stop listening to it. They “resist” responding to insulin’s signals. They are now “insulin resistant.”

Lifestyle factors also play a role: certain medications, chemicals around the house and garden, lack of good sleep, and chemicals in the soaps and cosmetics that we use on our body: anything that causes further inflammation in the body contributes to the furthering of insulin resistance. 

Insulin resistance leads to a vicious circle. When the cells of the body resist accepting energy from blood-glucose, we are actually in danger of death. Too much sugar in the blood is that dangerous. 

Accordingly, the levels of insulin in the blood increase dramatically, more and more. This is called hyperinsulinemia. Higher levels of insulin produce a stronger signal so that eventually the cells do accept the signal and open up to absorb the excess glucose. But the underlying condition remains. As the body produces more and more insulin, the stage is being set for diabetes, a serious illness. 

Gestational Diabetes, often dismissed as being just temporary, is a clear risk factor for diabetes and it is also a red flag for a potentially difficult start to breastfeeding. 

Symptoms of Insulin Resistance

Feeling hungry throughout the day, easily gaining weight, experiencing sudden drops in energy, loss of concentration and fatigue, are signs of progressing insulin resistance. 

Insulin Resistance and Lactation

Now that you understand the Dance of the Hormones, imagine the body attempting to create this dance pattern in the presence of Insulin Resistance and with perpetually higher levels of insulin in the body. It is not possible.

The result can be a lack of full maturation of the mammary tissue during pregnancy, delayed onset of lactation after childbirth, an unreliable supply, and early return of menstruation.

There are other results, such as mothers being unable to lose weight while breastfeeding, even needing to eat more calories to maintain their supply: they are in a struggle with their body’s insulin resistance. Drinking a sugar-laden “sports drink” is one way to force insulin to peak so its signal can get through all the resistance, and this is surely one reason that sports drinks are so popular for supply-challenged mothers.

As well, insulin resistance during our teen years, especially in combination with health problems such as eating disorders (not allowing the body to develop its normal fat pads at the onset of puberty, or being too thin to have menstrual cycles), or a hormonal condition called PCOS (polycystic ovarian syndrome – present in approximately 10% of women), can lead to a condition where the mammary glands do not fully develop at this time. This condition is known as insufficient glandular tissue, IGT.

Yet, even in the face of all this, most mothers are able to produce their personal, optimal supply. Her supply may not cover all of her baby’s needs, and she may have to top it off with donor milk or formula, but she and her baby will have that special and unique time together.

To navigate these breastfeeding hurdles, families require patience, understanding, and the guidance of a knowledgeable lactation consultant. 

We pass Insulin Resistance to our Babies in the Womb

Sadly, insulin resistance is passed from mother to baby in the womb. Our children gain weight more easily and are at risk to develop health problems linked to insulin resistance earlier in life. 

This cross-generational increase in insulin resistance is manifestly seen across the world in quickly rising levels of obesity, diabetes, kidney disease, heart disease and dementia. Because insulin resistance also increases what is called “systemic inflammation,” it promotes the development of inflammatory or autoimmune conditions, which can include depression and anxiety. 

The cross-generational passing of insulin resistance is a world-health tragedy. Yet it is never described in mainstream sources and very little research—on humans—has focused on ways that we might correct it. 

Solving Cross-Generational Insulin Resistance

On animals, however, a plethora of research exists. From these studies, we know that one way to turn it around is to eat foods and take supplements that are high in antioxidants.

In animal studies, antioxidants reduce and even eliminate the impact of a mother’s insulin resistance on her unborn children. These same antioxidants protect the delicate mammary and placental tissue, and thus support the maturation of the mammary glands during lactation. 

Insulin Resistance, Dehydration, and Lactation

One of the mechanisms that the body uses to get rid of excess blood-glucose is to pee it out. It does this by extracting water from the deeper tissues of the body and directing this moisture into the blood, diluting the sugar in the blood so it is less damaging as it passes out in the urine.

To do this, the body takes water first from the areas between the cells (the extracellular matrix), and then from within the cells. 

Only a fully hydrated extracellular matrix allows for fully functional cells and a fully developed mammary gland complex. By not addressing deep hydration, the problem remains. 

It is no coincidence that traditional postpartum soups and gruels, without exception, have deep-hydrating ingredients that maintain the extracellular matrix and keep the cells fully functional. We’ll talk about this in class. 

Additionally, extracts from lactogenic foods and herbs are frequently used in high-end cosmetic products because of their hydrating and moisturizing properties.

To summarize, the lactogenic diet is: 

  • Deeply hydrating
  • Uses herbs and foods and are anti-inflammatory
  • Contains herbs and foods that are used in traditional medicine to treat insulin imbalances.
  • Contains herbs and foods that are anti-anxiety and anti-depressant.
  • Contains herbs and foods that support immune health.
  • On top of this, uses kitchen spices and herbal galactagogues to positively influence the hormones of lactation: prolactin and oxytocin.


1) Valeggia, C. and Ellison, P.T. (2009), Interactions between metabolic and reproductive functions in the resumption of postpartum fecundity. Am. J. Hum. Biol., 21: 559-566.

Some Causes of Low Milk Supply that Respond to Foods and Herbs

Some Causes of Low Milk Supply that Respond to Foods and Herbs

Some Causes of Low Milk Supply that Respond to Foods and Herbs

Lactogenic foods and herbs are commonly “insulin sensitizing,” “blood-sugar balancing,” or have an “anti-diabetic” effect.

These foods also have an anti-inflammatory effect, quieting the “noise” of inflammation caused by insulin resistance but also by exposure to toxins, BPA, and PFORs. This quieting or calming of inflammation allows the hormones to communicate clearly about building and maintaining mammary glandular structures. (You can learn more about this in my class.)  

The following may help you understand why this may be important for you.


These hormonal imbalances can create lactation difficulties in a portion of mothers.

  • Insulin resistance (IR),
  • Thyroid imbalance (too high or too low),
  • Polycystic ovarian syndrome (PCOS),
  • Metabolic Syndrome, Syndrome X,
  • Gestational Diabetes, Pre-Diabetes, and types 1 and 2 Diabetes.

Insulin Resistance

Insulin resistance is an integral part of many hormonal imbalances. But why is insulin important to milk production?[i] Insulin resistance affects many systems in the body. Even the thyroid can be impacted by the inflammation that goes hand in hand with insulin resistance. So what is insulin resistance? Why is it so central, so important?

Insulin, a hormone produced by the pancreas, plays a key role in the development of mammary tissue during adolescence and pregnancy. It plays a role in the initiation of milk production after childbirth, and it contributes to the steadiness and reliability of milk production for the long term.

Insulin also plays a central role in fertility. When breastfeeding women begin to menstruate soon after childbirth (3 – 5 months, instead of returning only after a year or longer), insulin resistance is likely the cause.

For insulin to be fully functional and effective, our cells must be sensitive to its signals. Our cells must respond to its signals. When we become insulin resistant, the opposite occurs: our cells become insensitive and unresponsive to insulin.

Americans tend to acquire insulin resistance (IR) because:

  • We grow up eating the standard American diet
  • We are under stress at home, work and school
  • We tend to over-eat and under-sleep

The good news is that we can turn insulin resistance around and improve insulin sensitivity with:

  • Dietary changes (see Dr. Jason Fung’s books and lectures online),
  • LACTOGENIC Herbs and foods that improve insulin sensitivity, and
  • Anti-stress methods such as progressive relaxation and / or mindfulness.

Disclaimer: talk to your doctor about your health questions regarding insulin. Do not take the information in this book as a prescription.

[i] NommsenRivers, L.A., Riddle, S.A., Thompson, A., Ward, L. and Wagner, E. (2017), Milk Production in Mothers with and without Signs of Insulin Resistance. The FASEB Journal, 31: 650.9-650.9.


During adolescence, some girls will only partially develop their mammary glandular tissue (the glands that produce milk). While this is not common, it is also not rare. The medical term for this is mammary or breast hypoplasia. It is commonly referred to as IGT.

IGT stands for “Insufficient Glandular Tissue,” and it encompasses the entire range of partial development: slightly less mammary tissue than optimal, half the tissue, very little tissue, or practically no mammary tissue at all.

IGT has many causes, including hormonal imbalances during adolescence, radical weight loss and dieting during adolescence, and exposure to pesticides and pollutants in childhood.

IGT and PCOS (Polycystic ovarian syndrome) often appear together. In our online group, mothers often have both IGT and PCOS.


During pregnancy and also after childbirth, mothers with IGT can use a lactogenic diet to best develop their mammary glandular tissue at those times. For instance, mothers may drink infusions of herbs that are rich in nutrients and also insulin sensitizing, which improves mammary gland maturation. 

Nutritional Lacks

Nutritional deficiencies, especially low vitamin D, A, the B’s, iodine, iron, zinc or calcium, can impact lactation.[i] [ii] In the United States, magnesium and trace minerals are often lacking in our commercially grown, processed and packaged food. To handle the exertions of pregnancy, childbirth and lactation, and to maintain our own best health, we simply have to eat whole, fresh foods, and, if needed, to supplement with vitamins and minerals.

I know one mother with chronic low milk supply who was suddenly able to produce sufficient milk after her doctor prescribed a mega-dose of vitamin D. Another mother reported improvement only when she began eating foods containing vitamin B12, such as eggs, liver and dairy. I recall one mother whose supply rose considerable after eating steak. Did she need the iron, or the protein?

A well-balanced, whole foods diet along with any needed supplements is a common sense way to build reserves of all the nutrients needed for milk production.


[i] Lee, S., & Kelleher, S. L. (2016). Biological underpinnings of breastfeeding challenges: the role of genetics, diet, and environment on lactation physiology. Am J Physiol Endocrinol Metab, 311(2), E405-422. doi:10.1152/ajpendo.00495.2015

[ii] Kuznetsov, V. (2017). Clinical and pathogenetic aspects of hypogalactia in post-parturient women. Актуальні проблеми сучасної медицини: Вісник української медичної стоматологічної академії, 17(1 (57)), 305-307.

Not Always Obvious…

Mothers and healthcare providers can easily overlook the underlying causes of a mother’s lactation difficulties. A mother with insulin resistance, PCOS or Metabolic Syndrome might have a perfectly healthy outward appearance; persons with Pre-Diabetes are often unaware of their condition; and IGT may not be visibly apparent. Nutritional lacks are also invisible. Even thyroid disorders can come as a surprise, as they can develop suddenly after childbirth, even if the thyroid was not a problem before.

Medical Testing

Because underlying problems are not always apparent, healthcare providers should routinely test for thyroid function, blood sugar balance, and nutritional deficiencies if a mother has lactation difficulties. In most cases, treating the thyroid, improving insulin sensitivity, and supplementing as needed with zinc, iodine, magnesium, the B’s and / or vitamin D3 will support a mother’s efforts to improve her milk supply. 


[i] Lee, S., & Kelleher, S. L. (2016). Biological underpinnings of breastfeeding challenges: the role of genetics, diet, and environment on lactation physiology. Am J Physiol Endocrinol Metab, 311(2), E405-422. doi:10.1152/ajpendo.00495.2015

[ii] Kuznetsov, V. (2017). Clinical and pathogenetic aspects of hypogalactia in post-parturient women. Актуальні проблеми сучасної медицини: Вісник української медичної стоматологічної академії, 17(1 (57)), 305-307.

For information on our classes for mothers, IBCLCs and postpartum caregivers, go HERE.