Breastfeeding is important for the health of mothers.
For example, mothers who don’t breastfeed have an increased risk of breast and ovarian cancer.
Also, mothers who don’t breastfeed have an increased risk of developing type II diabetes later in life. Gestational diabetes in pregnancy also increases a mother’s risk of developing type II diabetes later in life. The good news is that breastfeeding can help offset this risk for mothers.
However, if a mother has diabetes, can this make breastfeeding success more challenging?
Evidence continues to emerge about possible reasons why some mothers struggle to make a full milk supply. One of the possible reasons for low supply being researched is insulin resistance.
Can Diabetes Impact Breastfeeding Success?
Here are 3 things we know about insulin, insulin resistance and breastfeeding.
#1: Insulin Is Involved In Breast Development And Milk Production
Insulin is a hormone made in the pancreas, which is important for controlling blood sugar levels and keeping them within a normal range. It helps keep your blood sugar level from getting too high (hyperglycaemia) or too low (hypoglycemia).
After eating, your blood sugar level rises. Insulin is released into your bloodstream, and signals cells to absorb sugar from the bloodstream. If you have more sugar in your blood than is needed, insulin helps store the sugar in your liver and releases it when your blood sugar level is low or if you need more sugar (e.g. between meals or during exercise).
Research has shown that mothers with markers for insulin resistance (e.g. obesity) are more likely to have a delay in their milk coming in, suggesting a role for insulin in the breast.
Indeed, insulin does appear to be important for breast growth and development and milk production. For example, animal studies have found cells in the breast must remain insulin sensitive (meaning insulin can easily bind to them) to develop and work optimally.
So, what if a woman is insulin resistant?
How might this affect her ability to make milk?
To explore this possibility, let’s look at what insulin resistance is first.
#2: Insulin Resistance Means Your Body Uses Insulin Less Effectively
Insulin resistance is a condition in which the body uses insulin less effectively to regulate blood sugar levels. If not resolved, more and more insulin becomes required to regulate blood sugar levels, until eventually the body cannot make sufficient insulin to regulate blood sugar levels, and type II diabetes results.
During pregnancy, the placenta makes hormones that help the baby grow and develop. These hormones also block the action of insulin, so more insulin is needed to control blood sugar levels.
In fact, later in pregnancy, the need for insulin is 2 to 3 times higher than normal. If a woman already has insulin resistance, her body may not be able to cope with the extra demand for insulin production, leading to higher blood sugar levels and gestational diabetes being diagnosed.
Research has shown that a particular gene is expressed more often in mothers who are insulin resistant compared to those who are not. This genetic expression may be a marker for linking insulin resistance with a low milk supply.
So what has the research found about insulin resistance and low milk supply?
#3: Insulin Resistance Is Associated With Low Supply
A recent study compared the electronic medical records of two groups of mothers. One hundred and seventy five mothers with a low milk supply without attachment or nipple problem were compared to 226 mothers with attachment or nipple problems but without a low milk supply. About 15% of the first group had diabetes during pregnancy (gestational, type 1, or type 2 diabetes) as compared to about 6% of those with attachment or nipple problems but not a low milk supply. All mothers in this study were no more than 90 days postpartum and highly motivated to breastfeed.
Research has now been planned to examine whether a drug used to control blood sugar in type II diabetes may improve insulin action in the breast, thus improving milk supply. While other approaches to insulin resistance such as dietary changes and exercise are more ideal, a study such as this is a great way for establishing further evidence of insulin resistance having the potential to impact a mother’s ability to make sufficient milk. This study is expected to conclude in July this year.
If you are concerned your ability to make milk may be impacted by insulin resistance, see your GP who may refer you onto an endocrinologist. It's also worth seeing a skilled and experienced nutritionist to help with dietary recommendations, which will likely include elimiating processed sugars, processed grains and low fat foods (which typically contain higher levels of sugar to compensate – full fat is often better). See the documentary That Sugar Film for more fantastic information.