What Effect Does Alcohol Have on Your Milk Supply?

Want to have a drink, but getting confused by all the information out there? With so many myths prevailing and misinformation, it can make your head spin. Having an understanding of how your milk is made and how alcohol affects you and your baby will help you make choices when it comes to having a drink with dinner or a night out with friends. Although there are guidelines, the effect of alcohol on milk supply is not quite one size fits all.

How is milk made?

Human milk is complex. It changes from morning to night, from day to day and during your lactation journey. It is superior nutrition for your baby containing everything they need to gain weight, grow and develop their immune system. 

Inside the breast are lobules that are clusters of alveoli which is where milk is made and stored. Each breast has about 15-20 lobules.(1) When your baby nurses, the hormones prolactin and oxytocin are released. Prolactin levels begin to increase in your bloodstream and tell the alveoli to make more milk. Prolactin levels are highest about 30 minutes after you begin to pump or nurse your baby.(2) There is a natural circadian rhythm of prolactin which is highest during the night. Middle of the night milk removal is important to sustain your supply during the daytime. Prolactin can make you feel relaxed so it is easier to fall asleep or be more rested during those dream-feeds. 

The alveoli take proteins, sugars, fats, white blood cells, enzymes and more from the blood to create milk. When oxytocin is released as soon as your baby begins to nurse, the muscles around the alveoli contract and milk is squeezed out. As your milk lets down, it moves through the ducts towards and then out the nipple.

How does alcohol get into your milk?

Because human milk is made from the blood, when alcohol enters the bloodstream some of it will be transferred into the breast milk. 2% or less of the amount of alcohol reaches the blood.(3) The liver works to metabolize the alcohol you drink, like a cleaning machine for your blood, but as long as there is alcohol in the bloodstream, it will be in your milk. 

Myth: pumping your milk does not eliminate alcohol faster from your milk supply. Time reduces the concentration of alcohol in your blood and your milk.

Fact: alcohol levels peak in both blood and breast milk between ½ - 1 hour after drinking, but there is a lot of variation from person to person.(3)

Alcohol is still detectable in milk for 2-3 hours per drink after consumption. The more you drink, the longer it will be detected in your milk. For example, three drinks might be detectable for 6-8 hours afterward.

What are the guidelines?

• The safest option is to not drink alcohol
• Up to one drink per day is considered safe while breastfeeding(4)
• Wait at least 2 hours after having one drink before nursing or pumping. Because alcohol peaks ½ - 1 hour after consumption, nurse your baby and then have a drink or nurse or pump while having your first drink since the peak will be after you are done breastfeeding for that session.

What is considered one drink?

• 12 ounces of 5% beer
• 8 ounces of 7% malt liquor
• 5 ounces of 12% wine
• 1 ½ of 40% or 80 proof liquor(4)

What else affects alcohol and breastfeeding?

• Drinking more alcohol increases the length of time it takes to leave the blood and your milk
• Eating food slows the absorption of alcohol and the peak of alcohol in your system will be slightly delayed.
• A mothers weight impacts the length of time alcohol is in the bloodstream
• Alcohol inhibits the release of oxytocin which signals the let down reflex. 
• Prolactin levels are decreased from drinking alcohol. People with a family history of alcoholism are more at risk. One study showed that among non-alcohol-dependent women who have a family history of alcoholism, they had prolactin levels that were lower than mothers who did not have a family history of alcoholism after consuming an alcoholic beverage.(8)

What effects can alcohol have on your baby?

• Babies may take about 20% less milk during nursing for 3-4 hours after mom drank alcohol.(3)
• More crying and fussiness 
• Startle more often
• They may sleep deeper and not wake as they normally would which can be dangerous(7)
• Disruptions to their sleep 
• Slower weight gain
• May affect long term motor development if the mother regularly drinks more than one drink daily(5)
• May affect long term reasoning skills of the child(6)

Is alcohol good for milk supply? 

Have you ever been told to have a beer to increase your milk supply? Historically, different beers were made from barley, malted barley and herbs or other ingredients for lactating mothers and wet nurses. The alcohol in these home brewed beers had a significantly lower alcohol content and were called “small beer”(9). The other ingredients in beers made for lactation like anise, fennel, dates, pepper, cinnamon and caraway are galactogogues and help increase milk supply. Barley and oats, like in stout beer, contain beta-glucan which is a type of fiber and can raise prolactin levels and increase milk supply.(10) Alcohol alone decreases supply. But because the alcohol content was minimal and other ingredients added that were nutritional and supported milk supply, the myth that having a beer will boost supply lived on.

You do not need to be deprived of a good time as a breastfeeding parent. Armed with information, you can make better choices about how much and when to enjoy a drink as well as when and how long it will be in your milk. If you are no longer feeling the effects of alcohol you drank, you are likely ok to nurse your baby. Safety always comes first and you should never sleep with your baby in the same bed if you or your partner have been drinking alcohol. Make sure you plan enough time to become sober before caring for your baby, nursing or pumping. 

Cheers!

Footnotes:

1. https://en.wikipedia.org/wiki/Mammary_alveolus
2. https://www.ncbi.nlm.nih.gov/books/NBK148970/#:~:text=When%20a%20baby%20suckles%2C%20the,the%20next%20feed%20(20).
3. https://pubs.niaaa.nih.gov/publications/arh25-3/230-234.htm
4. https://www.cdc.gov/breastfeeding/breastfeeding-special-circumstances/vaccinations-medications-drugs/alcohol.html#:~:text=have%20consumed%20alcohol%3F-,Not%20drinking%20alcohol%20is%20the%20safest%20option%20for%20breastfeeding%20mothers,a%20single%20drink%20before%20nursing.
5. https://www.academia.edu/26659698/Maternal_alcohol_use_during_breast_feeding_and_infant_mental_and_motor_development_at_one_year?auto=citations&from=cover_page
6. https://publications.aap.org/aapnews/news/13848
7. https://pubmed.ncbi.nlm.nih.gov/11839458/
8. https://publications.aap.org/pediatrics/article-abstract/125/5/e1162/81647/Breastfeeding-and-Prolactin-Levels-in-Lactating?redirectedFrom=fulltext
9. http://lactogenicdiet.blogspot.com/2011/10/beer-as-galactagogue-brief-history.html
10. https://www.ncbi.nlm.nih.gov/books/NBK501827/

Other Resources:

https://wicbreastfeeding.fns.usda.gov/how-breast-milk-made

https://onlinelibrary.wiley.com/doi/abs/10.1002/dev.420260804

https://www.laleche.org.uk/alcohol-and-breastfeeding/

https://pubmed.ncbi.nlm.nih.gov/24118767/

https://alcoholthinkagain.com.au/alcohol-your-health/alcohol-and-long-term-health/alcohol-and-the-digestive-system/

https://www.ncbi.nlm.nih.gov/books/NBK501469/