Breastmilk Changes During Infant Illness
by Anne Eglash MD, IBCLC, FABM
Holiday celebrations with family and friends are accompanied by the elephant in the room- influenza and it’s sidekicks such as norovirus and rhinovirus! This is the time of year that I give extra high fives and fist bumps to my breastfeeding families while I quietly genuflect to breastmilk for keeping my pediatric patients from severe illness. Because I am so razor focused on breastfeeding, I know for an absolute fact that my breastfed patients are less likely to succumb to the depths of illness that others around them do.
One of the most amazing and little-studied phenomenon shared on social media is the a change in breastmilk appearance when an infant is ill. Mothers who express milk notice that their milk might have a deeper yellow appearance when their infants are ill. Wouldn’t this visual make an awesome poster for families to see? But before we pound the nails into the wall, we need to understand what is happening.
I searched Pubmed for research trials, and found only 2 studies that explored this observation. In a 2012 study, a group of researchers evaluated breastmilk from mothers of 31 infants under 3 months of age who were hospitalized with fever. The infants had a variety of illnesses including diarrhea, respiratory infections, urinary tract infections, and meningitis. A second study from 2007 evaluated breastmilk from 36 mothers whose infants were hospitalized with bronchiolitis (severe lower respiratory infection). Both studies had control groups of mothers with healthy infants.
- Breastmilk of mothers with ill infants had higher concentrations of infection-fighting cells (such as lymphocytes and granulocytes) whether the mother was ill nor not.
- Breastmilk of mothers with ill infants had increased infection fighting cells ONLY if the mother was also ill.
- Breastmilk of mothers with ill infants had higher levels of IgA (the major antibody in breastmilk), and the IgA levels came down as the infants recovered.
- Breastmilk of mothers with ill infants had higher levels of tumor necrosis factor alpha (TNFα), which is an infection-fighting substance (cytokine) secreted from cells in breastmilk.
- The mothers whose infants had respiratory infections had more changes in their breastmilk as compared to infants who had fever from other infections such as a urinary tract infection or diarrhea.
See the Answer
Abstract
Introduction:
Breast milk from mothers of 31 infants, up to 3 months of age, who were hospitalized with fever, was sampled during active illness and recovery. Milk from mothers of 20 healthy infants served as controls.
Methods:
Breast milk from mothers of 31 infants, up to 3 months of age, who were hospitalized with fever, was sampled during active illness and recovery. Milk from mothers of 20 healthy infants served as controls.
Results:
Total CD45 leukocyte count dropped from 5,655(median and interquartile range: 1,911; 16,871) in the acutephase to 2,122 (672; 6,819) cells/ml milk after recovery with macrophage count decreasing from 1,220 (236; 3,973) to 300 (122; 945) cells/ml. Tumor necrosis factor-α (TNFα) levels decreased from 3.66 ± 1.68 to 2.91 ± 1.51 pg/ml. The decrease in lactoferrin levels was of borderline statistical significance.
Such differences were not recorded in samples of the controls. Interleukin-10 levels decreased in the sick infants’ breast milk after recovery, but also in the healthy controls, requiring further investigation. Secretory immunoglobulin A levels did not change significantly in the study or control group.
Discussion:
During active infection in nursing infants, the total number of white blood cells, specifically the number of macrophages, and TNFα levels increase in their mothers’ breastmilk. These results may support the dynamic nature of the immune defense provided by breastfeeding sick infants.
So far this very limited amount of research indicates that color change of breastmilk from moms with ill infants may be due to a higher concentration of infection fighting cells and their secreted immune-altering substances, not simply ‘more antibodies’. Breastmilk cells produce other weapons in addition to IgA, such as tumor necrosis factor alpha and other infection fighting cytokines that are shown in these studies to increase during infant illness. The higher concentration of cells in breastmilk were independent of whether the mother was also ill nor not, which means that the breastmilk changes during infant illness were in direct response to the infant’s needs. In addition, these changes occurred whether the infant’s infection was respiratory, gastrointestinal, or urinary. There is evidence that pathogens and perhaps other signals of illness transfer from the infant’s mouth into the lactating breast in a retrograde manner, signaling to the breastmilk that the infant needs heightened infection-fighting activity. This would be one advantage of direct breastfeeding over exclusive pumping.