It is known that babies whose diet is rich in glucose or fructose are at higher risk of becoming obese or suffering from metabolic diseases later in life. Given this risk, should diabetic mothers refrain from breastfeeding when their glucose levels (blood sugar) are high? No, suggests a study published in the journal
Diabetes Care by Canadian researchers including Patricia Lemieux, a professor at the Faculty of Medicine of Université Laval and researcher at the CHU de Québec - Université Laval Research Center.
Glucose and fructose are very scarce in human milk. This would explain why mothers' blood sugar has minor repercussions on the overall composition of their milk.
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To conduct this study, the researchers received assistance from 11 mothers with type 1 diabetes. The participants agreed to provide at least one milk sample at 3 time points: 6, 12, and 24 weeks after their child's birth. This milk, collected mid-feed into a sterile container, was frozen and subsequently analyzed in the laboratory. Additionally, to determine the amount of milk consumed by their child, the mothers had to weigh them before and after feeding using an electronic scale. Finally, they had to wear a device that continuously recorded their blood glucose levels.
The analysis of this data yielded several interesting findings. First, mothers' blood sugar measured between 90 and 120 minutes before feeding is correlated with the glucose and fructose content of their milk. However, it is not correlated with the concentration of other important components of milk, including lactose, which represents 85% of all sugars in human milk, proteins, and free fatty acids. Furthermore, the mother's blood sugar was not correlated with the leptin level (a hormone that regulates appetite) in the milk nor with the amount of milk consumed by the child.
"Glucose and fructose are very scarce in human milk. For comparison, the concentration of lactose is 100 times higher than that of glucose," reminds Patricia Lemieux. "For women who manage their diabetes well, the decision to breastfeed should not be influenced by their blood sugar levels."
Type 1 diabetes represents about 10% of all diabetes cases. In Canada, it is estimated that approximately 150,000 women live with type 1 diabetes. Do the study's conclusions also apply to women with type 2 diabetes?
"Our study cannot answer this question because there are several other factors to consider with type 2 diabetes," emphasizes Professor Lemieux. "However, the most recent guidelines from Diabetes Canada recommend breastfeeding for all diabetic patients."
The study published in
Diabetes Care was led by Lois Donovan, a professor at the University of Calgary.