Demystifying science | The impact of breast milk

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It’s quite the opposite: our taste for breast milk comes from an innate attraction to sugar.

“According to the dominant view, we are born with an innate preference for sweets, in part to facilitate breastfeeding,” explains Michael Goran, a biologist at the University of Southern California (USC), author of the book Sugarproof : Protect Your Family from the Hidden Dangers of Excess Sugar with Simple Everyday Fixes.

If a breastfeeding mother consumes a lot of sugar, this innate attraction to anything sweet can be exacerbated.

“Breastfeeding influences the development of neurological centers that regulate appetite,” explains Stéphanie Bayol, a biologist at the National Institute of Health and Medical Research (INSERM) in France.

The two main appetite-regulating centers in the brain control appetite and “reward circuits,” which make eating enjoyable. M^me Bayol demonstrated this link between breastfeeding and food preferences in rats whose mothers ate ultra-processed sweet, energetic and salty foods typical of “junk food”. As adults, these little rats ate more sugar and salt, but no protein. And they gained weight, compared to the healthy mother pups.

Carrot juice

Further evidence of the impact of maternal nutrition during breastfeeding comes from the United States. “Julie Mennella is famous for her studies on food preferences, notably with carrot juice in humans,” says M.^me Bayol. It shows that infants old enough to consume solid foods have a less aversion to vegetables if their mothers consumed them during pregnancy and breastfeeding. »

Maternal diet influences milk quality, Goran observed. The Californian biologist is currently following 200 children whose mothers ate more or less fructose, a type of sugar often found in ultra-processed foods and soft drinks, while she was breastfeeding. They are now 6 years old. So far, he has been able to see that a lot of fructose in breast milk increases the weight of babies at six months. He wants to follow them into adulthood, to see their risk of metabolic diseases and obesity.

Aside from food preferences, what link can there be between a breastfeeding mother’s diet and the health of her child later?

“Sugar can derail a child’s cognitive development,” replies Mr. Goran. Sugar has an impact on the development of the intestinal microbiota [les bactéries présentes dans les intestins]. And this microbiota has very strong links with the brain, in particular because of inflammation. »

According to Mr. Goran, the amount of sugar naturally present in breast milk, in the form of lactose, does not vary much from one mother to another.

Should a mother with a very poor diet avoid breastfeeding? The question is not settled, replies M^me Bayol. “I would say that we can talk to mothers about the impact of their diet on breastfeeding, on the quality of milk,” she adds.

Furthermore, questions about diabetic mothers who breastfeed remain. Endocrinologist at the Montreal Clinical Research Institute (IRCM), Rémi Rabasa-Lhoret indicates that a mother with type 1 diabetes (autoimmune) who breastfeeds her child has more advantages than disadvantages, according to studies. studies.

The same conclusion would also apply to type 2 diabetes, often linked to obesity.

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