According to the conclusion of researchers from Chalmers University of Technology, Sweden, in a new study published in the scientific journal Nutrients, babies born to mothers who drank cow’s milk were more likely to drink cow’s milk during their period. Breastfeeding lowers the risk of food allergies than other babies.
The results are based on a survey of the eating habits of more than 500 Swedish women and the incidence of allergies in their children at one year of age.
“We found that one-year-old babies whose mothers consumed more cow’s milk during lactation were healthier than other children. Despite the clear survey, we do not claim that drinking cow’s milk will be a cure for disease in general.” Mia Stråvik, PhD student in the Department of Food Science at Chalmers University of Technology, and first author of the study.
There are many factors behind food allergy risk, not just genetic factors. However, as Mia Stråvik explains, “Diet is one factor that the parents themselves can have a direct influence on. It’s quite common for young women to avoid dairy these days, in part because of popular trends and concerns, one of which is related to diets.”
She points out that allergies to milk proteins are uncommon in adults, so most women can consume milk and dairy products on their own without problems. Lactose intolerance is something else entirely, in that the body cannot break down the sugar in milk. And in this case, lactose-free dairy products will be tolerated by the body.
The hygiene hypothesis:
According to Professor Ann-Sofie Sandberg, who supervises Mia Stråvik, another explanation could be that the milk in the mother’s diet contains substances that stimulate the maturation of the immune system.
“During a child’s early development, there is a period when stimulation of the immune system is necessary for a child to develop a tolerance to different foods.”
According to one immunological hypothesis, early exposure to different microorganisms can act as a trigger for a child’s immune system, she explains.
“But, with today’s prevalence of microorganisms lower in our more hygienic society, substances introduced through the mother’s diet may be another way to stimulate growth. part of the immune system.”
Mia Stråvik’s study is not the first to link cow’s milk in a mother’s diet with a reduced risk of allergies in children. However, previous studies have often relied solely on questionnaire responses – both on eating habits and the presence of allergies. In this study, both the data and the conclusions were much more reliable.
“In this study, we were able to actually verify the reported amounts of milk and dairy products through biomarkers in the women’s blood and breast milk,” says Mia Stråvik. “Furthermore, all childhood allergies are diagnosed by a physician who specializes in pediatric allergies.”
This study is part of a larger research project built around a family cohort study of 655 families who gave birth at Sunderby Hospital near Luleå, northern Sweden, between 2015 and 2018. The project was initiated and the cohort formed by Ann-Sofie Sandberg from Chalmers, Professor Agnes Wold at the University of Gothenburg and chief physician and pediatric allergist Anna Sandin, affiliated with Umeå University and Sunderby Hospital.
The current study is the first to be published in science, focusing mainly on allergic diseases based on data collected from families in northern Sweden.
A clear connection
More than 500 mothers in the study detailed their eating habits at three stages – at 34 weeks of pregnancy, one month postpartum and four months postpartum. At the age of one, the children had a physical examination and identified all cases of food allergies, atopic eczema and asthma.
After the data were adjusted for various factors, such as genetic predisposition or reverse cause, the researchers were able to determine that there was indeed a clear link between mothers’ milk intake and milk intake. and dairy products and the incidence of food allergies in their children was smaller. .
“No matter how we looked at and interpreted the data, we reached the same conclusions,” said researcher Chalmers and co-author Malin Barman, Mia Stråvik’s Assistant Supervisor. However, the mechanism behind why milk has this anti-allergic effect, remains unclear. Here is a further explanation of the various theories.
Another finding in the study that Mia Stråvik highlights is that babies who are breastfed at 4 months of age, who eat more fruits and berries, tend to have higher levels of eczema – although although she stresses that further studies are needed before this connection can be said with certainty.
A follow-up study is currently underway to examine the health of children as young as four years old.
Learn more about: Children’s allergies
Allergies are the most common chronic illness affecting children and are becoming more common in Sweden and other industrialized countries.
Of the 508 children included in the current study:
- 7.7 percent of children (39) had a diagnosed food allergy by age one, most commonly to cow’s milk or eggs (or both)
- 6.5% of children (33) were diagnosed with atopic eczema and the number of children also diagnosed with asthma
- 23% of children are allergic to some type (including non-food) by the age of one
How does milk cause these effects?
It is not clear exactly why cow’s milk in a mother’s diet might reduce the risk of allergies in her baby. According to researcher Malin Barman, there are a number of possible explanations, which can be combined.
“One theory is that cow’s milk contains something that activates a baby’s immune system and helps them develop tolerance. This unknown cause may be found in the fat of milk or in its protein content. But it may also be the case that milk itself is neutral to the immune system. It may then be simpler that the higher milk fat intake results in a relatively lower intake of polyunsaturated fatty acids (PUFAs). This would be helpful, as we believe that high levels of polyunsaturated acids (PUFAs) in the mother’s diet may counteract the maturation of the infant’s immune system at an early age. “
Funding for this study
This study was funded by the Swedish Research Council, the Swedish Research Council for Health, Working Life and Welfare (Forte), Västra Götaland Region, Norrbotten Region, Magnus Bergvalls stiftelse, Wilhelm och Martina Lundgrens stiftelse, Per Håkanssons stiftelse, Stiftelsen Sigurd och Elsa Goljes Minne, Royal Society of Arts and Sciences in Gothenburg and Jane och Dan Olssons continued. The sponsors had no role in the study design; in data collection, analysis or interpretation; during the writing of the manuscript, or in the decision to publish the results.
Materials provided by Chalmers University of Technology.
- Mia Stråvik, Malin Barman, Bill Hesselmar, Anna Sandin, Agnes E. Wold, Ann-Sofie Sandberg. Maternal Intake of Cow’s Milk during Lactation Is Associated with Lower Prevalence of Food Allergy in Offspring. Nutrients, 2020; 12 (12): 3680 DOI:https://doi.org/10.3390/nu12123680
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Translator: Khanh Quynh