Impact of breastfeeding on the intelligence quotient of the children of Rawalpindi, Pakistan

INTRODUCTION

Breastfeeding is essential for proper growth and immunity of children. It has both short-term and long-term effects on the physical and mental growth of the children.¹ Short term influence of breastfeeding is protectiveness against various gastrointestinal and respiratory infections, and allergies. This protection leads to lesser mortality rate among the breastfed children in comparison to non-breastfed children.²

Long-term impact of breastfeeding is on the development of the brain and consequently intelligence quotient (IQ).³ All over the world, various studies in the literature have shown that the children who were breastfed had better IQ score on IQ assessment tools in contrast to the children who were not breastfed or were on some formula milk.^4,5 Furthermore, a study has also shown that breastfeeding duration also does matter and children with longer duration of breastfeeding had better IQ score than children with shorter duration of the breastfeeding.⁶ Consequently, academic performance was good among children who were on breastfeeding, and even the higher education levels among adolescence were higher in adulthood.^1,7

Different mechanisms have been suggested through which breastfeeding impact the brain growth and resultantly the intelligence quotient among children. It has been shown that children who were breastfed revealed greater grey matter volume in various lobes of the brain such as in the left and right parietal and left temporal lobes and higher stimulating power in the right frontal and temporal lobes for the sense of perception duties, while for the speaking function, the stimulating power was greater in the left temporal lobe. Furthermore, it has been also presented that the volume of the subcortical grey matter interceded the relationship between breastfeeding and cognitive function.^8,9 As the breast milk has higher amount of long-chain polyunsaturated fatty acids, such as arachidonic acid and docosahexaenoic acid and these are needed for the development of the brain during childhood. So, this could be the reason of favorable influence of breastfeeding on the children intelligence.^5,10

Around the globe, breastfeeding and intelligence quotient among the children is well studied, however, this topic could not get the spotlight that it should have, therefore, our study aimed to determine the influence of breastfeeding on the intelligence of children in Rawalpindi, Pakistan. It could help general public in understanding the importance of breastfeeding.

METHODS

This comparative cross-sectional was carried out in a general population of children of the Rawalpindi, Pakistan, for approximately 8 months from June 2022 to January 2023. Sample size was 88. WHO calculator was used to calculate the study sample size. 44 children were on breastfeeding, whereas, other 44 children were on formula milk. Patients’ enrolment in the study was done via non-probability convenient sampling and developed inclusion and exclusion criteria. Only those children who had, an age range between 7 to 12 years, no diagnosed physical and psychological disorders, and who had been on only either on breastfeed, or on formula milk, were selected in the study, while, those who had, age below 7 years or above 12 years, any physical or psychological disorders, and who had been on both breastfeeding and formula milk, were not included in the study.

Ethical approval and informed consent were taken before the start of the study and before the data collection, respectively.

Data was collected through a self-designed questionnaire. This questionnaire had two elements. First was about the socio-demographic characteristics and type of milk children took after birth. Socio-demographic features such as gender (male or female) and age. Milk portion has two further parts which were about type of milk and duration of the milk after birth. Two types of the milk which such as breast milk and formula milk were included. Regarding duration of any type of milk was divided into less than 6 months and more than 6 months. Whereas, the second portion was regarding the Intelligence assessment of the children. It was assessed by using Wechsler intelligence scale for children (WISC). Children were classified into seven classes based on their intelligence which was determined via the composite score range on WISC. These classes included children with extreme high (130 or above), very high (120-129), high average (110-119), average (90-109), low average (80-89), very low (70-79), and extreme low (69 and below). After completing the data collection, data analysis was performed via descriptive and inferential statistics by statistical package for the social sciences (SPSS) version 25 (Armonk, NY: IBM Corp.). The frequency and percentage of nominal data calculated, while means of numerical data were determined. Chi Square test was used to assess the association between milk type and intelligence. P value less than 0.05 was set as statistically significant.

RESULTS

Out of 88 participants, 54 (61.36%) were male children, while 34 (38.64%) were female children. The mean of age for the study population was 9.83 years with standard deviation (SD) of ±2.10 years. The overall mean score on WISC of intelligence quotient was 106 with SD of ±39, Whereas, mean score on WISC of intelligence quotient for breastfed children was 112 with SD of ±32 and mean score on WISC of intelligence for children who were on formula milk was 100 with SD of ±36.

Table 1 shows that the breastfed children had relatively higher intelligence quotient classes on WISC in comparison to children who were on formula milk. Furthermore, it also shows that the association between intelligence quotient and type of milk was significant.

Table 2 indicates that the breastfed children who had been on breastfeeding for longer duration had higher classes of WISC than the breastfed children who had been on breastfeeding for shorter duration. Moreover, it also elaborates that the relationship between the intelligence quotient and duration of breastfeeding was statistically significant.

Chi-square test p value for the assessment of association between type of milk and intelligence quotient was 0.003 and it was statistically significant.

Chi-square test p value for the determination of relationship between duration of the breastfeeding and intelligence quotient was 0.04 and it was significant.

DISCUSSION

This study has brought a very interesting topic of childhood in the spotlight, the association between breastfeeding and intelligence quotient among children of Rawalpindi, Pakistan.

This study showed that the children who had been on the breastfeeding had higher mean score on the WISC 112±32, whereas, for children who were on formula milk had relatively lower mean score of 100±36. Similar finding has been presented a systemic review that was conducted in the Brazil.³ A Canadian study also supported this research finding of higher score of intelligence quotient among breastfed children.¹¹

It has been also noted that the association between the type of milk and intelligence quotient among children is statistically significant. Consistent finding about the association between type of milk and intelligence quotient was noted by another study in literature.¹ Similarly, a study of United States of America presented alike impact of breastfeeding on the IQ of children.⁶

Impact of duration of the breastfeeding on intelligence was also observed in the study and this study suggested that longer the duration of breastfeeding, higher the WICS score or IQ. A Chinese study also endorsed that the higher intelligence association with longer breastfeeding duration.⁴ Another study of Denmark also recommended in their results that longer duration breastfeeding leads to better IQ level.¹²

Although this study has explained about the impact of type of milk and duration of breastfeeding on the IQ of children significantly, however, this study did not exclude the cofounders that could have impact the intelligence quotient among the children. These cofounders could be parents IQ levels, family/social environment, and socioeconomic background. These confounders might have influenced the results of current study, so further research work is required that could exclude the impact of these confounders. Furthermore, further research is also needed for the determination of the mechanism of the role of breastfeeding in the improvement of the intelligence quotient.

CONCLUSION

Breastfeeding has positive impact on the intelligence quotient of children. Children who were breastfed had better IQ than children were on formula milk. Duration of breastfeeding also influence the IQ of children, children who had been on breastfeeding for longer duration, had better IQ level than children who had been on breastfeeding for shorter duration. Health department should create awareness regarding the significance of breastfeeding among parents, so that children could achieve their full potential in their lives.

ACKNOWLEDGEMENTS

We would like to thank all participants who gave their precious time to us and who volunteered themselves for the study.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: The study was approved by the Institutional Ethics Committee

REFERENCES

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