Mother's Diet During Breastfeeding - Facts and Myths

Breastfeeding is the best method of nourishing a newborn not only because of the safety of breast milk, but also because of the numerous health benefits associated with this process. More and more scientific research confirms that stimulation can prevent the onset of chronic diseases such as type 2 diabetes, hypertension, dyslipidemia, or cardiovascular disease. Furthermore, it improves the development of cognitive functions in newborns, and infants fed with breast milk have a lower risk of obesity (C. Binns, M. Lee, W. Low, 2016). According to the recommendations of the World Health Organization and the latest guidelines of the Polish Society of Gastroenterology, Hepatology and Nutrition for Children, breastfeeding should be the only form of nourishment for a newborn for the first six months of its life, provided there are no medical contraindications (H. Szajewska et al., 2021). Even short-term or partial breastfeeding brings health benefits, as breast milk meets all the nutritional needs of the child, contains digestive enzymes, immune system cells, and microorganisms that colonize the digestive system of infants and help it function properly.

Human milk has a relatively constant composition, which is largely unaffected by the mother's diet. However, there are many mythical beliefs that put breastfeeding women under significant pressure. Carbohydrate, protein, calcium, or iron levels do not change significantly, even when these ingredients appear in small amounts on the breastfeeding menu. However, the diet can influence the quality of fat (fatty acid profile), but the milk content itself is more related to the age of the child – the older it is, the fatter the food. The situation is different in the case of vitamins A, D, and B vitamins – when the mother is poor in these vitamins, their amount decreases in the milk as well (M. Nehring-Gugulska 2017). The diet of a breastfeeding mother can affect the future health of her child in several other aspects. According to studies, an excess or deficiency of fats, especially saturated fats, can lead to a deterioration of the metabolic health of infants and a decrease in insulin sensitivity, which can affect the development of diseases such as obesity, type 2 diabetes, or hypertension (J. Aaltonen et al. 2011).

There are many misconceptions regarding the impact of a mother's diet while breastfeeding on the development of food allergies in infants. While there are reports that inadequate maternal nutrition may contribute to hypersensitivity and atopy in infants, there is no evidence that avoiding certain foods reduces the risk of allergic reactions. According to the latest guidelines, it is not recommended to introduce a diet during lactation to prevent allergies (H. Szajewska and Y. H. 2021). This measure should only be taken in the case of a confirmed allergy in the mother or child (H. Szajewska and Y. H. 2021). There are studies that indicate that long-term breastfeeding may have a protective effect on infants who are prone to eczema, allergies or asthma (N. Matsumoto et al. 2020; Y. Hu et al. 2021).

There is a lack of empirical evidence to support the widely held belief that colic in newborns is directly linked to what the mother consumes (M. Kidd et al., 2019). Instead, colic arises from the immaturity of the newborn's nervous and digestive systems, which is why they also occur in infants fed modified milk. Research indicates that the mother's diet has a minimal impact on milk composition, therefore, the intake of gas-producing foods cannot be connected to the onset of colic in infants (H. Szajewska et al., 2021). In rare instances, colic may be associated with a baby's intolerance to cow's milk protein, and only then should a dairy-exclusion diet be considered, but this applies to a limited number of newborns.

Although women often worry about drinking coffee because of its potential negative effects on the baby, current recommendations do not prohibit the consumption of this beverage. However, it is necessary to adhere to the daily limit of 300 mg of caffeine, which is equivalent to 3 cups of coffee or 6 cups of tea (M. Nehring-Gugulska 2017). It is also incorrect to claim that consuming coffee increases the baby's crying or leads to problems with falling asleep.

It is generally believed that during pregnancy and breastfeeding, a mother should eat for two. However, it is more precise to say that she should eat for two. This means that her diet should be focused on providing vitamins, minerals, and nutrients. In fact, during feeding, the caloric content of the diet should be slightly higher than the total energy requirement, by about 500 kcal in the first 6 months and then by 400 kcal in the next six months. However, one should not overdo it, as even then it is easy to gain weight, which increases the risk of overweight and obesity (M. K. Borszewska-Kornacka et al., 2013).

There are many myths about breastfeeding that make it difficult for young mothers to maintain a proper diet. According to current medical standards, the diet of breastfeeding mothers does not have to meet any special criteria other than to increase calorie intake. It is also recommended to follow the principles of a healthy diet, which should be based on vegetables, fruits, whole grain products, grains, beef, dairy, fish, and lean poultry. It is also important to limit the intake of processed foods as well, as they provide less nutritional nutrients than unprocessed products. Some studies suggest that it may be beneficial to slightly increase protein intake by 21 g, due to the increased need for this nutrient in both mother and child (F. Marangoni et al. 2016). It is also important to pay attention to the proper amount of DHA and EPA fatty acids, as a deficiency is associated with poorer overall health in infants (F. Marangoni et al. 2016). The daily intake should be around 250 mg, which equates to two servings of fish per week. There is no need to introduce additional dietary restrictions – this would lower the quality of the diet and increase the risk of nutritional deficiencies. It is also not recommended to consume alcohol, although it is not forbidden – in case of planned consumption, it is advisable to interrupt food intake. It is also important to know that the baby's crying is not related to the mother's poor diet, which is currently believed by almost 10% of mothers (K. Karcz, I. Lehman, B. Królak-Olejnik 2021). Mothers on vegetarian and vegan diets should be under medical supervision (to prevent possible calcium, iron, and vitamin B12 deficiencies), as well as those who require diet therapy due to their health condition. During lactation, it is important to ensure adequate fluid intake (about 3 liters of fluid per day). Most of this should be water, but other beverages such as teas, juices, cocktails or coffee can also be included in the total amount. It is also important to know that some herbal teas, such as dill, are not suitable for breastfeeding mothers, as their extracts should not be consumed, but small additions (e.g. as a spice) do not pose a threat. However, oils and teas made from Italian dill are not recommended due to the lack of appropriate safety data.