Women hear a lot of conflicting information about what they can or cannot eat while breastfeeding and these recommendations may vary according to culture and tradition, along with individual personal preference and finances. In some cultures a food may be considered beneficial to a breastfeeding mother, but in another culture mothers may be cautioned against the exact same food. For instance, spicy food is considered bad for babies in some societies, but in others spices form a big part of everyday cuisine.
Here are some myths and facts about a woman’s diet and breastfeeding.
Composition of Breastmilk
Myth: Breastmilk is made directly from what an individual eats
- Breastmilk is made in the breasts, directly from a mother’s blood. It is not made directly from the food she eats.
- When food, drink or medication are ingested, the substance is broken down by the digestive tract and molecule-sized components of the substance are absorbed into the blood. When these molecules get to the capillaries near the breast tissue, they move through the cells that line the alveoli and into the milk. This process is known as diffusion.
- Diffusion explains how drugs and other foreign substances enter milk. Many factors influence whether or in what quantity a substance will actually enter the milk.
- The process of diffusion allows good things, such as antibodies, to easily enter colostrum and mature milk. This means that breastmilk changes over time in sync with the mother’s environment, which is one of the important health aspects of breastfeeding.
Myth: If a woman has a poor diet the quality of her milk will not be good enough
- Breastmilk is a living substance that evolves in sync with the needs of a baby at every feed. It contains vital nutrients, immunity building cells and stem cells, food for healthy gut bacteria and many other health factors that cannot be replicated. These do not change with an individual’s diet. People who experience famine conditions still produce milk providing optimal nutrition for their babies.
- The type of fat in maternal diet is closely related to the type of fat in the milk the mother produces, although the caloric content of human milk is fairly consistent.[i]
- Breastfeeding responsively ensures that babies will receive all they need in order to grow well and remain healthy.
- Caring for and feeding a baby from your own body can use up a lot of energy at times. Eating a variety of nourishing and energy boosting foods as often as possible, can help to optimise your own health and energy reserves. Asking friends and family to provide such foods to you regularly in the early weeks and months can be a big support to you and your baby.
Fact: Some foods can change the taste of breastmilk
- Strongly flavoured foods, such as garlic, chilli or soy sauce, may change the taste of breastmilk. It’s possible that this can help a baby get used to the family diet before starting solids.
- Babies will have already started to get used to these flavours during pregnancy when they swallow amniotic fluid.
- Children acquire their family’s food habits and preferences gradually.
Fact: Breastmilk protects against toxins
- Although a healthy diet could be defined as varied, balanced, and natural (i.e. grown in situations that eliminate or limit pesticides, insecticides, and chemical fertilisers), breastmilk contains high levels of antioxidants which may help to compensate for any pre-natal and post-natal exposure to environmental chemicals. Breastmilk can counteract the neurological effects of contaminants transferred before birth, and also any in the milk.
- Research has shown that milk produced by vegetarian women has lower levels of environmental contaminants, such as polychlorinated biphenyls (PCBs). These substances are stored principally in the fatty tissues of the body, and vegetarian diets tend to contain less fats than diets with more animal products.[ii][iii]
- It is generally suggested that anyone, breastfeeding or not, avoids fish which may be high in mercury. This includes predator fish such as swordfish and shark or freshwater fish from waters reported as contaminated by local health agencies.[iv]
Myth: You need to eat special foods to breastfeed
A breastfeeding mother doesn’t require special foods to produce milk or increase her milk supply. Milk production is determined by the amount of milk removed from the breast.
- Unless there is a physical or physiological reason for low milk production, a mother who breastfeeds on cue will be able to produce enough milk for her baby, regardless of what she eats.[v]
- There is no particular food that must necessarily be eaten, especially if this is something that the mother is not used to or doesn’t like.[vi] All the nutrients that are found in one food are also found in others, so a mother can still get the nutrients she needs. For example, omega fatty acids can be gained through algal or soybean oil, walnuts, chia, hemp and flax seeds instead of fish.
Myth: You need to drink milk to make milk
- Human beings are the only animals that consume milk produced by other animals.
- No other mammalian mothers drink milk, yet they all produce milk perfectly tailored to the needs of their young.
- Milk is sometimes seen as a source of calcium, but there are plenty of other easily available foods such a broccoli, peppers and spinach which contain even more calcium per serving as well as other nutrients too.
- In some cultures, people traditionally do not drink milk or eat dairy products at all, yet mothers succeed in breastfeeding their children.
Myth: If you are vegan you won’t be able to breastfeed
- The concept of an “ideal” diet can vary across different families, cultures, economic situations, religions, and also different seasons. Yet, almost always, all over the world, even in situations of deprivation, mothers produce milk that helps their babies grow well.
- Vegan diets can sometimes be low in Vitamin B12, and It’s important to know how to keep your vitamin B12 levels up.[vii] See Vitamins and Minerals for suggestions on how to absorb enough.
Fact: A breastfeeding mother may feel hungry and thirsty more often
- Breastfeeding can make us use up more calories than usual and we may feel more hungry and thirsty.
- How many extra calories we need depends on how much breastmilk we are producing (influenced by baby’s age and whether breastfeeding is exclusive), percentage of body fat (including how much body fat we have laid down in pregnancy), body size, and how active we are.
- A woman’s metabolic rate becomes more efficient during lactation and a small increase in grains, vegetables and fruit may be all that is needed.
- Weight gained during pregnancy is often gradually lost throughout the course of breastfeeding.
- Many mothers feel thirsty when they breastfeed, especially when their baby is newborn. It’s a good idea to have a glass of water available while breastfeeding, but it’s not necessary to drink more than you feel comfortable with, as it doesn’t help to increase milk supply and it may be unpleasant.[viii]
- Some women like to drink herbal teas and infusions to increase liquid intake. However, excessive amounts of some herbal teas and infusions can risk depleting milk supply, so they need to be used moderately and with caution.[ix]
Myth: Certain foods always need to be avoided
- There are no specific foods you always need to avoid just because you are breastfeeding.
- However, if parents suffer from allergies this can increase the possibility of their baby having the same allergy. Allergic reactions to substances in mother’s milk may appear as skin, respiratory and intestinal problems (or a combination of any of these) in a baby.
- If a baby has an obvious reaction every time a mother eats a certain food, she may choose to eliminate that food from her diet. Keeping a food diary can help identify if a pattern of fussy behaviour emerges every time a particular food is eaten.
- Although mothers may be advised to avoid high-risk foods during all or part of their pregnancy and to continue to avoid these foods during lactation, research indicates that this practice does not decrease the incidence of allergy by two years of age, but it does delay the onset of allergy.[x] More recent research shows that avoiding high-risk foods, such as peanuts, may not be necessary.[xi][xii]
- Normal caution may be needed if drinking raw, unpasteurised juices. If a mother were to develop food poisoning from inadequately washed ingredients this would not pass to her baby via her breastmilk. However, it could be passed on via contact contamination.[xiii]
Fact: Food allergies in breastfed infants are usually due to substances passing into breastmilk rather than breastmilk itself
- Substances in breastmilk coat a baby’s intestines, which prevent microscopic food particles from “leaking” through into your baby’s bloodstream.
- When food particles do pass into the blood (something that is more frequent in a formula fed baby), these food particles may be treated as foreign substances by his white blood cells, which attack them, and can cause painful allergic reactions.
- The top three food antigens are cow’s milk protein (mostly the betalactoglobulin component), soy bean protein, and egg white. Other common antigens are peanuts and fish, especially cod.
Fact: A mother’s diet does not affect the amount of lactose in her milk
- The amount of lactose in a mother’s milk has nothing to do with her diet; her body manufactures lactose solely for her baby.
- Lactose intolerance occurs when the body no longer makes enough of the enzyme lactase, which is needed to digest lactose, the main carbohydrate in milk. Lactose intolerance is rarely a problem for babies. They are born with the ability to produce lots of lactase because they depend on their mother’s milk for nutrition in the first year of life and the lactose in mother’s milk is needed for brain development.
- Some infants experience galactosemia, an extremely rare genetic condition that is present from birth and affects an individual’s ability to metabolise the sugar galacatose properly, hence requiring urgent medical care.
Fact: Excess lactose in babies can be misdiagnosed as an allergy or colic
- High volumes of lactose can overwhelm a baby’s digestive system. This can be caused by babies consuming large amounts of breastmilk, or when mothers have oversupply.
- When there is not enough lactase to break down all the lactose, the excess lactose causes gassiness and discomfort, and frequently green, watery or foamy stools, sometimes with small amounts of blood.
Vitamins and Minerals
Myth: There is not enough iron in breastmilk
- The iron in human milk is more readily absorbed by your baby than iron in cow’s milk or iron-fortified formula. This means that the quantity of iron in human milk is optimal for your baby, despite being less than that found in cow’s milk.
- As with calcium, the levels of this mineral in human milk are constant, despite variations in the maternal diet or the mother’s body stores.[xiv]
- A full-term healthy baby usually has no need of additional iron until about the middle of his first year, around the time he starts taking solids.
- Some vitamins and proteins are better absorbed if other vitamins and minerals are present at the same time. For example, iron is utilised better if vitamin C is present in the diet.[xv]
- The high lactose and vitamin C levels in human milk aid the absorption of iron, and breastfed babies do not lose iron through their bowels.
Fact: Vitamin B 12 and calcium are important for a balanced diet
- Vitamin B12 and calcium are important for a balanced diet. Some people, including vegans and vegetarians, use a supplement for their vitamin B12 intake.
- One study found that while vegetarian mothers tended to consume less calcium than other mothers, this did not affect the levels of calcium in their breastmilk.[xvi]
- If a mother is not consuming dairy products, calcium can be obtained from other sources, such as bok choy (a type of cabbage), sesame seeds, calcium enriched tofu, tamari, soy sauce, greens, whole grains and some nuts and dried fruit. For example, a cup (227 grams) of cooked bok choy provides 86 percent of the amount of calcium contained in a cup (240 ml) of milk. Half a cup (113 grams) of ground sesame seeds – which can be added to baked goods, pancake batter, or sprinkled on salads or cereals – contains twice as much calcium as a cup (240 ml) of milk.
- Other sources of calcium include blackstrap molasses, calcium-enriched tofu, collards, spinach, broccoli, turnip greens, kale, almonds, and Brazil nuts. Some types of algae (sea vegetables, such as wakame) fermented foods (miso), and seasonings including tamari and soy sauce can also contribute to enriching a diet with calcium, as well as many other minerals that are especially important to a breastfeeding mother.[xvii]
Fact: Iodine and selenium are crucial minerals
- Iodine and selenium are crucial minerals. Good food sources of iodine include kelp, seaweed, sea fish, shellfish and grey Celtic sea salt. Iodine can also be found in plant foods, such as cereals and grains, but the levels vary depending on the amount of iodine in the soil where the plants are grown.[xviii]
- The best dietary source of selenium is Brazil nuts. It is widely found in other plant and animal foods, including other nuts, cereals, meat, fish and eggs.[xix]
Fact: Vitamin D deficiency (rickets) occurs because of a deficiency in sunlight exposure, NOT because of a deficiency in human milk.
- Vitamin D is different from some of the other vitamins in our food, as it is actually a hormone produced by the kidneys. Vitamin D controls blood calcium concentration and affects the immune system, and is produced by the body when sunlight hits the skin.
- Breastmilk doesn’t naturally contain high levels of Vitamin D as, in the past, babies would absorb most of their Vitamin D from exposure to sunlight.
- Changes in the way we live our lives, with reduced exposure to sunlight, and with the foods we eat which don’t contain sufficient Vitamin D, might mean that mothers don’t have enough vitamin D in their own bodies to pass to their babies via breastmilk.
- Our bodies are designed to make very large amounts of vitamin D through exposure to the sun (10,000-20,000 IU in 24 hours, after 15-20 minutes of summer sun exposure in a bathing suit or 45-60 minutes of exposure for those with darker skin tones). However, in adults and children, the desire to avoid overexposure and sunburn has eclipsed our ability to absorb adequate amounts of sunlight to keep our vitamin D status at a normal level.[xx]
Fact: Some women may need extra Vitamin D
- Breastfeeding mothers who have adequate amounts of vitamin D in their bodies can successfully provide enough vitamin D for their nursing children through breastmilk. However, lifestyle changes have led to some women not having enough vitamin D.
- It is recommended that pregnant and nursing mothers obtain adequate vitamin D or supplement as necessary. Women who are unsure of their vitamin D status undergo a simple blood test before making a choice to supplement.
- The optimal way to get Vitamin D is through sunlight and the NHS states: “Between late March/early April to the end of September, most people can get all the vitamin D they need through sunlight on their skin and from a balanced diet. You may choose not to take a vitamin D supplement during these months.”[xxi]
- The Vitamin D Council states that women taking a supplement of 6,000 IU of vitamin D each day shouldn’t need to give their baby a vitamin D supplement, as their breastmilk will contain enough vitamin D. However, women who aren’t taking a supplement or are taking less than 5,000 IU/day of vitamin D, or aren’t getting a good amount of sun exposure, should give your baby a vitamin D supplement.[xxii]
- If a baby is born with a deficiency in Vitamin D, due to the mother’s own low levels, this may not be reversed by the mother taking supplements.[xxiii]
- Research[xxiv] has demonstrated that children are able to store several months worth of vitamin D when they are exposed to only a few hours of summer sunlight.
Myth: Food which makes a mother gassy will make her baby gassy
- Sometimes a mother finds that foods like broccoli and cabbage make her gassy. Gas from a mother’s intestinal tract cannot pass into her blood and eventually into her breastmilk for her baby to drink.
- However, when food is digested, some of the proteins do enter the blood and may then pass into a mother’s milk. Some babies may be sensitive to a particular protein and react with gas and fussiness.
- In many families, nursing mothers can eat whatever they like and be confident that the vast majority of babies do not have any problems with food proteins.
- For many fussy and gassy babies, the gassiness and fussiness can be due to other reasons, not always related to what food a mother has eaten.
Written by Anna Burbidge for La Leche League GB, March 2019
[i] Sheri Lyn Parpia Khan. Maternal Nutrition During Breastfeeding. New Beginnings, 2004; 21 (2): 44.
[iii] Dagnelie, P.C. et al. Nutrients and contaminants in human milk from mothers on macrobiotic and omnivorous diets. Eur J Clin Nutr, 1992; 46 (5): 355-66.
[iv] US Food & Drug Administration. Eating Fish: What Pregnant Women and Parents Should Know, https://www.fda.gov/Food/ResourcesForYou/Consumers/ucm393070.htm (accessed 1 March 2019).
[v] Sheri Lyn Parpia Khan. Maternal Nutrition During Breastfeeding. New Beginnings, 2004; 21 (2): 44.
[vii] La Leche League International. The Womanly Art of Breastfeeding. Eighth Edition, 2010; 125.
[x] Vonlanthen, M. Lactose Intolerance, Diarrhea, and Allergy. Breastfeeding Abstracts, 1998; 18 (2): 11-12.
[xii] Du Toit G et al. Randomized trial of peanut consumption in infants at risk for peanut allergy. N Engl J Med, 2015; 372 (9): 803-813.
[xiii] La Leche League International. The Breastfeeding Answer Book. Third Revised Edition, 2012; 537.
[xiv] Sheri Lyn Parpia Khan. Maternal Nutrition During Breastfeeding. New Beginnings, 2004; 21 (2): 44.
[xvi] Specker, B. Nutritional concerns of lactating women consuming vegetarian diets. Am J Clin Nutr, 1994; 59 (Suppl): 1182S-86S.
[xvii] Sheri Lyn Parpia Khan. Maternal Nutrition During Breastfeeding. New Beginnings, 2004; 21 (2): 44.
[xxiii] The Breastfeeding Network. Vitamin D and Breastfeeding. 2017. https://breastfeedingnetwork.org.uk/wp-content/dibm/vitamin%20D%20and%20breastfeeding.pdf (accessed on 13 February 2019).
[xxiv] Hollis, B. et al. Vitamin D Supplementation during Pregnancy: Double Blind, Randomized Clinical Trial of Safety and Effectiveness. J Bone Miner Res, 2011; 26 (10): 2341–2357.