Diet is a very important factor when breastfeeding, as it can greatly influence the composition of breastmilk. Breastfeeding women should be mindful of the food they consume while breastfeeding for many reasons. Some foods can alter the taste of breastmilk (which can make breastfeeding more difficult) and some contain substances that are contraindicated for babies.

Foods with a very strong taste, like garlic or asparagus, should be avoided, as well as drinks with high caffeine content, like chocolate, coffee or black tea. Teas, in general, should be consumed with caution, as many can cause side effects that affect both the mother and the baby.

Some studies show that colic or gas in babies can be influenced by the mother's diet. Foods like dairy products, peanuts and seafood, for example, can produce by-products after digestion and can be absorbed into breastmilk, causing colic in babies.

Foods to avoid

The following food and drinks should be avoided when breastfeeding:

1. Alcohol

Alcohol is rapidly available and absorbed into breastmilk within 30-60 minutes of consumption. Alcohol levels in breastmilk is is equivalent to the alcohol level found in the mother's bloodstream.

Alcohol in breastmilk can affect the baby's nervous system and cause drowsiness and irritability. Frequent consumption overtime can affect neurological and psychomotor development and even cause delays in speech and walking. In addition, the baby's body is not equipped to efficiently eliminate alcohol compared to an adult, and this can lead to liver failure.

Alcohol intake can also decrease milk production and reduce intestinal absorption of nutrients that are important for the growth and development of the baby. Therefore, alcohol consumption while breastfeeding should be avoided or greatly reduced.

If considering alcohol intake, the mother should pump and store her breastmilk beforehand to offer to the baby. If pumping is not an option, the mother should wait 2 to 3 hours to breastfeed after intake of small amounts of alcohol (e.g. one beer or one glass of wine)

2. Caffeine

Food that is rich in caffeine (e.g. coffee, pop, energy drinks, green tea and black tea) should be avoided or consumed in small quantities when breastfeeding. Babies are unable to digest caffeine as efficiently as adults, and excess caffeine in babies can lead to irritability and difficulty sleeping.

When large amounts of caffeine are ingested (e.g. over 2 cups of coffee per day), iron levels in the breastmilk can decrease, which can decrease hemoglobin levels in the baby, resulting in anemia.

The maximum recommended caffeine intake while breastfeeding is 200mg per day (around 2 cups of coffee per day). Decaffeinated coffee is an excellent alternative.

3. Chocolate

Chocolate is rich in teobromine, which has comparable side effects to caffeine. Some studies have shown that 113g (about 4oz) of chocolate contains about 240mg of teobromine, and that this can be detected 2.5 hours after consumption. These levels of teobromine can cause irritability and difficulty sleeping in the baby. Therefore, breastfeeding women should avoid eating large amounts of chocolate every day. A good compromise is eating about 28g of chocolate, which contains approximately 6mg of teobromine (which will not affect the baby).

4. Food with a strong taste

Foods that contain a strong taste (e.g. garlic, asparagus, onion, and some condiments) can cause breastmilk to have a different smell. These foods can especially alter breastmilk if consumed on a daily basis or in large quantities. This can result in an aversion to breastfeeding in the baby, which may complicate your breastfeeding journey.

5. Sugary foods

Foods that are high in sugar are low in nutrients such as fiber, vitamins and minerals. This can interfere with the production and quality of breast milk. Therefore, it is recommended to limit your intake of sugary foods as much as possible and to opt for fresh and natural foods. Following a balanced diet provides will provide you with all the nutrients necessary for your health and for optimal breast milk production.

Sugary foods to avoid or consume in moderation include candied fruits, crackers, cookies and soft drinks.

6. High-fat foods

Processed foods that are high in fat, especially trans fat, could modify the fat composition of breast milk. This can lead to negative effects on the baby's development, however more scientific studies are needed to confirm this relationship.

Trans fats can be found in foods such as refined soybean oil, margarine, snacks, sausages, microwave popcorn, pizzas, hamburgers and frozen lasagnas.

7. Raw food

Food that is served raw (like raw fish used in japanese cuisine, oysters, and unpasteurized milk) has a high risk of contamination and food poisoning, which can cause a gastrointestinal infection in the mother. These infections usually result in symptoms like diarrhea or vomiting,

Although this will not affect the baby, food poisoning can lead to dehydration in the mother, which can impact breastmilk production. Therefore consumption of raw food should be avoided, otherwise they should only be obtained from trusted sources.

8. Some types of teas

Some types of tea can affect breastmilk production and cause side effects in the baby. Teas that should be avoided include lemongrass, oregano, parsley, peppermint, ginseng, kava andillicium verum. They should be avoided whenever possible, or consumed only under the supervision of a doctor.

9. Food that causes allergies

Some women may have food allergies and the baby may develop their own allergies after the mother consumes them.

Breastfeeding women should be especially cautious if consuming the following foods:

Milk and dairy products
Soy
White flour
Eggs
Nuts
Corn and corn syrup, the latter which is found in high frequency in processed food products (this can be confirmed on the food label)

These foods have a higher probability of provoking allergy symptoms, and can result in allergies in the baby. Symptoms of a food allergy in babies include skin redness, itching, eczema, constipation or diarrhea. If any of these symptoms emerge, it is important to recall the foods the mother consumed 6 to 8 hours prior to breastfeeding.

If you suspect that any of these foods have caused an allergy in your baby, you should eliminate them from your diet and consult your pediatrician to confirm a cause for the allergy (as there are many reasons a baby can develop allergies that are not food-related).

10. Aspartame

Aspartame is an artifical sweetener that rapidly breaks down into phenylalaline in the female body. Phenylalaline is a type of amino-acid that is absorbed in breastmilk and can be especially dangerous to babies who have been diagnosed with phenylketonuria (diagnosis can be confirmed with a capillary prick in the heel).

A better alternative to sugar is stevia, a natural sweetener that is safe for use at all phases of life. Learn more about the health benefits of stevia and how to use it.

What to eat

It is important to maintain a balanced diet to ensure that all nutrients necessary for successful breastfeeding are consumed. A balanced diet is made-up of protein (e.g. lean meats, chicken without sin, fish, seeds and legumes), carbohydrates (e.g. whole wheat bread, rice and boiled potatoes) and good fats (e.g. extra-virgen olive oil).