There's no denying that babies love breast milk, but you may be wondering why. What does breast milk taste like? What's in it that is so important for infants? Is it safe for adults to drink — and should they?
Breast milk tastes quite different from cow's milk. It can also be more watery or more creamy, depending on the time of day.
Here, we look at the nutrients in breast milk and what impact they have on its taste, as well as the different foods and lifestyle choices that can affect a person's milk.
What does breast milk taste like?
The taste of breast milk can vary from person to person. It may be thicker or thinner depending on the time of day, and it is even affected by the lactating person's diet.
Adults who've tried it often say that breast milk tastes sweet and creamy, but in a different way from cow's milk. While both types of milk share similar components, including the milk sugar lactose, bovine milk contains more fat, minerals and proteins, according to a 2016 review published in the journal Nutrients. Human milk, on the other hand, contains these nutrients as well as antibodies, stem cells, enzymes and hormones that are designed specifically for a baby's first year of life. While cow’s milk does contain these elements, they are specific to the needs of a cow.
The creaminess of breast milk likely comes from the fat content, which the same review reports as being between 3.5% to 4.5% fat. Whole cow’s milk from a grocery store is usually around 3.25%. The milk also comes out of the breast warm, roughly at body temperature of around 98.6 degrees Fahrenheit (37 degrees Celsius).
But just like cow's milk, human milk can become spoiled if left out too long, making it smell rotten and taste bitter. In addition, a 2016 review published in The American Journal of Clinical Nutrition found that storing breast milk, including freezing and defrosting it, can change its vitamin and mineral composition and affect the way breast milk tastes.
What factors affect the taste of breast milk?
When the body makes breast milk, it is creating nutrition from food the person has eaten, while also putting living cells into the milk to be passed onto the child. Exactly which nutrients and cells are included depends on what the baby needs as it grows, especially in the first six weeks of life, said Dr. Alexa Mieses Malchuck, a family physician at the UNC Family Medicine Center, North Carolina.
"The first milk [after a baby is born] is called colostrum, and it's very unique," Mieses Malchuck told Live Science. "It's small in volume, but packed with power and essential for newborns."
Colostrum milk is very low in sugar but high in components related to building the immune system, including immunoglobulin A, a type of antibody.
After the colostrum, about a week or two into the baby's life, comes what's called "transitional milk," which has more sugar and electrolytes, Mieses Malchuck said. Then, after around four to six weeks, breast milk becomes known as "mature milk," and its makeup of nutrients, including sugar, fats, vitamins and minerals, stays fairly constant until the child reaches toddlerhood.
Still, mature milk can be affected by changes to daily life. According to Mieses Malchuck, if someone has a cold, the antibodies their body makes can also be found in their breast milk, while the time of day can change a person's milk, with evening feeds containing melatonin, a hormone that helps regulate sleep.
There are even changes within a single feeding. The first milk that comes out is called foremilk, which is thin and watery and aimed at satisfying the baby's thirst. This is followed by what's called hindmilk, which contains two to three times as much fat as foremilk.
Does lifestyle affect the taste of breast milk?
The components of breast milk, and therefore the taste, can also be influenced by physical activity and diet, as well as a person's smoking and drinking habits.
Strong flavors, such as garlic, mint or chili, or meals high in sugar or salt can change the taste of breast milk, according to a 1995 review published in the Journal of Human Lactation.
Some of these ingredients can affect breast milk in other ways. A 2016 study, published in the journal Breastfeeding Medicine, found that ginger can increase the amount of milk a person produces, while a 1993 review published in Pediatric Research found that breastfeeding after consuming garlic encouraged infants to drink more.
"Really any substance that a person ingests or otherwise uses can be deposited into the breast milk, including alcohol, nicotine and caffeine," Mieses Malchuck said.
Can adults drink breast milk?
The American Academy of Family Physicians recommends that children be breastfed for at least the first year, but Mieses Malchuck said the greatest benefit happens when a baby receives breast milk for at least six months. But with all its nutrients and immune-boosting properties, why stop breastfeeding? Should adults drink breast milk?
The answer is no: adults should leave breast milk for babies. This is because it is designed as a super source of nutrition to support babies’ growing needs. Adults are not babies, therefore the nutrition in breast milk is not designed to support them. Unlike babies, adults can also produce their own antibodies, so they don’t need to consume breast milk to build their immune systems.
Since breast milk is not readily available, some people are turning to online sites to purchase bottled breast milk. However, the safety of this milk is a concern, as there is a risk that harmful pathogens can be passed through the human into the breast milk. Just as this can have repercussions in babies, it can also negatively impact adults. This is why donated breast milk is screened first to ensure it is safe.
However, there’s not a surplus of breast milk available for curious adults. Many women find it challenging to feed their babies enough breast milk to grow. Donated breast milk is often reserved for premature babies, for whom the antibodies and nutrition are particularly critical for their health.
