What Do We Know of Herbs and Breastmilk?

Herbal remedies taken while breastfeeding lack good research information about safety and effectiveness

(RxWiki News) In the US and throughout the world, many women use herbal supplements while they are breastfeeding. It is important to know about the safety and effectiveness of these herbs.

A recent study reviewed some of what is known about certain herbs that are taken while a woman is breastfeeding.

Unfortunately, however, a lot of information is still not known regarding herbs' effectiveness.

Although many herbs are thought to be safe by women and researchers, there is also not a lot of good research to confirm their safety.

A woman may use various herbs while breastfeeding, but she may want to discuss what's known about them with her OB/GYN or her child's pediatrician.

"Ask the pediatrician about any herbs you take while breastfeeding."

This paper, authored by Katarzyna Budzynska, MD, of the Boston University School of Medicine, and her colleagues, discussed the issues related to taking herbal supplements while breastfeeding.

Because herbal products are considered "dietary supplements" in the US, they are regulated differently than other medications.

Dietary supplements include herbs, vitamins, minerals, enzymes and other kinds of natural substances often sold in grocery, drug or health stores.

Instead of the US Food and Drug Administration's standard rules for pharmaceuticals, the rules for marketing and testing herbal medicines for safety are determined by the Dietary Supplements Health and Education Act.

However, herbal medications can have positive and negative effects in a woman's body just as much as any other medication can.

It's therefore important for doctors to be aware of what herbal medicines women might be taking while they are breastfeeding, the authors said.

Any of these herbs may have effects on a breastfed baby too. For example, some products, such as yerba mate, kola nut and guarana, contain caffeine which can be transmitted to a baby through breastmilk.

Women may use different herbal remedies for certain breastfeeding needs, such as increasing milk supply, relieving engorgement, treating mastitis (infection of the breast tissue) or other issues.

For example, a number of herbs are thought by women in different cultures to help boost milk production. These include fennel seed, caraway seed, anise seed, dill seed, fenugreek, alfalfa herb, goat's rue herb, torbangun, blessed thistle herb and milk thistle seed.

However, even though these have often been used by women in hopes of increasing milk production, there has not been much scientific research to show whether these herbs are effective or how they might help. Fenugreek is one of the most popular of these, but there is still a lot that researchers don't know about it.

"Although fenugreek appears to have a good safety profile, particularly at doses typically used (3-6 g of powdered seed), its effectiveness as a [milk production booster], optimal dose, and adverse effect profile in infants have not been established in clinical trials," the researchers wrote.

"Clinicians should be aware that a few case reports of fenugreek allergy suggest cross-reactivity with peanut allergens," they wrote.

Women may also take herbal supplements for reasons unrelated to breastfeeding, such as St. John's wort for depression.

However, one study found increased drowsiness or colic in a few babies when the mothers took St. John's wort but not in a comparison group.

Overall, there is too little research information available about many herbs to know enough about their safety or effectiveness.

If a mother is taking certain herbs, including those related to breastfeeding needs, she should be sure the product is of high quality, the authors noted.

"Some researchers have reported finding heavy metals and pesticides in herbal supplements on the US market," the researchers wrote. "A study found lead levels higher in breast milk of women taking Chinese herbal medicines than controls."

However, a 2008 FDA law related to manufacturing practices for dietary supplements may decrease the amount of contamination that may have occurred in herbal products.

The law "...requires all manufacturers to produce products that provide consistency in identity, purity, strength and composition, helping to ensure that all legal products are free from contamination," the authors wrote.

"However, clinicians should remain alert to the possibility of heavy metal exposures, such as lead, mercury, cadmium and arsenic, in breastfeeding mothers who are using herbal remedies, particularly remedies that come from China and the Indian subcontinent," they wrote.

The authors did not state that women should not use herbal supplements. However, they should be aware that little information exists from medical studies on most herbal medicines' safety and effectiveness, and women should discuss what they use with their doctor.

This paper was published in the August issue of Pediatrics in Review. It was funded by the National Center for Complementary and Alternative Medicine at the National Institutes of Health.

One author is supported by an award from the American Cancer Society, and another is employed at Traditional Medicinals in California and has received a grant from the National Center for Complementary and Alternative Medicine.

Review Date: 
August 16, 2013