Like carrots, celery, cumin, and parsley, dill (Anethum graveolens) is an apiaceous vegetable. Dill is a good source of the chemopreventive flavonoids quercetin and kaempferol. Fresh dill is also a dietary source of vitamin C, manganese, iron, and the monoterpenes carvone, D-limonene, and anethofuran.
Dill also contains beta-carotene and other carotenoids (which makes it a source of vitamin A), coumarins, myricetin, myristicin and dillapiole. Dill has been shown to have anti-inflammatory, antifungal, antibacterial, insecticidal and antioxidant properties and may improve cholesterol profile and glucose metabolism. Dill has been found to have antibacterial activity against H. pylori infection, suggesting anti-ulcer properties. One study found that dill seed extract reduced gastric irritation in mice by protecting the gastric mucosa.

Breast cancer-related effects of eating dill

Dill has been shown to inhibit estrogen metabolism in the laboratory. Dill has been used in several traditional medicine systems to increase milk production in breast-feeding women and also in cattle for the same purpose. Since its use as an aid to lactation has been widespread and continues today, it is likely that dill has some effectiveness in this regard, but the mechanism of action has not been explained and the implications for breast cancer risk are not clear.
One study using a rat model found that rats fed high dose dill extracts had longer estrous cycles and increased blood progesterone concentrations than controls, results which are suggestive but again difficult to interpret in light of the high doses used in the experiment.


Dill flavonol quercetin has been shown to increase the effectiveness of both Adriamycin (doxorubicin) and Taxol (paclitaxel) chemotherapy in multidrug resistant ER+/PR+ breast cancer cells, in part by eliminating cancer stem cells. In addition, quercetin has been reported to increase the sensitivity of ER+/PR+ cells to 5-fluorouracil (5-FU), thereby increasing its treatment effects. Quercetin has also been found to inhibit the migration and adhesion of triple negative (ER-/PR-/HER2-) breast cancer cells and to significantly inhibit tumor progression in a mouse model of triple negative breast cancer. Finally, quercetin also acts as an iron chelator, which can help reduce iron's breast cancer-promoting effects in some women.


Dill is also a source of kaempferol. Diets abundant in kaempferol have been found to be associated with reduced breast cancer risk. Kaempferol has also been shown to inhibit the growth of ER+/PR+ breast cancer cells, in part through inhibition of glucose uptake.
Kaempferol has also been found to inhibit both primary tumor growth and lung metastasis in a mouse model of breast cancer. Kaempferol has also been reported to reduce the degree of heart and kidney damage caused by Adriamycin in rat models of chemotherapy.
In addition, kaempferol may protect against the cancer-promoting effects of triclosan, an antibacterial chemical which is an endocrine disruptor, to which most people are routinely exposed.

Bottom line

Based on the available evidence, the amounts of dill normally used as a herb or spice in food probably are safe, however very frequent or highly concentrated uses (such as in dill pesto sauce) might not be.

Additional comments

Both dill weed (the dried leaves) and dill seed come from the same plant. Dill essential oil has been found to be induce chromosome aberrations and appears to be cytotoxic for normal cells. Therefore, dill essential oil should be avoided.

Sources of information in this webpage

The information above, which is updated continually as new research becomes available, has been developed based solely on the results of academic studies. Clicking on any of the underlined terms will take you to its tag or webpage, which contain more extensive information.
Note that while we are continually searching for new evidence specifically concerning dill, there is not much interest in it among breast cancer researchers, so few directly relevant studies are available.