Blackberries are recommended for breast cancer
The evidence that blackberries could be beneficial in fighting breast cancer is derived in part from studies of other berries, as well as of blackberries in particular.
Breast cancer-related effects of eating blackberries
Blackberries contain resveratrol, which has been shown to suppress the proliferation of breast tumor cells. This effect is independent of the estrogen receptor status (ER) of the cells. Resveratrol also induces apoptosis (cell death) of breast cancer cells. In addition, blackberries contain cyandin-3-glucoside, lignans, ellagic acid, the flavonoid myricetin and other potentially beneficial substances. Cyandin-3-glucoside has been shown to possess both chemo preventive and chemotherapeutic activity. Postmenopausal women with breast cancer and a high intake of plant lignans have been found to be less likely to die from their breast cancer than those with a low intake. Ellagic acid has been shown to inhibit cancer formation. Myricetin has antioxidant properties. The combination of chemicals in blackberries may more effectively prevent cancer than any one of the component chemicals alone.
Additional comments
Blackberries contain relatively high levels of phytoestrogens (in the form of lignans such as enterolactane) compared to other berries.
Marionberries are a type of blackberry (a cultivar cross between Chehalem blackberries and Olallie blackberries). Loganberries are a hybrid cross between between a blackberry and a raspberry.
Note that while we are continually searching for new evidence concerning this food, there is not much interest in it among cancer researchers so few recent studies are available.