Researchers say Kelp seaweed may be the next food enlisted in breast cancer prevention, if they can replicate findings from an animal study conducted at the University of California. In the animal study conducted researchers found the seaweed effectively reduced levels of estradiol, a hormone associated with breast, endometrial and ovarian cancers, in rats. The rats also experienced a lengthening of their menstrual cycles, another good sign when it comes to preventing breast cancer. Women who have longer cycles have fewer periods over their lifetimes, and fewer periods are linked to a lower risk of the disease.

When treating two women with menstrual problems researchers came up with the idea of doing the above study. After the women began taking kelp supplements, which are available in health food stores, they saw a significant decline in painful symptoms and a lengthening of their menstrual cycles. One of the women also had a drop in blood estradiol levels which led researchers to believe it was worth doing further controlled studies on kelp .

Although the results of Kelp are beneficial researchers say until further study is done it should not be used as a supplement to ward off breast cancer as kelp supplements could have different results from individual to individual and due to its high levels of iodine it could lead to accumulation of heavy metals.