Researchers at the University of California, Berkeley, have found that kelp lowered levels of the potent sex hormone estradiol in rats, and raised hopes that it might decrease the risk of estrogen-dependent diseases such as breast cancer in humans.

“Brown kelp seaweed makes up more than 10% of the Japanese diet,” said Christine Skibola, lead author of the study. “Soy has gotten most of the attention, but our study suggests that kelp may also contribute to these reduced cancer rates among Japanese women.”

The type of kelp used in this study, bladderwrack, is closely related to wakame and kombu, the brown seaweeds that are most commonly consumed in Japan.

Source: University of California, Berkeley, Feb 05, 2005