Brown Seaweed May Have Potential as a Breast Cancer Preventive

DALLAS—Consumption of seaweed and soy may contribute to the lower rates of postmenopausal breast cancer seen in Japan, and seaweed/soy supplementation could be a potential cancer preventive in this country, Jane Teas, PhD, of the University of South Carolina, said at the Susan G. Komen Foundation National Grant Conference.

In a preliminary study of healthy postmenopausal women, Dr. Teas found that use of seaweed and soy supplements affected the women’s hormone levels.

In this study, 12 healthy postmenopausal women, half of whom had been treated for early breast cancer, received 5 g/d of a low-iodine brown seaweed supplement (Alaria esculenta) for 6 weeks and seaweed plus a powdered soy supplement for 21 weeks. The results suggest a synergistic interaction between seaweed and soy, she said.

“Of particular interest in our study was the change in urinary estrogen metabolites associated with cancer,” Dr. Teas said. She noted that women with breast cancer have been shown to have a lower ratio of 2-hydroxyestrone to 16-alpha-hydroxyestrone than do healthy women. “We found that seaweed and soy favorably increased this ratio, and the increase in 2-hydroxyestrone was significant.”

The study also showed that for several variables, women who had been treated for breast cancer had different patterns of hormonal response than women who had never had breast cancer. Said Dr. Teas, “This suggests that diet after breast cancer treatment could be an important area for study.”