Better protection against osteoporosis with fewer side effects
Plant-based estrogen prevents osteoporosis. It requires lower concentrations than conventional animal estrogen and has fewer side effects. Animal-based estrogen therapies can cause an increase in vaginal bleeding or endometrial hyperplasia, a precursor to endometrial cancer. A research team led by Harray K. Genant of the University of California, San Francisco has shown that low doses of plant-derived estrogen do not produce these side effects (Archives of Internal Medicine 5 December 1997). The low doses of the herbal treatment also don't induce increased headaches or nausea like standard treatment does. The estrogen used in the study continued to provide relief from menopausal symptoms such as hot flashes and night sweats.
Genant believes the new findings have potentially far-reaching implications for the prophylactic treatment of osteoporosis and heart disease in postmenopausal women, as risks could be reduced and drug treatment tolerability improved. The majority of women who start estrogen replacement therapy stop after a year or two because of the side effects. This negates estrogen's long-term protective effects on bone and cardiovascular disease.
"Estrogen is the best therapy to prevent osteoporosis," says Genant. “However, for it to be effective, it must be taken long-term. Many women stop therapy after a short time because they cannot tolerate the side effects.”
The two-year study involved 406 postmenopausal women. The results show that women taking plant-based esterified estrogen with a daily supplement of 1 g of calcium - a standard ingredient in estrogen therapy - had increased bone mineral density in the spine, hips and entire body. Bone mineral density continued to decrease in patients receiving placebo.
Estrogen replacement therapy is intended to compensate for the lack of estrogen, which the ovaries no longer produce after menopause. Estrogen deficiency leads to accelerated bone loss, putting women at greater risk of fractures and developing osteoporosis. The risk of heart disease is also increasing.
In the previous prevention of osteoporosis, women took 0.625 mg of estrogen from animals daily. Doses as low as 0.3 mg did not conclusively protect against bone deterioration. The new study, however, shows that plant-based estrogens at a daily level of 0.3 mg have a statistically significant effect on bone maintenance, says Genant."As with most medications, the lower the dose, the fewer side effects there are," he explains.
The study also points to the possibility that the hormone progestin may have a lesser therapeutic role. Progestin is an adjunctive component of estrogen replacement therapy in women with an intact uterus. This hormone is given to reduce the risk of endometrial cancer. With plant-based estrogen therapy, this hormone may not be needed or may only be needed in lower doses. However, since these findings are based on only two-year observations, larger and longer studies are required to be reliable.
Lowering progestins may be beneficial as it often causes unwanted side effects including bleeding, chest pain, swelling, cramps and depression.
The Heidelberger Verlag Spektrum der Wissenschaft is the operator of this portal. Its online and print magazines, including "Spektrum der Wissenschaft", "Gehirn&Geist" and "Spektrum – Die Woche", report on current research findings.
