Plant Estrogens May Reverse Postmenopausal Weight Gain
Postmenopausal weight gain associated with a lack of estrogen is a common problem faced by women. While estrogen replacement therapies are one solution for combating postmenopausal symptoms, it does increase the risk of developing breast and uterine cancer. Researchers have recently discovered that some plant estrogens can actually reverse postmenopausal weight gain in ovariectomized obese mice without the development of mammary gland or uterine cancer.
A recent article in the scientific journal PLoS One addresses a common problem faced by postmenopausal women: mid-life weight gain. Weight gain following menopause is associated with estrogen hormone deficiencies. Studies have shown that replacement hormone therapy decreases weight gain and prevents redistribution of fat to the abdominal cavity in postmenopausal women.
Other conditions that surface with a deficiency in estrogen include osteoporosis, diabetes and metabolic syndrome, which are sometimes treated with hormone replacement therapy. However, prolonged use of replacement hormones also places a woman at an increased risk of developing breast and uterine cancer.
Animal studies demonstrate that mammary gland and uterine cancers initiated by estrogen replacement therapy are linked to estrogen alpha receptors on the mammary gland and uterine tissues that respond unfavorably to the exogenous estrogen.
One way around this problem hypothesized by the researchers of the study was to find a safe estrogen that would react favorably with fat tissue in reversing weight gain, but not react with the mammary and uterine tissues unfavorably. Their theory was that plants, which are known to possess a type of estrogens of their own, may be close enough alike to human estrogen to provide some benefits, but not enough alike to induce cancer. The researchers decided to use plants that historically have been used in alleviating the symptoms of menopause.
In the study, extracts from two plant species were isolated and tested for their efficacy for estrogen-like properties. In addition, twenty female mice with their ovaries removed were fed a high fat diet to induce obesity. The mice were then separated into treatment groups that were fed the estrogen-containing plant extracts, and into control groups that did not receive the estrogen-containing plant extracts.
What the researchers found was that the mice given the plant extracts lost the weight gained from ovariectomy and high fat diet prior to the treatment phase of the experiment. The control mice without treatment remained obese. Furthermore, analysis of the mammary glands and uteruses of the treated mice showed no signs of cancerous growth. Other tests using cell culture and biochemical analyses demonstrated that the plant hormones were selective in the tissue type response with fat tissue being responsive to the plant extract hormones, whereas mammary gland and uterine tissues were not responsive to the hormones.
The conclusion of the study by the researchers was that the tested plant extracts show promise as having selective estrogen alpha receptor activity that may reverse postmenopausal weight gain in women. Further studies are needed to isolate the plant hormones from the extracts and verify that they represent a new class of compounds that can be used safely in long term replacement hormone therapy for treating postmenopausal symptoms such as weight gain, osteoporosis, diabetes and metabolic syndrome.