One of the current theories in the scientific community is that women may experience depression from estrogen withdrawal after the birth of a child, during menopause or during the last few days of their menstrual cycle. Numerous studies have been done concerning the positive and negative effects of plant estrogens in food. Here we look at some of the available information concerning increased consumption of specific plant foods and symptoms that may be associated with decreased levels of estrogen in women.
Scientists are still studying the affects that estrogen and other hormones have on parts of the brain, including the hypothalamus and the hippocampus, which are responsible for memory and spatial navigation, among other things. A recent study by Japanese scientists indicates that levels of estrogen in the hippocampus are greater than those in blood plasma. However, their findings do not seem to support the theory that depression during menopause is depression from estrogen withdrawal.
Reduced levels of estrogen occur during menopause because the ovaries have stopped functioning. While the ovaries are a major estrogen producer, estrogen can also be synthesized in the body, and specifically the brain, from cholesterol and other hormones. While studies have shown that plant estrogens in food, specifically soy isoflavones have the potential to reduce premenstrual symptoms and menopausal symptoms, there is no clear evidence supporting their use for the relief of depression.
A study by the Bio-Psychology Group at the University of Leeds in the United Kingdom concluded that soy isoflavones "may have potential to reduce specific premenstrual symptoms". The "specific" symptoms mentioned are headache, breast tenderness, cramps and swelling. Soy isoflavones are the best known phytoestrogens or plant estrogens. In food, however, the quantity of these components may vary. Studies have shown that women who ate muffins made from soy flour did not experience a reduction in menopausal symptoms. But, women who took a standardized supplement containing isolated soy isoflavones noted a significant reduction of menopausal symptoms.
A review of publications and studies concerning complementary and alternative therapies for menopausal (often referred to by researchers as "climacteric") symptoms by Reinhard-Hennch, Strowitzki and von Hagens concluded that black cohosh, lifestyle modifications and phytoestrogens may relieve climacteric symptoms. Specifically, they noted that black cohosh may relieve hot flashes. Phytoestrogens, hop and Salvia are promising, but less convincing at this time. St. John's wort may be helpful for moderate depressive symptoms. Phytoestrogens have a potential for the prevention of osteoporosis and cardiovascular disease.
This study concluded that phytoestrogens and black cohosh should not be given to breast cancer survivors, but other studies contradict this conclusion. Laboratory analysis has shown that black cohosh has no effect on estrogen-sensitive breast cancer cell lines. Studies in Japan indicate that women with a high dietary intake of soy (rich in phytoestrogens) during their lifetime have both a reduced risk of developing breast cancer and an increased survival rate when breast cancer does develop. Even scientific researchers rarely agree about the benefits of plant estrogens in food.
The most recent scientific evaluation of black cohosh does not indicate that it contains any compounds that would have an estrogen-like effect on the body. No one is sure why black cohosh relieves hot flashes, but many women swear by it (this writer included). Black cohosh was used traditionally by Native American healers to treat symptoms related to hormonal imbalances, as well as many other conditions. It was widely used because it was widely available.
Some research suggests that black cohosh works by binding to serotonin receptors. Serotonin is a neurotransmitter, meaning that it transmits signals among nerves in the brain and body. Low levels of serotonin have been associated with depression. The newest anti-depressants work by inhibiting the rapid breakdown of serotonin in the body, increasing its ability to perform its many functions. 5-HTP is a dietary supplement which the body can covert to serotonin. It has been used in Europe and other countries to treat mild to moderate depression.
Whether women experience depression from estrogen withdrawal or because of changes or imbalances in levels of other hormones, low levels of serotonin or other chemicals in the body is unclear. It is known that women are much more likely to suffer from depression than are men.