Read "What Can I Do About Hot Flashes And Night Sweats?"
Considered by many to be the hallmark of menopause, hot flashes are the most common menopausal symptom in Western societies. According to NIH -- The National Institute of Health -- a hot flash is a sudden temporary onset of body warmth, flushing and sweating. The intensity and frequency of hot flashes varies greatly from woman to woman. Hot flashes are considerably less common in non-Western countries such as Japan, Hong Kong, Pakistan, and Mexico, where studies show that 10% or less of menopausal women experience hot flashes. It has been postulated that the low incidence in Japanese women is due to their high-fiber, low-fat diets and high dietary intake of soy products.
Diets high in phytoestrogens have been shown to help reduce menopausal symptoms. Soy products, such as Revival Soy Protein tofu, tempeh, soymilk, and miso contain large amounts of phytoestrogens, which are plant hormones with weak estrogen-like effects. Conversely, high-fat, low-fiber diets are associated with higher estrogen activity. Since Asian women tend to have lower levels of estrogen before (and after) menopause, the drop in estrogen levels that occurs in menopause may be less dramatic, resulting in milder symptoms at menopause, or none at all. Fiber increases fecal excretion of excess estrogen, which may account for the protective effect of a high fiber diet against a variety of hormone sensitive conditions, including breast cancer. Other foods specifically indicated for hot flashes include flaxseed, high-lignan flaxseed oil, fennel, celery, and parsley. Both flaxseed and high-lignan flaxseed oil are rich in lignans, which can function to help normalize estrogen levels. Fennel, celery, parsley, and all legumes are excellent sources of phytoestrogens.
While most authors state that hot flashes, also known as vasomotor flushes, are experienced by 80% to 90% of American women, others report that only 50% of women experience hot flashes. The Mayo Clinic reports that 75% of menopausal and post menopausal women experience hot flashes.
Our incomplete understanding of hot flashes is reflected not only by the lack of consensus over how common they are, but also by the multitude of theories to explain what causes them. The most widely accepted theory is that hot flashes are caused by a deficiency in circulating estrogen as a result of declining ovarian function. We know that fluctuating estrogen levels are at least part of the picture, because many women experience relief from hot flashes while taking estrogen.
This theory, however, does not fully explain the phenomenon of hot flashes, as many menopausal and post-menopausal women with low estrogen levels never experience hot flashes, while other women simultaneously experience hot flashes and symptoms of a relative estrogen excess. Signs of estrogen excess or estrogen dominance include weight gain, breast tenderness, heavy menstrual flow, and erratic mood swings. Furthermore, studies consistently show a 30% improvement in hot flashes in women who are treated only with placebos. We can infer from the response to placebo that hot flashes are a complex neuroendrocrine phenomenon affected by a variety of factors including our thoughts, expectations, and emotions. The wide range of stimuli that trigger flushing further attests to the multi-factorial nature of hot flashes. Common triggers include: spicy food, hot drinks, alcohol, sugar, caffeine, stress, hot weather, hot tubs and saunas, tobacco, and "heated" emotions. Be sure to read Power Surge's Menopause Survival Tips.
Another explanation for hot flashes is that they are triggered by a brief but sudden downward adjustment in the body's internal temperature setting. We know that both estrogen and progesterone play a role in temperature regulation, but we do not fully understand specifically how these two
hormones, or a multitude of others, may trigger a shift in the body's thermoregulatory center. Some research indicates that hot flashes may be triggered when declining levels of estrogen and progesterone cause a withdrawal of naturally occurring opiates, chemicals in the brain that have a significant impact on mood, pain control, and hormone modulation.
Studies indicate that stabilization of either estrogen or progesterone can minimize hot flashes. Natural progesterone cream has been shown to afford significant relief from hot flashes. A recent double blind, placebo-controlled study conducted at St. Luke's Hospital in Bethlehem, Pennsylvania found that 83% of women had a decrease in the frequency and/or severity of their hot flashes while using transdermal progesterone. These results are comparable to the effectiveness of prescription estrogens, as several studies showed that prescription estrogens relieved hot flashes in approximately 85% of women. Studies demonstrate that regular exercise for as little as 3.5 hours per week also lowers the frequency and severity of hot flashes. Exercise is clearly a key element of any program to minimize menopausal symptoms, given its additional benefits for bone and cardiovascular health.
A number of medicinal plants used for centuries by indigenous cultures have gained reputations as female tonics. The tonifying effects of these herbs are most likely due to the presence of phytoestrogens, as well as the plants' abilities to nourish the endocrine glands and increase blood flow to the pelvic organs. Herbs commonly used to alleviate hot flashes include black cohosh, motherwort, chaste tree berry, blue cohosh, ginseng, dong quai, licorice, sarsaparilla, and false unicorn. A variety of nutritional supplements have demonstrated a beneficial effect on hot flashes as well. Bioflavonoids have been shown to decrease the incidence of hot flashes, particularly when they are taken with vitamin C. Their effect on hot flashes may be due to the structural similarity between certain bioflavonoids and our body's own estrogens. Studies have shown that menopausal women tend to have lower levels of vitamin C than pre-menopausal women do. Extensive research indicates that vitamin C strengthens the blood vessel membranes and acts as a potent antioxidant. Vitamin C is considered an essential nutrient for optimal functioning of the adrenal glands, an important source of post-menopausal hormone production. During perimenopause and menopause, the body begins producing more estrogen at sites other than the ovaries. The adrenal glands, as well as adipose and muscle tissue, assume an increasingly important role in hormone synthesis as ovarian function begins to slow down.
Pantothenic acid (vitamin B-5) also plays an important role in the maintenance of normal adrenal gland function. Providing the adrenal glands with optimum nutrition may help ease the body's transition to alternate sites of hormone synthesis. Para-aminobenzoic acid (PABA), another B-complex vitamin, has been shown to promote circulating levels of the body's own estrogens. It is considered a pro-estrogenic compound, capable of modifying the body's estrogen metabolism. PABA appears to be an innocuous substance even when consumed in large amounts.
Several studies report significant reductions in hot flashes with vitamin E supplementation. A number of clinical trials, from as early as the 1940's, reported that vitamin E controlled flushing in more than 50% of the cases. It is thought that vitamin E may act as an estrogen substitute, thereby regulating hot flashes. Vitamin E also has additional beneficial effects for the cardiovascular system as well as being an antioxidant.
Glandular products are not hormones, but are considered by some to be a potential source of hormone precursors. Supplementing with adrenal tissue concentrate has therapeutic value as a food substance, and is thought to support the female endocrine system.
Women react to hot flashes in many ways. Some women feel cleansed and energized after a flash, while others dread them. Many women are looking for natural ways to ease the transition through menopause. For some women, a diet rich in phytoestrogens is all that is needed. Others find more success using a combination of natural products along with exercise and a healthy diet.
Dr. Holly Zapf
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