Soy & Women
Soy and Menopause | Soy and Osteoporosis | Soy and Calcium
Soy and Menopause
More than 1/3 of the women in the US, about 36 million have been through menopause. With a life expectancy of about 81 years, a 50-year-old woman can expect to live more than one third of her life after menopause. Scientific research is just beginning to address some of the unanswered questions about these years - about the poorly understood biology of menopause and how diet, especially soy, can aid in reducing some of the symptoms.
Many physiological changes during menopause are related to decreased estrogen production. These include difficulty in regulating body temperature, which can result in "night sweats" and "hot flashes." However, experiences vary from culture to culture around the world.
Studies indicate that consuming natural isoflavones, which are found in soy food products, may reduce the frequency and intensity of hot flashes in menopausal women. Isoflavones have been shown to function similarly to estrogen-replacement therapy, which is used by many women to ease menopause symptoms.
For more information on menopause, click here to go to the North American Menopause Society’s Website.
Heart disease is the number one killer of North American women. Nearly 39,000 Canadian women die each year from heart disease and 267,000 American women die from heart attacks—six times as many women as will die from breast cancer.
Soy protein operates on a number of levels to reduce heart disease risk. One of those is its ability to reduce blood cholesterol. Various researchers have studied the cholesterol-lowering ability of soy protein specifically in women. Dr. Scott Washburn from Wake Forest University showed in peri-menopausal women that 20g of soy protein with isoflavones significantly reduced total cholesterol and LDL-cholesterol compared to the control (carbohydrate) diet.
For more information on your heart health, click here to go to the American Heart Association Internet site.
Soy and Osteoporosis
Osteoporosis is often referred to as the silent disease because it develops slowly over a number of years without symptoms. Osteoporosis is a condition that affects especially older women and is characterized by decrease in bone mass with decreased density and enlargement of bone spaces producing porosity and fragility.
The risk of osteoporosis in women rises as estrogen levels decrease, both during peri-menopause and following menopause. Without estrogen's protective effects, the rate of bone loss is increased; it is highest during the first five to seven years after menopause.
Estrogen is well-recognized for helping to maintain bone mass. Estrogen down regulates the activity of bone-dissolving cells, known as osteoclasts. Research presented at the North American Menopause Society confirmed that soy foods have beneficial effects on the activity of bone cells. Post-menopausal women, who consumed soy drink or soy each day for a period of three months, experienced a drop in NTx -a chemical marker showing that bone-dissolving cells were less active when consuming the soy diet. The level of a protein called osteocalcin also increased indicating that the bone-making cells were more active.
Osteoclast is a type of bone cell that removes bone tissue by removing its mineralized matrix and breaking up the organic bone. This process is known as bone resorption. Osteoclasts and osteoblasts are instrumental in controlling the amount of bone tissue: osteoblasts form bone, osteoclasts resorb bone.
For more information about osteoporosis, visit the National Osteoporosis Foundation’s Website.
Soy and Calcium
Calcium-enriched soy beverages are an excellent source of dietary calcium. Health Canada recognizes fortified plant-based beverages (with 275 mg or more of calcium) to be an excellent source of calcium.
Studies revealed that consumption of foods containing soy protein (containing high levels of naturally occurring isoflavones) resulted in significant increase or maintenance in bone mineral content and density at the lumbar spine after six months.
Short and long term studies have found that soy protein consumption prevents bone loss in the spine of women suffering menopausal symptoms and bone mineral content in the spine of post-menopausal women. In addition, a recently published two-year study found that consumption of two servings of isoflavones-rich Soy Beverage each day prevented bone loss in a group of menopausal women.
While the exact manner in which soy isoflavones exert a protective effect on bone is not known at this time, research does show that soy isoflavones are selective estrogen receptor modulators (SERMs) and studies suggest they stimulate bone formation and reduce bone resorption.