Soy : Health Benefits, Part 2

by MedlinePlus

(Page 2 of 4)

Cognitive function

A recent study suggests that isoflavone supplementation in postmenopausal women may have favorable effects on cognitive function, particularly verbal memory. Further research is necessary before a firm conclusion can be drawn.

Colon cancer prevention

There is not enough scientific evidence to determine if dietary intake of soy affects the risk of developing colon cancer.

Crohn's disease

Due to limited human study, there is not enough evidence to recommend for or against the use of soy as a therapy in preventing Crohn's Disease. Further research is needed before a recommendation can be made.

Cyclical breast pain

It has been theorized that the presence in soy of "phytoestrogens" (plant-based compounds with weak estrogen-like properties) such as isoflavones may be beneficial to pre-menopausal women with cyclical breast pain. However, due to limited human study, there is not enough evidence to recommend for or against the use of dietary soy protein as a therapy for this condition.

Diarrhea in adults

Due to limited human study, there is not enough evidence to recommend for or against the use of soy-polysaccharide/fiber in the treatment of diarrhea. Further research is needed before a recommendation can be made.

Endometrial cancer prevention

There is not enough scientific evidence to determine if dietary intake of soy affects the risk of developing endometrial cancer.Theoretical concerns have been raised that soy may actually increase the risk of endometrial cancer because of the presence in soy of "phytoestrogens" (plant-based compounds with weak estrogen-like properties), such as isoflavones. This remains an area of controversy. Recently, some scientists have theorized that isoflavones may reduce the risk of cancer by blocking estrogen effects in the body, based on laboratory studies showing isoflavones to partially block (non-competitively inhibit) estrogen receptors. In fact, early research suggests that soy isoflavones do not have the same effects on the uterus as estrogens, such as increasing the thickening of the endometrium (lining of the uterus). Genistein has been found in laboratory and animal studies to have other anti-cancer effects, such as blocking new blood vessel growth (anti-angiogenesis), acting as a tyrosine kinase inhibitor (a mechanism of many new cancer treatments), or causing cancer cell death (apoptosis).

Gall stones (cholelithiasis)

Due to limited human study, there is not enough evidence to recommend for or against the use of soy as a therapy in cholelithiasis. Further research is needed before a recommendation can be made.

High blood pressure

Due to limited human study, the effects of dietary soy on blood pressure are not clear. Further research is necessary before any recommendation can be made.

Kidney disease (chronic renal failure, nephrotic syndrome, proteinuria)

Due to limited human study, there is not enough evidence to recommend for or against the use of soy in the treatment of kidney diseases such as nephrotic syndrome. People with kidney disease should speak to their healthcare provider about recommended amounts of dietary protein, and should bear in mind that soy is a high protein food.

Menstrual migraine

One study of a phytoestrogen combination in the prophylactic treatment of menstrual migraines reduced the number of migraine attacks suffered. Further research is needed before a recommendation can be made.

Obesity, weight reduction

Due to limited human study, there is not enough evidence to recommend for or against the use of soy for weight reduction. Preliminary research suggests that a high-soy-protein and low-fat diet can improve the body composition in overweight and obese people, losing fat but preserving muscle mass. However, further research is needed before a recommendation can be made.

Osteoporosis, post-menopausal bone loss

It has been theorized that the presence in soy of "phytoestrogens" (plant-based compounds with weak estrogen-like properties) such as isoflavones may increase bone mineral density in post-menopausal women and reduce the risk of fractures. A small number of studies in this area report benefits, particularly in the lumbar spine (lower back). One study showed that there was more benefit from using soy in women in later menopause, or those with a lower body weight or calcium intake. However, most studies have not been well designed or reported. Until better research is available, a firm conclusion cannot be drawn. Individuals at risk for osteoporosis should speak with a qualified healthcare provider about the therapeutic options for increasing bone mineral density.

Prostate cancer prevention

It has been theorized that the presence in soy of "phytoestrogens" (plant-based compounds with weak estrogen-like properties) such as isoflavones may be beneficial in the treatment of prostate cancer. In addition, the isoflavone genistein has been found in laboratory and animal studies to have anti-cancer effects, such as blocking new blood vessel growth (anti-angiogenesis), acting as a tyrosine kinase inhibitor (a mechanism of many new cancer treatments), or causing cancer cell death (apoptosis). These mechanisms have not been clearly demonstrated to work in humans.Preliminary research has examined the effects of dietary soy intake on prostate cancer development in humans, but results have not been conclusive. Better study is needed before a recommendation can be made.

Stomach cancer

Preliminary study suggests that intake of soy products may be associated with a reduced risk of death from stomach cancer. Further investigation is needed before a conclusion can be drawn.

Type 2 diabetes

Several small studies have examined the effects of soy products on blood sugars in people with type 2 ("adult-onset") diabetes. Results are mixed, with some research reporting decreased blood glucose levels, and other trials noting no effects. Overall, research in this area is not well designed or reported, and better information is needed before the effects of soy on blood sugars can be clearly described.

Uses based on tradition or theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Anemia, anorexia, antifungal, antioxidant, antithrombotic, atherosclerosis, athletic endurance, attention deficit hyperactivity disorder (ADHD), autoimmune diseases, breast enlargement, cancer prevention (general), chronic respiratory problems (cough, phlegm), cystic fibrosis, diabetic neuropathy, fever, gastric cancer, gastrointestinal motility, headache, hepatitis (chronic), inflammation, insect repellant, lymphoma, memory enhancement, nosebleed (chronic), osteosarcoma, pancreatic cancer, premature ovarian failure, prostate cancer, rheumatoid arthritis, urinary tract cancer, vaginitis, vasoregulator.

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