Soy health

Benefits of soy

There is no denying that soy has many health benefits. These health benefits are mainly coming form the quality of the soy proteins and form the isoflavones genistein and daidzein. These are the main health benefits of soy:

Soy improves bone health Soy products, such as soy milk, do not contain a lot of calcium but the soy isoflavones may help to reduce the osteoporosis risk. Several studies have suggested that soy isoflavones may be a factor in helping to prevent bone loss. The isoflavone genistein seems to inhibit bone breakdown and may have similar effects than estrogens in maintaining bone tissue. Soy can also indirectly improve bone health. Diets which are high in animal protein cause more calcium to be excreted in the urine. Replacing animal protein with soy protein may help to prevent calcium loss from the bones.

Soy relieves menopausal symptoms
Epidemiological data show that Asian women suffer less from hot flashes and night sweats compared to Western women. These symptoms of menopause are caused by low estrogen levels. Estrogens play a role in the body temperature control. Soy isoflavones can through their estrogen-like effect control these menopausal symptoms.

Soy reduces risk for heart diseases
In countries were soy products are ingested regularly, the rates of cardiovascular diseases is low. Research suggests that soy may help to prevent heart disease by reducing total cholesterol, low density lipoprotein cholesterol and preventing plaque buildup in the arteries, which could lead to stroke or heart attack. These health benefits are also mainly attributes to the soy isoflavones. The soy isoflavone genistein may also increase the flexibility of blood vessels.

Soy helps to prevent certain cancers
Several studies have indicated that a regular intake of soy foods may help to prevent hormone related cancers such as breast cancer, prostate cancer and colon cancer.

Soy is very nutritive
Soy products such as tofu, tempeh and soy milk are very rich in protein. This protein is of very high quality because it contains all essential amino acids. The amino acids of soy combine very well with the amino acids of cereals. The soy protein is therefore very important for vegans.
Soy is a good source of lecithin and vitamin E. These natural antioxidants prevent oxidation of LDL cholesterol. Soy is rich in magnesium, which plays an important function for the bones, heart and arteries.

Soy and cholesterol

Cholesterol and your heart

Cholesterol is a soft fatty substance. Cholesterol does not dissolve well in water. This weak ability of cholesterol to dissolve in water is a major factor in the development of atherosclerosis. The body gets cholesterol the food but it is also produced by the body. Cholesterol is mainly produced in the liver, but also in the adrenal glands and reproductive organs. Cholesterol is a necessary component of your body cells and is a building material for hormones such as estrogen and testosterone.
Cholesterol can cause problems when high levels in the bloodstream are present. These high levels lead to hardening of the arteries, coronary heart disease and other vascular disease problems.

When cholesterol is measured in the blood 3 cholesterol levels are determined: LDL-cholesterol (bad cholesterol), HDL-cholesterol (good cholesterol) and triglycerides.
LDL-cholesterol or "bad cholesterol" has the property to build up plaque on the inner walls of the arteries which feed the heart and brain. Together with other substances the LDL-cholesterol forms a plaque that can clog the arteries.
HDL-cholesterol or "good cholesterol" carries cholesterol away from the bloodstream and back to the liver thereby decreasing the risk of plaque build-up.
Triglycerides are the normal fats. Blood triglyceride may also play a role in forming plaque.

Soy can reduce cholesterol
Soy products help to control the cholesterol level because:
soy is cholesterol-free
the soy proteins reduce the cholesterol level
most of the fats in soy products are poly-unsaturated
soy isoflavones prevent atherosclerosis
soy contains soluble fibers which reduces the amount of cholesterol circulating in the blood.
It is known that in countries were traditional soy products are consumed daily, the rates of cardiovascular diseases are low. There is some research that suggests that soy foods may help to prevent heart disease by reducing total cholesterol, low density lipoprotein cholesterol, blood pressure and possibly preventing plaque build-up in the arteries (atherosclerosis). Before the age of 60, man have more problems than women with their cholesterol levels. After menopause, when the production of natural estrogens drops, cholesterol levels in women will go up and the women become more suseptible to heart attacks. The soy isoflavones have a weak estrogen actity which is large enough to help reduce the cholesterol levels.

Meta-analysis of the effects of soy protein intake on serum lipids
JW Anderson examined the relation between soy protein consumption and serum lipid concentrations in human in his meta-analysis of 38 controlled clinical trials, involving more than 730 volunteers. In most of these studies, animal protein was replaced with soy protein (average 47g per day). The intake of energy, fat and cholesterol was similar when the subjects ingested control and soy-containing diets.

These were the findings:
Replacing animal protein with soy protein reduced cholesterol with 9.3%.
Volunteers on the soy diet had their LDL cholesterol levels dropped on average by 12.3%.
The HDL cholesterol increased by 2.4% in volunteers on soy-containing diets.