Many soya products contain soya protein, which scientists agree helps lower blood cholesterol. Also, many soya products are low in saturated fat and contain soluble fibre, which can also contribute to lowering blood cholesterol. Products providing at least 5g of soya protein per serving will be able to carry this claim on the pack: ‘The inclusion of at least 25g of soya protein per day as part of a low saturated fat diet can help reduce blood cholesterol levels.’ So says State Registered Dietician and Registered Nutritionist Tanya Carr. Tanya is a member of the British Dietetic Association and the Nutrition Society, and is a consultant dietician to Alpro (Europe’s leading producer of dairy-free products).
Soy reduces cholesterol absorption from the gut, and increases excretion. The overall effect is a lowering of LDL cholesterol by up to 30 per cent, and a simultaneous increase in HDL cholesterol by up to 15 per cent . The Italian National Health Service now provides soy in the form of textured vegetable protein free to all patients with hypercholesterolaemia (a genetic predisposition to extremely high blood levels of cholesterol). They found that adding soy to a low fat diet dropped cholesterol levels by an impressive 26 per cent.
Soy contains Genistein, an isoflavone which has been the subject of well over 300 research papers to date. Its ability to inhibit the growth of certain cell types is cardio-protective. As oxidised cholesterol begins to accumulate in the artery walls, and an atheroma forms, the artery responds by growing more smooth muscle cells in the affected areas. As they grow, they contribute, along with the growing mass of cholesterol, to the gradual blocking of the vessel. Genistein blocks this smooth muscle response. It is presumed this plays a role, together with the soy’s cholesterol lowering effect and anti-oxidant content, in reducing heart disease in those Far Eastern countries where soy is so widely eaten, and where coronary heart disease is so uncommon.
Despite these assertions, the intake of nonfermented soy should be treated with caution, as this is the fundamental difference between the East and the West. In Asia soy is fermented from six months to three years and is eaten as a condiment, not as a replacement for animal protein as in the West.
Here is an extract on a number of key points concerning the use of Soy by Russell L. Blaylock MD, author of The Taste That Kills and Health and Nutrition Secrets That Can Save Your Life.
‘When soybeans are processed, the excitotoxic amino acids (glutamate and aspartate) are not only released, they are concentrated. This is especially so in soy protein isolates and soy protein concentrates, which are used in soy milk.
It has been shown that human blood levels of glutamate increase as much as 20 times on glutamate-loading with concentrations found in such hydrolysed proteins. These high blood levels are transferred into the human brain, especially under certain circumstances. Even in the completely normal brain, glutamate, aspartate and other excitotoxins can enter the brain via the circumventricular organs, which include the hypothalamus. One of the most sensitive structures in the brain is the arcuate nucleus. It is easily destroyed by levels of glutamate found in hydrolysed proteins and this has been proven in laboratory studies.
It is also known that the blood-brain barrier contains glutamate receptors and that free glutamate at these concentrations can open the barrier, allowing these high levels of glutamate freely to enter the brain.
It is also known that a multitude of conditions open the barrier, including strokes (both gross and silent), brain injury, brain tumours, certain pesticides, mercury, lead, autoimmune disorders (lupus, rheumatoid arthritis, etc), radio frequency radiation (cell phones), seizures, multiple sclerosis and infections. Anyone with these or related conditions should avoid products that contain high levels of excitotoxins, such as hydrolysed soy products. This constitutes a large percentage of the population.
Experiments have also shown that early exposure to glutamate can alter – permanently -the baby’s vascular reactivity. This would have major implications in cardiovascular disease. Likewise, early exposure to higher levels of glutamate, equal to that of food-based excitotoxins, results in behavioural problems, endocrine disruption, increased susceptibility to seizures early in life and alterations in lipid profiles that increase the likelihood of cardiovascular disease later in life. In fact, newer studies have shown that elevated blood glutamate significantly increases free radical generation in the endothelial lining of blood vessels – the very mechanism that causes atherosclerosis.
Recent research has also shown that many tissues and organs in the body contain glutamate receptors and that overstimulation of these receptors can cause a number of clinical problems. For example, glutamate receptor stimulation of pulmonary tissues can result in bronchiospasm (as in asthma) and worsening of pulmonary function in cases of lung diseases. The heart muscle and heart conduction system (AV and SA nodes) also contain numerous glutamate receptors. The pancreas (islets of Langerhans) also contains abundant glutamate receptors, and explains the resulting diabetes.
Even more frightening is the recent discovery that glutamate greatly enhances the growth of a number of cancers, especially brain cancers such as glioblastoma and the malignant astrocytoma. Breast, lung and ovarian cancers have also been shown to spread and metastasise faster when glutamate levels are elevated. This has been proven and is beyond dispute.’
Blaylock adds that we know that glutamate toxicity is greatly increased under certain conditions, which include low magnesium levels, deficient mitochondrial energy production such as occurs in hypoglycaemia, and mitochondrial disease during ageing, together with all of the neurodegenerative diseases i.e. most chronic diseases plus Alzheimer’s, Parkinson’s and amyotrophic lateral sclerosis
(ALS), the latter known also as ‘Lou Gehrig’s disease’ – a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord. An increase in glutamate toxicity also occurs during inflammation and when associated with other toxins including mercury, lead, cadmium, aluminium, pesticides, fluoride and industrial chemicals. This would affect tens of millions of Americans, who should be avoiding soy products.
‘Soybeans,’ Blaylock continues, ‘and especially their hydrolysed and processed products, contain high levels of manganese, aluminium and fluoride, all of which are powerful cell toxins, especially for brain cells.
Recent studies have shown that when aluminium is combined with fluoride, which occurs very easily, brain levels of aluminium are doubled. Extensive research connects aluminium in the brain with most of the neurodegenerative diseases. When hydrolysed as in soy milk, the fluoride and aluminium easily bind, forming neurotoxic fluoroaluminum compounds. The concentration at which this occurs is 0.5 ppm, a very small concentration. Fluoroaluminum compounds interact with G-proteins, which are common cell communication systems especially in the brain and operate most of the glutamanergic receptors in the brain (glutamate receptors).
I would call attention to a most important study reported in the Journal of the American College of Nutrition in the year 2000. It describes a 25-year study of middle-aged individuals consuming a diet containing tofu, which found a strong association with brain atrophy and cognitive impairment and the consumption of this soy product. Brain atrophy was determined by MRI scans. In fact, low brain weight was seen in 12 per cent of men consuming the lowest amount of tofu and 40 percent consuming the highest amount. This indicates a dose-response effect, making a stronger case of neurotoxicity’.
It seems that we must be careful to take into account that soy based products which have been demonstrated to work against high cholesterol may do so at a price, with growing evidence, quite apart from the GM debate, that there are a number of potentially serious side effects.