THE SCOOP ON SOY

Most of us have heard that Soy protein is the most complete vegetable source of protein with all the 8 essential amino acids needed for proper assimilation and protein synthesis in the body. Also in recent years soy has been touted as a perfect milk substitute under the silk® brand name. Soy also contains isoflavones which are claimed to be beneficial to health. So is Soy really a super food or is it just another food fad headed for demise?

A little bit of history on soy first. Soy was first used as food as early as 1100 BC by the Chinese. The Chinese learnt to ferment soy beans to make tempeh, natto and tamari. Contrary to popular belief the Chinese and the Japanese eat soy sparingly as a condiment and not as a replacement for conventional dairy and meats.

Even though soy has all the 8 essential amino acids it lacks the sulfur containing amino acids, methionine and cystine. Also most soy processing denatures and destroys Lysine which is one of the most important amino acids for protein synthesis. So even thought soy is high in protein content, in most modern soy foods, it is not bio available. Soy foods also contain trypsin inhibitors that inhibit protein synthesis and pancreatic function. Lab animals fed a diet of soy exhibited stunted growth and pancreatic disorders. Soy also increases the body’s need for vitamin D which is needed for strong bones and growth. Also Soy hinders in the absorption of iron and zinc, both of which are essential for healthy brain development. Soy also lacks cholesterol (yeah the dreaded cholesterol!) which is essential for proper brain development in children.

In recent years, phytoestrogens present in soy have received widespread attention. What do these estrogen promoters do in the body? We all know estrogen is the female sex hormone responsible for sexual development in girls. High doses of these estrogen inducing compounds present in soy formulas are implicated in the current trend towards increasingly premature sexual development in girls and retarded sexual development in boys. Also it’s widely known that cancerous cells are very sensitive to the hormone estrogen. That’s the reason estrogen blockers are used in breast cancer therapy in women. So a diet rich in soy should be avoided by women that are predisposed to developing breast cancer. The other estrogen side-effect is the promotion of belly fat deposition. So a soy rich diet has been linked to hypothyroidism and weight gain in the mid section. Also estrogen production suppresses the production of testosterone in men leading to hair growth and a depressed sexual libido. So the men reading this article shouldn’t be disheartened if they love soy. They may not be able to perform but at least they will look good with a head full of hair!

To top it all off most soy products sold in the US are engineered with genetically modified organisms (GMOs) in order to increase yields and many studies are now linking GMOs to the production of cancerous cells in the body. So is all soy damned? No, as long as it’s fermented (fermentation process destroys the natural toxins found in soy) and made from organic soy it’s relatively harmless in small quantities.

FAT FACTS

Try saying this 10 times as fast as you can! All jokes apart, in this article I would like to elucidate the difference between the various fat types and show which ones are good and which ones are to be avoided.

Edible fat can be categorized into four main types:

(i) Saturated Fat: The fat that is present in living cells and is derived mainly from animals and some plants. This type of fat has all the carbon atoms bonded to hydrogen atoms. These fats are abundantly present in animal sources and need no special extraction techniques and can withstand high heat without disintegration of free radicals. Mostly derived from milk and other animal sources. Some vegetable sources of these fats are coconut oil, palm oil and cocoa butter. These fats are solid at room temperature. These fats have received bad publicity in the recent decades due to bad research and good marketing by the vegetable oil and the pharmaceutical industry. Contrary to popular belief these fats haven’t been shown to increase long term cholesterol production in the human body. These fats are ideal for cooking at high temperatures due to their inherent stability at withstanding high heat.

(ii) Mono-unsaturated Fat: These fats are missing one hydrogen atom per C-C bond resulting in a double C=C bond. These fats are derived from nuts like walnuts and almonds and require no special processing techniques in order to derive as the nuts are rich in these types of fat. Olive oil is also rich in MUF and is derived by cold pressing olives which again are rich in oil. These fats have been found to be very healthy for the heart and for general well being. These fats cannot withstand very high heats like saturated fats. Best eaten raw or on salads.

(iii) Poly-unsaturated Fat: As it implies this type of fat has many more C=C double bonds and is mainly derived from vegetables and grains sources such as corn. Since these vegetables and grains are naturally low in fat a large quantity has to be processed in order to derive very little oil. These oils require a lot of processing with fancy chemicals and techniques such as hexane and supercritical carbon dioxide in order to remove impurities and prolong shelf life. In the process it loses most of the vitamins naturally present in the oil. These fats suppress immune response and are hence used in organ transplants. Believe it or not these oils were invented before human consumption for use in the paint industry, but after WWII and the post industrial revolution era the vegetable oil industry aggressively started promoting it as a healthy saturated fat substitute (based on an inconclusive study by Ancel Keys). Not suited for high temperature cooking these fats disintegrate to liberate free radicals that are the cause of a lot of modern aging ailments. Best used in salad dressings and low temperature cooking.

(iv) Trans-Fat: The only man-made fat that is derived by pumping hydrogen gas at a high pressure into poly-unsaturated vegetable fats at a high temperature in the presence of nickel catalyst. Contrary to popular belief repeated deep frying in vegetable oil doesn’t yield trans-fat due to the lack of a nickel catalyst to complete the reaction. This type of fat is to be avoided like the plague.

Contrary to popular belief the safest oil to cook in is saturated fat as it withstands high temperatures and doesn’t liberate harmful free radicals and hasn’t been conclusively shown to increase the body’s long term cholesterol production. Since the saturated and MUFs require the least amount of processing they are safest and healthiest to consume. PUFs are also safe to consume if not used for high temperature cooking and if they are balanced by an intake of saturated and MUFs.

Just remember one thing: saturated and mono-unsaturated fats are readily available in nature and have been consumed by humans for hundreds of thousands of years while the poly-unsaturated vegetable oils are a recent creation of the 20^th century. Our bodies have evolved over several hundred thousand years consuming saturated and mono-unsaturated fats and so these are most biocompatible with the human body.

Food for thought: there was little use of edible vegetable oil before 1940s and one person in a million died of a heart attack. Now, 60 years after the rapid adoption of vegetable oil one person in 500 dies from a heart attack. Coincidence? I think not!