The approach of the New Year always brings people to my door with questions about detox, weight loss and turning vegetarian. Almost always, the biggest problem I have is in informing my clients and putting correct the facts about vegetarian alternatives to meat. In particular it's my old favourite... setting the record straight about soya and soya products.
Many people are keen to become vegetarian, partly because of their beliefs in eating meat, disagreement about the conditions in which the animals are reared but increasingly because they are worried about the quality of the meat and what chemicals have been used to produce them in the interest of generating profit. Others change because they have a constitution that is simply intolerant to or incompatible with meat.
But whatever the reason, many have turned to meat alternatives such as soya as a substitute to the taste and texture of meat. However, over the past decade or so, there has been much media coverage on soya - its health benefits but increasingly the potential risks. This post attempts to clarify some important facts about soya and its use as a foodsource, why the health concerns have arisen but crucially, the numerous health benefits of traditional fermented soya and soya products which has somehow 'got lost in translation' due to the over zealous, profiteering food manufacturers of the West which has mistakenly generated confusion and alarm about the humble soya bean.
Deciding to become vegetarian is a big step requiring commitment, discipline and a deep belief in the reasons not to eat meat. It is a dietary choice and some would argue, a way of life - not all succeed especially if they lack the belief, the dedication to their choice and are swayed more by following a fad rather than a matter of real commitment to being a vegetarian. There are many who don't do their 'research' when embarking on a significant dietary change nor indeed find out about the health consequences of switching foods to vegetarian alternatives such as soya. So let's have a look at this remarkable food and what it can offer to those who want to start the New Year with a new dietary regime.
Why soya is so popular
Soya has always been popular in the far east, particularly in countries such as Japan, China, Korea and Indonesia where their cuisine is inherently designed around this staple food. It became incredibly popular in the West especially the US after the Food & Drug Administration (FDA) authorised use of health claims in October 1999 about the role of soy (soya) protein in reducing the risk of coronary heart disease (CHD). As a result of these and other studies into its protective benefits against the development of cancer, the multinational soy industry has invested millions of dollars into finding alternative uses and new markets for soybeans and soy protein foods including a custom-designed soybean. Many leading scientists at the time expressed deep concerns about genetically-manipulated soy and other crops.
Historical use of soyaThe humble soybean, also known as soya bean (Glycine max (L)., Merr Leguminosae) has been used for centuries in the far east for more than 2000 years. It started life in China from about 1000BC really by accident when it was discovered that the growth of a certain mold (fungus) on the soybeans destroyed the toxins present in the beans. Moreover, it increased the nutrient content of the soybeans which presented food opportunities for the people. The mold contamination had the effect of fermenting the soybeans and led to the creation of the still popular foods: tempeh, miso and natto. A few hundred years later, a simple process involving soaking & cooking the beans followed by treatment with a substance extracted from seawater (called nigari) yielded a product we called today as tofu (fermented soybean curd).
Plant defences & the chemical constituents of soya
Most plants have defence mechanisms as a way of protecting themselves from being eaten by foraging animals, in addition to other invaders and destructive processes such as radiation from the sun, bacteria, viruses and fungi. One of the these inherent protective systems is in its chemical constituents, collectively called anti-nutrients as it is, in essence, toxic to those who consume it and is particularly un-appetising to foraging animals. One of these anti-nutrients is phytic acid (also known as phytate) which is present in high concentrations in soya beans. Phytate has a high binding capacity to important minerals such as zinc (Zn), copper (Cu), Iron (Fe), magnesium (Mg) and calcium (Ca). It has a particularly strong affinity for Zn, a mineral that supports wound healing.
Health risks of unfermented soya
A consequence of phytate ingestion for humans is that it can lead to a number of health disortders from mineral deficiency and a host of other associated health conditions such as:
- digestive distress (due to enzyme inhibitors in soya)
- poor immune function and ultimately immune failure
- PMS (premenstrual syndrome)
- reproductive disorders (in both men and women)
- ADD and ADHD (attention deficit disorder & attention deficit hyperactive disorder)
- increased risk of heart disease
- increase risk of cancer
- loss of libido
Soya has a high content of substances known as goitrogens which are thought to block the production of thyroid hormone. This presents all sorts of metabolic problems including a lack of efficient oxygen delivery to cells. Some argue that this starvation of cells to oxygen optimises condition for the onset of cancer. Furthermore, unfermented soyabeans also reduces the bioavailability of glucose to cells and the high phytate concentration accentuates the effects of genistein, an isoflavone which blocks the production of thyroid hormone. Phytate also binds up Zn and Cu which impacts further on thyroid hormone metabolism. This can indirectly have consequential effects on reproductive hormone metabolism which could explain, in part, some of the reproductive disorders seen, particularly in women since they are more likely to consume higher quantites of soya products.
The limiting effects of soya isoflavones is to impair cell division, memory consolidation, tissue repair and blood vessel health. However, it the very action of regulating cell division that made genistein a popular substance for fighting cancer. However, the benefits came at a high cost for Western women who were consuming large quantities of unfermented soya and soya isolates, sold on the idea of cancer-protective benefits of genistein with little regard for cellular damage to normal cells. Consuming large quantities of high genistein soya products to alleviate symptoms of menopause as a guard against bone loss (osteoporosis) and breast cancer actually promotes the onset of cancer by limiting blood supply (and therefore oxygen) to healthy cells not to mention the risk of other problems such as memory loss, reduced hair growth and senile dementia.
Health benefits of fermented soya
Traditional soya foods can be divided into 2 groups:
- fermented products eg. miso, tempeh, tamari, natto, soy sauce, shoyu
- non-fermented products eg. tofu, soya milk
- improved digestibility
- enhanced nutrition
- medicinal benefits
- increased bioavailability of isoflavones
Moreover, the fermentation process reduced the levels of genistein as well as releasing a number of other nutrients and transforms soya beans into a nutritious food. The microbes used in the fermention process boosts normal gut flora and so serves a crucial probiotic role and eating small amounts of fermented soya actually confers protection against cancer rather than promoting it. Other medicinal benefits are derived from the phyto-oestrogen content which can mitigate the worst symptoms of the menopause by mimicking weak oestrogenic activity, reduce cholesterol levels thereby inhibit atherosclerosis and so reducing CHD risk. Extensive studies on the traditional asian diets have further supported these medicinal benefits witnessed by the significantly lower incidence of such diseases in the far east compared to the West. Modern soya cuisine of the West has developed into something that is almost unrecognisable from the eastern counterpart with unsurprising health consequences.
Getting the most of soya
Soya should be regarded as a wholefood and fermented soya beans and products such as miso, tempeh and natto confer a number of health benefits as discussed above. It is important to conduct proper research into soya if deciding to become vegetarian to ensure that nutrition isn't compromised if cutting out meat, fish, poultry and dairy products. There are a multitude of ideas for cooking with soya and and a number of delicious and creative recipes readily available. And these meals are not confined to vegetarians!
Special ConsiderationsThere are certain groups of people who should exercise caution when considering soya. These include the following:
- soya and women - women tend to eat soya because of the beneficial effects in menopause. However, all of the above apply and fermented soya is essential, preferably organic. For women who cannot tolerate soya, ground linseeds, red clover tea and sage tea can all help to reduce symptoms. A consultation with a medical herbalist is highly recommended.
- soya and infants - infant formulas that are soya-based can have too much sugar in them and is not really an ideal replacement to breast milk. However, if breast-feeding is a problem, consider goat's milk (also better for those who have problems digesting cow's milk). Recent research suggest a 2-fold risk of developing thyroid abnormalities in infants fed on soya milk and unsurprising given that using a phyto-oestrogen rich food source for a baby as a sole source of nutrition is bound to have consequences on a undeveloped system not designed to cope with it.
- people who should avoid soy - people with thyroid disorders, digestive problems eg. IBS or those with sensitive systems such as food intolerances.
ConclusionsWhole soya foods have nourished entire civilisations for centuries and the health benefits of traditional soya diets are glaringly obvious. Modern, Western diets, mainly due to the commercial activities of food manufacturers have sold many on the idea of soya but have modified and manipulated the traditional fermented soya with a detrimental impact on health. My response to this movement is.. 'if it ain't broke, why fix it?' It is always best to seek proper advice and conduct proper research into vegetarian alternatives before embarking on a strict dietary regime as it can lead to dificiency states such as anaemia (a common risk for vegetarians). Experiment with food and vary the menu so that it is easier to stick to a vegetarian diet and to ensure a balance of all the nutrients that are essential for health. Alternatively, if you want to avoid soya altogether, there is incredible variety from cooking vegetables - look into any Indian vegetarian cookbooks.
Good menu choices can be found from the Vegetarian Society but remember the above: www.vegsoc.org/ or any books by Sophie Grigson (for vegetarian recipes).