Sourdough bread – the ‘staff of life’
One practitioner of allopathic medicine thinks that modern baking techniques have had a detrimental effect on the nutritional value of bread and is pushing for the return of the slower, more health-boosting techniques associated with sourdough breadmaking, a hallmark of Polish breads such as rye.
Dr Marc Sircus, founder of the International Medical Veritas Association (IMVA) and a prolific writer on the subject of health and nutrition, is a passionate advocate of sourdough bread. He believes that it holds the key to a wide range of health benefits, which is why he refers to it as the ‘staff of life.’
According to his research, before the introduction of baker’s yeast in the 1950’s, most commercial bakeries made bread using a sourdough starter. Generally speaking, this involves making a small bowl of dough and then leaving it out to ferment for two to three days. When added to fresh dough, the bacteria and wild yeast spores present in this mixture set off a series of chemical reactions that release carbon dioxide. This, in turn, makes the dough rise. Proofing using this traditional method, which has been around since at least the time of the ancient Egyptians, is an entirely natural process and usually takes around six to eight hours.
By contrast, baker’s yeast, which is made in a laboratory and often contains additives and proving accelerants such as bromide, effectively forces bread dough to rise at a much faster rate. Of course, bread that can be baked in under three hours has obvious economic and time saving benefits for the baking industry. Sircus maintains that this was the main motivation for the move away from sourdough baking. However, the difference in proofing time leads to a major difference in the nutritional value between the two.
Although bread in general has the potential to provide us with a regular source of important B vitamins, as well as key amino acids (the building blocks of protein) and a wide range of minerals such as iron, magnesium, zinc, calcium and selenium; the starches present in it need to be sufficiently prepared to allow for optimal absorption by the body.
Firstly, phytins (or phytic acid) found in grain and cereal products, which can hamper the gut’s ability to absorb these nutriments, need to be neutralized by at least 90% before their inhibitory effect is removed. Experiments conducted in Belgium showed that this can be achieved through the natural bacterial action of proofing, provided it is allowed to continue for long enough; and to a lesser extent, via cooking or baking. According to Sircus, “In naturally leavened bread, the combination eliminates all phytin, while in yeasted bread about 90% remains.”
Secondly, in order for bread to be efficiently digested, the nature of the starches present in the dough needs to be altered. Again, this is achieved via the slower, more natural proofing process associated with sourdough baking. Essentially, the longer the fermentation process is allowed to continue, the more likely it is that the bacteria and enzyme cultures in the dough will have time to break down the starches into easier-to-digest components, such as sugars and amino acids – a process that is interrupted by the speed of fast-rise yeasts.
A study by a Canadian researcher found that eating sourdough bread did not lead to the spikes in blood sugar levels compared to other types of breads, especially those containing refined flours. Aside from the presence of fibre, it would appear that this is due to the fact that the sourdough proofing process actually ‘changes the nature of the starches in the bread, creating a more beneficial bread.’ This assertion was corroborated by a separate study in Sweden, which found that sourdough bread is actually lower in carbs than other types of bread, possibly because these are used up during the fermentation process.
Sourdough fermentation also appears to improve bread quality in a number of other ways: not only does it seem to prolong shelf life but it also has the potential to increase loaf volume.
The health benefits extend even further. It is well known that baker’s yeast can encourage the overgrowth of candida in the body, leading to a whole host of health problems, including persistent thrush, tiredness and indigestion. By contrast, eating sourdough bread, which contains lactobacilli, the bacteria found in natural yoghurt, actually improves digestive health and provides you with the ‘good’ bacteria needed to keep yeast in check.
Many researchers are now beginning to think that poorly fermented wheat may be responsible for the surge in gluten-intolerance and wheat allergies being seen around the developed world. In fact, a recent study, conducted over the course of two months, found that test subjects with coeliac disease who were given sourdough wheat bread experienced none of the usual reactions they usually had to wheat gluten.
While this was a relatively small study, and more research needs to prove these findings inconclusively, it certainly seems clear that eating high fibre, naturally leavened bread offers a number of fantastic health benefits. So why not join the sourdough revolution? The only thing you have to lose is a few inches around your waistline!
 Sour Dough Bread and Health, Marc Sircus, http://www.danreid.org/health-alerts-sour-dough-health.asp
 Sourdough Bread Has Most Health Benefits, Prof Finds, University of Guelph, http://www.uoguelph.ca/news/2008/07/sourdough_bread.html
 Journal of Cereal Science, Vol. 36 (2002) pp. 339-346