Kimchi, kombucha, sauerkraut, tempeh, miso, kefir and sourdough breads; what do these have in common? They are lacto-fermented foods. Fermentation is the conversion of sugars (plant carbohydrate, starches and fiber) into alcohol and organic acids by yeasts or bacteria, under anaerobic (no oxygen) conditions. Historically, fermentation was utilized as a preservation technique. During the growing season when foods were plentiful, they would be fermented and stored for consumption during the winter months.
Fermented foods contain the beneficial bacteria Lactobacillus acidophilus. These lactobacilli are ubiquitous, present on the surface of leaves and roots of plants growing in or near the ground. Bacteria use the sugars in foods as food. In the process of metabolizing the sugars, the bacteria produce several byproducts. The main byproduct, lactic acid, acts as a preservative by inhibiting the growth of other putrefying bacteria. Other byproducts include short chain fatty acids (SCFA). SCFA are important for maintaining intestinal epithelial barrier function, regulating proliferation and tumor suppression. In the immune system, SCFA have several anti-inflammatory effects but are also important for stimulating immune function.
Research has identified a long list of health conditions that may be helped by consuming lacto-fermented foods, including colitis, constipation, diarrhea, gas, gastric reflux and heartburn, Crohn’s disease, gum disease, and high cholesterol. Recent studies have also shown a positive effect of probiotics from fermented foods on autism and obesity.
The process of fermentation also breaks down food into a more easily digestible form. For example, soybeans, are high in protein but difficult to digest without being fermented. The fermentation process breaks the proteins down into amino acids, which are readily digestible. Traditional Asian foods like miso, tempeh and tamari (soy sauce) are all products made from fermented soybeans. Additionally, the process of fermenting foods increases the amounts of some vitamins and minerals in foods, including biotin (B7), nicotinic acid (B3), riboflavin (B2), thiamine (B1), vitamin B12, and vitamin K2.
All grains contain a compound called phytic acid. The phytic acid can block the absorption of calcium, zinc, iron, magnesium and other minerals, which may lead to mineral deficiencies. Soaking and fermenting grains before cooking them will neutralize the phytic acid creating a far more nutritious grain. Other toxic chemicals found in foods that can be eliminated by fermentation include oxalic acid, prussic acid, nitrites, nitrosamines and glucosides, permitting the safe(r) consumption of some foods.
The main lacto-fermented food in Europe is sauerkraut. However, fermented foods are not restricted to cabbage. Cucumbers, beets and turnips are also foods for fermentation. In Russia and Poland one finds pickled green tomatoes, peppers and lettuces. The Japanese, Chinese and Koreans prefer pickled preparations of nappa cabbage, turnip, eggplant, cucumber, onion, squash and carrot. For example, Korean kimchi, is lacto-fermented cabbage with other vegetables and seasonings, and is traditionally eaten on a daily basis. The fermenting of fruit is less well known but, nevertheless, found in some cultures. The Japanese are noted for fermented umeboshi plums, and the peoples of India ferment fruit with spices to make chutneys.
Eating fermented foods in a live state is a healthful practice, because it supplies your digestive tract with living cultures that are essential to breaking down food, assimilating nutrients, and providing fuel to intestinal and immune cells. However, many commercially available fermented foods have been pasteurized, in order to provide a consistent product to the consumer. Pasteurization is a process of heating food, to a specific temperature for a definite length of time, and then cooling it immediately. It is intended to slow microbial growth in food. Examples are yogurt, which is pasteurized after culturing (unless labeled “contains live cultures”); and sauerkraut, which has been pasteurized to extend the shelf life.
Lacto-fermentation is not an exact science, but an artisanal craft. Stop by the Ottawa Farmers’ Market for more information and resources on how to ferment at home. And to try some samples, of course.
Brewer Park, July 7, 2013, 10am-2pm
Westboro Byron Park, July 20, 2013, 10am-2pm
This guest post was by Jayda Siggers, the founder of EatWhole BeVital Nutrition, a nutrition consulting and food education practice, will be joining us at our Westboro and Brewer Park locations to answer your questions and to share her cooking and food preparation tips in her question and answer sessions, hands-on displays and demonstrations. For upcoming dates, please visit events. Jayda received her PHD in Clinical Nutrition from the University of Copenhagen focusing on neonatal gastrointestinal physiology, nutrition and immunology. Jayda is an advocate for whole foods, and science-based nutrition and contributes to multiple online resources about nutrition and wellness and healthy recipes.