Everyday at dinner, my mother would bring Kimchi to the table. I myself am not a big fan of the taste of Kimchi, but in my opinion, my mother, like all Koreans, might be. During the SARS outbreak 11 years ago, my uncle convinced me to eat Kimchi by telling me that the reason Korea was not affected by SARS was that all Koreans ate Kimchi. 11 years later, I am still asking myself what is so special about this fermented vegetable that Koreans and a few foreigners are crazy about. So I came up with the research question for this blog post: What are the positive and negative effects of consuming fermented food, and what is the chemistry behind them?
Kimchi is not the only type of food that has been through fermentation. Our favorites such as cheese, yoghurt, and smoked salmon have also been through this process. So, to begin, what is the definition of fermented food? According to Peter Sahlin at Lund Institute of Technology, fermented food is any foods influenced by lactic acid producing microorganisms. Similarly, fermentation was categorized by the World Health Organization as a “technique for preparation/storage of food.” This is because in the developing countries, one tenth of the children below the age of five die because of dehydration because of diarrhoea caused by unhygienic conditions. In this case, lactic acid fermentation has been discovered to “reduce the risk of having pathogenic microorganisms grow in the food.” (Sahlin, 1999)
Fermentation of foods has been an ancient traditional practice. Tiberius the Roman emperor always had a barrel of sauerkraut when he traveled to the Middle East because Romans knew of the effects of lactic acid that included protection from intestine infections. (Schachter, R. ) Over the years, fermented foods have continued to be known to create beneficial probiotics to our guts. Having healthier guts lead to healthier digestion, which means having better absorption of nutrients, vitamins and minerals, improving overall health. In addition, fermented foods have helped in relief from lactose intolerance, prevention of colon cancer and prevention of reoccurrence of bowel disease. (Sisson, M., n.d.)
The beneficial effects of fermented food are caused by the lactic acid bacteria that form during fermentation which increases the acidity of the food (decrease the pH) as the bacteria convert energy from sugars and starches into lactic acid. (Erickson, Fayet, Kakumanu & Davis) Lactic acid bacteria, according to Sally Fellon, writer of Nourishing Traditions are ‘beneficial organisms that produce numerous helpful enzymes as well as antibiotic and an anti-carcinogenic substances.” (Pickl-It., n.d.) From what I have previously learned, acids such as lemon are able to kill harmful bacteria. When I connect this fact to my research, I could most likely conclude that when fermenting food, the food is not only stored at a state where harmful bacteria are not able to cultivate, but also the production of beneficial enzymes are not interfered, hence resulting in the beneficial effects of fermented food, such as improvement in digestion.
However, when fermented food are over consumed, there can be negative health impacts.
Even though aldehydes are not toxic substances, if one encounters a high toxic level of aldehydes through foods such as kombucha tea, some pickles, wine and beer, one’s health may be damaged. Aldehydes are a type of organic compound produced by fermenting organisms, or oxidation of alcohols. They commonly contaminate cigarette and other smoke such as smog, vehicle and factory exhaust, synthetic fragrances, and others. (Schachter, R., n.d.) The human body has enzymes that are able to convert the aldehydes into a less-harmful substance, but when there is a high level of aldehydes, the aldehydes can become toxic and travel to the brain, causing neurological diseases. Another harmful effect of aldehydes is that it damages red blood cell membranes. What this means is that red blood cells will become “less flexible in passing through tiny capillaries, altering hemoglobin” (oxygen transporter in RBC). In other words, there will be less oxygen available to the cells in the body, especially the brain. (Pierini, C., ASCP, C., & CNC. n.d.)
Despite that my sources suggest both negative and positive health implications of fermented food, they are not clear about the specific diseases that can be caused by the negative impacts of fermented food, but only clear about the specific diseases that can be prevented by the positive impacts. From this, I may be able to assume that the positive consequences of eating fermented food may be greater than the negative consequences, and if I would like to avoid the negative consequences, I may need to avoid certain types, such as alcohol, although this may not be a problem as I am not an alcohol consumer.
After learning about the effects of fermented foods, I realized that it was no coincidence that my mother had intestinal problems. I learned that all this time, when my mother was bringing Kimchi to dinner table, she was eating the fermented vegetable for her health rather than for the taste.
1. Erickson, L., Fayet, E., Kakumanu, B., & Davis, L. (n.d.). Retrieved from http://fss.kstate.edu/FeaturedContent/CarcassDisposal/PDF Files/CH 5 – Lactic Acid Fermentation.pdf
2. Pickl-It: What is lactic acid?. (n.d.). Pickl-It. Retrieved September 15, 2013, from
3. Pierini, C., (ASCP), C., & CNC. (n.d.). A Health-Destroying Toxin We Can’t Avoid And Must Detoxify. Vitamin Research Products. Retrieved September 16, 2013, from http:// www.vrp.com/digestive-health/a-
4. Sahlin, P. (1999). Fermentation as a method of food processing. Retrieved from: www.eden-foundation.org/project/articles_fermentation_thesis.pdf
5. Schachter, R. (n.d.). Risks and Benefits of Fermented Foods Consumption | Wake Up World. Wake Up World.
Retrieved September 14, 2013, from http://wakeup-world.com/2013/04/01/risks-and-
6. Sisson, M. (n.d.). The Health Benefits of Fermented Foods | Mark’s Daily Apple. Mark’s Daily Apple. Retrieved September 14, 2013, from
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