The Benefits of Eating Fermented Foods

What Is Fermentation?

Fermentation is the process whereby bacteria, yeast, or other microorganisms are used to convert naturally-occurring carbohydrates, under anaerobic conditions, into alcohol or organic.

There are, broadly speaking, two types of fermentation: alcoholic (or ethanol fermentation), and lactic acid fermentation.

In alcoholic fermentation, bacteria and yeast break down pyruvate (formed during glucose metabolism) into ethanol and carbon dioxide. This type of fermentation produces such things as bread, beer, and wine.

The pyruvate molecules created during glucose glycolysis can be fermented even further, utilising lactic acid fermentation to convert the existing lactose into the desired lactic acid.

What are the benefits of fermentation?

Fermenting food brings several benefits. It serves to improve the digestion of food, for a start. Your body must have adequate digestive enzymes in order to properly digest, absorb, and utilise the nutrients found in food. When vegetables such as cabbages and cucumbers can sit and steep until their sugars are sufficiently broken-down to encourage the growth of bacteria, fermentation has taken place.

Beneficial bacteria thrive in fermented foods, working as reinforcements for the positive bacteria that lie in our digestive systems. Since 70-80% of our natural immune system exists in our digestive tract, maintaining the proper ratio of gut flora is essential.

Fermentation is also an excellent preservative for food. During the fermentation process, micro-organisms produce alcohol, acetic acid, and lactic acid, all of which are natural bio-preservatives, used to prevent spoilage, whilst retaining the food’s nutrients. Lactic acid reduces the pH level of the food, inhibiting the cultivation of harmful bacteria, and also affects various phosphoproteins (such as casein, found in milk and other dairy produce), inducing a finer suspension that seems to assist with digestibility.

Fermentation and Probiotics

Probiotics are a type of microorganism that has been proven to promote health-giving properties in animals and humans. The natural probiotics contained in fermented drinks and foods is the reason they are so beneficial.

Probiotics help to balance up the gut’s good bacteria, as well as assisting in tuning up our natural immune system. Up to 70% of the human immune system originates in the intestine, so incorporating fermented foods, rich in probiotic bacteria, into your diet helps to maintain the health of your intestinal tract.

Notable Health Benefits of Fermentation

Improved digestion

The process of fermentation helps to break down nutrients into forms that are more easily digestible. Certain foods, like the protein-rich soybean, are entirely indigestible before the fermentation process. It breaks down the complex protein of the bean into amino acids that are readily digestible, the result being those staples of Asian cooking such as soy sauce, tempeh, and miso.

Suppressed H. pylori

H. pylori (Helicobacter pylori infection) is a known risk factor in many gastrointestinal diseases. Several fermented foods have proven useful in the suppression of H. pylori infection, notably yoghurt and other fermented milk products.

Anti-cancer effects

Cancer is caused by the mutation or activation of abnormal genes in the body that control cell division and growth. Research is starting to show that fermented foods and their associated probiotic cultures may be able to decrease exposure to chemical carcinogens. A number of recorded effects of fermented food seem to suggest this, including the detoxification of ingested carcinogens, the alteration of the intestinal environment and reduction of bacterial populations responsible for the generation of carcinogenic compounds, the production of metabolic products that induce apoptosis or programmed cell death, the production of compounds responsible for inhibiting tumour cell growth, and the stimulation of the immune system, allowing it to defend itself from the proliferation of cancer cells.

Enhancement of the bioavailability of nutrients

Fermentation assists in the creation of new nutrients, and studies show it improves the availability, quantity, and digestibility of several dietary nutrients. Microbial cultures produce B vitamins, including niacin, thiamine, folic acid, biotin and riboflavin. Fat and protein bioavailability are enhanced through bacterial enzymatic hydrolysis, and lactic acid bacteria aid in the production of butyric acid, lactic acid, short chain fatty acids (SCFA) and amino acids.

Reduction of symptoms of lactose intolerance

Lactobacillus transforms the lactose in milk into lactic acid, which might be easier to digest. Lactic acid in yoghurt has been shown to reduce symptoms of lactose intolerance among individuals who are lactase-deficient. This beneficial effect seems to be the result of lactic acid bacteria that exists in fermented milk, and which increases lactase in the small intestine.

Treatment of Inflammatory Bowel Disease

Fermented milk with a supplement of probiotics has exhibited a direct effect on bowel disorders. Clinical trials have shown that probiotics can reduce abdominal pain, constipation, flatulence and bloating in patients suffering from inflammatory bowel diseases, such as Crohn’s disease.

Some common fermented foods

All culinary cultures have some sort of fermented food or drink among their fare. These are some of the most common, which can usually be found in any well-stocked supermarket.


Kefir is a drink that combines alcoholic fermentation and lactic acid fermentation of the lactose in milk. It is known to stimulate the immune system, reduce the symptoms of lactose intolerance, and lower cholesterol.


A spicy fermented food, popular in Korea, kimchi is low in fat and carbohydrates and has high levels of phytochemicals, minerals, vitamins and dietary fibre


Kombucha is a sour tonic drink, made from sweetened tea that has been cultured with a colony bacteria and yeast. It is known to reduce blood pressure, improve levels of cholesterol, and detoxify the body.


Miso is a paste-like food that has a salty-sweet flavour. It is a staple in Japanese cuisine, being used to cook miso soup, and as a seasoning.


A famous German dish, sauerkraut is made from finely chopped cabbage and fermented by lactic acid-producing bacteria. Studies show that this fermentation process enhances the protection of blood vessels, as well as increasing levels of vitamin C, manganese and dietary folates.


It’s hard to think of any cultured food that is better-known for its health benefits in the way that yoghurt is. Probiotic yoghurt boasts extremely high levels of calcium, B vitamins, zinc, protein and, of course, probiotics.


Certain fermented foods ought to be avoided whilst pregnant, due to the chance of contamination if they have been improperly fermented.

Tyramine, a natural substance often found in fermented and aged drinks and foods, is recognised as a migraine trigger and should be avoided by those who suffer from migraines.

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