Fermented food: An Ayurvedic perspective

In recent years, fermented foods have gathered a lot of attention as the holy grail for good gut health. From sauerkraut, to kombucha and kefir to sourdough bread, it’s everywhere.

So what is fermented food?

Fermentation is a natural chemical process that occurs when microorganisms (bacteria or yeast) convert energy from carbohydrates (sugars) in an environment without oxygen. The outcome is alcohol, lactic acid and gases which gives the food its characteristic tangy flavour.

Humans have been fermenting foods for thousands of years. It helps to preserve the food which was very helpful in a time without fridges and packaging to prolong their shelf-life.

Benefits of fermented food

Fermented foods are partially digested (by bacteria or yeast) and this makes them more bioactive and bioavailable, easier for us to digest. They also contain some live microorganisms which are similar strains to those which support our gut health (probiotics) and reduce inflammation.

Fermented foods increase the bioavailability of polyphenols (antioxidants) from food (1). Antioxidants work to scavenge pathogens, keeping our gut safe and healthy. In addition the fermentation process helps reduce anti-nutrient compounds of certain foods, again, making them easier to digest (2).

Some fermented foods have shown to contain high levels of short-chain fatty acids (SCFA). SCFA are the by-product of the natural breakdown of sugars by our own microbes in the gut. They are used as an energy source for colon cells and are used to build the gut wall lining. SCFA also stimulate the production of mucous from our body’s own cells to coat the gut lining (3). This mucous has two functions – it protects our gut wall and also feeds our own gut cells (4). Again, this is great because it helps to strengthen our gut barrier (5), making sure no bacteria leaks into our bloodstream, causing illness.

A point to consider here is that while some fermented foods such as kimchi, kefir or sourdough bread are made using a few fresh ingredients, others such as the typical loaf of packaged Hovis bread will contain a long list of artificial ingredients (emulsifiers, preservatives, artificial sweeteners). These additional ingredients can play havoc with our gut health. So, choose carefully.

The Ayurvedic view

As with everything in nature, Ayurveda categorises food according to their qualities. Qualities in terms of the taste they produce, the elements they contain and so the action they have within the body. Fermented foods have a sharp and sour taste. They are fiery in nature and so will stoke the digestive fire within us. This is great for someone who has sluggish digestion such as someone with a Vata or Kapha make-up. However, give a Pitta person too much fermented food on a hot Summer’s day and you might see a reaction e.g. heartburn, rashes, acid reflux, loose stool or heavy periods in women.

You’ll notice that Ayurvedic diet and nutrition plans that include bread will state that the bread should be without yeast or unleavened. Ayurveda traditionally used fermented wines for medicinal purposes and it is here that we can see that it’s considered to be something to be taken in small quantities, not in excess (6).

And this may have something to do with the higher histamine content of fermented foods. Histamine is a chemical which has wide-ranging effects in the body and brain, performing many vital functions. One of these is regulating our immune response. However, if there is an overproduction of it (as in allergies), we eat foods that produce high levels of histamine, or have reduced capability to break it down, we accumulate an excess. This is where we tend to see those typical allergy-type reactions such as headaches, hives, itchy skin, or gastrointestinal symptoms.

Conclusion

The takeaway message is that fermented foods no doubt have numerous benefits for our gut health. However, as with all foods, it’s important to understand that not everything will suit all people or at all times – while fermented foods can be a useful addition for some, it can irritate the constitution of others.

Universal tips:

• Eat fresh

• Eat seasonally

• Eat according to your constitution and according to your current state of health

References

1. Yang et al. (2023) Effects of fermentation on bioactivity and the composition of polyphenols contained in polyphenol-rich foods: A review. Foods, 12(17)

2. Cabuk et al. (2018) Effect of fermentation on the protein digestibility and levels of non-nutritive compounds of pea protein concentrate. Food Technology & Biotechnology, 56(2)

3. Leeuwendaal, N.K., Stanton, C., O’Toole, P.W. and Beresford, T.P. (2022) Fermented foods, health and the gut microbiome. Nutrients, 14(7)

4. Schroeder, B.O. (2019) Fight them or feed them: how the intestinal mucus layer manages the gut microbiota. Gastroenterology Report, 7(1)

5. Hansson, G.C. (2012) Role of mucus layers in gut infection and inflammation. Current Opinion in Microbiology, 15(1)

6. Lad, V. (2012) Textbook of Ayurveda: General principles of management and treatment. The Ayurvedic Press: Albuquerque