Fermenting Good Health: The Health Benefits of Fermented Foods By Sarah Coleman
Sarah Coleman BHSc BA | is a naturopath, freelance writer and content creator.
Do you know that one-third of the food eaten worldwide every day is fermented?
A growing awareness of the health benefits of fermented foods has led to an explosion in their popularity over the last two decades. As a result, we are learning through science how fermentation can make our food more nutritious and help maintain the healthy populations of microbes in and on our bodies (the human microbiome).
Let’s explore what fermented foods are and how they can benefit your health.
What are fermented foods?
Fermented foods are produced by the action of various microorganisms, such as bacteria, yeasts, funghi and their enzymes (2).
Microorganisms that cause fermentation can be (2,4):
- Already be present on the food to be fermented.
- On the utensils used to prepare the ferment.
- In the environment surrounding the food.
- Introduced into the food as a “starter culture” (e.g. yoghurt culture or kombucha SCOBY).
The final product may or may not contain the live microbes were involved in fermentation. Therefore, there are two main categories: (2):
- Fermented foods that still contain live microorganisms, e.g. yoghurt, kefir, most cheeses, miso, natto, tempeh, non-heated fermented vegetables such as sauerkraut, most kombuchas.
- Fermented foods that no longer contain live microorganisms, e.g. sourdough bread, wine, roasted coffee and cocoa.
Consuming foods with live microorganisms still present adds another layer of potential health benefits that we will discuss later.
Fermentation “pre-digests” your food!
Fermentation “pre-digests” components of raw foods before we eat them, breaking down complex food chemicals into forms that are easier for our bodies to absorb and use.
Sourdough bread is a good example. If you love the chewy tang of traditional sourdough bread, there is good news. Wholewheat sourdough fermentation:
- Reduces a bread’s glycemic index, meaning it has less effect on your blood sugar levels than conventional, mass-produced bread (1).
- Reduces compounds called phytates by more than half. Breaking down these “anti-nutrients” allows health-promoting proteins and minerals such as calcium, magnesium, iron and zinc to be absorbed more easily into your body in your digestive tract (1,2).
- Breaks down specific proteins and carbohydrates that cause allergies and intolerance in some sensitive people (1,2).
Healthy nutrients: a by-product of fermentation
Research shows that fermented foods can produce health benefits in two different ways:
- directly through us consuming live microbes (probiotic effect).
- indirectly through us consuming the compounds microbes excrete during fermentation
To understand how this works, let’s take a look at Kombucha, a fermented sweetened black tea. The fermenting process is activated by a SCOBY, a rubbery “Symbiotic Community Of Bacteria and Yeasts”. The magic starts when you float a SCOBY in a room-temperature brew of sweetened black tea.
Once the sweetened black tea interacts with the SCOBY, it releases a cocktail of healthy compounds. These include organic acids (including acetic and glucuronic acid), amino acids (including lysine), vitamins (including C and B complex), minerals (including copper, iron, magnesium and zinc), enzymes, antibiotic substances, bacteria, and yeasts (3).
When you drink kombucha, you take in all the nutritious byproducts of fermentation mentioned above and an assortment of bacteria and yeasts released from the SCOBY that may act as probiotics.
Health benefits in the gut and beyond
The microbes that live in our gut play a central role in many aspects of our health, such as immunity and brain function. There is increasingly strong evidence that when the population of these microbes are out of balance (gut dysbiosis), inflammation and immune-mediated diseases can develop (e.g., inflammatory bowel disease and asthma).
Regular consumption of fermented foods that contain live microbes (e.g., sauerkraut, kefir, etc.) may offset the proinflammatory effects of gut dysbiosis. (7).
Studies of populations with diets rich in fermented foods have shown improvements in health, including reduced risk of disease and increased longevity. In general fermented foods have been found to have a range of health effects on our bodies.
Fermented milk consumption is consistently associated with reduced risk of breast and colon cancer, type 2 diabetes, weight maintenance, and cardiovascular, bone, and digestive health in humans.
Are fermented foods for everyone?
Certain lactic acid bacteria used to ferment cheese, meats, vegetables, legumes, and wine can form compounds called “biogenic amines”, a group of chemicals that include histamine and tyramine.
Some people are sensitive to biogenic amines, and they can trigger symptoms such as headaches and inflammation. However, some sensitive people can tolerate small to moderate amounts of fermented foods, and others none at all.
Suppose you have a health condition associated with a sensitivity to histamine and/or tyramine. In this case, it is best to discuss the role of fermented foods in your diet with your health practitioner.
Regularity and moderation is key
Fermented foods have been a part of human diets for at least 14,000 years, and they will remain so for a long time to come. By including moderate amounts of fermented foods in your diet regularly, you can improve your health and discover a whole new universe of flavours!
Over to you ~ do you have a favourite fermented food or drink?
Sarah Coleman is a naturopath, freelance writer and content creator. Find her at www.complementarywords.com or blogging about fermentation, home herbalism and slow food at www.thekitchenapothecary.com. When not writing, she enjoys life on her small farm in Tasmania, being walked by her dog and hunting down the funkiest of ferments.
(1) Gobbetti, M, De Angelis, M, Di Cagno, R, Calasso, M, Archetti, G & Rizzello, CG 2019, ‘Novel insights on the functional/nutritional features of the sourdough fermentation’, International Journal of Food Microbiology, vol. 302, pp. 103–113.
(2) Marco, ML, Sanders, ME, Gänzle, M, Arrieta, MC, Cotter, PD, De Vuyst, L, Hill, C, Holzapfel, W, Lebeer, S, Merenstein, D, Reid, G, Wolfe, BE & Hutkins, R 2021, ‘The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods’, Nature Reviews Gastroenterology & Hepatology, pp. 1–13.
(3) Martínez Leal, J, Valenzuela Suárez, L, Jayabalan, R, Huerta Oros, J & Escalante-Aburto, A 2018, ‘A review on health benefits of kombucha nutritional compounds and metabolites’, CyTA – Journal of Food, vol. 16, no. 1, pp. 390–399.
(4) Melini, F, Melini, V, Luziatelli, F, Ficca, AG & Ruzzi, M 2019, ‘Health-Promoting Components in Fermented Foods: An Up-to-Date Systematic Review’, Nutrients, vol. 11, no. 5, p. 1189.
(5) Rezac, S, Kok, CR, Heermann, M & Hutkins, R 2018, ‘Fermented Foods as a Dietary Source of Live Organisms’, Frontiers in Microbiology, vol. 9.
(6) Savaiano, DA & Hutkins, RW 2020, ‘Yogurt, cultured fermented milk, and health: a systematic review’, Nutrition Reviews.
(7) Stiemsma, LT, Nakamura, RE, Nguyen, JG & Michels, KB 2020, ‘Does Consumption of Fermented Foods Modify the Human Gut Microbiota?’, The Journal of Nutrition.