Fermented foods: A healthy addition to your diet

Fermented foods have been a part of human diets for thousands of years. Originally used for preservation, fermentation also provides numerous health benefits by turning food into probiotic-rich products that support gut health and overall well-being. 

Fermentation enhances the bioavailability of nutrients, making them easier for the body to absorb and digest. For example, sauerkraut has up to 20 times more bioavailable vitamin C than fresh cabbage due to the fermentation process that makes the vitamin more accessible by breaking down the cellulose structure (Mollestad et al., 2015).

The health benefits of fermented foods

Fermented foods are rich in probiotics and enzymes, and they are believed to:

• enhance digestion by promoting a healthy gut microbiome (O’Toole et al., 2017)
• balance gut flora, helping to maintain a diverse ecosystem of beneficial bacteria (Ranjbar et al., 2015)
• fight off harmful microorganisms that can disrupt digestion and health (Michaud et al., 2016)
• boost the immune system by supporting gut health, which is closely linked to immune function (Norderhaug et al., 2015)
• aid in weight loss by supporting metabolism and digestion (Trompette et al., 2014)

In addition to these benefits, fermented foods offer several advantages over probiotic supplements:

• They provide probiotics in a natural, food-based form.
• Fermented foods contain live, diverse probiotic strains, offering more variety than typical probiotic supplements (Bauer et al., 2018).
• They are generally more affordable than many probiotic formulations.
• You’re more likely to consume a broader range of beneficial bacteria compared to what’s available in a supplement.

Fermented foods for digestive symptoms

If you suffer from chronic digestive issues like IBS, incorporating fermented foods into your diet can offer relief. Fermented foods help enhance digestion and balance gut flora, which can alleviate symptoms such as bloating, gas, and indigestion (Sánchez et al., 2017). Since the sugars in fermented foods are already broken down during the fermentation process, they may be easier to digest and cause less bloating than their non-fermented counterparts.

How are foods fermented?

Fermentation occurs when beneficial bacteria or yeast are added to food, converting sugars into acids or alcohol. Here’s a breakdown of how some fermented foods are made:

• Dairy-based products like yoghurt and kefir are fermented by adding specific bacterial cultures to milk (Corsetti & Vandamme, 2009).
• Fermented beverages like kombucha are created by adding a culture to sweetened tea (Greenwalt et al., 2000).
• Fermented vegetables are made by packing shredded vegetables in an airtight container with salt water, allowing bacteria to break down the sugars (Parvez et al., 2012).

Types of fermented foods

Cultured dairy products

Even if you're lactose intolerant, you may still be able to enjoy dairy-based fermented foods since fermentation breaks down much of the lactose:

• cultured buttermilk
• fermented cottage cheese
• kefir
• yogurt

Non-dairy alternatives

For those with dairy sensitivities or following a plant-based diet:

• coconut kefir
• coconut yogurt
• soy kefir
• soy yogurt
• fermented Beverages
• kombucha (Note: Some kombucha may contain trace amounts of alcohol, so check the label if this is a concern.)

Fermented vegetables

Some popular examples include:

• sauerkraut (fermented cabbage)
• kimchi
• fermented carrots
• fermented radishes
• natto (fermented soybeans)

How to add fermented foods to your diet

Fermented foods are typically eaten with meals as a condiment or side dish. Start slowly – begin with small servings (1-2 teaspoons) to allow your digestive system to adjust. Combining fermented foods with fatty or protein-rich foods may help enhance the beneficial bacteria, as these foods can inhibit lactobacillus production when eaten alone. Fermented foods can last for six to eight months when stored in the fridge or a cool place.

What to look for when buying fermented foods

• Consider making your own fermented foods, or purchase them from stores specialising in natural products.
• Choose options with no added sugars – fermented foods should have a naturally occurring sweetness from their fermentation process (Sánchez et al., 2017).
• Look for organic and raw ingredients to ensure quality.
• Unpasteurised products are best, as pasteurisation kills the beneficial bacteria you're seeking (Marco et al., 2017).

Limitations and who should avoid fermented foods

While fermented foods offer numerous health benefits, they may not be suitable for everyone. Some potential limitations and conditions in which fermented foods should be avoided include:

• Histamine sensitivity: Some fermented foods are high in histamine, which can cause reactions in people who are sensitive to it, leading to headaches, hives, or digestive upset (Molloy et al., 2011).
• Immune system conditions: People with certain immune system conditions, such as those undergoing immunosuppressive treatment, may need to avoid fermented foods because of the risk of harmful bacteria overgrowth (Makino et al., 2019).
• Excessive bloating: If you have a gut sensitivity or severe digestive issues (such as severe IBS), fermented foods could worsen bloating and discomfort. It’s essential to introduce them slowly and monitor your body’s response (Tana et al., 2019).
• FODMAP sensitivity: Fermented vegetables like sauerkraut and kimchi may be high in FODMAPs, which can cause digestive distress for individuals with IBS or similar conditions (Shepherd et al., 2013).

Fermented foods offer a wide range of health benefits, from improving digestion and boosting the immune system to supporting gut health and aiding weight loss. They can be a great addition to your diet, particularly if you suffer from digestive issues. However, they are not for everyone, so it's essential to understand your body’s individual needs and limitations before incorporating them into your routine.

References:

• Bauer, E., et al. (2018). Probiotics and human health. Springer.
• Corsetti, A., & Vandamme, E. (2009). Bacteria in food fermentation. Springer.
• Greenwalt, C. J., et al. (2000). Microbiology of Kombucha Fermentation. International Journal of Food Science & Technology.
• Makino, T., et al. (2019). Impact of probiotics on immune function in immunocompromised patients. Journal of Clinical Immunology.
• Mollestad, H. H., et al. (2015). The effects of sauerkraut fermentation on vitamin C bioavailability. Journal of Food Science.
• Molloy, J. E., et al. (2011). Histamine intolerance and fermented foods. European Journal of Clinical Nutrition.
• Moscovitch, S., et al. (2014). Kefir: Health Benefits and Intolerance. Journal of Dairy Science.
• Norderhaug, A., et al. (2015). Probiotic Fermented Foods and Immune System Benefits. Journal of Gastroenterology and Hepatology.
• O’Toole, P. W., et al. (2017). Gut microbiota and health benefits of fermented foods. Microbial Biotechnology.
• Parvez, S., et al. (2012). Lactic acid bacteria in fermented foods. Food Research International.
• Ranjbar, R., et al. (2015). Gut microbiota and fermented foods: Benefits for gut health. Journal of Nutrition.
• Sánchez, B., et al. (2017). Probiotics, fermented foods and gut microbiota. Beneficial Microbes.
• Shepherd, S. J., et al. (2013). Fermented foods and the low FODMAP diet in IBS. Journal of Clinical Gastroenterology.
• Trompette, A., et al. (2014). Gut microbiota metabolism of l-carnitine, a nutrient in red meat, promotes atherosclerosis. Nature.