Fermented foods are growing in popularity and there is increasing evidence that fermented foods provide additional health benefits beyond their nutrient content. Fermented foods are rich in beneficial probiotics and have been associated with a range of health benefits, including better digestion and stronger immunity.
What is fermentation?
Fermentation is an ancient technique of preserving food. The process is still used today to produce foods like wine, cheese, sauerkraut, yogurt, and kombucha. Fermentation is a natural process through which microorganisms like yeast and bacteria convert starch and sugars into alcohol or acids. These then act as a natural preservative and give fermented foods a distinct zest and tartness.
Fermentation also promotes the growth of beneficial bacteria, known as probiotics. The probiotics produced during fermentation can help restore the balance of friendly bacteria in your gut. A healthy gut is linked with many aspects of health including mood and behaviour, perceived energy level, weight, food cravings, hormone balance, immunity, and overall wellness.
Which foods are fermented?
Common fermented foods include kimchi, sauerkraut, kefir, tempeh, natto, kombucha, and yogurt. Well made sourdough bread is also a fermented food along with cheese, salami, beer, wine and olives.
Initially, increasing your intake of fermented foods could cause temporary bloating until your body gets used to them.
What are the health benefits?
Fermented foods are often more nutritious than their unfermented counterpart. In addition to containing probiotics, fermented foods have enhanced nutritional and functional properties due to the transformation of substrates and the formation of bioactive and bioavailable end-products in the foods. As a result, fermented foods have been shown to exert anti-oxidant, anti-microbial, anti-fungal, anti-inflammatory, anti-diabetic and anti-atherosclerotic activity.
Fermentation helps break down nutrients in food, making them easy to digest. For example, lactose, the natural sugar in milk, is broken down during fermentation into the simpler sugars, glucose and galactose. This means that those with lactose intolerance are often fine eating fermented dairy like kefir and yogurt. In sourdough bread, the fermentation process breaks down gluten, so people who are sensitive* to gluten can enjoy well made sourdoughs.
*this does not include people with coeliac disease.
Fermentation helps break down and destroy antinutrients, such as phytates and lectins, which are compounds found in seeds, nuts, grains, and legumes that interfere with the absorption of nutrients. Therefore, consuming fermented beans or legumes like tempeh increases the absorption of beneficial nutrients, making them more nutritious than unfermented alternatives.
The probiotics produced during fermentation can help restore the balance of friendly bacteria in your gut and may alleviate some digestive problems. Evidence suggests that probiotics can reduce the uncomfortable symptoms of irritable bowel syndrome as well as help with the symptoms of bloating, gas, and constipation.
Research has shown that consuming fermented foods can lead to significant improvements in balancing intestinal permeability and barrier function. Gut dysbiosis (microbial imbalance of the intestine) is associated with inflammatory and immune-mediated diseases such as, inflammatory bowel disease and asthma. Regular consumption of fermented foods can help to prevent these proinflammatory effects of gut dysbiosis.
The bacteria that live in your gut have a significant impact on your immune system. Due to their high probiotic content, fermented foods can give your immune system a boost and reduce your risk of infections like the common cold. Additionally, many fermented foods are rich in vitamin C, iron, and zinc, all of which are proven to contribute to a stronger immune system.
Other health benefits
Studies have shown that fermented foods may also promote:
- Mental health: A few studies have linked the probiotic strains Lactobacillus helveticus and Bifidobacterium longum to a reduction in symptoms of anxiety and depression. Both probiotics are found in fermented foods.
- Weight loss: While more research is needed, some studies have found links between certain probiotic strains, including Lactobacillus rhamnosus and Lactobacillus gasseri and weight loss and in particular, reducing abdominal fat.
- Heart health: Fermented foods have been associated with a lower risk of heart disease. Probiotics may also modestly reduce blood pressure and help lower total and “bad” LDL cholesterol.
The bottom line
Typical western diets characterised by high intakes of sugar, salt and saturated fat as well as unhealthy lifestyles contribute to the likelihood of gut dysbiosis. This in turn contributes to global epidemics of obesity, depression, and mental health problems. A diet that can positively influence the microbiota is presently one of the most important areas of scientific and medical research. Therefore, the regular consumption of fermented foods can have a significant influence on reducing risk of disease and maintaining good health.