- Joe Williams
- Registered Nutritionist
Photo credit, Getty Images
Fruits and vegetables
Popular across cultures, the process of fermenting food is making a comeback. Recognized as a source of “good” bacteria, fermented foods consumed regularly can contribute to the good health of the digestive system. Want to know what it's all about? Registered nutritionist Jo Williams tells us more.
What is fermentation?
Fermentation is an ancient technique for preserving food and beverages, practiced long before the era of refrigeration.
During fermentation, microorganisms such as bacteria, yeast or fungi transform organic compounds such as sugars and starch into alcohol or acids.
These act as natural preservatives and improve the taste and texture of fermented foods, giving them a strong, salty and slightly sour flavor.
There are two main methods of fermentation: spontaneous, when microorganisms naturally present in the food or environment trigger fermentation, or by the addition of a “starter culture”.
The production of kimchi or sauerkraut is an example of spontaneous fermentation, while a starter culture is used to produce kefir or natto.
Fermentation is used in the production of many foods and drinks we enjoy, such as yogurt and cheese.
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Nutritional Profile of Fermented Foods
There are many variables involved in the fermentation process.
These include the micro-organisms at work, the nutritional contribution of the ingredients used and the environmental conditions to which the food is exposed.
Consequently, these factors give rise to thousands of different variations of fermented foods, with associated differences in their nutritional contribution and microbial diversity.
Lemon slices and juice
What are the main health benefits of fermentation?
1. Source of beneficial bacteria
Most fermented foods contain bacteria that have a potential probiotic effect.
This means that these bacteria can help restore the balance of bacteria in the gut, supporting digestive health and alleviating digestive issues.
The amounts of probiotics vary, however, and the number of bacteria that reach the gut, where they may be beneficial, depends on a number of factors, including the food in which they are provided, with the most beneficial being those that provide fiber, called prebiotics.
2. Easier to digest
Thanks to the bacterial breakdown of certain natural sugars and starches, fermented foods are easier to digest.
For example, fermentation breaks down the lactose in milk into simpler sugars – glucose and galactose – meaning that if you're lactose intolerant, products like yogurt, kefir and cheese may be suitable for you.
3. Improves nutrient availability
When we ferment certain foods, we will help increase their health potential.
This involves producing more vitamins and minerals and making them more assimilable by our body.
Indeed, certain natural compounds, such as phytic acid found in legumes, including soy, can prevent the absorption of nutrients such as iron and zinc.
Fermentation eliminates these “anti-nutrients”, making their nutritional content easier to access.
Similar benefits have been seen with sourdough, with improvements in mineral availability, lower glycemic responses, and better protein breakdown.
Additionally, by stimulating the beneficial bacteria in your gut, you can promote their ability to make vitamins B and K.
Fermented yogurt
4. May Improve Mood and Behavior
Our understanding of the gut and its impact on our mood and behavior is evolving rapidly, and it appears that fermented foods may play an important role.
Certain strains of probiotic bacteria, including Lactobacillis helveticus and Bifidobacteria longum, commonly found in fermented foods, may improve symptoms of anxiety and depression.
Another strain, Lactobacillis casei Shirota, may also influence cortisol production and minimize the physical symptoms of stress.
5. May Support Heart Health
Eating fermented foods as part of a healthy, balanced diet appears to be associated with a lower risk of heart disease.
The mechanisms at play may include modest reductions in blood pressure and improvements in cholesterol balance.
6. May Support Immune Function
Incorporating a range of fermented foods into your diet can support your immune function and reduce your risk of infection.
Studies suggest that beneficial gut bacteria, in the form of probiotic supplements, may be particularly helpful in reducing upper respiratory infections.
It is not yet known whether this effect is replicated by the inclusion of fermented foods in the diet.
7. May Promote Weight Loss
Although more research is needed, some studies suggest that certain strains of beneficial bacteria may promote weight loss and reduce belly fat.
Are fermented foods safe for everyone?
Fermented foods are safe for the majority of people, but some people, such as those with histamine intolerance, may experience side effects.
Additionally, if fermented foods are new to you or you're not used to a high-fiber diet, you may experience symptoms like bloating and gas.
The introduction of fermented foods to a seriously ill or immunocompromised person should be done with caution and under the supervision of a general practitioner or other healthcare professional.
When preparing your own fermented foods, always follow recipes and be sure to use sterile equipment and carefully follow fermentation times and temperatures.