Hippocrates said it best - “All disease begins in the gut.” The latest research confirms you can’t ignore your microbiome if your goal is to prevent, improve or reverse disease.
Fermentation is the process where microorganisms break down sugars in foods.
Fermented foods are associated with many health benefits including improved inflammation, immune function, metabolic syndrome, and gastrointestinal function.
Best sources include yogurt, kimchi, sauerkraut, kombucha, tempeh, apple cider vinegar, and others.
It may be best to eat/drink fermented foods with a meal to improve digestibility and nutrient absorption.
Fermented foods can be consumed daily, even multiple times a day for benefits.
Only those who have been directed by their doctor need to avoid fermented foods. They are safe and encouraged for children and pregnant women.
Gradually increase your intake to reduce the chances of bloating and discomfort as your body adjusts.
One important health strategy touted by expert researchers Drs. Justin and Erica Sonnenburg, PhDs, authors of The Good Gut and many other published works, including eating more fermented foods.
What is fermentation?
Fermentation is the process by which bacteria, yeasts, and other microorganisms break down carbohydrates - mainly glucose - into alcohol, gases, and acids in an anaerobic (low oxygen) environment. Fermentation has been practiced for thousands of years in cultures all around the world in the production of cheese, bread, beer, wine, yogurt, and other common foods.
Fermented foods are associated with a variety of health benefits to consumers including improved digestion and nutrient availability, enhanced microbiota diversity, health promotion, and disease prevention and improvement – especially for those with inflammatory, gastrointestinal or metabolic conditions.
A remarkable study found a 10-week intervention of 6 servings a day of fermented foods reduced inflammatory markers, improved immune function, and more greatly enhanced microbiome diversity than a high-fiber diet alone.
A randomized, controlled trial pooling results from two studies found women reporting minor gastrointestinal symptoms experienced significant improvement after 4 weeks of fermented milk compared to non-fermented milk.
Another example of health improvement was found in a review of randomized, controlled trials – yogurt consumption trended towards a decreased waist circumference, metabolic syndrome risk, and overweight/obesity status.
A recent systematic review of 125 papers focused on fermented foods reports that many health-promoting substances have been found in fermented foods including:
Antioxidant compounds. GABA, folates, phenolic compounds, CLA.
- Anti-hypertensive compounds. ACE-inhibitory peptides, GABA.
- Increased nutrient levels. folate, vitamin K2, riboflavin.
- Probiotic strains.
The best sources include those that are unsweetened and have live bacteria. Examples include:
- Yogurt (from both dairy and non-dairy milk);
- Apple Cider Vinegar;
- Fermented Vegetables (clearly labeled as such, not just pickled);
- Some cheeses (again clearly labeled with live cultures – cottage cheese, feta).
Best time to eat fermented foods
There is no evidence to suggest that a time of day is more ideal than others to consume fermented foods; however, it does appear that consuming them with a meal, rather than alone, helps improve nutrient absorption and digestibility of meal components.
Can I eat them every day?
Yes, fermented foods can be consumed every day. Research from The Sonnenburg Lab finds multiple servings a day to be ideal for microbiome diversity. However, consider a few things with daily consumption. Some fermented foods are high in sodium and added sugar. Choose unsweetened fermented foods as often as possible to minimize sugar intake. If you are salt-sensitive or have hypertension, eat them less frequently or choose low-sodium options.
Who should avoid fermented foods
Those with certain health conditions may be advised to avoid or minimize fermented foods, such as those who are immunocompromised or those with histamine intolerance (a substance found in fermented foods). Follow your doctor and dietitian’s guidance on what foods are appropriate for you. Pregnant women and children need not avoid fermented foods these are excellent foods to consume regularly for their associated health benefits.
Potential side effects and how to avoid them
If you ramp up your fermented food intake rapidly, you may experience temporary bloating as your microbiome and digestion adjust. Gradually increase your intake to your desired level over a few weeks to reduce your chances of discomfort.
Extensive research has confirmed fermented foods are indigenous to cultures around the world and may hold the key to improved health. Consume daily, or at least regularly, unsweetened fermented dairy products, vegetables, and beverages for potential improvements in blood pressure, metabolic syndrome risk, weight, inflammation, and immune dysfunction.
- NIH. Health-Promoting Components in Fermented Foods: An Up-to-Date Systematic Review.
- NIH. Associations between Yogurt Consumption and Weight Gain and Risk of Obesity and Metabolic Syndrome: A Systematic Review.
- Stanford Medicine. Fermented-food diet increases microbiome diversity, decreases inflammatory proteins, study finds.