• Diet and Nutrition
• Digestive Health

Fermented Foods: Healthy? Or Not?

For the last decade or so, fermented foods and beverages have become a popular health trend in the United States. In other parts of the world, fermented foods have been a staple for centuries. Yet the health benefits of these foods and drinks are up for debate.

What Happens During Fermentation?

During fermentation, the bacteria or yeast in the food or drink reacts with natural sugars. The reaction creates lactic acid or alcohol, which not only helps preserve the food (increasing its shelf life), but also creates lots of friendly bacteria and helpful enzymes. Many foods advertised as “probiotic” include these friendly bacteria and enzymes.

Because your gut is the largest part of your immune system, many believe that by increasing the amount of good bacteria, you’ll help keep illness away.

What Foods are Fermented?

The most common fermented foods are:

• Sauerkraut and kimchi: Fermented cabbage
• Yogurt and kefir: Fermented milk
• Tempeh: Fermented soybeans
• Kombucha: Fermented tea
• Pickles: Fermented cucumbers
• Wine: Fermented grapes
• Beer: Fermented starch (such as barley)

Are There Health Benefits to Eating Fermented Foods?

It’s widely believed that the increased amount of friendly bacteria that fermentation provides can improve digestion, and that by flooding your gut (stomach, intestines and bowel) with good bacteria, you’ll digest food more easily. Because your gut is the largest part of your immune system, many believe that by increasing the amount of good bacteria, you’ll help keep illness away – everything from allergies to cancer to autoimmune disorders and inflammation.

But some experts warn that the topic is prone to exaggeration and you shouldn’t believe everything you hear when it comes to the benefits of fermentation. The number of research studies on the subject is limited. But of the studies that have been conducted, support has been found for the idea that frequent consumption of fermented foods can reduce the risk of (or improve):

• Type 2 diabetes
• Coronary heart disease
• Impaired glucose metabolism
• Cardiovascular disease
• Irritable bowel syndrome
• Hypertension (high blood pressure)
• Osteoporosis
• Muscle soreness
• Depression
• Brain function
• Infection control

While some studies show that fermented foods may promote weight loss, others have shown they can actually contribute to obesity.

The nutritional value of fermented foods can be altered in the fermentation process. To retain the benefits, you may need to prepare the food yourself, a hobby that many people enjoy. Most fermented foods in supermarket jars or cans have been pasteurized and cooked at high heat, killing any friendly bacteria. 

Source: United Nations University; Tufts University Health & Nutrition Letter; FoodandNutrition.org;