Ask the Diet Doctor: Should I Add More Fermented Foods to My Diet?
Will eating foods such as sauerkraut, kimchi, kefir, and kombucha improve your health?
Q: I keep hearing about fermented foods. Are they really that beneficial or is all the news hype?
A: Fermentation is the process by which yeast or bacteria convert sugar to alcohol, and it occurs when bread leavens or beer and wine are made. While the buzz about kimchi, sauerkraut, and other foods exaggerates their perks, research has shown fermented foods can improve your health in at least a few ways.
In a study in Nutrition Research, participants ate regular, unfermented kimchi (a traditional Korean pickled cabbage dish, pictured above) for four weeks and then switched to fermented kimchi for another four weeks. During the fermented phase, participants showed improvements in cholesterol and carbohydrate metabolism in addition to increased weight loss compared to when they consumed unfermented kimchi. It appears that either the bacteria that causes fermentation, the changes in foods as a result of fermentation, or both are required for the health perks.
Another study published in the Journal of Bioscience and Bioengineering found that longer fermentation periods resulted in higher levels of antioxidants in kimchi. This suggests that it isn't just the bacteria in fermented foods that are responsible for the improvements in health but also the changes that occur in the foods due to fermentation.
It's not known how often you should consume these foods for maximum benefit, but if you are looking to reap the rewards illustrated in first study, they will need to become part of your everyday diet. You can start by adding these foods:
If you're buying these foods at a local or farmers' market, there's no guarantee that they are fermented, so be sure to ask.