Why Fermented Foods Should Be on Your Plate, and How They Help Gut Health

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Shira Lenchewski

Historically, fermented foods played a significant role in our ancestors’ diets. And according to registered nutritionist and clean-eating coach, Shira Lenchewski, the food world’s recent rediscovery of kimchi, sauerkraut, and even kefir is kind of a big deal. “Nostalgia aside, I’m really hoping this fermentation resurgence sticks because it’s actually really good for us.” In simple terms, fermentation means that the sugars and carbohydrates in a food have been broken down by beneficial (or “good”) bacteria, resulting in the formation of lactic acid, which our taste buds recognize as a complex, pungent burst of flavor. “Fermentation also yields a crucial benefit, far more important than an enhanced flavor profile—a healthy gut.” In fact, that might be part of the reason why food allergies (gluten, lactose, etc.) were nowhere near as prevalent in our grandparents’ days as they are now. Here, Lenchewski breaks down the basics of gut health, its affects on overall wellbeing, and the far-reaching benefits of fermented foods. (For more on gut health from Dr. Junger, click here.)

Q: Why is gut health so important?

A: In 400 BC, Hippocrates famously said, “All disease begins in the gut.” His words are even more true today than they were then. As the largest mucosal organ of the body, the gut plays a central role in maintaining the immune system. The intestinal lining functions as the bouncer at the door, deciding what’s allowed to pass through into the bloodstream. The characters lobbying for access range from essential nutrients to dangerous pathogens and toxins. And in order for the door to run smoothly, the gut ecosystem must be healthy.

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Q: How does gut health affect immunity and intolerances—gluten, specifically?

The gut lining is a tightly woven net, permeable only to small molecules when healthy. Unfortunately, there are all sorts of factors that can disrupt this delicate lattice, including infections, toxin exposure (mercury, pesticides, and BPA), antibiotic overuse, stress, excess sugar, alcohol, and yes, gluten. When the net becomes irritated (also known as leaky gut), the lining breaks apart, allowing harmful particles to seep through into the bloodstream. The infusion of undigested food particles causes the body to attack them as it would pathogens. Over time, this immune response translates to food allergies and sensitivities. Enter the vague—and frustrating—symptoms, like GI distress, bloating, fatigue, and inflammatory skin conditions…symptoms that are often mistakenly attributed to other ailments.

Ultimately, the integrity of the lining is the most important variable in gut health, and it relies heavily on the type and diversity of beneficial bacteria that reside there.

Q: Is there a way to reset a damaged gut ecosystem?

Resetting your flora is totally possible. The GI tract is one big ecosystem, made up of over 500 diverse bacterial species. But when we talk about beneficial bacteria, we’re typically referring to lactic acid producing bacteria like lactobacillus and bifidobacteria, which you may recognize from oral probiotic labels.

It wasn’t until the last decade that we realized 90% of the cells in the human body are microbial. Meaning that we are, in essence, more bacterial than anything else. But if these numbers have you reaching for your hand sanitizer, stand down. The majority of these bugs are fairly neutral, and many are actually working for us.

This is all to say that our intestinal flora have a much bigger impact on overall health than the medical community initially presumed. As we continue to understand the human microbiome better, it appears that we have only scratched the surface of the relationship between our gut and countless maladies: depression, chronic fatigue, obesity, and aging-related diseases among them. There are many researchers (myself included) who believe understanding these broader physiological implications of gut bacteria will be one of the most important medical endeavors of the 21st century. The ultimate goal? Making the GI tract an inviting place for beneficial bacteria to settle down and procreate.

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Q: What are cultured vegetables exactly?

Fermenting raw vegetables is one of the oldest, most cost-effective means of food preservation around, and it’s arguable that we’ve never needed it more. The process typically starts with shredded or sliced vegetables placed in a low-oxygen container at room temperature. In this environment, the lactobacilli and naturally occurring enzymes multiply, producing a mineral-rich functional food with deep-rooted health benefits. Your best bets: unpasteurized (the pasteurization process kills the live cultures) sauerkraut, kimchi, and fermented greens like daikon and radish greens.

Here are a some readily available options:

1. Mother-in-Law Kimchi

2. Probiotic Boost’s Spicy Turmeric Kraut

3. Crock & Jar’s Pickle Kraut

4. Bio-K (fermented brown rice)

5. Organic Sauerkraut

Q: So what exactly are the benefits of fermented foods?

A: Gut health: When the protective lining of the gut is inflamed, the body is more vulnerable to allergies, infections, and yeast overgrowth. Lucky for us, lactic acid bacteria have the ability to reduce intestinal permeability, thereby restoring the net. They also create pH changes in the GI tract that make it difficult for pathogens to survive. Sayonara, leaky gut.

Digestion: Raw cultured vegetables are essentially pre-digested, meaning that the bacteria have broken down the naturally occurring sugars in the vegetables, so that you don’t have to. The enzymes in fermented vegetables also assist in digesting foods eaten along with them, particularly grains, legumes, and meat.

Nutritional boost: The fermentation process makes nutrients more bio-available for the body to absorb. For instance, the amount of vitamin C in sauerkraut is significantly higher than in the same serving of fresh cabbage. This is because the vitamin C in fresh cabbage is woven into the fibrous plant walls, so it’s less readily available for the intestinal cells to take in. The same goes for starches, like rice and legumes, which have significantly enhanced B vitamins post-fermentation. And in wheat-based products, like sourdough, fermentation has been shown to degrade gluten, making it less inflammatory.

Detoxification: Both the beneficial bacteria and the active enzymes act as potent detoxifiers in the intestines. Beneficial microbes ferment fiber from foods like onions, garlic, leeks, artichokes, and chicory root as a means to fuel their own growth. These foods are also called prebiotics, known for amping up the detoxification process.

Sugar cravings: Yeast and pathogenic bacteria feed off sugar. The more sugar you ingest, the more hospitable you’re making your intestines for harmful microbes. This creates a less-than-ideal cycle: the more sugar you eat, the more “bad” bacteria you have…which makes you crave more sugar. The reverse, however, is also true, meaning the fewer of these “bad” bacteria you have, the less you crave sugar.

Weight: Emerging research suggests gut microbes also affect hormones that regulate our metabolism—leptin, in particular, which is known for limiting appetite. So in addition to influencing our thirst for sugar, unfavorable bacteria may also make it more difficult for some people to feel full, leading to overeating and subsequent weight gain.

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Q: We hear great things about kefir, should we buy into the hype?

A: If you tolerate lactose and your gut is healthy, there’s a lot to love about high-quality fermented milk, especially goat milk kefir. Milk sugars are broken down during the fermentation process, so kefir naturally contains less lactose than milk, and goat milk kefir has even less. Kefir also contains active lactase enzymes, which is why some people with lactose intolerance digest it with ease.

Milk-based kefir is loaded with tryptophan, an amino acid affectionately known as “nature’s Prozac,” because of how it soothes the nervous system. However, if you think you may have leaky gut, I recommend holding off, because consuming lactose now may contribute to dairy/casein sensitivities down the line.

Another great option I’m quite fond of is coconut kefir, which is essentially fermented coconut water. Cocobiotic and Healing Movement make great ones.

Q: So what’s the story with supplements? Can we just take probiotics and call it a day?

A: Yes, and no. The word probiotic—pro meaning “for” and bios meaning “life”—is a pretty accurate description of what these beneficial microbes do for our bodies. Oral probiotics are a great addition for most people out there, especially populations for whom unpasteurized foods are dangerous, like pregnant women and immuno-compromised folks. In these cases, it’s best to select the type that’s refrigerated because it will have more active cultures and higher enzyme activity. The oral supplements, however, have nowhere close to the enzymatic activity of foods like raw sauerkraut, kimchi, and coconut kefir. (See Bio-K above.)

Q: How do we start incorporating fermented foods into our diets?

A: If you’re new to the fermenting game, I recommend starting slow. We’re talking one teaspoon a day, and building up from there, based on how you feel. Some people experience gas and bloating early on, but this tends to subside. Veterans are known for eating upwards of ½ cup a day. Since kimchi and sauerkraut are sour, they pair really well with dietary fat and grains. I love kimchi with brown rice and sauerkraut with dark-meat chicken meatballs.

Here are a few goop recipes, which include elements of fermented food, to get you started:

White Pear Kimchi

Beef Bulgogi KyeRito

Bibimbap