Sunday 22 October 2017

Should you ferment your food?

Fermented foods are undergoing a bit of a renaissance, with shops struggling to keep foods like sauerkraut and kimichi on the shelves. Claire O'Mahony gets to the guts of fermentation

How often do you consider your gut? Probably not all that often unless it's to worry when it's protruding over your waistband. But with strong evidence pointing to a healthy digestive system meaning better overall health, it's becoming clear that we should be thinking about our inner workings just that little bit more.

You can blame modern living for a lot of digestive problems, with bad diets and stress being the particular culprits. It's resulted in an increased interest in gut health of late and books like Vicki Egson's Gut Gastronomy which has recipes to heal the digestive system are flying off the shelves. We're fairly famililar with probiotic drinks, which contain healthy bacteria that are delivered straight to the gut and have been popular since the 90s, but more recently there's been a developing and widespread interest in fermentation - a thousands-year old form of preservation that can give the same health benefits.

What's interesting about fermented foods is that they're marrying an ancient tradition with our current obsession with healthy eating. We eat fermented foods everyday - coffee, chocolate, cheese, ketchup and even wine - and they tend to be things that appeal to our palate.

"There's a very high element of naturalness in the fermentation process. You're depending on good micro-organisms to generate a product for you that has taste, aroma, mouthfeel and so on that's very attractive," says Professor Gerald Fitzgerald, Professor of Food Microbiology and Head of the School of Microbiology at University College Cork.

But of course - and sadly - it's not a case of embarking on a diet of pure cheddar washed down with a vat of wine under the auspices of being healthy.

Just because a food is fermented, that doesn't necessarily mean that it has health-giving properties. Professor Fitzgerald makes the distinction between probiotic and non-probiotic fermented food.

"Probiotics are a particular type of organism, mostly bacteria that can be delivered to the host in a fermented food like a yoghurt.

"But when you go out and buy feremented foods like cheese or salami, they would typically not contain probiotic bacteria.

"They would be produced through the action of regular fermenting bacteria that would have not have any health attributes attributable to them per se. That's not to say that the food itself isn't good for you, but it's not the bacteria," he says.

Sandor Katz is the author of The Art of Fermenation and Wild Fermenation, both regarded by many as blueprints for fermentation.

"For many ferments, the main nutritional benefit of fermentation is to make minerals and other nutrients more bio-available, along with various metabolic byproducts of the process.

"One benefit unique to fermented foods is the bacteria themselves, but these are not present in all fermented foods, only those fermented by bacteria, as opposed to pure yeast or other fungi, and not heated after fermentation.

"For pickles, live bacteria are found in the sour garlic dill pickles of my youth, but not the heat-processed vinegar pickles that fill supermarket shelves," he says.

"Similarly sauerkraut [fermented cabbage] or kimchi [Korean spiced fermented cabbage] or yoghurt or blue cheese, that has not been heat-processed, will have live bacteria intact.

"Most commercial wines are fermented by pure yeast, but traditional wines or wines made by natural fermentation feature live bacterial cultures as well. If you want to eat bacterially rich foods, you have to seek them out or make them."

Katz sees two reasons for the growing level of interest in fermented food. "In part I think it is a manifestation of a broader renewed interest in food, where it comes from, and how it is produced.

"Once you start interrogating your food with questions such as these, fermentation is always part of the answer," he says.

"Another reason for the renewed interest in fermentation is growing awareness of the important role of bacteria in our bodies. Live-culture ferments are bacterially rich, and there is a rapidly growing appreciation of the positive implications eating these probiotic foods can have for our well-being."

According to Cork-based nutritional consultant Mary Carmody, many of her clients who have digestive problems find that eating fermented foods helps alleviate their symptoms and that her local health store is struggling to items like sauerkraut and kimichi in stock, such as the demand for them.

"A healthy gut is the basis of good health," shes says. "The benefits of fermented food is that they help strengthen the immune system; they contain anti-cancerous substances, they feed good bacteira in the gut and help with conditions like irritable bowel syndrome."

For those not entirely sure what to do with saurkraut, which doesn't tend to feature heavily in an Irish diet, Carmody suggests using it as a pickle or added to a sandwich instead of lettuce or served with rich meats and good quliaty sausages.

"One or two tablespoons could be added to a stir-fry into brown rice, scrambled eggs, shiitake mushrooms, carrots or onions and a drop or two of soya sauce or sesame oil drizzled on top," she says.

Her other recommendations for incorporating fermented food in the diet is good quality soya sauce, although ones containing MSG should be avoided; miso soup, which helps digestion and is a complete protein as it contains all the amino acids required by the body and tempeh, made from fermented, lightly cooked soya beans which is rich in fibre and helps maintains a healthy digestive tract.

Kimchi, the Korean dish made from fermented vegetables, with chillies, garlic and salt is not to everyone's taste but even if you're not enamoured, it's worth trying to cultivate a liking for it.

"It has anti-cancer and heart health benefits. It also protects against harmful bacteria such as helicobacter pylori which is also common in my clinic these days," Carmody says.

For clinical nutiririonist April Danann, who give workshops and talks in fermentation, what differentiates fermented food from other food trends that appear on our radar is that, from her experience, people are investing in it.

When blueberries were hailed as the miracle superfood, they were being bought in shops but nobody was rushing out to buy blueberry trees. The same doesn't apply to fermenting.

"They're equipping themselves to ferment at home," she says. "Fermenting might be like a yoga thing but yoga is not a fad. People have incorporated it into their lives and into their lifestyle."

She's often asked what is the one change someone should make in terms of diet, and her answer is always 'apple cider vinegar', which is made by fermenting fresh apple juice, and to take it religiously.

"Make it something that you take seven days a week, every single day and it could be once, twice or three times but take it consistently and you will absolutely see results. It could be a tiny little increase in energy to something really dramatic. Everybody has a different response to it," she says.

Danann has encountered many stories over the years of apple cider vinegar helping in many ways, especially with pain and inflammation.

For those who would like to experiment with fermentation at home, she suggests trying a ginger bug, which is made from a ginger bulb, sugar, some treacle and water and left for a few days until it's bubbling and then poured off to become the basis for other fruit-juice based drinks.

Sandor Katz proposes starting with fermenting vegetables. "There's no need for starter cultures, it's on the veggies or equipment, jars are perfect and it's easy, safe, fast, delicious, and incredibly healthy.

"I definitely like to encourage interested people to make their own, but these days you can buy great fermented products, often locally made. There has been an explosion in small fermentation enterprises, especially those making fermented vegetables, kombucha, and other beverages."

One of the most appealing things about the fermented food trends is how widely available these foods are and their relative safety - while eating inordinate amounts of sauerkraut isn't going to make you feel particularly good, it's not dangerous.

"It's the rare person who is not regularly eating fermented foods and drinking fermented beverages. Fermentation is an important element of food traditions in nearly all parts of the world," says Katz.

"We need to value fermentation for its ability to make nutrients more readily available to us, and seek out ferments with live bacterial cultures in order to encourage greater bio-diversity in our microbiota."

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