Are fermented foods really worth the hype?
Fermentation is one healthy food trend that’s going nowhere. But do the touted nutritional benefits stand up to scrutiny?
If you thought the wellness world would swiftly get over ’kraut and kombucha, you’re very much mistaken. Global sales of fermented foods are expected to reach £32billion by 2023*.
Ready to geek out? Fermentation is an age-old practice that involves the controlled action of live microbes (bacteria and yeasts) to preserve food and enhance its flavour, texture and nutritional make-up. And fermented foods are hiding in plain sight – yoghurt, cheese, chocolate and coffee are all technically fermented. During fermentation, microbes (naturally present or added) consume sugars in foods they’re living on, like dairy or vegetables, producing gases and acids. Microbial end products give fermented foods their fizz and tangy flavour – think of the tartness of yoghurt or the bitterness of kombucha – and create a preservative effect by lowering the ph, preventing the growth of harmful microbes.
While preservation was the initial draw, now it’s the potential health benefits. First, with disease risk. There’s no robust evidence showing cause and effect, but studies have found links between consuming fermented food and the risk of developing certain conditions; yoghurt has been associated with a lower risk of metabolic syndrome, while kimchi has been linked with a lower incidence of asthma. It sounds promising, but other factors could be at play. It’s true, though, that fermentation improves the digestibility of some foods. For example, kefir is made with bacteria that break down lactose, making it more digestible for people with an intolerance.
As for the alleged benefits for the gut microbiome? Kept in balance, it forms a key part of your immune system, helps you digest food and influences mood and behaviour through the various neurotransmitters it produces. But antibiotics, lowfibre diets and stress disrupt this community, leading to the interest in probiotics – live microbes that can have health benefits when consumed in the right quantity. Because fermented foods are made with live microbes, it’s assumed that these reach the gut after being consumed – and, yes, some studies support this. But, should they reach their destination, the physiological effects aren’t yet fully understood. While some fermented foods retain living microbes, such as raw ’kraut found in the fridge, others undergo processing that renders them inactive. Soya and pasteurised sauerkraut (the cheaper stuff in jars) are made stable by heat processing, sourdough is baked
– and there aren’t yet enough credible studies looking at the health effects of fermented foods to make any claims.
Though proven gut benefits are pending, fermented foods are still worth a shot. Sauerkraut is rich in fibre and vitamin C, and naturally carbonated fermented drinks contain less sugar than fizzy pop. Don’t like kimchi? Try a carrot ’kraut. Dairy fan? Try milk kefir on your cereal. While we wait to learn more about the effects of ferments, they still have much to offer.