Fibre – the secret superfood under our noses

The health benefits associated with a high-fibre diet have been acknowledged since the 1950s, but it is only now that the true value of this diverse substance is becoming clear. Dietary fibre (or roughage) is the part of ingested food that cannot be broken down by our own digestive enzymes. So what do we get out of it?

Fibre isn’t just fibre, it encompasses a huge diversity of plant-derived compounds. In all its forms it can even be considered as a sort of “nature’s Ozempic”, being a highly effective appetite suppressant. It also soaks up excessive fat, cholesterol and glucose, reducing the absorption of these potentially harmful ingredients and discharging them from the system. Fibre is also a natural chelating agent, absorbing and purging toxic heavy metals such as lead.  Microbial fermentation in the colon can also break fibre down to produce beneficial chemical by-products such as fatty acids.

Another unglamorous but important function is maintenance of the gut wall. Bacteria in the gut will first set about the fibre and leave the mucus of the gut wall unassailed. Then certain unwelcome microorganisms cannot so easily cross into the bloodstream to potentially activate the immune system, causing low-level inflammation and a risk of higher blood pressure.

So how do we get enough fibre? Calculating your intake is not such a simple matter because aspects such as the degree of ripening of a fruit and cooking can alter a food’s fibre content. One example is how the fibre content of a green banana is some four times higher than that of a ripe one. But a largely plant-based diet including such fare as oatcakes, dried fruit, nuts, the humble baked bean on wholemeal toast and the surprisingly fibrous avocado and raspberry will certainly help you on your way.

Side effects of switching to a high-fibre diet may temporarily include more frequent sojourns to the loo and more flatulence, but these less endearing phenomena wane as the microbiome adapts to the new diet. Other common outcomes are moderate weight loss with the fibre absorbing a lot of water causing a feeling of satiety with less urge to snack.