Fibremaxxing is trending, so why are bowel cancer rates still rising?

Key takeaways: If protein defined the past decade of food innovation, fibre may be shaping the next one. Across social media, consumers are embracing ‘fibremaxxing’ – a trend encouraging people to boost their daily fibre intake through everything from breakfast cereals and snack bars to beans, seeds and wholegrains. The movement reflects growing consumer interest in gut health, microbiome diversity and preventative nutrition. Yet behind the trend lies a sobering reality. Despite unprecedented attention on digestive wellness, 96% of people in the UK still fail to meet recommended fibre intake levels, while bowel cancer remains the country’s fourth most common cancer and second biggest cancer killer. More worrying still, rates are climbing among younger adults – a trend experts say can no longer be ignored. “Bowel cancer is more common in the over 50s, but there is a growing body of evidence globally that bowel cancer is increasing in younger people, including within the UK,” says Genevieve Edwards, chief executive of Bowel Cancer UK. “We don’t know exactly why this is yet, but researchers currently believe it may be due to genetic, environmental and lifestyle factors. It’s important that we see more research into this before we can say for certain what is causing this increase.” The trend has attracted increasing attention from researchers and public health experts. Dr Megan Rossi, research fellow at King’s College London and founder of gut health brand Bio&Me, notes that between the early 1990s and 2022, bowel cancer rates among under-24s increased by 96%, while cases among 25-49-year-olds rose by 72%. “Given this has happened over a relatively short period of time, it can’t be down to genetics alone, and the research is pointing to our diet and lifestyle as key factors in creating a more inflammatory environment,” she says. Despite bowel cancer’s prevalence, talking about bowel habits remains uncomfortable for many consumers. Edwards believes lingering embarrassment continues to create a barrier to early diagnosis. “Bowel cancer sadly does still carry a degree of stigma, with patients being reluctant to talk about their symptoms or take part in screening due to a perceived awkwardness around bowel issues or ‘poo’,” she says. “This can lead to delays in diagnosis and patients being diagnosed at a later stage when the disease is more difficult to treat. Thankfully, this stigma is becoming less as more people become aware of the disease.” The consequences can be significant because bowel cancer is highly treatable when caught early. As Edwards notes, “bowel cancer is treatable and curable, especially if diagnosed early. The earlier the diagnosis, the greater the chance of survival, so overcoming this stigma is crucial.” Symptoms are often overlooked because they can resemble less serious conditions. Some people may experience bleeding from the bottom, blood in their stool, changes in bowel habits, unexplained weight loss, persistent fatigue or abdominal pain, while others may experience no symptoms at all. Recognising bowel cancer can be challenging because many of these symptoms overlap with far less serious conditions. One reason fibre has become such a prominent talking point is the growing body of evidence linking it to bowel health. According to Dr Rossi, fibre works in a unique way because it feeds the microbes living in the large intestine rather than being digested directly by the body. “When these microbes ferment fibre, they produce beneficial compounds called short-chain fatty acids, including butyrate, which helps nourish the cells lining the bowel and has been linked to reduced inflammation and healthier bowel function,” she says. Fibre also helps increase stool bulk and reduce the amount of time waste products remain in contact with the bowel lining. The evidence linking fibre and bowel cancer prevention has become increasingly compelling. Dr Rossi points to research suggesting that around 54% of bowel cancer cases are preventable and that approximately 28% of UK cases are linked to inadequate fibre intake. “In fact, large studies suggest that for every additional 10g of fibre consumed per day, the risk of bowel cancer may be reduced by around 10%.” That helps explain why fibremaxxing has gained such traction online. Unlike many viral nutrition trends, Dr Rossi believes the movement is largely heading in the right direction. “Anything that encourages people to think about fibre is generally positive, especially given how little of it we’re eating.” However, she warns that consumers shouldn’t mistake fibremaxxing for a challenge to consume as much fibre as possible. “The goal shouldn’t be to consume the highest amount of fibre possible overnight. Increasing fibre too quickly – a practice sometimes dubbed ‘fibre dumping’ – can lead to bloating and digestive discomfort, particularly for people moving from a very low-fibre diet.” Instead, Dr Rossi argues that variety matters just as much as volume. “Fibre is found across a huge variety of plant foods, including fruits, vegetables, wholegrains, legumes, nuts, seeds, herbs and spices. And it’s not just about quantity; diversity is another important element because different fibres nourish different groups of beneficial gut microbes.” The enthusiasm surrounding gut health hasn’t translated into meaningful increases in fibre intake. “Awareness has certainly improved, but knowledge doesn’t always translate into behaviour change,” notes Dr Rossi. “Many people still underestimate how much fibre they actually need. Adults in the UK are recommended to eat 30g per day, yet the average intake remains stubbornly below 20g.” Convenience, habit and perceptions around healthy eating continue to hold consumers back. “There’s also the perception that eating more fibre requires a complete dietary overhaul, when in reality it’s small changes that can make a meaningful difference.” Dr Rossi advocates simple swaps such as choosing wholegrain bread over white, adding beans and lentils to meals and increasing plant diversity throughout the week. Growing evidence around fibre, microbiome diversity and bowel health also suggests the conversation is moving beyond digestive comfort alone. “We now know that fibre and microbiome diversity are closely connected. A more diverse microbiome is generally associated with better resilience and overall gut health.” The enthusiasm surrounding gut health may be creating new conversations about fibre, but Edwards believes the bigger goal is getting people to talk more openly about bowel cancer itself. “Bowel cancer is the UK’s fourth most common cancer and its second biggest cancer killer, with an estimated 390,000 people across the country now living with and beyond the disease,” she says. “By raising greater awareness of bowel cancer and its symptoms, we can save lives and make a real positive difference to the quality of life of those affected by it.”