University of Otago – Ōtākou Whakaihu Waka nutrition experts are advocating for dietary fibre to be officially recognized internationally as an essential nutrient. This would mark the first new essential nutrient in over 50 years. Researchers propose that fibre should be considered alongside existing essential nutrients like specific amino acids and vitamins.
Associate Professor Andrew Reynolds, a co-author of the proposal, stated that increasing dietary fibre intakes would deliver greater health benefits in Aotearoa New Zealand than increasing any other essential nutrient, given that current intakes are below World Health Organization (WHO) recommendations. He indicated that the disease burden associated with diabetes, heart disease, and colorectal cancer would be expected to be significantly reduced by such a dietary change.
The argument is presented in a paper published in Nature Food by Associate Professor Reynolds, Professor Sir Jim Mann, and Emeritus Professors Gerald Tannock and John Cummings. They contend that recent advances in understanding dietary fibre indicate it now meets the criteria for essentiality. This position is supported by over 100 years of research into fibre's chemistry, physical properties, physiology, and metabolic effects, alongside recent meta-analyses and clinical trials, many conducted at Otago.
Associate Professor Reynolds mentioned that the research team found overwhelming evidence of benefit from causal associations between dietary fibre intake and health outcomes. Studies indicate that increased fibre intake improves body weight, cholesterol, blood sugars, and blood pressure. Longitudinal studies also show that individuals with higher fibre intakes experience less heart disease, type 2 diabetes, colorectal cancer, and reduced premature mortality.
Prioritizing increases in high-fibre foods such as whole grains, legumes, vegetables, and whole fruit is likely to yield substantial health benefits. Increased recognition and prioritization of fibre could also encourage food producers to reformulate products with higher fibre content.
For a nutrient to be recognized as essential, it must be beneficial to human health, not produced by the body, and its absence must result in a measurable deficiency state. The authors propose that the role of the gut microbiome addresses the previous limitation regarding a clear deficiency state. Professor Mann stated that the gut microbiome largely depends on dietary fibre, and a healthy gut microbiome is linked to numerous health benefits. Professor Tannock's prior work has demonstrated that low fibre intakes result in a relatively unfunctional gut microbiome, with increased fibre restoring its function and relationship with the human host.
Currently, New Zealanders consume an average of 20g of fibre daily, whereas the WHO recommends at least 25g per day. Associate Professor Reynolds noted that an average increase of just 5 grams per day would meet this minimum healthy intake.
Simple and inexpensive methods for New Zealanders to increase fibre in their diet include consuming whole grains like oats, wholegrain bread, and wraps, which are good sources of fibre. Tinned legumes such as cannellini beans, butter beans, kidney beans, black beans, and lentils are also excellent, affordable sources of fibre that can supplement or replace meat in meals. Most vegetables, whether fresh, frozen, or tinned, are considered good sources of fibre.
Professor Mann concluded that recognizing dietary fibre as an essential nutrient would help ensure that dietary guidelines, nutrition education, and health professionals place greater emphasis on adequate fibre intakes. This shift is expected to lead to reformulation of food products and changes in food labelling, potentially reducing the burden of non-communicable diseases in New Zealand.