In more tangible terms, a high-fibre diet can increase lifespan and boost cognition. According to a 2022 study from Japan, of 3,700 participants, those who had the highest fibre intake were at the lowest risk of suffering from dementia. “Fibre is a profoundly important part of diet that is closely linked to gut health, reducing the risk of constipation and colorectal cancer,” says Bernard Corfe, Professor of Human Nutrition at Newcastle University.