According to the World Health Organization (WHO), non-communicable diseases include heart attacks and stroke, cancers, chronic respiratory diseases, and diabetes among others. They kill around 41 million people globally each year.
Researchers behind the study included 185 observational studies containing data that relate to 135 million person-years and 58 clinical trials involving 4,635 adult participants.
It was commissioned by WHO to inform the development of new recommendations for optimal daily fibre intake and to determine which types of carbohydrate provide the best protection against non-communicable diseases (NCDs) and weight gain. Currently, most people worldwide consume less than 20 g of dietary fiber per day.
The observational and clinical studies undertaken over nearly 40 years, suggest that eating at least 25g to 29g or more dietary fiber a day can lead to a 15-30 percent decrease in all-cause and cardiovascular-related mortality, comparing those who eat the most to those who eat the least.
In addition, according to the study, eating fibre-rich foods also reduced incidence of coronary heart disease, stroke, type 2 diabetes and colorectal cancer by 16-24 percent. Per 1,000 participants, the impact translates into 13 fewer deaths and six fewer cases of coronary heart disease.
Focus on fiber
"Previous reviews and meta-analyses have usually examined a single indicator of carbohydrate quality and a limited number of diseases so it has not been possible to establish which foods to recommend for protecting against a range of conditions," corresponding author Professor Jim Mann, the University of Otago, New Zealand, said.
"Our findings provide convincing evidence for nutrition guidelines to focus on increasing dietary fiber and on replacing refined grains with whole grains. This reduces incidence risk and mortality from a broad range of important diseases.
"The health benefits of fiber are supported by over 100 years of research into its chemistry, physical properties, physiology and effects on metabolism. Fibre-rich whole foods that require chewing and retain much of their structure in the gut increase satiety and help weight control and can favorably influence lipid and glucose levels. The breakdown of fiber in the large bowel by the resident bacteria has additional wide-ranging effects including protection from colorectal cancer."