High dietary fibre intake linked to lower all-cause and cardiovascular mortality

By Bianca Nogrady
High consumption of dietary fibre is associated with signi­ficant decreases in all-cause and cardiovascular (CV) morta­lity, new research published in The Lancet, has found.

A series of systematic reviews and meta­-analyses looked at data from 185 prospective studies and 58 randomised controlled trials involving 4635 adults and 135 million person­ years of data that reported on carbohydrate quality and non­communicable disease inci­dence, mortality and risk factors.

The analysis found that higher intakes of total dietary fibre were associated with a 15% to 31% reduction in all-cause, coronary heart disease (CHD) and stroke mortality, and in the incidence of CHD, stroke, type 2 diabetes and colorectal cancer compared with lower intakes.

Among individuals with higher dietary fibre intake, there were 13 fewer deaths per 1000 participants, from all­ cause mortality or CHD disease, and six fewer cases of CHD, over the course of the studies.

Researchers also saw a dose­ response relation between total fibre intake and total mortality, CHD, type 2 diabetes and colorectal cancer.

The best outcomes were seen in individuals who consumed 25 to 29g daily of fibre, who showed improvements in six of the seven critical outcomes.

Dietitian Professor Clare Collins, Director of Research at the University of Newcastle’s School of Health Sciences, said the findings were important in showing the value of complex carbohydrates, which includes wholegrains and foods high in dietary fibre, and kicking back against the movement to give up all carbohydrates.

‘Poor old carbohydrate is like the baby that’s been thrown out with the bathwater,’ Professor Collins told Medicine Today. ‘I don’t think people really understand that carbohydrate varies from table sugar through to a wholemeal, nine­-grain bread or to brown rice, legumes, vegetables and fruit.’

She said the targets in the study were consistent with recommendations in the Australian Dietary Guidelines of 25 g of fibre daily for women and 30 g daily for men, and stressed that people should eat a broad range of foods that are high in fibre and wholegrains.

The only surprise in the study was that the evidence in favour of low­ glycaemic index foods was not as strong as expected, she said.
Lancet 2018; doi: 10.1016/ S0140-6736(18)31809-9.