Popular diets directly challenged by findings from 40-year fibre study

11 Jan 2019

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A new study commissioned by the World Health Organization has found high fibre diets decrease risk of heart disease.

In what is one of the most comprehensive studies of its kind, a report published to The Lancet has revealed that people who eat higher levels of dietary fibre and wholegrains have lower rates of non-communicable diseases (NCD) compared with people who eat lesser amounts. However, links for low glycaemic load and low glycaemic index diets are less clear.

The conclusion was drawn from observational studies and clinical trials covering almost 40 years, which showed that eating between 25g and 29g of dietary fibre shows significant health benefits. This includes a decrease of up to 30pc in all-cause and cardiovascular-related mortality when comparing people who eat the highest amount of fibre to those who eat the least.

Eating fibre-rich foods also reduced incidence of coronary heart disease, stroke, type 2 diabetes and colorectal cancer by as much as 24pc, with 13 fewer deaths and six fewer cases of coronary heart disease per 1,000 study participants.

Commissioned by the World Health Organization (WHO), the study aimed to develop new recommendations for optimal daily fibre intake to see what types of carbohydrates provide the best protection against things such as NCDs and weight gain.

Challenging fad diets

Food that falls under this recommended fibre intake includes pasta, bread, nuts and cereals. For example, higher intakes of wholegrains were associated with a reduction in NCD risk by as much as 33pc, translating to 26 fewer deaths per 1,000, with seven fewer cases of heart disease per 1,000 people.

“Fibre-rich whole foods that require chewing and retain much of their structure in the gut increase satiety and help weight control and can favourably influence lipid and glucose levels,” said the study’s corresponding author, Jim Mann of the University of Otago in New Zealand.

“The breakdown of fibre in the large bowel by the resident bacteria has additional wide-ranging effects including protection from colorectal cancer.”

Speaking to The Guardian, Mann said that the findings considerably challenge many popular diets that reject carbohydrates because of their correlation with sugar. The problem is exacerbated by vested interests from different groups wanting to put forward diets – such as the keto diet – as the answer to people’s problems.

“There is the commercial vested interest, which there is an enormous amount of from chefs and celebrity chefs and so on. And there is also the professional vested interest,” he said, speaking of some doctors and scientists.

Colm Gorey was a senior journalist with Silicon Republic