Boosting dietary fibre by just 5g a day can reduce blood pressure, researchers say.
Eating more fibre reduces blood pressure and the risk of heart attack and stroke, according to Australian researchers.
They say their review provides evidence of fibre’s key role in managing blood pressure and should be included in clinical hypertension guidelines.
The review included three meta-analyses with 12 randomised clinical trials and 10 observational studies and found that low intake of fibre-rich foods was a major contributor to high blood pressure and cardiovascular disease.
One meta-analysis found that patients with established cardiovascular disease who consumed the highest levels of fibre had a 25% lower risk of all-cause mortality than those consuming the least, they said.
“For high-fibre consumers, this is equivalent to 60 fewer deaths per 1000 people,” the researchers wrote in Hypertension.
The researchers said the minimum daily dietary fibre for adults with hypertension should be more than 28g per day for women and more than 38g per day for men.
Each extra 5g per day was estimated to reduce systolic blood pressure by 2.8mmHg and diastolic BP by 2.1mmHg, they said.
“This would support a healthy gut microbiota and the production of gut microbiota-derived metabolites called short-chain fatty acids that lower blood pressure,” the researchers wrote.
The average daily consumption of fibre in Australia was just around 20g per day, said lead author Associate Professor Francine Marques from Monash University.
Only 28% of Australians met what was considered “adequate intake” of fibre, she said, and less than 20% met suggested dietary targets as recommended in their research.
Professor Marques told TMR the current evidence showed the gut microbiome played a key role in lowering blood pressure via fibre intake.
“We don’t have enzymes to digest fibre, so they reach the large intestine intact. There, some types of fibre can be digested by gut microbes,” she said.
“This process produces substances called short-chain fatty acids, which we and others have now shown reduce blood pressure.”
Professor Marques said dietary fibre was “a crucial yet underappreciated part of hypertension management”.
“By incorporating dietary fibre into treatment plans and empowering patients to increase their intake, we can significantly reduce the burden of hypertension and improve cardiovascular outcomes,” she said.
“Despite numerous guidelines recommending lifestyle modifications as first-line treatment for hypertension, specific recommendations regarding fibre intake have been notably absent.”
The researchers said lack of knowledge about which foods contained fibre, poor cooking skills and high costs were barriers to consuming more fibre.
“Diets that were most aligned with the Dietary Approaches to Stop Hypertension diet were 18% more expensive than diets least aligned,” they wrote.
They noted that most randomised clinical trials included in the meta-analyses were shorter than 12 weeks and used different types of fibre which had different properties. The impact of different fibre types on blood pressure was still not completely understood, they said.
