A new study has found that, for most of us, the fiber we eat can protect our heart health, lowering the risk of high blood pressure, heart disease or stroke by up to 20%. It’s more evidence showing that a healthy gut leads to a healthy heart.
When the fiber you eat reaches the large intestine, some of it is broken down by gut bacteria, which release short-chain fatty acids (SCFAs) as a by-product. These SCFAs play a crucial role in the gut-heart axis, contributing significantly to heart health protection, predominantly by lowering blood pressure.
New research by Monash University has demonstrated, for the first time, just how important these gut microbes and the SCFAs they produce are to heart health. They did so by examining the health of people with a rare genetic variant that significantly impacts the function of receptors that bind to SCFAs.
“We wanted to determine whether people with these genetic modifications had an increased risk of hypertension and major adverse cardiac events, including acute coronary syndrome, heart failure, and ischemic stroke,” said Professor Francine Marques, the study’s co-corresponding author and head of the Hypertension Research Laboratory, aka the Marques Lab.
Using the large-scale health research database UK Biobank, the researchers examined data from individuals with rare variants in the genes regulating SCFA-binding receptors and compared their cardiovascular medical history to that of control individuals. They found that the affected population had a much higher incidence of high blood pressure (hypertension) and a long-term risk of cardiovascular disease.
“The study found that disruption in these receptors is associated with up to 20% increased prevalence of hypertension and heart disease or stroke – even after accounting for other risk factors like body weight and smoking,” said lead and co-corresponding author, Leticia Camargo Tavares, PhD, a research fellow at the Marques Lab.
The researchers examined this population, without the protection against heart disease afforded by microbe-produced SFCAs, to see what would happen if they ate the recommended fiber intake.
“If they consumed adequate dietary fiber, but were unable to turn this into protection against heart disease, then this would prove the importance of short-chain fatty acids signaling in cardio-protection,” Marques said.
“Consistent with our hypothesis, the prevalence of hypertension was significantly higher in this cohort, even among those who ate a diet rich in fiber,” added Tavares.
For most of us, there isn’t too much to worry about, though. When the researchers examined individuals with rare genetic variations, they meant very rare.
“However, it is worth mentioning these rare genetic variants occur in less than 1% of individuals,” said Marques.
Which means that, for the vast majority of individuals, eating the recommended intake of dietary fiber should have a cardioprotective effect.
Marques previously led a clinical trial investigating the effect of taking an SCFA supplement on blood pressure, and a further trial is currently recruiting participants. The researchers aim to develop a commercially available supplement that will increase SCFA levels and, consequently, enhance heart health.
The study was published in the journal Cardiovascular Research.
Source: Monash University
