Researchers at Columbia University Mailman School of Public Health and colleagues evaluated whether dietary fibre intake was associated with decreased inflammation in older adults and if the fibre was inversely related to cardiovascular disease.
The results showed that total fibre, more specifically cereal fibre but not fruit or vegetable fibre, was consistently associated with lower inflammation and lower CVD incidence. Until now, there had been limited data on the link between fibre and inflammation among older adults, who have higher inflammation levels than younger adults. The study findings are published in JAMA Network Open.
Examples of dietary fiber sources. Photo credit: NIH
The research includes data from a large and well-characterized prospective cohort of elderly individuals, with detailed data on dietary intake, inflammation, and incidence of CVD. The study confirmed previously observed associations between dietary fibre and CVD. It extended those investigations to include the source of the fibre, the relationship of fibre with multiple inflammatory markers, and to test whether inflammation mediated the relationship between dietary fibre and CVD.
Participants received a food frequency questionnaire administered to those without prevalent CVD at enrollment of the 4125 adults enrolled in the Cardiovascular Health Study from 1989 to 1990. They then followed up visits to develop CVD (stroke, myocardial infarction, and atherosclerotic cardiovascular death) through June 2015. Blood samples were assessed for markers of inflammation.
“Higher intakes of dietary fibre are associated with lower CVD risk. A common hypothesis has been that higher fibre intakes reduce inflammation, subsequently leading to lower CVD risk,” said Rupak Shivakoti, PhD, assistant professor of epidemiology at Columbia Mailman School.
“With findings from this study, we are now learning that one particular dietary fibre – cereal fibre – but not fruit or vegetable fibre was associated with lower inflammation. With findings from this study we now are learning that cereal fibre has the potential to reduce inflammation and will need to be tested in future interventional studies.”
Although there are data to suggest that fibre, in general, might have anti-inflammatory effects by improving gut function, modifying diet and satiety (e.g., reduced-fat and total energy intake), and improving lipid and glucose profile metabolism, why cereal fibre but not vegetable or fruit fibre is associated with lower inflammation is not clear and warrants further investigation, noted Shivakoti. Further, he notes that it is unclear whether cereal fibre per se or other nutrients in foods rich in cereal fibre are driving the observed relationships.
“Additionally, we learned that inflammation had only a modest role in mediating the observed inverse association between cereal fibre and CVD,” observed Shivakoti. “This suggests that factors other than inflammation may play a more significant role in the cereal fibre–associated reduction in CVD and will need to be tested in future interventions of specific populations.
Source: Columbia University