Low fiber linked to higher blood clot and heart attack risk, study finds

A new study has found that low fiber consumption is linked to the presence of unstable or high-risk plaque in coronary arteries — the type of plaque that can trigger blood clots and cause heart attacks. The multi-center study led by researchers at Lund University, Sweden, also links dietary patterns to the composition of the plaques, or how potentially dangerous they are. 

Using advanced cardiac imaging, namely computed tomography, the researchers examined the presence and type of plaque and showed that dietary patterns affect atherosclerosis (the atherosclerotic plaques) in the coronary arteries.

Moreover, diet was related to the appearance of the plaques, reflecting their composition. Participants in the study had no symptoms of heart disease and no known or diagnosed cardiovascular disease at the start of the study.

The results revealed that those with the least healthy dietary patterns had a higher prevalence of atherosclerosis.

“When we matched people’s coronary artery images with their dietary patterns, we could not only see that there is an association between dietary pattern and the presence of plaque in the coronary arteries, but also that the composition of the plaques, how dangerous they can be, is related to diet,” says lead researcher Isabel Goncalves, professor of cardiology at Lund University and senior consultant at Skåne University Hospital.

Link between diet and heart health

The study is based on data from 24,097 people between 50 and 64 years old who participated in SCAPIS, a large national population study. Participants were asked to complete a dietary questionnaire.

The researchers used a dietary index to investigate the link between diet and heart health. This index shows dietary patterns with high scores for regular intake of foods rich in whole grains and fiber, vegetables, fruit, nuts, and vegetable oils.

Low scores were assigned for the regular intake of red meat, crisps, and sugary drinks.

The researchers examined participants’ hearts using computed tomography, which can reveal early signs of fat deposits or atherosclerotic plaques in the heart’s arteries.

The findings reveal that those with the least healthy dietary patterns had a higher prevalence of atherosclerosis. Among the 8,344 people with the least healthy diet, 44% showed some form of coronary artery changes.

The results indicate a link between the food we eat and serious heart problems caused by atherosclerotic plaques, such as heart attacks.This compares to 36% in the group (6,139 people) who had the “healthiest” diet. Serious changes, such as coronary artery narrowing of at least 50% and high-risk plaque, were 1.6 times more common among those who had the least healthy diet.

“After adjusting for a variety of factors, we saw that the association between dietary pattern and atherosclerosis is mediated by abdominal obesity, high blood pressure, and high levels of triglycerides,” says Goncalves.

“Our results suggest that an unhealthy, low-fiber diet may contribute to changes in the body and metabolism, which in turn may lead to unfavorable plaque characteristics. We hope that the results of this study can encourage more proactive prevention measures and early interventions, for instance, on diet.”

Even though the study, published in Cardiovascular Research, did not investigate the mechanisms, the researchers conclude that the results indicate a link between the food we eat and serious heart problems caused by atherosclerotic plaques, such as heart attacks.

“There is no single foodstuff that determines health, but rather the overall dietary pattern,” notes Ingrid Larsson, nutritionist and associate professor at the Sahlgrenska Academy, University of Gothenburg.

“A diet with more vegetables, fruit, whole grains, fiber-rich foods, nuts, low-fat dairy, rapeseed, and olive oil, and less red meat, processed meats, crisps and similar snacks, and sugary drinks was linked to fewer high-risk plaques. This is in line with the Swedish and international dietary guidelines.”

The WHO recommends a dietary fiber intake of at least 25 g daily, but research indicates many people don’t reach that goal. Nutrition Insight previously examined this dietary fiber gap in the global population alongside opportunities to fortify with Tate & Lyle, Comet, Alland & Robert, and Sensus.