Low-Fibre Diet Tied to Riskier Coronary Plaque

Using advanced cardiac imaging, namely computed tomography, the researchers examined the presence and type of plaque and showed that the dietary pattern - the composition of what we eat - affects atherosclerosis (the atherosclerotic plaques) in the coronary arteries. Additionally, diet was also related to what the plaques in the arteries looked like, reflecting their composition. The people in the study had no symptoms of heart disease and no known or diagnosed cardiovascular disease at the start of the study.

"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 Isabel Goncalves, professor of cardiology at Lund University and senior consultant at Skåne University Hospital, who led the study, now published in Cardiovascular Research.

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

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. To analyse the link between diet and heart health, the researchers used a dietary index. This index shows dietary patterns with high scores for regular intake of foods rich in whole grains and fibre, vegetables, fruit, nuts and vegetable oils - and low scores for regular intake of red meat, crisps and sugary drinks.

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

The results showed 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 per cent showed some form of coronary artery changes. This compares to 36 per cent in the group (6,139 people) who had the healthiest diet. Serious changes, such as coronary artery narrowing of at least 50 per cent and with 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. Our results suggest that an unhealthy, low-fibre diet may contribute to changes in the body and metabolism which in turn may lead to unfavourable plaque characteristics. We hope that the results of this study can encourage more proactive prevention measures and early interventions, for instance on diet," says Isabel Goncalves.

Even though the study did not investigate the mechanisms, the researchers contend 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. A diet with more vegetables, fruit, whole grains, fibre-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," says Ingrid Larsson, nutritionist and associate professor at the Sahlgrenska Academy, University of Gothenburg.