A new research has provided some visual evidence to support the advice that too much red or processed meat is bad for your heart while oily fish is good for you.

In an observational study involving nearly 20,000 participants, British researchers used heart imaging to see how these foods affected heart health.

The images revealed that those who ate more red and processed meat had poorer heart function, smaller ventricles and stiffer arteries. The researchers also found that as study participants ate more fish, their arteries were stretchier and their hearts worked better.

“Previous studies have shown links between greater red meat consumption and increased risk of heart attacks or dying from heart disease,” said the study co-author Dr. Zahra Raisi-Estabragh, a clinical research fellow at Queen Mary University in London.

“For the first time, we examined the relationships between meat consumption and imaging measures of heart health. This may help us to understand the mechanisms underlying the previously observed connections with cardiovascular disease.”

The study included 19,408 participants in the UK Biobank database. The researchers examined associations of self-reported intake of red and processed meat with heart anatomy and function.

Three types of heart measures were analysed.

First, cardiovascular magnetic resonance (CMR) assessments of heart function used in clinical practice to assess volume of the ventricles and the pumping function of the ventricles.

Second, novel CMR radiomics used in research to extract detailed information from heart images such as shape and texture (which indicates health of the heart muscle).

Third, elasticity of the blood vessels (stretchy arteries are healthier).

The analysis was adjusted for other factors that might influence the relationship including age, sex, deprivation, education, smoking, alcohol, exercise, high blood pressure, high cholesterol, diabetes, and body mass index (BMI) as a measure of obesity.

The research was presented at an online meeting of the European Society of Cardiology. Findings presented at medical meetings are considered preliminary until published in a peer-reviewed journal.

Speaking further on the study, Dr. Raisi-Estabragh explained that “the findings support prior observations linking red and processed meat consumption with heart disease and provide unique insights into links with heart and vascular structure and function.”

The associations between imaging measures of heart health and meat intake were only partially explained by high blood pressure, high cholesterol, diabetes, and obesity.

“It has been suggested that these factors could be the reason for the observed relationship between meat and heart disease,” said Dr. Raisi-Estabragh.

“For example, it is possible that greater red meat intake leads to raised blood cholesterol and this in turn causes heart disease. Our study suggests that these four factors do play a role in the links between meat intake and heart health, but they are not the full story.”

She noted that the study did not look into alternative mechanisms. But she said: “There is some evidence that red meat alters the gut microbiome, leading to higher levels of certain metabolites in the blood, which have in turn been linked to greater risk of heart disease.”

“This was an observational study and causation cannot be assumed. But in general, it seems sensible to limit intake of red and processed meat for heart health reasons,” Dr. Raisi-Estabragh concluded.