Heart Scan Study Shows Low Fiber Diet Drives Dangerous Heart Plaques

Heart Scan Study Shows Low Fiber Diet Drives Dangerous Heart Plaques

How strong is your plate? A Swedish study using advanced cardiac imaging shows that diets high in fiber and red meat increase the risk of dangerous coronary artery disease.

Study:Low-fiber diet is associated with high-risk coronary plaque features. Photo credit: Reiteruperone/Shutterstock.com

A recent Swedish study analyzed the link between poor nutrition and coronary atherosclerotic plaque, a leading cause of early death. The paper was published inCardiovascular research.

introduction

Globally, cardiovascular disease (CVD) is a leading cause of death and disability. Coronary artery disease is responsible for most premature deaths due to CVD, primarily through the buildup of atherosclerotic fatty plaques over decades. These can rupture, blocking one or more arteries in the heart and causing a heart attack or sudden coronary death.

New methods are being investigated to identify plaques at risk of rupture. Coronary Computed Tomography Angiography (CCTA) is an emerging technology that promises an accurate and non-invasive diagnostic method. It is currently used internationally to assess the risk level of plaque.

The Mediterranean diet and other similar diets predict a low risk of CVD. Much of this effect is due to their high fiber content. Diet indexes use multiple foods to compare diets for their health-related properties.

Kaluza et al. built an anti-inflammatory dietary index (DI) using foods that correlated with inflammatory markers such as high-sensitivity C-reactive protein (HSCRP). This was validated in Swedish prospective studies over 16 years of follow-up, where outcomes such as death, aortic aneurysm and heart failure were lower in people with a higher DI who consumed low levels of anti-inflammatory foods.

Fruits, vegetables, nuts, whole grain bread, breakfast cereal or oatmeal, canola and olive oil, coffee, tea, chocolate, red wine and beer are among foods with anti-inflammatory properties. Conversely, potato chips, red meat, and sugary drinks are linked to systemic inflammation.

The current study used a similar DI to examine the association with coronary atherosclerosis, coronary plaque risk from CCTA, and cardiovascular risk factors.

About the study

The current study used data from the Swedish Cardiopulmonary Bioimage Study (SCAPIS), including 24,079 adults between 50 and 64 years of age. All were free of clinical cardiovascular disease at the start of the study. They responded to an invitation to participate in the study sent to a randomly selected population sample.

Their diet was analyzed using the Dietary Index (DI), which is based primarily on the content of plant foods and low in inflammatory foods such as processed or red meat and sugary drinks. The healthiest group was in the highest tertile of the nutritional index and reflected more plant-based and anti-inflammatory foods, while the lowest tertile reflected diets high in inflammatory foods.

CCTA was used to detect and stratify coronary plaque into three categories: any plaque, a significant plaque, and high-risk plaque. High-risk plaque features include mild attenuation of CCTA (uncalculated plaque) and significant stenosis (arterial narrowing of 50% or more). These predict a tenfold increase in coronary event rates after five years compared to people with normal coronary arteries.

Study results

People in the lowest dertil (most inflammatory) were younger and less likely to have a family history of cardiovascular events. In this lowest tertile, 62% were men compared to 33% in the highest tertile. They had elevated high-sensitivity C-reactive protein levels, the highest cardiometabolic risk (elevated blood lipids, blood pressure, diabetes), lower exercise duration, and higher likelihood of smoking, alcohol consumption, and total energy intake.

Coronary plaques were detected in 44.3% of people with the lowest DI, compared to 36.3% of people with the highest DI, indicating a higher prevalence of plaque in people with less healthy diets. With 6.0% of people in the lowest di-tertile compared to 3.7% in the highest.

Specifically, for noncalculated plaques with significant stenosis, the rates were 0.9% for the lowest DI and 0.9% for the highest DI. Calcification, higher total burden, and increased likelihood of significant vessel narrowing all correlated with the lowest ditertile.

People in the bottom two DiT tertiles were more likely to have plaque, and the more segments involved, the more significant narrowing and plaque calcification. In statistical models adjusted for age and gender, high-risk plaque was 67% higher in the lowest tertile (odds ratio 1.67) compared to the highest tertile.

After adjusting for additional factors such as waist circumference, triglyceride levels and high blood pressure, this association was attenuated and in some cases not significant.

Non-significant non-calcified stenosis was 23% higher in the lowest tertile, while calcified non-significant stenosis was 37% more common. The right coronary and left anterior descending arteries are more commonly affected in people with lower DI.

Lower DI may increase the risk of coronary atherosclerosis in part due to its association with increased waist size, higher blood pressure, and increased blood triglyceride levels. These factors account for between 21% and 57% of the differences in plaque characteristics, with waist circumference having the greatest influence.

These results confirm that CVD risk is increased in obesity, which is more common in individuals with unhealthy dietary patterns. These, in turn, are linked to lifestyle factors such as smoking, drinking and sedentary habits.

Women with low DI had worse coronary plaque disease status than men. However, the stronger association in women was observed primarily for overall plaque presence, not for all specific plaque types. Total calorie intake and educational status influenced DI and not the presence or characteristics of plaque. Conversely, age and gender influenced the presence and risk status of plaque.

Both DI- and plaque-related outcomes were affected by age and gender, smoking, waist size, triglycerides, and hypertension. These factors were not correlated with each other except higher kidney output and lower waist size and alcohol consumption in women compared to men.

It is important to note that dietary information was self-reported using a food frequency questionnaire, which introduces potential recall bias and uncertainty in estimating actual intake. Additionally, the study lacked detailed data on participants' ethnicities, limiting its generalizability beyond Swedish populations.

Conclusions

This is the first large study to examine cardiovascular risk profiles using CCTA-based coronary assessment and self-reported dietary habits in a middle-aged population-based cohort. Its novel findings correlate an anti-inflammatory diet low in fiber and high in red meat with an increased risk of developing high-risk coronary plaques.

The effect could be driven in part by increased waist size, higher blood triglyceride levels and high blood pressure. Altered metabolic pathways and circulatory shifts thus influence the ultimate impact of nutrition on coronary atherosclerosis.

While supporting previous research, the current study extends it by using granular plaque phenotypes to compare outcome variability with differences in DI. However, as an observational and cross-sectional study, it can only establish associations and not the cause.

“Our results strengthen the importance of cardioprotective nutritional recommendations. “”

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