New Insights on Heart Health: It’s About Food Quality, Not Just Fat or Carbs

Recent evidence indicates that maintaining heart health doesn’t necessarily mean cutting out pasta or potatoes. In fact, a low-fat diet might not be the answer either.

A study spanning nearly three decades, tracking close to 200,000 individuals in the U.S., suggests that some low-fat and low-carb diets promote better heart health than others. The focus here isn’t primarily on the carbs or fats themselves, but rather on the overall quality of the foods consumed.

Conducted by public health researchers at Harvard University, the research highlights that diets high in processed foods and unhealthy fats or lacking sufficient vegetables, fruits, whole grains, and healthy fats may not support cardiovascular health effectively over the long term. This is true even if such diets are technically low in carbs or fats.

According to Harvard epidemiologist Zhiyuan Wu, who led the study, simply looking at nutrient composition without considering food quality might not yield genuine health benefits.

Individuals in the study who followed healthy and varied diets rich in essential macronutrients reported higher levels of “good” cholesterol and lower levels of harmful fats and inflammatory markers. This contrasted with participants whose diets lacked these key elements. Notably, they also experienced a considerably lower risk of developing coronary heart disease, which is a leading cause of heart attacks.

“These results suggest that both healthy low-carb and low-fat diets may enhance cardiovascular health through similar biological pathways,” Wu noted.

He added that focusing on overall diet quality can allow flexibility, enabling people to adopt eating habits that suit their preferences while still promoting heart health.

The participants, all health professionals, may have had greater health awareness and access to healthcare compared to the general population. While this is somewhat limiting, the extensive follow-up period of over 5.2 million person-years adds weight to the findings.

This research contributes to a growing body of evidence suggesting that reducing processed food intake and increasing the consumption of whole grains and vegetables is generally beneficial for various health outcomes. Strict dietary plans focused solely on calorie, carb, or fat counts may not be necessary.

“This study shifts the conversation away from the longstanding debate about low-carb versus low-fat diets,” said Harlan Krumholz, a cardiologist at Yale University and editor-in-chief of the Journal of the American College of Cardiology. “The key takeaway is that the quality of food significantly influences heart health. Whether a diet leans toward lower carbohydrates or fats, prioritizing plant-based foods, whole grains, and healthy fats is linked to better cardiovascular outcomes.”

The findings were published in the Journal of the American College of Cardiology.