The main nutritional principle for heart health has been named

The long-standing debate over what is better for the heart - cutting carbohydrates or reducing fats - may not be as critical as once thought. This is the conclusion reached by Harvard University researchers after analyzing data from nearly 200,000 men and women in the United States over a period of approximately 30 years. The results showed that the key factor is not the amount of fats or carbohydrates, but the quality of food. The study was published in the Journal of the American College of Cardiology (JACC).

Participants who followed a varied and balanced diet with adequate amounts of vegetables, fruits, whole grains, and healthy fats had higher levels of "good" cholesterol and lower markers of inflammation in the blood. In addition, they were significantly less likely to develop coronary heart disease - the leading cause of heart attacks.

At the same time, nominally "low-carb" or "low-fat" diets based on processed foods and an excess of animal fats or proteins did not provide such benefits.

"Focusing solely on macronutrient composition without considering food quality may not lead to improved health," noted Harvard University epidemiologist Zhiyuan Wu, who led the study.

According to him, healthy low-carbohydrate and low-fat diets appear to affect the cardiovascular system through similar biological mechanisms. This means that people do not necessarily need to strictly adhere to one type of diet - what matters more is the overall balance and quality of their food intake.

The study is based on participants' self-reports, and all of them were healthcare professionals, which may limit the generalizability of the results to the broader population. However, the duration of observation - more than 5.2 million person-years - makes the findings highly compelling.

Yale University cardiologist Harlan Krumholz noted that the study helps move beyond the long-standing "carbs versus fats" debate. "What matters most for the heart is the quality of food. Diets based on plant-based foods, whole grains, and healthy fats are associated with better cardiovascular outcomes," he emphasized.

The study authors believe that strict counting of calories, fats, or carbohydrates may be less important than avoiding ultra-processed foods and focusing on whole, natural foods. It is this approach, in their view, that provides the greatest benefit for heart health in the long run.