Harvard researchers tracked nearly 200,000 people for 30 years, revealing that heart health isn't determined by low-carb or low-fat diets alone. The key factor was diet quality, emphasizing whole foods over processed options. Participants consuming varied diets rich in vegetables, fruits, whole grains, and healthy fats showed significantly better cholesterol levels and lower heart disease risk compared to those with poor-quality diets, even if technically low-carb or low-fat.

This study, published in the *Journal of the American College of Cardiology*, suggests focusing on overall food quality offers flexibility while supporting cardiovascular health. The findings challenge the long-standing low-carb versus low-fat debate, indicating both healthy versions may share beneficial biological pathways.