Study: Whole Grains and Plant-Based Foods Key to Lowering Heart Disease Risk

New research shows 'quality' diets, not just low-fat or low-carb, are linked to reduced coronary heart disease risk.

Published on Feb. 11, 2026

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A long-term study of nearly 200,000 adults found that low-fat and low-carb diets rich in plant-based foods, whole grains, and unsaturated fats were associated with a lower risk of coronary heart disease. Diets high in refined carbs and animal-based fats and proteins were linked to higher risk. The findings suggest it's the overall quality of the diet, not just the macronutrient ratios, that matter for heart health.

Why it matters

This study provides important insights into the dietary factors that can impact the risk of coronary heart disease, the most common form of heart disease. The findings challenge the notion that low-fat or low-carb diets alone are the key to heart health, and instead highlight the importance of focusing on the overall nutritional quality of the diet.

The details

The study, published in the Journal of the American College of Cardiology, analyzed the self-reported eating habits of nearly 200,000 health professionals over more than 30 years. Researchers classified low-fat and low-carb diets into 'healthy' and 'unhealthy' categories based on the types of foods consumed. They found that people who most closely followed a healthy low-carb diet had a 15% lower risk of coronary heart disease, while those on the unhealthiest low-carb diets had a 14% higher risk. For low-fat diets, the risk reduction for the healthiest was 13%, and the increase for the unhealthiest was 12%.

  • The study followed participants for more than 30 years, starting in the 1970s and 1980s.
  • The findings were published on February 11, 2026.

The players

Dr. Qi Sun

Lead study author and a specialist in nutrition and epidemiology at the Harvard T.H. Chan School of Public Health.

Kristina Petersen

An associate professor of nutritional science at Penn State who studies diet and risk of cardiovascular disease.

Dr. Clyde Yancy

Chief of cardiology at Northwestern University's Feinberg School of Medicine.

Dr. Dariush Mozaffarian

A cardiologist and director of the Food is Medicine Institute at Tufts University.

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What they’re saying

“It's the quality of your diet that matters, not any particular macronutrient like fat or carbohydrates.”

— Dr. Qi Sun, Lead study author (Journal of the American College of Cardiology)

“Those are relatively large risk reductions for a lifestyle change.”

— Kristina Petersen, Associate professor of nutritional science (Journal of the American College of Cardiology)

“The study confirms what we've learned over the last 20 years.”

— Dr. Dariush Mozaffarian (Journal of the American College of Cardiology)

What’s next

Researchers plan to further investigate the specific dietary components and food combinations that provide the greatest benefits for heart health.

The takeaway

This study underscores that a 'quality' diet focused on whole, plant-based foods is key for reducing the risk of coronary heart disease, regardless of whether the diet is low in fat or carbs. The findings challenge the notion that any single macronutrient is the sole driver of heart health.