This year, more than 610,000 Americans will die from heart disease. It’s the leading cause of death for men and women. 

For decades, doctors and nutritionists prescribed low-fat diets to people trying to lower their risk of heart disease. Saturated fats in meats and dairy products were thought to clog our arteries. 

A growing body of research suggests this advice was wrong. For most people, it’s carbohydrates that are the true cause of heart disease. 

A report published last year in The Lancet studied nutrition among people across 18 different countries. Researchers found that people who ate the least saturated fat had the highest rates of heart disease and mortality. Meanwhile, people who consumed the most saturated fat had the lowest rate of strokes.  

Limiting intake of carbohydrates, rather than fats, is a surer way to decrease the risk of heart disease. An analysis of more than a dozen studies published in the British Journal of Nutrition found that patients on low-carb diets had healthier body weights and cardiovascular systems than those on low-fat diets. 

I’m a cardiologist in Virginia and my own patients have seen the benefits of a low-carb, high-fat diet firsthand. 

Consider Marj. At age 71, she lost over 100 pounds in a year without medication, meal replacements, or surgery -- just by cutting out sugars and starches and eating healthier food.

Denise had out-of-control diabetes. Her blood sugar was frequently over 250 -- a level far above normal -- despite being on insulin. Then she started a low-carb diet. After only a week, she was off insulin and had near normal blood sugar levels. 

When Jeff started working with me, he had severe lipid abnormalities. Four months later, his HDL cholesterol – commonly known as “good cholesterol” – had increased by 13 points. And his triglyceride level plummeted from 468 to 78 – as well below the normal level of 150. All of this was without medication or exercise.

The mistaken belief that fats cause heart disease stems from weak, outdated research. Back in 1961, the American Heart Association published its first report recommending that people limit consumption of animal fats and dietary cholesterol. 

But that hypothesis had never been put to the test in a clinical trial. A controlled trial is the only way to prove a cause-effect relationship, rather than a mere correlation that could occur due to some unknown variable.   

Eventually, the National Institutes of Health started conducting clinical trials. However, these trials were deeply flawed. Additionally, when evidence contradicted the dominant medical narrative, researchers effectively buried it. One NIH study, which found little-to-no relationship between saturated fats and various health problems, was conducted between 1968 and 1973 but wasn’t published for another 16 years.

Despite the flimsy evidence against saturated fats, mainstream nutritionists still advise people to eat carbohydrates and steer clear of fats. The AHA recommends restricting saturated fat consumption to 6 percent of total calories. Federal guidelines encourage people to eat fat-free or low-fat dairy and plenty of grains. 

This advice is dooming hundreds of thousands of people to early death and disability. 

For decades, our public health leaders have dispensed deadly dietary advice. That needs to change. Many doctors, myself included, have seen how low-carb diets help patients lose weight, reverse their diabetes, and improve their cholesterol.

Dr. Eric Thorn is a cardiologist affiliated with the Virginia Hospital Center.