Want a healthier heart? Eat a steak

I'm a cardiologist — and I encourage patients to eat red meat.

This advice defies conventional wisdom. For decades, nutritionists and physicians have urged people to limit consumption of red meat and other fatty foods, which were thought to cause heart disease.

But new studies debunk this conventional wisdom. Indeed, it now looks like low-quality carbohydrates — not saturated fats — are driving America's heart disease epidemic. It's time to stop demonizing steak.

The medical community frowns upon the kinds of saturated fats found in meat, dairy and coconut oil. The American Heart Association recommends avoiding red meat — and if people insist on eating it, they should “select the leanest cuts available.” Federal nutritional guidelines suggest that less than 10 percent of one's daily calories come from saturated fats, while the AHA recommends even less.

These recommendations have never been supported by rigorous research. The idea that saturated fats cause heart disease stems from decades-old observational studies. Researchers asked participants to complete lengthy questionnaires about their eating habits and then tracked their health over time.

Researchers noticed that people who ate lots of saturated fats were more likely to contract heart disease. They concluded that meat and dairy were the root of all our chronic diseases, especially heart disease. Yet subsequent researchers found that in many cases, scientists cherry-picked data to support that conclusion.

More importantly, these kinds of observational claims are weak science. In 2011, a comprehensive analysis of 52 separate claims made in observational studies concluded that none — that's right, zero — could be confirmed in a clinical trial — a more rigorous type of science.

Observational studies can only show correlation, not prove causation. Vegetarians, for example, have lower rates of heart disease. Is this due to their meatless diet? Or because they smoke less and exercise more regularly than people who eat large amounts of meat? Observational studies cannot sort out these kinds of issues.

In recent years, numerous teams of researchers worldwide have reviewed all the data on saturated fats — and concluded that these fats do not have any effect on cardiovascular mortality.

A recent, comprehensive review of two dozen high-quality studies conducted by Purdue University researchers found no link between red meat intake and any negative cardiovascular outcome. In a separate 2014 analysis that examined 72 different observational and clinical trials involving more than 650,000 people, the lead researcher concluded that “[I]t’s not saturated fat that we should worry about.”

So what should we worry about? Carbohydrates.

Consider how the American diet has evolved. The most recent government data reveals that from 1970 to 2014, the availability of red meat fell 28 percent. Whole milk availability declined 79 percent. And animal fats — like butter and lard — dropped 27 percent.

If saturated fats were truly unhealthy, then obesity, diabetes and heart disease rates should have plummeted alongside this drop in saturated fat consumption.

Instead, disease rates have skyrocketed — largely because Americans replaced saturated fats with carbohydrate-rich grains. From 1970 to 2014, grain availability surged 28 percent. The body converts these carbohydrates to glucose, thereby raising blood sugar levels which — over time — can contribute to obesity, diabetes and heart disease.

New research supports this idea. The largest-ever analysis of diet, which included 135,000 people in 18 countries, revealed that people who consumed high-carb diets were 28 percent more likely to die during the study than people with lower carbohydrate intake. By contrast, those who consumed the highest amounts of saturated fats had the lowest rates of stroke.

While this is observational data, it’s not alone in contradicting government recommendations.

Even more revealing is a recent controlled clinical study on people with Type 2 diabetes conducted with high-quality evidence. Researchers from Indiana University found that minimizing carbohydrates while encouraging fat — including saturated fat — actually reversed diabetes in 60 percent of patients after 1 year. The diet also reduced inflammation and triglycerides, and increased HDL — so-called good cholesterol — all strong indicators of improving cardiac and metabolic health.

Additional research points specifically to the potential benefits of eating red meat while decreasing carbs. Two studies led by researchers at the University of Western Australia found that substituting carbohydrate-rich foods with red meat reduced inflammation and blood pressure.

Medical experts have long dispensed unproven advice about meat. But newer, better research indicates that red meat and saturated fats aren't harmful when combined with a lower carbohydrate diet.

So if you're looking to safeguard your heart, fire up the grill and cook that burger — but skip the bun and the pasta salad.

Scher is a cardiologist in San Diego.

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Graham