High-protein diets are everywhere, but not all protein is created equal. For heart health, the key is moderation. Virtanen's study found middle-aged and older men who ate higher amounts of protein were slightly more likely to develop heart failure than men who ate lower amounts.

"Very high intake of meat, especially processed red meat, is not good for overall health," said Dr. Jyrki Virtanen, author of a recent study on protein consumption. "Those who are used to eating very high amounts of meat could consider moderating their intake."

The U.S. Department of Agriculture's recommendation for protein is 0.8 grams of protein per kilogram of body weight or about 0.36 grams of protein per pound of body weight. For a 155-pound adult, that's roughly 56 grams. For a 190-pound adult, it's about 68 grams. The USDA has a calculator to help determine a recommended daily allowance.

High protein-rich diet

Virtanen and his colleagues looked at data from 2,441 Finnish men over two decades and found 334 cases of heart failure. The results showed men who consumed the highest amount of protein had a 33% higher increased risk of heart failure than men who consumed the lowest amounts.

"More research on this topic is needed," said Virtanen, an adjunct professor of nutritional epidemiology at the University of Eastern Finland. "But our findings indicate that high protein intake may have some adverse effects on health, especially if the protein is coming from animal sources." 

The American Heart Association's lifestyle recommendations for reducing cardiovascular risk emphasize a healthy eating pattern that includes:

1. Eating a variety of fruits and vegetables, whole grains, non- and low-fat dairy products, skinless poultry, fish, nuts, beans and non-tropical vegetable oils.

2. Limiting red and processed meat, sweets and sugary drinks.

Still, many people cling to the notion of eating lots of meat and protein, fueled in part by the enduring popularity of low-carb, high-protein diets such as Paleo, Ketogenic, Atkins and the Zone, said Jo Ann Carson, a dietitian, and professor at UT Southwestern Medical Center in Dallas.

"But if you use that very high protein diet to lose weight, typically the only way to keep that weight off is to continue to follow that dietary pattern, and there might be potential health issues there," said Carson, chair of AHA's nutrition committee.

"Probably the biggest problem with large amounts of protein is when it does not leave room in your diet for antioxidant-rich and fiber-rich fruits and vegetables and whole grains," Carson said.

In May, the AHA issued a new advisory recommending people up to their intake of omega-3 fatty acids by eating one or two servings of non-fried fish or shellfish a week. Carson said fish was among "the good-quality proteins people should be looking for, including lower-fat dairy and plant-based proteins, like soy and quinoa."