High-protein diet study has bad news for heart patients

A new study out of the Washington University School of Medicine has found that while following a high-protein diet may have excellent benefits when it comes to weight loss, there's also a major potential downside: an increased risk of heart attacks. The issue revolves around arterial plaque, particularly the unstable kind that can block off arteries.READ: High-protein diets may be dangerous for people trying to lose weight

Though dieting protocols vary, it is currently popular for doctors to recommend that their overweight patients stick to a high-protein, low-carbohydrate diet in order to lose weight. This diet is typically very effective in causing weight loss, helping control blood sugar and cravings. However, it is also controversial.

Relatively recent research highlighted the potential damage this diet may have on the kidneys, particularly in patients who are obese. Following that is a new study that likewise raises questions over heart health, namely the risk of heart attack that may be a consequence of following a high-protein diet.

Researchers found that this type of diet led to a greater quantity of plaque in the dieter's arteries, particularly unstable plaque that is more likely to rupture and end up blocking off an artery. The research builds upon a body of past studies that have linked high-protein diets to heart issues in people and animals.

The increased buildup of unstable plaque was found in mice fed a high-fat and high-protein diet compared to mice fed a high-fat low-protein diet. When the mice were given 46-percent of their daily calories in the form of protein, they developed around 30-percent more arterial plaque even though they didn't gain weight like the high-fat low-protein mice.

At the heart of the issue was the death of macrophages, an immune cell that typically cleans up the plaque from arteries. The researchers found that plaque in high-protein mice were 'macrophage graveyards' with large quantities of dead immune cells. This made them more unstable, paving the way for an eventual heart attack.