Does Protein Impact Heart Health?
Get to the heart of eating high-protein foods.
Protein is the "hot" macronutrient. The benefits of eating more protein are proclaimed by nutritionists, diet gurus, fitness buffs and food companies. While some extra protein can bump up metabolism a bit, could it also have consequences for heart health?
Followers of high-protein diets (like paleo, Atkins and Whole30) generally get their extra protein by eating more meat, which can be high in saturated fat. A diet higher in saturated fat is linked to heart disease. And in one widely touted study in a journal from the American Heart Association, protein itself was linked to a slightly higher risk of heart failure for middle-aged men.
So, are protein-rich foods themselves bad for the heart?
First, let's look at that AHA study. In it, the researchers followed men for 22 years and evaluated their heart health. While in general eating plant proteins was associated with a lower risk of heart failure, the researchers collected data on the men's diets only at the beginning of the study. And eating habits can certainly change over two decades.
When we use a broader lens to view the heart-health science surrounding certain protein-based foods, here's what we see:
Fish — Eating fish can save lives. It is estimated that 50,000 deaths from heart disease and stroke are avoided per year by eating fish. Eating at least two servings of fish per week is recommended to help prevent not just heart disease but also stroke, heart failure, sudden cardiac death and congestive heart failure.
Eggs — An egg a day is OK. In fact, in a recent clinical study, consumption of three eggs a day did not raise heart-health risk factors, as measured by blood analysis. (In this study, eating eggs did raise healthy levels of choline, a nutrient important for brain health.) Additionally, in a large meta-analysis, eating one egg a day was associated with reduced risk of stroke. Recent recommendations suggest most people can enjoy a whole egg daily within a healthy diet.
Soy — Since 1999, an FDA-approved health claim on the benefits of soy protein and heart disease has appeared on some soy protein foods: "25 grams of soy protein per day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease." However, this claim has recently been called into question, not because soy protein increases the risk of heart disease, but rather because it does not lower this disease risk as robustly as previously thought. A recent meta-analysis (a large-scale study) confirmed the positive effect on heart health that soy can have as part of a healthful diet.
Dairy foods — Nutrition researchers did a systematic review as well as a meta-analysis and found that dairy consumption either was not associated with cardiovascular disease or was associated with a lower risk of it. The Dietary Guidelines advise an overall shift toward eating more dairy to increase low intakes of calcium and recommend three servings of dairy each day, as part of a healthy diet.
Lean beef — Early research indicates that one key to beef's role in heart health is the company it keeps on a plate. Scientists completing a gold-standard clinical study found that lean beef can be a heart-healthy primary protein source when it's part of a healthy diet rich in vegetables, fruits, whole grains, nuts and beans.
In fact, this context of a "healthy dietary pattern" — looking at all the foods on the plate — appears to be important when examining heart health and all sources of protein. This is becoming increasingly clear as research emerges on the long-term effects of high-protein diets like paleo. In a recent study, researchers found that paleo dieters had increased levels of TMAO, a substance that's been linked to heart disease. But they also pointed out that a more well-rounded diet that includes whole grains, potatoes and other fiber-rich foods is likely necessary to maintain heart health when eating a diet rich in protein.
Serena Ball, MS, RD, is a registered dietitian nutritionist, food writer and recipe developer. She blogs at TeaspoonOfSpice.com and is the author of the best-selling The 30-Minute Mediterranean Diet Cookbook. Follow her @TspCurry on Twitter and Instagram.