Proteins are the building blocks of life, as they control the chemical reactions in cells. Despite the importance of proteins, scientists are still trying to determine what many of them do. One such scientist is Professor Beverly RO thermal, a molecular biologist at the University of Texas Southwestern Medical Center in the US, who has spent over twenty years investigating the many biological processes influenced by one particular protein, a regulator of Calcineurin 1.
Calcineurin, also known as CAN, is a protein that is particularly important in the nervous, immune and cardiovascular systems. “CAN is estimated to make up more than 1% of the total protein weight of our brains, and yet we only know a fraction of what it does,” says Professor Beverly Rothermel, a molecular biologist at the University of Texas Southwestern Medical Center.
BEV’s research has been fundamental to understanding how Regulator of Calci neurin 1 (RCAN1) controls CAN activity and how this impacts human health. Her lab was involved in the initial discovery and characterization of RCAN1, showing that when RCAN1 levels increase in a cell, the activity of CAN is reduced. This can have a significant effect because CAN is involved in many cellular processes. “The past twenty years of studying this remarkable protein have taken my laboratory in many interesting and often unexpected directions,” she says.
What role do CAN and RCAN1 play in the heart?
Heart disease is the number one cause of death worldwide. “The heart is very adaptable,” says BEV. “When you exercise, it undergoes beneficial remodeling to increase its power. In contrast, if it progresses to heart failure, it undergoes pathological remodeling. CAN signal is known to play a prominent role in this process.” BEV and her team hypothesized that increasing RCAN1 levels might reduce the chance of heart disease.
Bev used mice to test whether increasing levels of RCAN1 in the heart to inhibit CAN signalling would decrease the risk of heart failure. “We genetically engineered mice to have slightly higher levels of RCAN1 in the muscle cells of the heart,” she explains. Amazingly, the engineered mice had improved cardiac function in every model of heart failure that BEV and her team tested.
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 T MAO, 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.
You must be logged in to post a comment.