Featured article in the Spring 2019 Issue of Nutrition Close-Up; written by Marie Spano, MS, RD, CSCS, CSSD

Healthy strong muscles are important throughout the lifespan.

Resistance training and sufficient dietary protein help support muscle maintenance and strength. Research has shown the importance of both the total amount of protein consumed each day as well as the amount of protein per meal. However, emerging research is showing other factors within food, besides protein, influence the synthesis of new proteins in muscle.

Over the past several years, scientists have examined how amino acids and isolated sources of protein impact muscle protein synthesis. This research serves as a foundation to better examine aspects beyond protein. Leucine, an essential amino acid, turns on the machinery driving the synthesis of new proteins in muscle. While leucine is the switch turning this process on, all essential amino acids are necessary to provide the building blocks for muscle protein synthesis to be running optimally. Quality sources of protein including whey, egg, soy and beef contain all essential amino acids in appreciable quantities to support this process. Yet studies comparing protein-rich drinks and whole foods have led to results that cannot be explained by differences in leucine or the amount of high quality protein consumed.

One recent study was designed to examine how protein, in its whole, natural state in the form of eggs, impacted muscle protein metabolic responses. Researchers took resistance-trained men and gave them either whole eggs or egg whites, each containing 18 grams of protein, after exercise. Both the whole eggs and egg whites turned on the synthesis of new proteins in muscle. However, whole eggs increased muscle protein synthesis to a greater extent than egg whites. In this study, the authors noted that differences between whole eggs and egg whites cannot be explained by leucine content, the appearance of leucine within the bloodstream, or variances in the muscle signaling pathway. Researchers suggest there may be something about the whole egg matrix, which consists of high-quality protein, fat, vitamins and minerals, that may support a greater response in muscle compared to the response seen with egg whites.

Whole foods that are good sources of protein, such as eggs, provide a package of nutrients that may lead to greater muscle protein synthesis than equal amounts of isolated protein. Whole foods have a unique food matrix that include not only protein, but also vitamins, minerals, fats and other compounds that cannot be deconstructed and isolated or put back together with the same result. As evidence mounts to support the benefits of non-protein food compounds or the synergistic action of compounds found in whole foods, consumers would be wise to follow the age-old advice from registered dietitians: eat more whole foods closer to the way these foods are found in nature.

Marie A. Spano, MS, RD, CSCS, CSSD, is a nutrition communications expert and one of the country’s leading sports nutritionists. Spano has appeared on CNN as well as NBC, ABC, Fox and CBS affiliates, and authored hundreds of magazine articles and trade publication articles. She is lead author of the textbook Nutrition for Sport, Exercise and Health and co-editor of the NSCA’s Guide to Exercise and Sport Nutrition (Human Kinetics Publishers).

The Egg Nutrition Center partnered with Natalie Rizzo, MS, RD to write this blog post.

Eggs have a unique nutrition profile that is great for athletes of all ages. While they make a nice addition to any meal of the day, the nutrients in eggs can help with recovery after exercise. Just as stretching and cooling down is important after a workout, recovery nutrition is vital for repairing worn down muscle and revitalizing energy stores. But it’s not just the protein in eggs that make them a recovery food. Let’s take a look at the plethora of nutrients in eggs that help refuel a healthy athlete.

Protein

Research indicates that eating 20-30 grams of protein from foods that include leucine, such as eggs, may promote muscle repair after exercise¹. One large egg contains 6 grams of high-quality protein with all nine essential amino acids. The International Society of Sports Nutrition recommends athletes focus on whole food sources of protein that contain all of the essential amino acids to aid in muscle protein synthesis².

Vitamin D

This micronutrient is critical for bone health, and research suggests that adequate vitamin D intake reduces the risk of stress fracture, total body inflammation, illness, and impaired muscle function³. Unfortunately, adequate vitamin D intake is difficult to achieve due to variations in skin color, the time spent outdoors and geographic location. Eggs are one of the only natural food sources of vitamin D, with one large egg containing 6% of the daily value.

Lutein

This antioxidant has been known to accumulate in the eye, and scientists have recently discovered that it’s also present in the brain. Lutein in the eye may help athletes with visual performance and protecting the retina from damaging light⁴. Plus, new research in children suggests that lutein could have cognitive boosting capabilities and may even improve academic performance⁵. Luckily, lutein bioavailability is enhanced when it is consumed with dietary fat, making lutein from eggs a more absorbable source of lutein than many other foods⁶.

Other Benefits

Besides the impressive nutrient profile, eggs also have other practical applications for recovery, such as:

• Eggs are affordable. One egg only costs about 15¢, which is quite the nutritional bang for your buck.
• They are quick to cook. You can cook up an egg in less than 10 minutes, which will quickly satisfy a rumbling tummy and tired muscles after a tough workout.
• Eggs go with practically anything. You can put an egg on almost anything— pizza, pasta, grains, bread, oatmeal, veggies and more!