Life Extension Magazine®
Spread of food rich in protein and essential amino acids

Issue: December 2019

Protein Supplementation

Leading sports nutritionist Marie Spano answers our questions about protein’s importance, the best sources, and more.

By Laurie Mathena.

Marie Spano
Marie Spano

Most of us know protein is vital for building muscle.

Adequate protein ingestion also helps protect against muscle loss due to aging and dieting, aid in weight loss and weight management, and more.

In this exclusive interview, Marie Spano, MS, RD, CSCS, CSSD, one of the country’s leading sports nutritionists, talks to Life Extension® about the best protein sources, the proper amount to consume, and how important protein can be for long-term health.

—Laurie Mathena

LE: Let’s start with the basics. Why is protein so important?

Spano: Dietary protein helps build muscle and is needed for chemical reactions throughout the body. But our need for protein is really a need for amino acids, the building blocks that make up protein. The body breaks down proteins to get the amino acids.


LE: What happens if we don’t get enough protein?

Spano: When people consume a diet with insufficient protein, their bodies will break down skeletal muscle to help meet amino acid needs for critical processes. Over time, this can take a toll. Low protein intake is associated with reduced muscle mass and decreased strength throughout life.1,2

LE: How much protein do we need?

Spano: The Recommended Dietary Allowance (RDA) of protein for adults 19 and older is 0.8 grams per kilogram of body weight (0.8 g/kg). It is now generally recommended that older adults consume from 1.0 to 1.2 g/kg body weight of protein daily.3,4

A standard four-ounce serving of salmon provides 26 grams of protein.5 However, there are some concerns that a higher protein intake may be harmful to those with kidney disease.6 People with depressed kidney function should consult with a physician before consuming supplements with protein and amino acids.


LE: Should people try to get that protein in one sitting?

Spano: Definitely not! Protein intake should be evenly spaced throughout the day, in three or more meals. There’s a limit to the amount of protein a person can use at one time to build skeletal muscle.7 When we eat more protein and amino acids than we can use, we don’t store them for later use. That is why we must consume protein in “doses” or regular meals throughout the day.

LE: What are the best protein sources?

Spano: High-quality proteins contain all essential amino acids, those the body cannot make and therefore must consume. All essential amino acids are needed for muscle protein synthesis. Fall short in one or more, and muscle protein synthesis will not be sustained at the same rate.8

Most animal-based proteins contain all essential amino acids. Whey, seafood, and eggs are good examples.

Many plant proteins lack one or more essential amino acids. But some plant proteins, including pea protein isolate and brown rice, stand out for their higher leucine content. And two or more plant proteins can be combined to make a protein-rich product with all essential amino acids.9 Plant protein can also be fortified with the missing essential amino acids to make it a truly complete protein source.10

LE: What else should a person look for when choosing a protein supplement?

Spano: If you’re using an animal-based protein supplement such as whey or egg, look for one without a ton of other ingredients that you may not need. If you are lactose intolerant, choose whey protein isolate, which is 99% lactose free.

Ideally, plant proteins should be blended, including two or more types of proteins, or they should have the missing essential amino acids added.


LE: We often think of protein powder as something for bodybuilders. But does taking a protein supplement have benefits for all aging adults?

Spano: It might, if it helps that individual reach the correct amount of dietary protein intake. Muscle mass gradually decreases with age, a process called sarcopenia. Sarcopenia develops around the fourth or fifth decade of life,7 and can be worse due to chronic illness, inactivity, or inadequate protein and calorie intake.11 Once sarcopenia starts, a person loses 3% to 8% of muscle mass each decade6 while strength decreases by 3% per year after age 60.12 Simple tasks like opening a container of food or lifting groceries can become difficult, and the risk of dangerous falls increases.12

A higher protein intake has been shown in multiple studies to slow the progression of sarcopenia, improving quality of life.13,14 Regular physical activity, including resistance exercise, is also vital for slowing muscle loss. Protein powders make it easy to get more protein in the diet.

Marie A. Spano, MS, RD, CSCS, CSSD, is a nutrition communications expert and one of the country’s leading sports nutritionists for professional teams.

If you have any questions on the scientific content of this article, please call a Life Extension® Wellness Specialist at 1-866-864-3027.


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