By Karen Miller-Lane, ND, LAc
“The challenges of studying nutrition and aging are one of the reasons I’ve become more flexible in my beliefs around diet for optimizing health with age. What is clear from reviewing the current evidence is that most people would benefit from increasing their protein intake with age. While there may be some exceptional circumstances, for many people, higher dietary protein would help maintain skeletal muscle, improve immune function, and reduce frailty – all of which translate to an increase in lifespan and healthspan.”
Peter Attia, MD a Stanford/Johns Hopkins/NIH-trained physician focusing on the applied science of longevity and well-being
How many of us understand what protein does and why it is important, let alone how our needs change as we age? Protein is one of the macronutrients, along with carbohydrates and fats that we hear alot about when it comes to supporting good health. Based on the research over the past 40 years we now understand that increasing protein and resistance training can contribute to thriving as we age and prevent a condition called sarcopenia. Sarcopenia is the loss of muscle mass and strength as we age; it can increase the risk of falls and fractures as well as contribute to frailty. The focus for this article is the importance of protein. I will leave the importance of resistance training for another article. However, protein and resistance training go hand in hand. But, for now, let’s explore what protein is, what it does, why it’s important, how much we may need, and explore examples of how to get enough protein daily.
Proteins are essential for building new tissue and repairing old tissue. There are 20 amino acids that go into making a variety of proteins. Protein is made up of 20 amino acids. All of the 20 amino acids contribute to a wide array of cellular activity such as creating enzymes and hormones. We require approximately 300 grams of new protein per day. Of the 20 amino acids that are important for maintaining healthy muscle tissue and maintaining cellular activity, there are 9 essential ones that we need to get from our diet. Animal protein is considered a complete protein because it contains all of the 20 amino acids that we need. Plant based proteins are considered incomplete because they lack one or more of the essential amino acids.
Proteins are much more than we realize. For example, insulin and our liver enzymes are made of proteins. Insulin is composed of 51 amino acids and myosin (a protein for muscle contraction) is made up of thousands of amino acids. Liver enzymes are replaced every hour whereas muscle proteins have a half life of 15 days. Amino acids, such as leucine, are also signaling molecules that directly stimulate muscle protein synthesis - building and maintaining muscle. For every new protein that’s getting made in the body about 6 or 7 amino acids are getting recycled. The body replaces every protein in it about four times per year.
While we understand that young bodies have particular nutrition requirements, research is revealing that aging bodies have different nutrition and lifestyle requirements. According to Don Layman, a Professor of Food Science and Human Nutrition at the University of Urbana-Champaign, “aging increases the daily turnover of protein, meaning there is a greater need for protein intake simply to replace the tissue you already have.” For the past 40 years, Layman has investigated the role of dietary protein in muscle protein synthesis. He states, “We now know that protein efficiency goes down as we get older. If you give a 16 year old a certain amount of protein they will have a very good response. A 65 year old may have a 10% response or no response at all. As we get older, we can buffer that response with higher quality proteins and resistance exercise.”
“Your overall health is determined on keeping the muscle healthy because it keeps everything else healthy.” Don Layman, Ph.D.
When we get older, a higher level of certain amino acids such as leucine is required to stimulate maximum muscle stimulation and growth. Aging reduces the ability to breakdown and synthesize protein which reduces our ability to build muscle mass and strength. This is called anabolic resistance. The nutrition that allows you to easily build muscle in your 20s won’t be sufficient to keep building lean mass in your 50s and 60s. With the study of one of the essential amino acids leucine, Don Layman has found that if you give leucine to an older adult you can actually make the adult look just like a 16 year old in terms of muscle stimulation and growth. What we are learning is that while efficiency of synthesizing protein goes down, the capacity to respond does not. Resistance training and protein are a powerful signal for promoting protein synthesis, countering anabolic resistance, and maintaining muscle with age. The good news is it’s never too late to build muscle. We have the capacity to build and maintain muscle in our 60’s, 70’s and beyond. In order to do this we need to pay close attention to both the quantity and quality of our protein and incorporate consistent resistance training.
Current thought in the field is that if you have a dietary protein requirement that’s about twice the minimum RDA of 0.8 gm per kg (2 x 0.8 = 1.6 gm per kg), you can get the 65 year old to respond the same as the 20 year old in terms of muscle protein. ” Don Layman, Ph.D.
As we age, we have a greater need for protein simply to support cellular activity and the decreased ability to recycle our own protein. By increasing protein and focusing on high quality protein, we can maintain and build muscle and support the increasing need that comes with aging. The Recommended Daily Allowance (RDA) is a low water mark, it’s the minimum required to prevent disease. This may not reflect what is necessary to support optimal health.
The difference as we age between 0.8 gms of protein per kg of body weight and 1.6 gms of protein per kg of body weight is the difference between living and thriving. Using the formula above which reflects a dietary protein requirement that’s about twice the minimum RDA, let’s provide an example of a ballpark range of protein requirement. Using 1.6 gms per kg, a 60 year old, 140 pound woman (140 divided by 2.205 = 63.502 kg x 1.6 (gm per kg) would need approximately 101 grams of protein daily. For a 200 pound male that would be around 145 grams of protein daily. A number of leading authorities in the field are suggesting that these may be on the low end depending on exercise and activity level. Some authorities recommend 2 gms per kg.
Another consideration is how we look at the macronutrient protein. When we look at the macronutrients, protein, carbohydrate and fat amounts are often reflected in percentages such as ‘fat should be 20% of calories’. Based on current research, the amount of protein we get in a day should be an absolute number such as 100 gms NOT a % of calories such as ‘protein should reflect 30% of overall calories. Our need for protein is an absolute number and shouldn’t go down even if we are lowering overall calories. So if you are trying to lose weight, especially in our 40’s and beyond we need to be maintaining our absolute number of protein in grams. If I determine, for example, that I need to take in 1800 calories to lose weight and I need 101 grams of protein a day, I need to eat 101 grams of protein a day and work my other macronutrient calories of fat and carbohydrates around it.
Consuming the necessary or ‘absolute number’ of protein is important because when people are trying to lose weight they don’t think about what they are losing. We don’t realize that we are losing lean muscle along with fat. So not only do we have an increased tendency to lose lean muscle, we exacerbate this when trying to lose weight. Muscle helps us to burn fat and excess calories and it is important for good metabolic health - how we break down and use energy. Research continues to support the fact that building and maintaining muscle mass is critical for remaining active and healthy as we age. As we age, there is a greater need for protein to just replace the tissue we already have. Also with age there is a blunted response to protein and therefore building muscle. Protein is essential to increasing muscle mass and we shouldn’t short change our consumption of protein when on any weight loss plan. This is also why it is important to understand that we need to get an absolute number of protein based on age and activity, not as a percentage of calories.
When we look at protein there are two factors that go into a protein quality score:
What’s the composition of those 9 essential amino acids?
What’s its bioavailability? (how well do we digest it and absorb it)
Not all protein is equal, getting 20 grams of protein in a meal doesn’t mean we are digesting and absorbing 20 grams of protein. Animal proteins contain all the 20 amino acids. They are complete proteins. With animal proteins and most isolated proteins such as whey, even soy protein isolates, the digestion and absorption is pretty close to 100%. Digestion and absorption for animal proteins is usually 95% or higher. Digestion and absorption for plant proteins is approximately 60-70% available because we can’t digest the fiber attached to the protein. Plant proteins are incomplete in that they do not have all of the 9 essential amino acids. If you are eating a plant based diet, the three important essential amino acids to make sure you get enough of are leucine, lysine, and methionine because they will be limiting in adults for protein synthesis - the ability to absorb and utilize the protein. Lysine is always limited in grains, methionine is limited in legumes, and methionine is low in all plant products. Protein synthesis is limited by the availability of the 9 essential amino acids. If our 20 grams of protein is limited by methionine or especially leucine, the body will only make protein until the methionine or leucine runs out.
Don Layman explains that if you look at wheat protein on a cereal box and, for example, say it was wheat flour; and the cereal box says there’s 4 gms per serving of protein, there’s actually less than 2 grams that you can actually absorb. This is where quantity matters and if you are eating a plant based diet you should be aiming for 100 to 125 gms of protein per day to ensure an adequate amount of bioavailability. In our 50’s, 60’s and beyond, if you are only getting around 50 grams of protein a day, you may not be getting adequate amounts to support maintaining muscle and building new tissue, repairing old tissue, and the wide array of cellular activity that adequate protein provides.
You may be asking how I can navigate and apply this information today? In general, determine how much protein you need based on the recommendation of 1.6 grams per kg especially if you are 50 years or older and consider 2 gms per kg if you are an athlete or quite active. Remember, protein quantity and quality become more significant as we age.
I always recommend as close to a whole foods diet as you are able. This means the food you are eating and preparing is as close to how it came into the world - for example, an apple vs. an apple pie.
Examples of meeting protein needs in a day:
Breakfast options:
2 egg white/2 egg (4 egg) scramble (20 gms protein) - adding 1 oz of cheese increases this to 25 to 27 grams of protein.
¾ cup greek yogurt plain (add your own sweetener) with blueberries (17 gms protein)
High Protein Overnight oats (approx. 38 gms protein) see recipe below
Lunch options:
Salmon salad with 1 can of salmon on a bed of greens and veggies (38-40 gms
protein) or in a whole grain wrap.
Bean and Vegetable Enchilada Casserole (15 gms of protein) see recipe below
Mid-Morning or Mid-afternoon snack options:
Whey protein isolate or pea protein shake (20 to 25 grams of protein)
1 cup of edamame (17 grams of protein)
Dinner options:
4-6 oz of chicken or turkey breast - used in a veggie stir fry (4 oz = 35 gms; 5
Oz = 44 gms; 6 oz = 52 gms)
One pot lentils and Quinoa (19 gms protein) see recipe below
Examples of protein servings:
4 oz cooked chicken = 35 grams of protein
4 oz cooked turkey breast = 34 grams of protein
¼ pound or 4 oz of hamburger patty = 28 grams of protein
3 oz of shrimp = 18 grams of protein
3 oz of salmon = 17 grams of protein
1 hard boiled egg = 6 grams of protein
1 ½ cups of cooked tofu = 30 grams of protein
½ cup cooked black, pinto, lentils = 7 to 10 grams of protein
½ cup cooked split peas = 8 grams of protein
½ cup quinoa = 4 grams of protein
3.5 oz of wild rice = 4 grams of protein
The take home message is that our protein needs increase as we age. As we age, protein and resistance training supports getting stronger, staying active, having a healthy immune system, and improving our quality of life. What do you want to be doing in your 60’s, 70’s and beyond? Whatever it is, ensuring you get enough quality protein is essential to making that happen.
Dietary protein: amount needed, ideal timing, quality, and more | Don Layman, Ph.D. [peterattiamd.com podcast #224]
Recipes
High Protein Overnight Oats:
½ cup milk of your choice (may want to add a bit more if too stiff)
½ cup greek yogurt, 2% Fage plain yogurt, or vegan yogurt
½ cup old fashioned oats
1 tsp maple syrup or other sweetener of your choice (optional)
½ tablespoon chia seeds
1 scoop protein powder - ex. Whey protein isolate or pea protein powder
Berries and/or chopped nuts to top
Mix all the ingredients except berries in a jar or sealable bowl the night before. Store in the fridge. Add berries and/or nuts before you eat.
One Pot Creamy Spinach Lentils with Quinoa
Since this one-pot meal has loads of dried herbs, the lentils soaked it all up and brought everything together. Super simple and super delicious!
INGREDIENTS
2 tablespoons olive oil
1 large shallot chopped
1 cup chopped carrots
2 cups chopped mushrooms
2 - 3 garlic cloves minced
1/2 teaspoon red pepper flakes
1 teaspoon dried oregano
1/2 teaspoon dried thyme
1/2 teaspoon dried rosemary
2 bay leaves
1 cup green/brown lentils
2 cups vegetable broth
2 1/2 cups water divided
1 teaspoon miso paste optional*
1/2 cup red quinoa or variety of choice, uncooked
4 - 5 cups fresh spinach
Salt + pepper to taste
Olive oil fresh herbs and grated cashews* to garnish
I
INSTRUCTIONS
Heat the oil over medium heat in a large Dutch oven or cast iron pot. Add shallots and carrots and cook until the carrots have started to soften, about 3 - 4 minutes. Add mushrooms and continue to cook until mushrooms are juicy and tender, another 5 minutes.
Add garlic, red pepper flakes and herbs. Stir around until the whole mixture becomes fragrant, about 1 minute.
Pour in lentils, broth, 2 cups of water and miso (if using). Bring the mixture to a boil, cover and reduce to simmer for 15 minutes.
Remove the lid and add quinoa and remaining water. Stir to combine. Bring the mixture back to a boil, recover and reduce to simmer for another 15 minutes.
Remove pot from the heat, uncover and add spinach, stirring gently to combine. Taste (carefully!) and season with salt and pepper.
Serve with a drizzle of olive oil, fresh herbs and grated cashews.
The miso adds a great umami flavor, but you can just use sea salt if you don't have miso. You can also totally use parmesan if you want!
Makes 4 servings.
NUTRITION
Calories: 374kcal | Carbohydrates: 58g | Protein: 19g | Fat: 13g | Saturated Fat: 1g | Sodium: 457mg | Potassium: 1254mg | Fiber: 21g | Sugar: 6g | Vitamin A: 9205IU | Vitamin C: 15.5mg | Calcium: 100mg | Iron: 6.6mg
Bean and Vegetable Enchilada Casserole
A delicious vegetarian dish with Mexican flair.
INGREDIENTS
• 1 medium bell pepper, chopped
• 1 large onion, chopped
• 2 cloves garlic, minced
• 1 Tbsp. olive or avocado oil
• 1 can (14 oz.) black beans, drained and rinsed
• 1 can (14 oz.) pinto beans, drained and rinsed
• 1 package (16 oz.) frozen corn, thawed
• 1 can (28 oz.) pureed or crushed tomatoes
• 1 Tbsp. chili powder
• 1/2 tsp. ground cumin
• Dash of hot sauce, to taste
• Salt and freshly ground pepper, to taste
• 12 corn tortillas
• 1 cup grated reduced-fat Jack cheese
DIRECTIONS
Preheat the oven to 350 degrees. In a large saucepan, heat oil over medium heat and saute bell pepper, onion and garlic for five minutes. Add beans, corn, tomatoes and seasonings, including salt and pepper, if desired. Reduce heat to low and simmer for 15 minutes.
Assemble the casserole in a 9 x 13-inch baking dish. Cover bottom with one third of bean mixture. Layer six tortillas on top of beans. Repeat once more, ending with bean mixture on top. Sprinkle cheese on top and bake until hot and bubbly, about 30-40 minutes.
Makes 8 servings. Per serving: 320 calories, 7 g total fat (2 g saturated fat), 53 g carbohydrates, 15 g protein, 11 g dietary fiber, 677 mg sodium.
Recipe from the American Institute for Cancer Research.
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