When you hear the word protein, what comes to mind?
If you’re like most people, “protein” conjures images of muscles and fitness.
But it’s not just people who are avid gym-goers that need more protein than their sedentary counterparts. Older adults need extra protein too (1).
Unfortunately, most older adults fail to get enough protein in their diets to ensure healthy aging (1).
In turn, this can lead to many unintended consequences including muscle loss, osteoporosis (a disease where bones become weak), falls and fractures.
This article explains the importance of protein for healthy aging and how much protein older adults need for optimal health.
What Is Protein?
Protein is made up of amino acids — the building blocks of life. These amino acids are joined by chemical bonds and then folded in different ways to create structures that are important to our body’s functioning.
There are three main categories of amino acids (2):
- Essential amino acids: our bodies can’t make these so they must be consumed in the food we eat.
- Conditionally essential amino acids: these are not essential, except in times of stress or illness.
- Nonessential amino acids: our bodies can make these, even if we do not get them through the food we eat.
These amino acids are found in a variety of foods.
Foods That Contain Protein
Protein is essential to life. Therefore, it’s found in almost everything we eat.
But some sources are better than others.
The best sources of protein are animal products such as meat, poultry, fish, eggs and dairy products (with the exception of butter and sour cream) (2).
Protein from animal sources contain all the essential amino acids and are therefore considered complete proteins.
Plant products such as grains, grain products, legumes and vegetables also contain protein.
The majority of protein from plant sources are considered incomplete proteins because they lack one or more of the essential amino acids needed for human life.
Some of the best protein sources include (3):
- Ground sirloin: 24 grams per 3 oz.
- Tofu: 20 grams per 1/2 cup
- Tuna: 20 grams per 3 oz.
- Pork tenderloin: 18 grams per 3 oz.
- Chicken breast: 13 grams per 3 oz
- Cottage cheese: 13 grams per 1/2 cup
- Soy milk: 11 grams per 1/2 cup
- Milk: 8 grams per cup
- Peanut butter: 8 grams per 2 tbsp.
- Yogurt: 8 grams per 6 oz.
- Egg: 6 grams per 1 egg
These protein-rich foods contain different nutrients such as vitamins and minerals that others may not have, so it’s best to consume a variety of protein-rich foods — not just one or two.
What Does Protein Do?
There are many different types of proteins in our bodies. They all play important roles in our growth, development and day-to-day functioning. Here are some examples (4):
- Enzymes: these are proteins that carry out chemical reactions in the body. For example, pepsin is a digestive enzyme that works in the stomach to break down proteins in food.
- Antibodies: these remove foreign particles, such as viruses to help fight infection and protect the body.
- Messengers: some proteins act as hormones, which transmit signals to coordinate bodily functions.
- Structural component: these provide support in our bodies, for example, collagen is a protein that gives structure to our skin, bones and tendons.
- Transport and storage: these proteins transport different substances such as hormones, medicines, and enzymes throughout your body.
Without adequate protein, our bodies can’t function. But the body is unable to store excess protein, so it’s important to consume an adequate amount every day.
Why Older Adults Need More Protein
Older adults require more protein than their younger counterparts for several reasons including (5):
Between 15% and 30% of older adults are estimated to lose their appetite with aging (6).
There are many changes that occur with aging that have been tied to a reduction in appetite (7).
Older adults may wear dentures or have chewing difficulties which are both associated with a loss of appetite (8).
Constipation is also prevalent amoung older people which can lead to prolonged satiation and a reduction in appetite (9).
Medications can also alter sense of taste and smell which can reduce appetite. In fact, there are 250 commonly used drugs that alter these senses and its likely that older adults are taking at least one medication (10, 11).
Reduced Ability to Use Protein
One reason why this is thought to occur is due to a phenomenon termed “anabolic resistance.”
Anabolic resistance is the reduced ability to make muscle proteins in response to consuming a protein meal.
Older adults require much more than their younger counterparts to get the same muscle stimulating effect.
This may occur due to a reduction in the ability to use protein or reduced blood flow to the muscles (18).
But increasing protein above the recommended dietary allowance (RDA) can help decrease or slow the loss of muscle mass, especially when combined with resistance training.
Disease or Injury
Unfortunately, many health older adults fail to eat enough protein, but this situation is worsened when disease or injury strike.
Therefore, it’s important that older adults increase both their protein and calorie intake.
How Much Protein Do Older Adults Need?
The current RDA for protein is 0.8 grams per kilogram of body weight, or 0.36 grams per pound (24).
For example, a 150 pound (68 kg) person would need to consume 54 grams per day.
But the RDA only represents the amount needed to prevent a deficiency — it says nothing about what is optimal for healthy aging.
Older adults should consume protein in the range of of 1.0 to 1.2 grams per kilogram of body weight, or 0.45 to 0.55 grams per pound (1).
For a 150 pound (68kg) person this would be in the range of 68 to 82 grams of protein.
Those who are hospitalized or in a critical care setting may require higher amounts of protein (1).
It’s also important that calories are adequate. Consuming too few calories will result in protein being used for energy, which would further increase protein needs.
If your protein goal was 75 grams, for example, it would be best to have three equally space-meals (i.e. breakfast, lunch and dinner) consisting of 25 grams of protein.
The Bottom Line
The current RDA for protein is insufficient to optimize the health of older adults.
Too little protein leads to an increased risk of sacropenia (muscle wasting), osteoporosis and a weakened immune system.
Older adults should consume protein in the range of 1.0 to 1.2 grams per kilogram of body weight per day.
This protein should be equally distributed throughout the day in 25 to 30 gram doses to optimize the beneficial effects of protein for healthy aging.
Combine sufficient protein intake with resistance exercise to optimize health aging.