By Dr. Mercola
Although muscle loss is a natural effect associated with aging, it is not inevitable when you take steps to prevent the condition and strengthen your muscles. This type of muscle loss is called sarcopenia in medical circles. Sarcopenia will not occur consistently across age and gender, as it is linked to your dietary choices and exercise habits.
For instance, a healthy, active 60-year-old may have the muscle mass of a 30-year-old, while a sedentary middle-aged person, who primarily eats processed foods and struggles with insulin resistance may have the muscle quality of a 70-year-old.
Eating a diet rich in whole foods and staying active are key to preventing insulin resistance and maintaining muscle mass as you age. It is important to incorporate both nonexercise movement — walking, standing and avoiding sitting — as well as strength training in your daily routine to prevent as much age-related muscle loss as possible. This is essential for improving your mobility and reducing your risk of health conditions that significantly impact your quality of life.
Spreading Protein Throughout the Day Found to Reduce Sarcopenia
Recent research has confirmed previous studies demonstrating that an even distribution of protein over the day may help to maintain or grow muscle mass more effectively than including most of your protein intake at one meal.1 A Canadian study found that seniors who ate protein throughout the day maintained their muscles mass more efficiently, but it did not affect their mobility. The study tracked more than 1,700 men and women who were relatively healthy, over a period of three years.2
The participants were 67 to 84 years of age. During the study they provided the researchers information about the foods they ate and underwent yearly strength testing of their arms and legs, as well as testing for mobility. During the three-year study the researchers found all participants lost both strength and mobility. However, those who ate protein at each of their meals during the day retained better strength, although not greater mobility, than the people who ate their protein at just one meal.
This study was observational and thus could not define a cause and effect from the timing of protein intake. However, while the results could not draw definitive conclusions, it does confirm the results of past studies that demonstrate the timing of your consumption of protein has a significant impact on the development of muscle mass.3,4,5 This means timing may be as important as the amount of protein to best stimulate muscle protein synthesis.
In another study, researchers measured changes in protein synthesis in response to timing of protein intake between individuals who ate protein throughout the day and those who ate most of their daily protein at the evening meal.6 Those who consumed a moderate amount of protein at each meal experienced greater muscle protein synthesis than those who ate all of their protein at the evening meal.
During Protein Summit 2.0,7 nutrition experts discussed the role of protein in human health, finding the breakfasts of older adults are often dominated by carbohydrate foods. A discussion of protein requirement for older adults focused on optimizing the timing of protein intake and resulted in the following hypothesis based on previous research:8
"Habitually consuming 25 [to] 30 g[rams] protein at breakfast, lunch, and dinner provides sufficient protein to effectively and efficiently stimulate muscle protein anabolism and may delay the onset of sarcopenia, slow its progression, and/or reduce the magnitude of its functional consequences."
Age-Related Muscle Decline May Lead to Further Debilitation
From the time you're born until you're near age 30, your muscles continue to grow in strength and size. At some point between age 30 and 40 you start a gradual decline of muscle function and strength. This has an impact on your metabolic function, which helps explain why it's so much easier to lose weight when you're younger and easier to put on weight as you age.
People who are sedentary may lose up to 5 percent of their overall muscle mass every decade after age 30. 9 As you age, this loss also gradually increases in speed. This loss in muscle mass and strength is a large factor in frailty. Frailty is a clinical diagnosis in the elderly that increases your risk of falls, hospitalization, disability and mortality.10 It reduces your ability to cope with stressors and may be defined by meeting three of the following five factors:11
- Low grip strength
- Low energy
- Slowed walking speed
- Low physical activity
- Unintentional weight loss
Loss of strength and muscle mass may lead to impaired balance, reduced endurance and poor walking ability. These physical factors lead to an increase in falls, broken bones, disability and lack of independence. Contributing factors to sarcopenia include hormonal changes, inflammation and decline in activity, neurological function and nutrition.12 Recent research found mitochondrial decline and changes in the angiotensin system in your skeletal muscle may also contribute to a reduction in muscle mass and strength.
The Cost of Sarcopenia Is High
The estimated direct health care cost in the U.S. in 2000 from sarcopenia was $18.5 billion, representing approximately 1.5 percent of the total health care costs that year (the latest numbers available).13 However, those are only direct care costs and do not include indirect costs such as loss of work, loss of productivity to the employer and costs to replace workers.
A loss of muscle mass may also be related to metabolic dysfunction, such as insulin resistance and diabetes, which increase health care costs even further. While age-related muscle loss contributes to a number of health conditions, there are no current public health campaigns aimed directly at reducing your risk. Preserving your independence and physical function not only improves your quality of life, but also saves you thousands of dollars in health care costs.
Unfortunately, muscle loss may herald the onset of weight gain, loss of physical energy, loss of cognitive ability and greater vulnerability to disease, in effect, accelerated aging.
Too Much of a Good Thing Can Backfire
Although protein is essential, your ability to process it declines with age. This occurs at the same time your body begins to lose more muscle mass, which increases your requirement for protein.
To date, Americans consume more meat, and thus protein, per person than any other country.14 Making matters worse, most eat meat from animals raised in concentrated animal feeding operations (CAFOs). The meat from these animals is more prone to contamination with antibiotic resistant microbes and is nutritionally inferior to meat that is organically raised and grass fed.
Your body has an upper limit to the amount of protein you can actually integrate and use. This means that while it may be beneficial to spread out the protein you eat during the day, it is just as important to monitor the amount and quality of protein you eat. When you eat more protein that you can use, your body must process more nitrogen waste products, creating an environment that increases your risk of dehydration, placing an additional stress on your body.15
An excessive amount of protein may also stimulate your biochemical pathway called mammalian target of rapamycin (mTOR) that plays a significant role in the development of many cancers and in the regulation of the aging process.
Protein that isn't used by your body negatively affects the GCN2 pathway as well, which is also involved in aging. In other words, in your effort to slow the aging process and age-related muscle loss by eating protein at far greater amounts than your body can use, you may actually be speeding the process.
How Much Is Enough?
While it's important to get the correct amount of protein, there is not a current consensus of exactly how much is the right amount. Currently the National Academies of Sciences, Engineering and Medicine (which took over the task of developing dietary reference intakes [RDI] as of July 1, 2015, previously carried out by the Institute of Medicine) recommends men over the age of 19 get 56 grams of protein per day, and women over the age of 14 get 46 grams per day. These amounts apply for seniors over the age of 70 as well.16
Stuart Phillips, a professor of kinesiology at Canada's McMaster University, believes most people need up to 0.75 grams of protein per pound of total body weight, which is higher than the recommended RDI, in order to receive essential nutrients and amino acids found in animal-based proteins.17 However, disease and longevity researchers have a completely different recommendation. Valter Longo is a professor of biological science at the University of Southern California who has studied links between cancer and dietary intake.
Longo's research shows rates of cancer increase nearly 400 percent in people who eat 20 percent or more of their calories from protein when compared to people who limit their protein intake to 10 percent of their daily calories.
Along with a significantly greater risk of cancer, people who eat large amounts of protein per day also suffer from a much higher risk of mortality.18 Based on this research Longo recommends consuming no more than 0.37 grams of protein per pound of total bodyweight. This is nearly half the amount Phillips recommends.
However, as you age, the recommendations of these two scientists begin to converge as muscle wasting and loss of strength become important challenges faced by seniors. At this point the benefits of increasing protein intake to help lower your risk of death and disease rises above the potential risk of cancer.
General recommendations for the number of grams of protein per day that are based on age and gender don't appear to be specific enough. Compelling research suggests the key to good health is the precise measurement of protein in your diet. I prefer to use a formula that calculates your requirements based on your lean body mass, or muscle weight, only; not your total body weight. This is more relevant to your biological needs, irrespective of your overall weight, or your age and gender.
The formula I use is 0.5 grams of protein for each pound of lean body mass or 1 gram per kilo (2.2 pounds) of lean body mass. If you are pregnant, exercising aggressively or competing athletically, you may increase this by 25 percent. Seniors may also need more. If you are older and clearly losing muscle mass, consider gradually increasing your intake along with strength training until you notice an improvement, to identify a more ideal protein level.
To determine your lean body mass, you'll first need to know your percent of body fat. There are several ways of measuring your body fat percentage:19
- Body fat calipers: These may cost as little as $5. They may underestimate your current body fat by a couple percentage points but are surprisingly accurate for the cost.
- Body fat calculator:20 These tools estimate your body fat using several measurements. However, they can overestimate your body fat percentage.
- Body fat scales: These use an electric current through your body. They can be inaccurate as they are based on your degree of hydration.
- The Bod Pod: This method uses air displacement. It's accurate, but may be expensive at your location.
To reach a relatively accurate number inexpensively you may try using body fat calipers and a body fat calculator online and averaging the two numbers. Once you have this number, subtract your percent body fat from 100 and multiply the resulting percentage by your current weight. For instance, if your percent body fat is 15 percent, then 100 minus 15 percent is 0.85; multiply this by your body weight and you'll have your lean body mass in pounds or kilos.
Using this example, if you weigh 175 pounds, 0.85 multiplied by 175 equals 148 pounds of lean body mass. Now, multiply 148 times 0.5 (grams of protein per pound of lean body weight) and you get 74 grams of protein per day.
Convert Your Protein Grams to Food
A substantial amount of protein is found in both animal- and plant-based food products. Meats, fish, dairy products, nuts, seeds and some vegetables21 contribute to your protein intake. Remember to purchase foods that are organically raised, without genetically modified ingredients, and make sure they are certified grass fed meats.
Also keep in mind that many nuts are high in both healthy fats and in protein. Macadamia, pecans and pine nuts are high in fat and low in protein, helping to curb your hunger quickly while not contributing greatly to your protein intake.
To determine your protein intake, calculate your individual requirements as described above and record what you eat each day for several days. To make the overall process easier, consider creating an account with Cronometer.com/Mercola. This is one of the most accurate nutrition trackers out there, and it's free to use.22
You're Never Too Old to Start Exercising — The Key to Building Strong Muscles
Even if you think you're too old to start a program of high-intensity interval training (HIIT) or resistance training, there is still hope to prevent further muscle loss and build more muscle. You may start at any age and make significant advances that improve the quality of your daily life.
Exercise, when coupled with optimal nutrition, is a potent strategy to not only prevent muscle loss but also build new muscle. In the video above (originally filmed in 2011), my mother, who recently passed away, demonstrates part of her routine and talks about the progress she experienced in her daily life.
If you haven't exercised before, or haven't been to a gym in years, consider consulting with a personal trainer who can help you with the proper form and technique that will reduce your potential for injury and increase your chances of success.23 Personal trainers can also help to spot if you lose your balance or when your muscles tire lifting weights.
Strength training is essential to maintaining your muscle mass and body strength. However, it's important to remember that you are working to gain greater strength than you already have and not training to become Mr. Universe.
By incorporating strength training you improve your balance and your ability to do daily living tasks, such as bringing in groceries, climbing stairs or getting in and out of the car. Strength training may also help balance your blood sugar, as well as help to relieve pain in your joints as improved strength helps support your joints.
It is inspiring in your own journey to see what strength training and HIIT can accomplish. For a brief description of how exercise and strength training affected the lives of six senior athletes, read my previous article, "Shot of Inspiration — Superstar Seniors Exercise Well Into Their Golden Years."