Tag Archive for: sarcopenia

Protein Intake: Perspective Required

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The research paper that concluded that higher protein intake was associated with muscle loss and sarcopenia seems to offer more questions than answers. That’s actually a good thing, because future research can examine those questions. But there are questions that the researchers didn’t mention.

Researcher Observations

This is an observational study. Simply put, the subjects who completed all the tests were followed for several years, depending on when they joined the study. Therefore, no cause and effect can be inferred because the researchers were watching, not intervening.

The original number of subjects with sarcopenia was low at just 4.3%. With so many subjects over 72, the number should have been closer to 10%. The researchers acknowledged as much. If the study’s subjects had less sarcopenia than the general population, it’s hard to draw conclusions that are helpful to everyone.

My Observations

The single characteristic most closely associated with loss of muscle mass and sarcopenia was age. Protein intake was a covariate for sarcopenia but it was actually in the middle of the pack as a risk; a covariate is a separate attribute that can be measured alongside the primary variable being investigated.

The study included limited data on diet and exercise. I would expect that not very many subjects were exercising at levels high enough to sustain or increase muscle mass. That conflicts with the research data from clinical trials that show that increasing protein intake in older subjects on a weight training program increases strength and muscle mass.

What stood out more than anything was the limited amount of testing for sarcopenia and the mixed bag of testing procedures. If it’s such a problem, which every researcher in aging admits is the case, why aren’t there better diagnostic tools available to diagnose the condition? How can physicians treat a disease they aren’t diagnosing?

The Bottom Line

There is no reason to worry about protein intake as we get older based on this observational study. What we need to do is begin to retain muscle mass or reclaim our muscle through resistance training, better protein intake, and the strategic use of supplements. If you’re interested in a program to do just that, the Taking Back Your Muscle is still available on my website.

What are you prepared to do today?

        Dr. Chet

Reference: https://academic.oup.com/ageing/article/52/2/afad018/7036280

Is High Protein Intake Associated with Sarcopenia?

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If there’s one thing I’ve learned studying health, fitness, and nutrition for 35 years, it’s this: what we thought we knew yesterday may change based on what we learn today. Given that, I was still surprised to see an article in my news feed with a title “High Protein Intake Associated With Sarcopenia.” The Taking Back Your Muscle webinar uses strategies that research has shown help increase muscle strength, including eating more protein. What gives with this latest research?

Researchers selected as their subjects from the TwinsUK cohort. Subjects must be over 60 years old and have completed specific tests since 2010. Just over 3,300 men and women were selected to be included in the data analysis. Researchers examined a variety of variables including education, income, other diseases and conditions, strength, and muscle mass. Protein intake was measured. Researchers did find the opposite of what they expected: higher protein intake was associated with sarcopenia.

Did I get it wrong? I’ll talk about the rest of the study on Saturday. I wouldn’t change your protein intake just yet because there seems to be a larger problem that looms over us as we age. The article is open access, and you can read it at this link.

What are you prepared to do today?

        Dr. Chet

Reference:https://academic.oup.com/ageing/article/52/2/afad018/7036280

Aging Stressor: The Muscular System

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Sarcopenia is the number one issue that impacts muscles—that’s the loss of skeletal muscle mass and strength that comes with age. It can begin as early as the 20s in some and accelerates once we pass 60; it’s thought to be primarily due to the genetics of aging. There’s also little question that a sedentary lifestyle contributes to muscle loss. Losing muscle mass impacts not just strength, but also stamina, posture, balance, and the ability to move your body.

There are several types of muscle fibers, but they all appear to become slow-twitch fibers as we age. And they get smaller. However, and this is important, they don’t ever seem to go away completely. Strength training has been shown to be effective even for people who are 100 years old; they get stronger, which helps deal with all those issues I mentioned before. The research hasn’t demonstrated that muscles will get larger, but most studies end at three to six months, which is too soon to really judge results; it’s probably going to take more than six months to gain back what we lost over many decades.

The key to dealing with sarcopenia is strength training—the earlier in life the better, but it’s never too late. Strength training can encompass many approaches from doing squats by standing up from sitting in a chair (using a walker if balance is an issue), push-ups and other calisthenics, and weight training using bands, tubes, machines, and free weights.

There are hundreds of programs and thousands of exercises to help build strength using every modality. I think it should all begin with an evaluation by a healthcare professional to test posture and balance, as well as strength. The next step is to see a physical therapist who can evaluate your limitations and put together a plan to get you started safely; it’s hard to keep your positive attitude if you get hurt right away and need to pause. Once you get approval and a plan to train, then getting muscles prepared is important. Calisthenics, which include chair exercises for those with arthritis, are a good place to begin.

Final memo before Christmas on Tuesday with one more place to attack when we’re aging with a vengeance.

What are you prepared to do today?

        Dr. Chet

I’m Back!

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It’s been an interesting five weeks since my knee replacement. I’ve never taken that much time off before, but I’m healing well—just not as quickly as I want. Researching the best way to gain back joint strength and muscle loss, I’ve come across a new term that combines two conditions: osteosarcopenia. It’s a combination of the loss of bone mass and the loss of muscle mass.

Osteopenia is the loss of bone mass. While associated with aging, other factors play a part such as genetics, lack of exercise, and poor absorption of nutrients.

Sarcopenia, loss of muscle mass, is definitely associated with the lack of exercise, but there are other factors as well. One that was surprising was the deterioration of mitochondrial function, both in number and effectiveness of function. When mitochondria can’t produce energy effectively and can’t repair and replace themselves, it can impact every cell and organ, not just muscle.

I’ve spent a considerable amount of time looking at the research to find out possible solutions to mitochondrial decline. I can tell you that one of the keys is exercise: strength training, stretching, and aerobic exercise. The rest merits significant explanation. That’s why it will be the topic of this year’s Super Bowl Webinar Aging with a Vengeance: Reclaiming Your Power! on Sunday, February 13 at 3 p.m. Eastern Time. More information to come.

What are you prepared to do today?

        Dr. Chet

Essential Amino Acids for Older Adults

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One of the issues we all face as we get older is the loss of muscle mass; the technical term is sarcopenia. While some of the loss can be attributed to declining hormone levels as well as the decline in physical activity, we tend to eat less protein as we get older. Less protein intake means less muscle and other protein synthesis.

Researchers in Japan wanted to see if increases in muscle mass were related to protein intake, specifically EAAs. Instead of jumping right into supplementing with EAAs, they recruited 10 older men with a mean age of 69 and gathered nutritional information using a three-day dietary record. They put the men on a progressive weight training program, lifting three days per week for 12 weeks.

All men gained muscle mass, about one pound of muscle per leg. In analyzing the diet, the average protein intake was 99 grams of protein per day with 37 grams from EAAs. What they found was that those men with higher EAA intake, especially leucine, had a greater increase in muscle mass. It was even better if they had the EAAs with their breakfast.

This was a small preliminary study that examined current food intake with no intervention other than exercise. It may indicate that in order to be efficient at adding muscle mass, EAAs are important in older adults. What does this mean for you if you’re in that age group or an athlete wanting to add muscle mass? I’ll let you know on Saturday.

What are you prepared to do today?

Dr. Chet

 

Reference: J Nutr Sci vitaminol (Tokyo). 2017;63(6):379-388. doi: 10.3177/jnsv.63.379.

 

Can We Prevent Sarcopenia?

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Based on the research presented in Thursday’s Memo, the earlier we address the possibility that sarcopenia will affect us, the more likely we’ll succeed (1). I use fudgy words such as “likely” because we don’t know for sure, but based on the current status of research, here’s what we can do to prevent sarcopenia.

Use It or Lose It

In the study I talked about Thursday, the men who exercised regularly had a lower rate of decline in muscle function. The researchers speculate that chronic exercise helps preserve the motor units, thus preserving the ability of the nerve cells to send out nerve fibers to attach to muscle fibers.

That’s all well and good, but how can we make sure that we preserve the potential and perhaps increase our motor unit activity if we’ve lost some? Research shows that weight training will help. In several studies, resistance training increased muscle strength in the elderly; strength will improve balance and quality of life.

What kind of exercise will work best? It seems to be high intensity exercise. In a study on elderly mice, high intensity interval training (HIIT) increased the muscle mass, muscle fibers, and the number of mitochondria (2). This was a small study and it was on rodents, so the application to humans isn’t assured. To me, it means use your muscles as you mean to keep using them. The harder you exercise within your physical limitations, the better.

Focus on Protein

Retaining muscle mass is not only about exercise. For some reason, as we get older, we decrease our protein intake, but research shows that increasing protein intake can help retain muscle mass. If you don’t have protein in muscle cells, retaining or adding connections to those cells won’t matter much.

How much protein should people try to get? The current recommendation is 0.8 grams per kilogram body weight per day or a third of a gram per pound body weight; someone who weighs 200 pounds would need about 66 grams of protein per day. But research shows that bumping that up to 1.1 grams per kilogram body weight or a half gram per pound may be better as we get older. That’s 100 grams for a 200-pound person (3). That’s easy for even those who are math-challenged: whatever your goal weight, divide by 2, and that’s your daily goal for grams of protein.

It also seems better to stretch protein intake out throughout the day rather than a big slug at one time. Balanced intake will produce a sustained level of amino acids available for muscle repair throughout the day.

The research is far from complete in this area but it seems that as we age, our protein needs revert to when we were younger: we need more of it.

The Bottom Line

Sarcopenia can result in loss of strength and mass, but more important is the loss of quality of life. We don’t think balance while standing or moving is important until we fall; we don’t think brute strength is important until we need to move something and can’t. This week’s Memos give you an idea of how to prevent and perhaps improve nerve and muscle function.

Don’t think this is for only retirees; once you hit 40, it’s a downward trend. Starting early may help minimize the decline. One thing is clear: if you expect to be mobile when you get older, you need to work on it earlier rather than later.

What are you prepared to do today?

Dr. Chet

 

References:
1. J Physiol. 2018 Mar 11. doi: 10.1113/JP275520.
2. J Gerontol A Biol Sci Med Sci. 2018 Mar 14;73(4):429-437.
3. Nutrients 2018, 10, 360; doi:10.3390/nu10030360.

 

Research Update on Sarcopenia

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We know what sarcopenia is, but what can be done about it? Recent research may give us a clue.

Researchers in the United Kingdom examined a variety of variables related to sarcopenia in a group of men. Remember, a motor unit is a nerve and all the muscle fibers to which it attaches. They looked at the differences between the size of the motor units and the total units between 48 young men, 13 non-sarcopenic elderly men, 53 pre-sarcopenic, and 28 sarcopenic men.

The motor unit potential was greater in non-sarcopenic and pre-sarcopenic men than in young men. Why would that be? The researchers suggested that the nerves are still sending out nerve shoots trying to recruit more muscle fibers. This was not the case with the sarcopenic men; their motor unit potential was much lower. That could mean that once connections are lost, there’s no way to recover muscle function including strength.

While the researchers could not answer that final question with certainty, it’s apparent that preventing potential motor unit loss is critical. How? We’ll talk about that on Saturday.

What are you prepared to do today?

Dr. Chet
Reference: J Physiol. 2018 Mar 11. doi: 10.1113/JP275520.

 

So You Lose a Little Muscle—So What?

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Any of my former students who read the Memo should remember the following definition quite well:

A motor unit is a nerve and all the muscle fibers to which it attaches.

It’s called a unit because both sides of that equation are important. Muscle fibers contract when stimulated by a nerve. Reduce the number of fibers that the nerve can attach to, and the muscle won’t generate as much force. Losing a little strength is no big deal, right? How about walking up a flight of stairs? Or even being able to maintain balance while standing? Yes—it’s a big deal.

Sarcopenia is the progressive loss of muscle strength and function as people age. How much loss? Just look at the picture from the Journal of Physiology: the loss of muscle is obvious and with that, a loss of function. Let that sink in. I’ll talk about whether anything can be done about it the rest of the week.

What are you prepared to do today?

Dr. Chet

 

Reference: J Physiol. 2018 Mar 11. doi: 10.1113/JP275520.