Category Archives: Sarcopenia

Up To A Third Of Adults Over 50 Have Some Degree Of Muscle Loss (Sarcopenia), More Protein Doesn’t Seem To Help

Getting more protein may not prevent the loss of muscle mass or strength as we age.

What does seem to help is exercise (and certain plant foods1, and eating low-fat2):

The following study looked at 9 placebo-controlled studies (the gold standard of scientific investigation), and found no benefit from protein:

Clinical Effectiveness Of Protein And Amino Acid Supplementation On Building Muscle Mass In Elderly People: A Meta-Analysis, PLOS ONE, 30 September 2014

Conclusions: These results indicate that amino acid/protein supplements did not increase lean body mass gain and muscle strength significantly more than placebo in a diverse elderly population.

This next one was an exhaustive review of 37 studies from January 2000 to October 2013 that addressed the prevalence of sarcopenia and the effect of nutrition and exercise.

Prevalence Of And Interventions For Sarcopenia In Ageing Adults: A Systematic Review. Report Of The International Sarcopenia Initiative (EWGSOP and IWGS), Age and Aging, 21 September 2014

In a nut shell:

  • Up to a third (33%) of adults over 50 (living in the community, not in a care setting where, as you’d expect, the prevalence is higher) have some degree of muscle loss or reduced muscle function.
  • “Protein supplements have not shown consistent benefits on muscle mass and function.”
  • “Exercise interventions, especially those based on resistance training, may have a role in improving muscle strength and physical performance (moderate quality evidence), but not muscle mass.”

There are quite a few doctors and nutrition coaches advising people to consume more protein as they age to stem loss of muscle mass or strength (sarcopenia). Not only is the jury still out on whether eating more protein will prevent or turn around muscle loss, but it could be harmful. Eating more protein stresses the kidney, and, as we saw, causes detrimental calcium losses, and increases the risks for kidney stones and renal disease.

Regarding fat… Insulin resistance and chronic inflammation play a role in muscle loss as we age. Both of those are increased by dietary fat, especially saturated fat. Eat butter? It’s just not a good idea.

1 Compounds In Green Tomatoes And Apple Peels Stimulate Muscle Growth, Protect Against Muscle Wasting (Sarcopenia).
2 High Fat, Especially High Saturated Fat Diets Linked To Muscle Loss

Walmart To Drive Down Organic Prices With New Cheaper Line

WildOatsBlackBeansSays Clare O’Connor at Forbes:

“Starting this month, the big box giant aims to drive down the price of organic food nationwide with its new in-house line of 100 or so products in exclusive partnership with Wild Oats, a pioneering health brand of the 1980s.

Walmart’s new Wild Oats organic products — including kitchen cupboard staples like olive oil and black beans — will cost about 25 percent less than those sold by competitors, based on price comparisons of 26 national brands.”

By the way, Tim Worstall, also from Forbes, also discussing Walmart’s move , says:

“There’s no difference in the nutritional quality [of organic] as opposed to conventionally farmed.”

As you know, that’s not true. Just one example: my previous post describes a study that found alpha-tomatine, a naturally-occurring compound which fends off sarcopenia or muscle wasting, “is higher in organically grown tomatoes compared to conventionally grown tomatoes.”

This was interesting, from Reuters:

“Organic foods accounted for roughly 4 percent of total U.S. food sales in 2012.”

That’s not much, and it all but completely excludes the low-income sector: “Organic foods often cost more than their conventional rivals, and that has limited purchases by the legions of lower-income U.S. shoppers.”

This move by Walmart will increase access to organics.  If it ends up increasing demand, that would have several outcomes (at least on food), some desirable, some not so. It could erode the way organic food is currently produced (however, that is regulated by the USDA’s National Organic Standards Board) or it could put pressure on conventional agriculture to employ more organic and sustainable methods. I think both will happen.

Compounds In Green Tomatoes And Apple Peels Stimulate Muscle Growth, Protect Against Muscle Wasting (Sarcopenia)

GreenTomatoes3This is the most exciting thing I’ve read all day. Compounds in apple peels and green tomatoes could help preserve muscle as we age, staving off sarcopenia. The compounds are so effective that isolated, concentrated forms were shown to stimulate muscle growth in mice and human muscle cells.

Here’s the recent study. The compound in this one is tomatidine, found in green tomatoes:

Systems-Based Discovery of Tomatidine as a Natural Small Molecule Inhibitor of Skeletal Muscle Atrophy, The Journal of Biological Chemistry, 9 April 2014

Here’s the researchers’ prior study. The compound is ursolic acid, found in apple peels:

mRNA Expression Signatures of Human Skeletal Muscle Atrophy Identify a Natural Compound that Increases Muscle Mass, Cell Metabolism, June 2011

Of note, red tomatoes contain little tomatidine:

“In humans, dietary tomatidine comes from ingestion of alpha-tomatine, which is abundant in green tomatoes but typically decreases by approximately 99% as tomatoes ripen. … It is also interesting that alpha-tomatine is higher in organically grown tomatoes compared to conventionally grown tomatoes.”

Not only do these compounds reduce muscle atrophy and stimulate muscle growth, but they also reduce body fat (adiposity):

“Like other interventions that stimulate skeletal muscle hypertrophy, tomatidine also decreases fat. The mechanism by which tomatidine decreases fat is not yet known.”


“Importantly, ursolic acid’s effects on muscle were accompanied by reductions in adiposity, fasting blood glucose, and plasma cholesterol and triglycerides.”

AppleSarcopenia3The apple peel compound may also inhibit cancer growth:
Ursolic Acid Inhibits Proliferation and Induces Apoptosis of Cancer Cells In Vitro and In Vivo, Journal of Biomedicine and Biotechnology, 2011

Here’s a graphic that accompanied the ursolic acid (apple peel) study. The red and green parts show how researchers identified ursolic acid. Pretty creative! The purple part, the telling part, shows that giving mice ursolic acid promoted muscle growth:

Graphical Abstract

Wikipedia names these food sources for ursolic acid:

“Including apples, basil, bilberries, cranberries, elder flower, peppermint, rosemary, lavender, oregano, thyme, hawthorn, and prunes. Apple peels contain large quantities of ursolic acid and related compounds.”

Here’s a press release from University of Iowa on the tomatidine study and a few excerpts:
Green Is Good; Natural Compound From Green Tomatoes Increases Muscle, Protects Against Muscle Wasting, 9 April 2014

“As unlikely as it sounds, green tomatoes may hold the answer to bigger, stronger muscles.

Using a screening method that previously identified a compound in apple peel as a muscle-boosting agent, a team of University of Iowa scientists has now discovered that tomatidine, a compound from green tomatoes, is even more potent for building muscle and protecting against muscle atrophy.

In a new study, published online April 9 in the Journal of Biological Chemistry, Christopher Adams, associate professor of internal medicine and molecular physiology and biophysics in the UI Carver College of Medicine, searched for a small molecule compound that might be used to treat muscle atrophy. He zeroed in on tomatidine using a systems biology tool called the Connectivity Map, which was developed at the Broad Institute of MIT and Harvard University. Adams discovered that tomatidine generates changes in gene expression that are essentially opposite to the changes that occur in muscle cells when people are affected by muscle atrophy.

After identifying tomatidine, Adams and his team tested its effects on skeletal muscle. They first discovered that tomatidine stimulates growth of cultured muscle cells from humans.

“That result was important because we are looking for something that can help people,” Adams says.

Their next step was to add tomatidine to the diet of mice. They found that healthy mice supplemented with tomatidine grew bigger muscles, became stronger and could exercise longer. And, most importantly, they found that tomatidine prevented and treated muscle atrophy.

Interestingly, although mice fed tomatidine had larger muscles, their overall body weight did not change due to a corresponding loss of fat, suggesting that the compound may also have potential for treating obesity.

An attractive aspect of tomatidine is that it is a natural compound derived from tomatoes. It is produced when alpha-tomatine, which is found in tomato plants and in green tomatoes in particular, is digested in the gut.

Adams and his team previously used this same research strategy to discover that ursolic acid, a compound from apple peels, promotes muscle growth.”

They didn’t find that just eating green tomatoes and apple peels (compared to eating a concentrated supplement) would prevent muscle wasting, but they didn’t negate it either. Unfortunately, it’s the isolated, concentrated compound that has value for businesses, not the food. And a compound that can do all this would be ripe for the capitalist’s picking. Sure enough:

“We are now very interested in the possibility that several food-based natural compounds such as tomatidine and ursolic acid might someday be combined into science-based supplements, or even simply incorporated into everyday foods to make them healthier.”

To that end, Adams and his colleagues have founded a biotech company called Emmyon, “to accelerate this research and translate it to people.”

High Fat, Especially High Saturated Fat Diets Linked To Muscle Loss

As people age, they lose muscle mass. That muscle loss is called sarcopenia. Inflammation and oxidative stress are thought to be at the root of sarcopenia. Dr. Holly Van Remmen’s research focuses on how oxidative stress damages mitochondria, and:

“The impaired function of mitochondria also has a detrimental effect on the way motor neurons ‘talk’ to the muscle to achieve muscle contraction,” Dr. Van Remmen said.

This new study now implicates dietary fat in these processes:

Dietary Fat and Fatty Acid Profile Are Associated with Indices of Skeletal Muscle Mass in Women Aged 18–79 Years, The Journal of Nutrition, March 2014

“Age-related loss of skeletal muscle mass results in a reduction in metabolically active tissue and has been related to the onset of obesity and sarcopenia. Although the causes of muscle loss are poorly understood, dietary fat has been postulated to have a role in determining protein turnover through an influence on both inflammation and insulin resistance.”

Dietary fat is linked to inflammation and insulin resistance, evidence for which I’ve given over the years.

“This study was designed to investigate the cross-sectional relation between dietary fat intake, as dietary percentage of fat energy (PFE) and fatty acid profile, with indices of skeletal muscle mass in the population setting. Body composition [fat-free mass (FFM; in kg)] and the fat-free mass index (FFMI; kg FFM/m2) was measured by using dual-energy X-ray absorptiometry in 2689 women aged 18–79 y from the TwinsUK Study and calculated according to quintile of dietary fat (by food-frequency questionnaire) after multivariate adjustment.”

Quintiles. Did you see that? They divided the women into 5 groups based on fat intake. Why didn’t the saturated fat study use quintiles? Or quartiles? When you want to see difference among groups, the more groups the better. (The Sat Fat study used 3 groups.)

“Positive associations were found between the polyunsaturated-to-saturated fatty acid (SFA) ratio and indices of FFM, and inverse associations were found with PFE, SFAs, monounsaturated fatty acids (MUFAs), and trans fatty acids (TFAs) (all as % of energy). Extreme quintile dietary differences for PFE were −0.6 kg for FFM and −0.28 kg/m2 for FFMI; for SFAs, MUFAs, and TFAs, these were −0.5 to −0.8 kg for FFM and −0.26 to −0.38 kg/m2 for FFMI. These associations were of a similar magnitude to the expected decline in muscle mass that occurs over 10 y.”

So, as the polyunsaturated-to-saturated fatty acid ratio went up, muscle mass went up. As total fat, saturated fat, monounsaturated fat, and trans fat intakes went up, muscle mass went down.

“To our knowledge, this is the first population-based study to demonstrate an association between a comprehensive range of dietary fat intake and FFM [Fat Free Mass or muscle mass]. These findings indicate that a dietary fat profile already associated with cardiovascular disease protection* may also be beneficial for conservation of skeletal muscle mass.”

That profile which protects against heart disease and now sarcopenia is:

  • Low dietary fat – of all types.
  • High polyunsaturated-to-saturated fatty acid ratio, which is … more plant food, less animal food.