Not only is there an epidemic of obesity, but another widespread problem is also sarcopenia, the age-related loss of muscle tissue. Sarcopenia literally means “poverty of flesh,” and it’s the most common cause of premature disability and loss of independence associated with aging. The combination of obesity and sarcopenia is particularly unhealthy as both increase the risk of health problems.
One of the most effective ways to reduce the impact of sarcopenia is to strength train. Although some loss of muscle mass with age is inevitable, working your muscles against resistance reduces muscle and strength losses significantly. Researchers have identified a protein, called ATF4. that plays a role in the age-related loss of strength and muscle tissue – and guess what foods contain a chemical that blocks this protein? Apples and green tomatoes.
It’s hard to argue with the nutritional benefits of apples. When you bite into a crunchy apple, you’re meeting 14% of your day’s requirements for vitamin C, getting 4 grams of fiber and bathing your body with tons of natural anti-inflammatory chemicals and antioxidants. Plus, a medium apple has only 95 calories.
Unique Compounds in Apples and Green Tomatoes May Prevent Muscle Loss
Here’s something else you need to know about apples. According to this study, apples contain a chemical called ursolic acid that has an unusual function. It blocks ATF4, the protein that plays a key role in the breakdown of skeletal muscle. In addition, researchers have identified another natural compound called tomatine, abundant in green tomatoes, which suppresses muscle breakdown during periods of inactivity and starvation.
Can these natural dietary compounds slow down muscle aging or even prevent sarcopenia? Preliminary research looks encouraging. In aging mice, these compounds increased muscle mass and strength by 10% and 30% respectively, enough to make them more youthful from a muscle health standpoint.
The question is whether you can get enough of these compounds naturally from foods or whether you need a more concentrated source like an extract or supplement. Scientists are already looking into the possibility of creating concentrated versions of these compounds as a way to slow down muscle aging. Ursolic acid is abundant in the outer skin of apples, so to get ursolic acid naturally, don’t peel your apples. Also, make sure you’re buying organic apples since they’re not heavily sprayed with pesticides.
Ursolic acid from apples has another potential benefit as well. In studies carried out on mice, ursolic acid turns on brown fat, a kind of inefficient fat that generates heat and gives your metabolism a boost. Mice that got ursolic acid in their diet gained less body fat and lost less muscle, and actually became stronger. That’s a satisfying combination!
Ways to Prevent Sarcopenia
As mentioned, the number one thing you can do to ward off sarcopenia and stay functional as you age is to strength train. When you work your muscles against resistance, your muscles adapt by growing larger and becoming stronger. That’s important since muscles decrease in size as you age as functional muscle tissue is replaced with fat. Because of the total number of functional motor units decreases, you lose strength as well as muscle size.
The type of muscle fibers most affected by aging are fast-twitch fibers, the ones that generate force and power. Slow-twitch fibers, the ones involved in endurance, are less affected. To preserve fast-twitch muscle fibers, focus on heavy resistance training and power movements like plyometrics and kettlebells.
Other Dietary Factors that Contribute to Sarcopenia
As you age, you may need to consume more protein to preserve lean body mass, especially if you exercise. With age, you develop anabolic resistance, meaning your muscles become less responsive to the protein you take in through diet. As a result, you need to add more protein to your diet and consume it at regular intervals.
The best approach is to take in 20 to 30 grams of protein at every meal. In addition, some studies show exercise helps combat anabolic resistance. Of the dietary amino acids, one of the most important is leucine since it turns on the mTOR pathway, a pathway involved in muscle protein synthesis. In fact, the effects of leucine on muscle protein synthesis is 10-times greater than any other amino acid. Leucine is a type of branched-chain amino acid abundant in animal-based protein sources as well as eggs, egg whites, cheese, and fish. Keep in mind, you must get leucine from dietary sources since it’s an essential amino acid your body can’t make.
Especially as we age, it’s important to get ENOUGH calories. If you don’t consume sufficient calories, you lose weight and a portion of that weight comes from muscle tissue. Even if you’re trying to lose weight, it’s not a good idea to create a large calorie deficit, especially if you’re over the age of 50.
Interestingly, antioxidants may play a role in preventing sarcopenia. Some research suggests that oxidative damage contributes to loss of muscle tissue with age – a good reason to eat more fruits and vegetables. In addition, some studies show long-chain, omega-3 fatty acids stimulate muscle protein synthesis and help preserve strength.
The Role of Vitamin D in Sarcopenia
These days you hear a lot about vitamin D and the role it plays in health. People who are deficient in vitamin D experience muscle weakness and fatigue and supplementation with vitamin D improves muscle strength. This raises the question as to whether vitamin D at least partially protects against sarcopenia. Some studies have found a link between low vitamin D and sarcopenia, although it’s not clear whether low vitamin D actually CAUSES sarcopenia. Still, you want to avoid a vitamin D deficiency.
The Bottom Line?
Sarcopenia is a serious health problem that’s now at epidemic proportions and it’s clearly a lifestyle disease. Eat your fruits and vegetables, including apples and green tomatoes, but make sure you’re getting enough protein, long-chain omega-3s, and vitamin D as well to keep your muscles strong and healthy.
References:
Iowa Now. “Keeping older muscles strong”
Curr Opin Clin Nutr Metab Care. 2009 Jan; 12(1): 86-90. doi: 10.1097/MCO.0b013e32831cef8b.
Endocrinol Metab 88:5766-5772 Abstract, Medline, Google Scholar
Today’s Dietitian. Vol. 14 No. 9 P. 62. September 2012.
Clinical Endocrinology. Volume 73, Issue 5. November 2010. Pages 581-587.
BMC Physiology 2011, 11:10 doi:10.1186/1472-6793-11-10.
Clin Calcium. 2014 Oct;24(10):1527-33. doi: CliCa141015271533.
Acta Biomedica, vol. 81, supplement 1, pp. 37-45, 2010.
Am J Clin Nutr. 2012 Feb;95(2):428-36. doi: 10.3945/ajcn.111.021915. Epub 2012 Jan 4.
J Nutr Health Aging. 2013 Jan;17(1):82-9. doi: 10.1007/s12603-012-0389-1.
Related Articles By Cathe:
The Strange Ingredient in Apples That May Help with Muscle Hypertrophy
5 Tips for Building Muscle When You Eat a Plant-Based Diet
Is Muscle Loss the Only Reason Your Metabolism Slows with Age?
