Here’s a frightening statistic. According to Today’s Dietitian, around one in five adults over the age of 60 have some degree of disability. Here’s another shocker. The risk of being disabled is 1.5 to 4.6 times higher in people with sarcopenia. In fact, around half of all adults over the age of 80 have sarcopenia that make them less functional.
What is sarcopenia? It’s the age-related loss of muscle mass, and it becomes more common with age. Although some muscle loss is inevitable with aging, there’s much you can do from a lifestyle standpoint to preserve muscle and strength so you can avoid becoming less functional as the years go by.
Although sarcopenia isn’t a disease, it’s damaging to health and well-being. When you lose muscle and muscle strength, your risk for injury rises, and the odds of losing your independence rises too. Loss of muscle mass also has repercussions for metabolic health. When you lose muscle, insulin sensitivity falls too. When you have less muscle, there’s less muscle to take up glucose from the bloodstream. So, muscle loss because of sarcopenia contributes to insulin resistance and an increased risk of type 2 diabetes.
Muscle Loss, Myostatin, and Inflammation
Why do we lose muscle mass with age? Myostatin plays a key role in muscle loss related to aging. Myostatin is a myokine, a hormone-like protein released by muscle cells, that prevents skeletal muscles from growing too large. It puts the brakes on muscle growth. In fact, animals that lack myostatin develop very large muscles, to the point they’re unhealthy and have a shortened lifespan. When you’re young, you have lower levels of myostatin and that favors muscle growth. When you get older and myostatin increases, muscle growth becomes more limited.
Another factor that contributes to sarcopenia is inflammation. As we age, inflammation increases. That’s not a positive for your health, but low-grade inflammation also reduces muscle protein synthesis. Other factors include a drop in hormones that contribute to muscle protein synthesis, like testosterone and growth hormone, and anabolic resistance.
What about dietary factors? It’s clear that not getting enough protein will worsen sarcopenia, but what about eating foods high in sugar? Let’s look at what science shows about sarcopenia and diets high in sugar.
Does a Diet High in Sugar Worsen Sarcopenia?
Sugar temptations and refined carbohydrates are a constant temptation for many people. Therefore, it’s not surprising that most people get more sugar in their diet than the amount experts recommend – only 10% of calories from sugar. According to the American Heart Association, American children and adults greatly exceed that amount. Adults consume around 77 grams of sugar per day while children knock down 81 grams of the sweet stuff daily from sugary beverages and snacks.
Is there a link between eating sugar and sarcopenia? Yes, at least an indirect link. People who have type 2 diabetes experience a greater loss of muscle mass and strength as they age than non-diabetics. In one study, diabetics who had wide fluctuations in blood glucose experienced more profound loss of muscle strength and mass than those who had more stable blood glucose levels.
A diet high in sugar increases the risk of obesity and type 2 diabetes, and those are risk factors for sarcopenia. But is there a more direct link between sugar and sarcopenia? In a rat study, animals that ate a diet high in sugar had less muscle mass and more body fat than those who ate a diet low in sugar. Plus, the animals that munched on low-sugar fare had higher rates of muscle protein synthesis after their meals. Greater synthesis of muscle proteins and less muscle protein breakdown is the key to preventing sarcopenia. When you don’t consume enough protein, there are less available amino acids to use for muscle protein synthesis.
Another problem with diets high in sugar is they’re low on the nutritional scale since sugar contains no nutrients, only calories. When you eat a diet high in sugar, you crowd out healthier food sources that contain the protein your body needs to build new muscle tissue. There’s also some evidence that long-chain omega-3s from fatty fish, like salmon, reduces muscle loss by countering anabolic resistance. So, a meal of salmon and non-starchy vegetables is better for preserving muscle mass and preventing sarcopenia than a meal from a fast-food restaurant.
Make sure you’re getting enough of vitamin D, the sunshine vitamin, too. Studies show a link between vitamin D and muscle strength. The risk of vitamin D deficiency rises with age, too. When in doubt, check a vitamin D level to make sure you’re not deficient.
The Bottom Line
The best approach to prevent sarcopenia due to aging is to:
- Stay physically active and train with weights.
- Eat an anti-inflammatory diet that contains as little sugar and as few refined carbohydrates as possible.
- Increase your protein intake slightly after the age of 60.
- Maintain a healthy body weight.
- If you’re diabetic, control your blood sugar level.
- Add omega-3s to your diet from sources such as fatty fish. (also a good source of protein)
- Manage stress (Stress increases cortisol and that increases muscle breakdown)
- Get adequate sleep to lower cortisol.
- Maintain a healthy vitamin D level.
If you do the things listed above, you will have a better chance of maintaining lean muscle mass and avoiding the gain in body fat that comes with aging.
References:
- Shou, J., Chen, PJ. & Xiao, WH. Mechanism of increased risk of insulin resistance in aging skeletal muscle. Diabetol Metab Syndr 12, 14 (2020). https://doi.org/10.1186/s13098-020-0523-x
- Siriett V, Platt L, Salerno MS, Ling N, Kambadur R, Sharma M. Prolonged absence of myostatin reduces sarcopenia. J Cell Physiol. 2006 Dec;209(3):866-73. doi: 10.1002/jcp.20778. PMID: 16972257.
- Ogama N, Sakurai T, Kawashima S, et al. Association of Glucose Fluctuations with Sarcopenia in Older Adults with Type 2 Diabetes Mellitus. J Clin Med. 2019;8(3):319. Published 2019 Mar 6. doi:10.3390/jcm8030319.
- com. “New Study Finds Link Between Sarcopenia and Type 2 Diabetes”
- “Nutrition’s Role in Sarcopenia Prevention” Becky Dorner, RD, LD, and Mary Ellen Posthauer, RD, LD, CD. Today’s Dietitian. Vol. 14 No. 9 P. 62.
- org. “How much sugar is too much?”
- Dhillon RJ, Hasni S. Pathogenesis and Management of Sarcopenia. Clin Geriatr Med. 2017;33(1):17-26. doi:10.1016/j.cger.2016.08.002.
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