Have a look at Nutrition
Sarcopenia is one of the major health conditions that causes decline in quality of life in senior population. Sarcopenia, which was covered in a previous blog, is a gradual loss of muscle mass, typically with aging at 1-2% per year starting around age of 50 (Marcell, 2003). The lack of muscle mass maintenance and strength escalates the tendency to fall, leading to increased risk of fractures and injuries! Performing exercise regularly helps maintaining healthy physical status, especially resistance training, but keeping optimal daily nutrition is also very important to aid in recovery and muscle growth from each workout and thereby maintaining muscle functions. Thus we are going to review three nutritional tips that may be beneficial for preventing muscle loss and other detrimental physical changes with aging.
There are several nutritional strategies that are considered beneficial if you apply it to your daily diet. First, make sure of having sufficient intake amount of vitamin D. Vitamin D is well-known for the role of regulating calcium level and maintaining phosphorus level in the blood which are important for our bone health. However, it also takes substantial part in improving muscle strength. According to Ceglia (2009), poor vitamin D status is associated with worse muscle functions whereas sufficient vitamin D intake leads to increase in the rate of muscle-protein synthesis (MPS), which is responsible for maintaining and gaining muscle mass. As well, it is found in another study that vitamin D increases fast-twitch muscle fiber (used in powerful bursts of movement, such as sprinting) size and decreases muscle inflammation (Girgis et al., 2013). Until you reach 70 years old Recommended Daily Allowance (RDA) for vitamin D is 600IU/day and it goes up to 800IU/day after 70 (Health Canada, 2012). Since vitamin D mainly comes from your skin when it gets exposed to sunlight, it will be challenging for people, who do not spend sufficient time under sunlight, to meet the recommended daily amount of vitamin D. We can only get moderate amount of vitamin D just from food sources so consuming vitamin D supplements may be useful to meet the required daily amount especially for those who spend most of the day indoor with several possible reasons such as overnight work hours, health status, and so on.
Research suggests sufficient intakes of high quality protein (rich in leucine) is beneficial for enhancing MPS in senior population. RDA for optimal daily protein intake for senior population, proposed by Health Canada, is 1.0-1.2g/kg/day whereas it’s 0.8g/kg/day for young adults. Older adults have lower responsiveness for anabolic effects (i.e. promoting cell growth) with amino acids intake compared to younger adults (Greig, 2013). This anabolic resistance can be effectively overcome with higher intake of protein, which is why RDA for daily protein intake is higher for seniors, in combination with resistance exercises (Greig, 2013). Consuming the recommended amount of protein as a form of whole food is the best option however there are many other options easily accessible these days such as protein powder and energy bar. Caution should be used for people with kidney disease or high levels of uric acid when consuming animal protein as dysfunctional kidney would not be able to filter all the waste products from protein metabolism resulting in other medical issues (Scialla and Anderson, 2013). Using plant derived proteins can be a good alternative for those with kidney issues, of course, after a consultation with physician or other qualified health professionals. If you are wondering what kind of food to start off with, tuna, salmon, chicken or turkey, and eggs are good start. You can also eat red meat in moderation but people with inflammatory related health issues should be cautious with the amount they consume (Severi, 2018).
Sufficient protein intake is essential for seniors and yet, many of food sources for protein often are acidic which may make our body harder to stay in slightly alkaline state. Having slightly alkaline pH level is known to be ideal for our body’s ability to maintain or grow muscle mass (Schwalfenberg, 2012). Thus, keeping the balance between intake of acid-producing nutrient such as meat and intake of alkalizing food such as fruits and vegetables is important. There was a three-year study done with older adults with reduced acid load diet and it was found that the alkaline diet resulted in preservation of their muscle mass (Schwalfenberg, 2012). The justification for the result is that as high dietary acid loads induce low-grade acidosis which may lead to muscle loss, lowering the dietary acid load led the participants of the study to preservation of their muscle mass (Schwalfenberg, 2012). It also suggests that the correction of acidosis may preserve muscle mass in conditions, such as diabetic ketosis and renal failure, which includes muscle wasting as one of their consequences. Consuming meat is important as it is a good source of complete protein and same goes for fruits and vegetable as it is a source of healthy carbohydrate that come with essential vitamins and minerals.The problem usually arises not from a particular food but from the cumulative effect of highly acidic diet so always eating with higher ratio in alkalizing food relative to acidic is the key. As acidic food also provides other kinds of benefits that are definitely crucial to maintain our overall health, we must make sure that our diet is never one-sided but in good balance.
References
Ceglia L. (2009). Vitamin D and Its Role in Skeletal Muscle. Current opinion in clinical nutrition and metabolic care. 2009;12(6):628-633. doi:10.1097/MCO.0b013e328331c707.
Kelly, J. T., & Carrero, J. J. (2017). Dietary Sources of Protein and Chronic Kidney Disease Progression: The Proof May Be in the Pattern. Journal of Renal Nutrition, 27(4), 221-224. doi:10.1053/j.jrn.2017.04.001
Girgis, C. M., Clifton-Bligh, R. J., Hamrick, M. W., Holick, M. F., & Gunton, J. E. (2013). The Roles of Vitamin D in Skeletal Muscle: Form, Function, and Metabolism. Endocrine Reviews, 34(1), 33-83. doi:10.1210/er.2012-1012
Greig, C. A. (2013). Nutritional approaches to the management of sarcopenia. Nutrition Bulletin, 38(3), 344-348. doi:10.1111/nbu.12046
Health Canada. (2012, March 22). Vitamin D and Calcium: Updated Dietary Reference Intakes. Retrieved from https://www.canada.ca/en/health-canada/services/food-nutrition/healthy-eating/vitamins-minerals/vitamin-calcium-updated-dietary-reference-intakes-nutrition.html
International Osteoporosis Foundation. (2013, January 18). Which nutritional factors help preserve muscle mass, strength and performance in seniors?. ScienceDaily. Retrieved June 26, 2018 from www.sciencedaily.com/releases/2013/01/130118111714.htm
Marcell, T. J. (2003, October 01). Review Article : Sarcopenia: Causes, Consequences, and Preventions | The Journals of Gerontology: Series A | Oxford Academic. Retrieved from https://doi.org/10.1093/gerona/58.10.M911
Pfeifer, M., Begerow, B., & Minne, H. W. (2002). Vitamin D and Muscle Function. Osteoporosis International, 13(3), 187-194. doi:10.1007/s00198020001
Schwalfenberg, G. K. (2012). The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health? Journal of Environmental and Public Health, 2012, 727630. http://doi.org/10.1155/2012/727630
Scialla, J. J., & Anderson, C. A. M. (2013). Dietary acid load: A novel nutritional target in chronic kidney disease? Advances in Chronic Kidney Disease, 20(2), 141–149. http://doi.org/10.1053/j.ackd.2012.11.001
Severi, C. (2018). Faculty of 1000 evaluation for Meat intake and risk of diverticulitis among men. F1000 - Post-publication Peer Review of the Biomedical Literature. doi:10.3410/f.727191472.793547279
Sherwood, L. (2015). Human physiology: From cells to systems. Australia: Brooks/Cole.