Written by Jessica Patella, ND. This is a study of 51 elderly participants who consumed 20 grams of a protein supplement daily. There was an increase in a hormone by 45.8% which plays a beneficial role in bone health. Additionally, protein supplementation with zinc was beneficial for bone health.
An estimated 35-50% of older residents in long-term care facilities are malnourished (1). And, as many as 65% of elderly in hospitals are malnourished (1). Research shows sufficient nutrient and protein intakes are important for bone health and for reducing the risk of osteoporosis, a major concern for the elderly (2). A recent study has shown that supplementation with zinc and whey protein decreased markers for bone breakdown in frail elderly (3).
Insulin-like growth factor (IGF-1) is a hormone that plays a role in bone health. Dietary proteins and zinc have been shown to increase insulin-like growth factor (IFG-1), thereby decreasing the risk of bone loss (3).
The present study assessed the effect of zinc and protein supplements on insulin-like growth factor (IFG-1) levels and bone health markers in undernourished, elderly participants. A total of 51 participants completed the study. The average age was 85 years (ranging from 66.7 to 105.8 years) and 85% were women (3).
A total of 5 participants acted as controls and were not given any supplementation. The rest of the 47 participants were given a daily dose of 20 g protein supplement (15 g whey protein; 5 g essential amino acids; 550 mg calcium). A random selection resulted in half the protein supplemented participants also receiving 30 mg per day of oral zinc added to the protein powder. The protein was given in the evening or throughout the day for four weeks.
At the end of four weeks, IGF-1 decreased by 16.8 % in the untreated controls indicating an increased risk of bone loss (91.4 +-21.5 vs 54.8 +/- 16.8 mcg/l) (3).
In contrast, IGF-1 increased in the protein supplement group by 45.8%, reaching a plateau by the second week of supplementation, indicating a decrease in the risk of bone loss (73.3 +/- 8.3 vs. 107.8 +/- 15.5; p=0.0001).
IGF-1 increased even more rapidly in the zinc and protein group, reaching significance by week 1 (p=0.027), indicating a more rapid decrease in the risk of bone loss. At the end of four weeks, there was no difference with or without zinc on IGF-1 levels (zinc+ protein at baseline: 82.6 +/- 9.0; 1-week: 110.3 +/- 3; 4-weeks: 101.5 +/-11.2 mcg/l; total 29.2% increase) (3).
Bone resorption or breakdown was measured by the marker called CrossLaps. This remained stable in the control group, but decreased significantly in the zinc and protein group by week 2, indicating a decrease in bone loss (baseline: 0.56 +/- 0.04; 2-weeks 0.46 +/- 0.04 ng/ml; p<0.05) (3).
In conclusion, both protein supplements increased IGF-1 in undernourished elderly participants. Protein supplementation with zinc also decreased bone breakdown markers (3). In addition, protein supplementation with zinc accelerated the increase in IGF-1, which would be desirable for recovery after surgery or in rehabilitation of undernourished elderly (3). Researchers conclude that the combination of protein and zinc is beneficial for frail elderly at risk of an osteoporotic fracture, although future research should confirm the results (3).
Source: Rodondi, A., et al. “Zinc increases the effects of essential amino acids-whey protein supplements in frail elderly.” The journal of nutrition, health & aging 13.6 (2009): 491-497.
© 2017 Springer International Publishing AG. Part of Springer Nature.
Posted June 20, 2013.
Jessica Patella, ND, is a naturopathic physician specializing in nutrition and homeopathic medicine and offers a holistic approach to health. She earned her ND from Southwest College of Naturopathic Medicine in Tempe, AZ, and is a member of the North Carolina Association of Naturopathic Physicians. Visit her website at www.awarenesswellness.com.
References:
- Malnutrition and Older Americans. National Resource Center on Nutrition, Physical Activity and Aging.
- Rizzoli R, Bonjour J P. Dietary protein and bone health. J Bone Miner Res 2004; 19: 527-531. Rodondi A, et al.
- Zinc Increases the Effects of Essential Amin-Acids-Whey Protein Supplements in Frail Elderly. 2009; 13: 491-497.
