L-Glutamine Supplementation Improves the Benefits of Combined-Exercise Training on Oral Redox Balance and Inflammatory Status in Elderly Individuals

Abstract

Although regular combined aerobic-resistance exercises can ameliorate the inflammatory status and redox balance in elderly population, it is unclear whether protein or specific amino acid supplementation could improve such benefits. Therefore, we aimed to evaluate the inflammatory status and redox indexes through of the saliva of 34 elderly subject nonpractitioners (NP group, 73.3±6.6 years) and 49 elderly subject practitioners of a combined-exercise training in moderate intensity (CET group, 71.9±5.8 years) before (pre) and after (post) 30 days of supplementation with L-glutamine (Gln) or placebo (PL). Our results showed that, both in pre- and postsupplementation, the salivary levels of nitric oxide (NO⋅) and TNF-α were lower, whereas the levels of uric acid and IL-10 (as well as IL-10/TNF-α ratio) were higher in the CET groups than in the NP groups. In postsupplementation, both groups supplemented with Gln (NP-Gln and CET-Gln) showed higher salivary uric acid levels compared to baseline. In addition, lower NO⋅ levels were found in the CET-Gln group postsupplementation than presupplementation values. Whereas the CET-Gln group showed lower GSH levels postsupplementation, NP-Gln subjects showed lower GSSG levels at the same time point, both compared to baseline. Interestingly, salivary peroxidase activity was lower only in NP groups (NP-PL and NP-Gln) postsupplementation than baseline values. A positive significant correlation between salivary peroxidase activity and GSH levels, and also between salivary peroxidase activity and uric acid levels were observed in the CET-Gln group both pre- and postsupplementation. No differences were found in albumin, total antioxidant activity (TEAC), and reducing power analysis between groups, pre- or postsupplementation. In conclusion, the elderly subjects from the CET group showed a better inflammatory response and redox balance and, for the first time, it was shown that daily supplementation with Gln for 30 days can improve these benefits with putative association with a healthy aging.

Elderly Subjects Supplemented with L-Glutamine Shows an Improvement of Mucosal Immunity in the Upper Airways in Response to Influenza Virus Vaccination

“…In spite of the literature showing a gap of data concerning the effects of Gln supplementation in the SIgA production, particularly in the mucosa of the upper airways, recently, our group was able to demonstrate that elderly practitioners of combined exercise training that were supplemented with Gln presented an improvement of some antioxidant parameters [ 15 ]. Corroborating this beneficial effect of Gln in elderly subjects, another study developed by our group, also recently published [ 14 ], in which the same group of elderly practitioners of combined exercise training was evaluated, the Gln supplementation was able to increase the levels of specific antibodies, particularly IgM and IgA, for the influenza virus vaccine.…”

“…In relation to the mucosa of the upper airway, it has been demonstrated that the oral Gln supplementation showed the capacity to modulate the production of pro- and anti-inflammatory cytokines by elevating the salivary levels of IL-10 and decreasing the TNF-alpha after an exhaustive exercise session [ 58 ]. However, Almeida et al [ 15 ] recently showed that Gln supplementation for 30 consecutive days did not change the salivary levels of IL-10 and TNF-alpha in an elderly population.…”

“…All volunteers were selected and recruited from the Discipline of Geriatrics and Gerontology belonged to the Federal University of São Paulo (UNIFESP). It is worth mentioning that the overwhelming majority of them have participated in other studies recently published by our group [ 14 , 15 ]. None of them took any antioxidant/multivitamin supplements and had a diet with a protein intake of more than 1.75 g/kg body mass at the time of the study; moreover, no participants used anti-inflammatory drugs in the last two months.…”

“…The volunteers participating in this study were separated into two groups: the L-glutamine group (Gln, n = 42) and the placebo group (PL, n = 41), following the same supplementation schedule previously reported by our group [ 15 ]. Briefly, the Gln group was supplemented with 0.3 g/kg/day of L-glutamine (Tongliao Meihua Biological Sci-Tech Co. Ltd., Tongliao, China) plus 10 g/day of maltodextrin (PR Netto Indústria e Comércio de Alimentos Ltd.a., São Paulo, Brazil), while the PL group were supplemented with 10 g/day of maltodextrin only.…”

“…In this respect, recently, our group was able to demonstrate that a group of elderly subjects supplemented with L-glutamine showed enhancement of both humoral and cellular immunity against influenza virus vaccination [ 14 ]. Furthermore, we also showed that oral L-glutamine supplementation presents a notable capacity to modulate oxidative stress and inflammation and to improve salivary redox indexes in the same group of elderly subjects [ 15 ]. It is paramount to highlight that glutamine (Gln) is a non-essential amino-acid preferentially produced by the musculoskeletal tissue that presents pleiotropic actions in many systems, especially in the immune system.…”