The Effect of Elevated Protein Intake on DNA Damage in Older People: Comparative Secondary Analysis of Two Randomized Controlled Trials.

A high protein intake at old age is important for muscle protein synthesis, however, this could also trigger protein oxidation with the potential risk for DNA damage. The aim of this study was to investigate whether an increased protein intake at recommended level or well above would affect DNA damage or change levels of reduced (GSH) and oxidised glutathione (GSSG) in community-dwelling elderly subjects. These analyses were performed in two randomized intervention studies, in Austria and in New Zealand. In both randomized control trials, the mean protein intake was increased with whole foods, in the New Zealand study (n = 29 males, 74.2 ± 3.6 years) to 1.7 g/kg body weight/d (10 weeks intervention; p < 0.001)) in the Austrian study (n = 119 males and females, 72.9 ± 4.8 years) to 1.54 g/kg body weight/d (6 weeks intervention; p < 0.001)). In both studies, single and double strand breaks and as formamidopyrimidine-DNA glycosylase-sensitive sites were investigated in peripheral blood mononuclear cells or whole blood. Further, resistance to H2O2 induced DNA damage, GSH, GSSG and CRP were measured. Increased dietary protein intake did not impact on DNA damage markers and GSH/GSSG levels. A seasonal-based time effect (p < 0.05), which led to a decrease in DNA damage and GSH was observed in the Austrian study. Therefore, increasing the protein intake to more than 20% of the total energy intake in community-dwelling seniors in Austria and New Zealand did not increase measures of DNA damage, change glutathione status or elevate plasma CRP.

The Saliva of Probands Sucking an Iota-Carrageenan Containing Lozenge Inhibits Viral Binding and Replication of the Most Predominant Common Cold Viruses and SARS-CoV-2.

PURPOSE: The aim of this study was to investigate whether sucking of an iota-carrageenan containing lozenge releases sufficient iota-carrageenan into the saliva of healthy subjects to neutralize representatives of the most common respiratory virus families causing common cold and SARS-CoV-2. PATIENTS AND METHODS: In this monocentric, open label, prospective clinical trial, 31 healthy subjects were included to suck a commercially available iota-carrageenan containing lozenge. Saliva samples from 27 subjects were used for ex vivo efficacy analysis. The study's primary objective was to assess if the mean iota-carrageenan concentration of the saliva samples exceeded 5 µg/mL, which is the concentration known to reduce replication of human rhinovirus (hRV) 1a and 8 by 90%. The iota-carrageenan concentration of the saliva samples was analyzed by UV-Vis spectroscopy. The antiviral effectiveness of the individual saliva samples was determined in vitro against a panel of respiratory viruses including hRV1a, hRV8, human coronavirus OC43, influenza virus A H1N1pdm09, coxsackievirus A10, parainfluenza virus 3 and SARS-CoV-2 using standard virological assays. RESULTS: The mean iota-carrageenan concentration detected in the saliva exceeds the concentration needed to inhibit 90% of hRV1a and hRV8 replication by 134-fold (95% CI 116.3-160.8-fold; p < 0.001). Thus, the study met the primary endpoint. Furthermore, the iota-carrageenan saliva concentration was 60 to 30,351-fold higher than needed to reduce viral replication/binding of all tested viruses by at least 90% (p < 0.001). The effect was most pronounced in hCoV OC43; in case of SARS-CoV-2, the IC90 was exceeded by 121-fold (p < 0.001). CONCLUSION: Sucking an iota-carrageenan containing lozenge releases sufficient iota-carrageenan to neutralize and inactivate the most abundant respiratory viruses as well as pandemic SARS-CoV-2. The lozenges are therefore an appropriate measure to reduce the viral load at the site of infection, hereby presumably limiting transmission within a population as well as translocation to the lower respiratory tract. TRIAL REGISTRATION: NCT04533906.