Nutraceutical Supplementation: Effect of a Fermented Papaya Preparation on Redox Status and DNA Damage in Healthy Elderly Individuals and Relationship with GSTM1 Genotype A Randomized, Placebo-Controlled, Cross-Over Study

Our study group consisted of 54 elderly patients without major invalidating diseases who were randomly divided into two fully matched groups. Group A was given a certified fermented papaya prepa- ration 9 g/day by mouth, while group B received placebo. Treatment was carried out in a cross-over manner with a 3-month supplementation fol- lowed by a 6-week washout period. Blood samples were drawn at entry and on a monthly basis to check routine parameters, redox status, and 8- OHdG in circulating leukocyte DNA. Polymorphism analysis of GSTM1 was carried out as well. The glutathune-S transferase M1 (GSTM1) geno- type was null (−) in 40% and 46% of groups A and B, respectively. GSTM1 (−) smokers had a significantly higher level of plasma DNA adducts and leukocytes level of 8-OHdG than their GSTM1 (+) coun- terparts (P < 0.01). There was a weak correlation between cigarettes smoked/day and DNA adduct (r: 0.61, P < 0.05), which also correlated with antioxidant concentrations, but only in GSTM1 (−) smokers (P < 0.01). The fermented papaya preparation (FPP)-supplemented group showed a significant enhancement of the antioxidant protection (P <