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Objective: Age related hearing loss (ARHL) or presbyacusis is a complex condition caused by an interaction between environmental and genetic factors and is the most prevalent sensory impairment in the elderly. To date, only few environmental/lifestyle risk factors have been found. Research into risk factors underlying ARHL is increasingly urgent as populations grow older. Here, we investigate the relationship between ARHL and educational/occupational factors in a large cohort of people from isolated villages in Italy, Crimea region, Caucasus and Central Asia. Methods: Two thousand and sixty-eight people (aged 40-95 years) were recruited and analysed. Education was classified at five levels: no education, elementary, secondary, high school and university. Cases and controls were defined after a detailed evaluation of the hearing phenotype. Data were analysed using a mixed-effects logistic regression. Results: A statistically significant association between ARHL and education was detected. People with no education showed a higher association with the condition than people with a higher education ( p < 0.001). Explanations could be many, including individual jobs. A strong correlation (φ > 0.45) between occupation and level of education was also found. Conclusion: Present findings provide a better knowledge of environment/lifestyle factors related to ARHL and might help in defining new preventive strategies for aging people. [ABSTRACT FROM AUTHOR]

Food preferences are the main factor driving food intake and choice. There are good reasons to suspect some genetic influence on food acceptance, not least because genetic factors are implicated in a number of factors that are likely to be related to food choice. In addition, some food dislikes show themselves early in life, before there is any evidence for aversive experiences. Although taste has been widely studied in regards of pure tastes such as bitter or sweet perception, the relationship between taste-related genes and food preferences has seldom been explored. In this work we investigated relationship of 37 taste-related genes with food preferences. The study was carried out during a scientific expedition through Caucasus and Central Asia (Silk Road) analyzing more than 400 samples from 5 different countries. A food preference questionnaire was administered to each participant and a DNA sample was obtained. Other information, such as age, sex, life style and anthropometrical measures, were also collected. We found significant associations with variants of: (1) TAS1R2 [Correction added after initial online publication on 27 Aug 2012. TAS1R3 was changed to TAS1R2.] gene and liking of Vodka ( P= 1.6 × 10−3), white wine ( P= 4.0 × 10−4) and lamb meat ( P= 1.6 × 10−3); (2) PCLB2 gene and preference for Hot Tea ( P= 8.0 × 10−4); (3) TPRV1 gene and beet liking ( P= 3.8 × 10−5); and (4) ITPR3 gene and liking of both lamb meat (5.8 × 10−4) and sheep cheese (8.9×10−4). These findings give a new insight on a better understanding, of genetic factors influencing food preferences which is critical to the development of effective dietary interventions, especially for people that may be genetically not predisposed for liking specific nutrients. [ABSTRACT FROM AUTHOR]

Eye colour is a highly transmissible and discernible trait in humans. A genome-wide association scan for variants associated to eye pigmentation was carried out on a large group of individuals coming from the Silk Road. Significant associations were detected not only with HERC2 (P-value=4.99 × 10(-37)) and OCA2 (P-value=4.51 × 10(-9)) genes but also with CTNNA2 gene (P-value=4.06 × 10(-8)). Moreover, the multifactor dimensionality reduction analysis clearly showed the effect of HERC2 haplotype over OCA2 mostly associated with SNP, thus enabling a highly accurate eye-colour prediction. Finally, the regression tree analysis showed that individuals carrying a given combination of haplotypes have a significant probability to show a blue or green/grey iris colour as compared with brown, with a gradient from west to east.