Physical activity attenuates the influence of FTO variants on obesity risk: A meta-analysis of 218,166 adults and 19,268 children

Background: The FTO gene harbors the strongest known susceptibility locus for obesity. While many individual studies have suggested that physical activity (PA) may attenuate the effect of FTO on obesity risk, other studies have not been able to confirm this interaction. To confirm or refute unambiguously whether PA attenuates the association of FTO with obesity risk, we meta-analyzed data from 45 studies of adults (n = 218,166) and nine studies of children and adolescents (n = 19,268). Methods and Findings: All studies identified to have data on the FTO rs9939609 variant (or any proxy [r2>0.8]) and PA were invited to participate, regardless of ethnicity or age of the participants. PA was standardized by categorizing it into a dichotomous variable (physically inactive versus active) in each study. Overall, 25% of adults and 13% of children were categorized as inactive. Interaction analyses were performed within each study by including the FTO×PA interaction term in an additive model, adjusting for age and sex. Subsequently, random effects meta-analysis was used to pool the interaction terms. In adults, the minor (A-) allele of rs9939609 increased the odds of obesity by 1.23-fold/allele (95% CI 1.20-1.26), but PA attenuated this effect (pinteraction= 0.001). More specifically, the minor allele of rs9939609 increased the odds of obesity less in the physically active group (odds ratio = 1.22/allele, 95% CI 1.19-1.25) than in the inactive group (odds ratio = 1.30/allele, 95% CI 1.24-1.36). No such interaction was found in children and adolescents. Concl

Peat in horticulture and conservation: the UK response to a changing world

Peat bogs are increasingly recognised as valuable habitats for wildlife and important stores of carbon. Yet the UK horticultural industry relies heavily on peat sourced from bogs in the UK and Republic of Ireland. Environmentalists, government and horticultural businesses in the UK now recognise the environmental consequences of using peat in horticulture, and the industry is turning increasingly to sustainable raw materials. In this paper, the strengths and weaknesses of campaigning since 1990 to implement this change are analysed, with the intention of providing useful information for other countries facing similar challenges. The campaign encountered deeply-ingrained practices so that the shift in behaviour has been slow and, although now widespread, still meets resistance in some quarters. The UK Government introduced targets for peat replacement which have helped stimulate the industry to develop suitable alternatives. The major gardening retailers have included peat replacement targets in their environmental codes of practice, and these are being met through incremental peat dilution with alternative materials such as green compost and processed timber by-products. Legislative requirements for European biodiversity conservation have led the UK government to terminate peat extraction on significant areas of former commercial extraction. The importance of peatlands for carbon sequestration and the major issue of climate change are increasingly focusing attention on peatland conservation, pointing towards the need for a more consistent approach to the use of peat across the European Community