A LINE-1 component to human aging: Do LINE elements exact a longevity cost for evolutionary advantage?

Advancing age remains the largest risk factor for devastating diseases, such as heart disease, stroke, and cancer. The mechanisms by which advancing age predisposes to disease are now beginning to unfold, due in part, to genetic and environmental manipulations of longevity in lower organisms. Converging lines of evidence suggest that DNA damage may be a final common pathway linking several proposed mechanisms of aging. The present review forwards a theory for an additional aging pathway that involves modes of inherent genetic instability. Long interspersed nuclear elements (LINEs) are endogenous non-LTR retrotransposons that compose about 20% of the human genome. The LINE-1 (L1) gene products, ORF1p and ORF2p, possess mRNA binding, endonuclease, and reverse transcriptase activity that enable retrotransposition. While principally active only during embryogenesis, L1 transcripts are detected in adult somatic cells under certain conditions. The present hypothesis proposes that L1s act as an ‘endogenous clock’, slowly eroding genomic integrity by competing with the organism’s double-strand break repair mechanism. Thus, while L1s are an accepted mechanism of genetic variation fueling evolution, it is proposed that longevity is negatively impacted by somatic L1 activity. The theory predicts testable hypotheses about the relationship between L1 activity, DNA repair, healthy aging, and longevity

Dietary determinants of childhood obesity : the role of the family

Original article can be found at : http://www.remedicajournals.com/ Copyright Remedica Medical Education and Publishing Ltd. (UK) [Full text of this article is not available in the UHRA]The article reviews the evidence regarding the role of the family in determining dietary risk factors for childhood obesity. The factors that may contribute to the association between healthy eating habits and dining with family members include learning to eat at a slower pace and learning how to follow internal satiety. Several parent-child feeding strategies are also cited which include restriction of access to particular foods by parents.Peer reviewe

Quality of life and associations with health-related behaviours among older adults with increased cardiovascular risk

Background and aims: A better understanding of the relationship between cardiovascular disease risk factors and quality of life (QoL) in older age is needed to inform development of risk reduction strategies. This cross-sectional study investigated the association of QoL with health-related behaviours in older adults at risk of heart failure. Methods and results: Older adults (N Z 328) at risk of heart failure residing in Melbourne, Australia, provided data on QoL and health-related behaviours including physical activity, diet, smoking and alcohol consumption. Multiple linear regression modelling was used to examine associations between health-related behaviours, QoL and its constituent domains. After adjustment for age, gender, body mass index and comorbidities, current smoking was found to have a negative association with the mental component score (MCS) of QoL (b = Z 0.174, p = 0.01), with a positive association seen between MCS and physical activity (b Z 0.130, p Z 0.01). Current alcohol use had a positive association with the physical component score (PCS) (b Z 0.120, p Z 0.02) and saturated fat intake consumption had a negative association with the physical functioning domain of QoL (b Z 0.105, p Z 0.03) but was not associated with either PCS or MCS. Conclusion: Engagement of older adults at increased cardiovascular risk with behavioural risk factor modification using QoL as a driver of change may offer new opportunities to promote healthy ageing. Development of such strategies should consider that for some behaviours which are cardiovascular risk factors (alcohol intake, in particular), the positive association to QoL is complicated and needs further deliberation.Thara Govindaraju, Tracy A. McCaffrey, John J. McNeil, Christopher M. Reid, Ben J. Smith, Duncan J. Campbell, Danny Liew, Alice J. Owe

Energy density of the diet and change in body fatness from childhood to adolescence : is there a relation?

Original article can be found at: http://www.ajcn.org/ Copyright American Society for Nutrition [Full text of this article is not available in the UHRA]Background: The contribution of energy density (ED) of the total diet to increased risk of obesity from childhood into adolescence is unclear. Objective: We assessed the relation between the ED of the diet in childhood, calculated in a number of ways, and change in adiposity from childhood to adolescence. Design: In a prospective study, 48 children (30 boys, 18 girls) were initially studied at age 6 – 8 y (baseline) and followed up at age 13–17 y. Daily ED, energy intake, and food intake were assessed at baseline by 7-d weighed food records concurrent with estimates of total energy expenditure (TEE) by doubly labeled water. ED was calculated with the use of 5 published methods. Obesity risk was defined with the use of body fat from total body water by isotope dilution. Body fat was normalized for height and expressed as fat mass index (FMI). Change in adiposity was calculated as follow-up FMI minus baseline FMI. Results: Misreporting of energy intake at the group level at baseline was low relative to the TEE. ED of the total diet at baseline by the 3 methods for calculating ED that excluded all or most beverages was prospectively associated with change in FMI. However, ED of the total diet by any of the methods was not associated with change in the percentage body fat, body mass index, or waist circumference z scores. Conclusion: The methods used to calculateEDand to assess obesity risk lead to different conclusions about the relation between the ED of the diet in childhood and gain in fat into adolescence.Peer reviewe