No association between blood telomere length and longitudinally assessed diet or adiposity in a young adult Filipino population.

PURPOSE: Telomeres, DNA-protein structures that cap and protect chromosomes, are thought to shorten more rapidly when exposed to chronic inflammation and oxidative stress. Diet and nutritional status may be a source of inflammation and oxidative stress. However, relationships between telomere length (TL) and diet or adiposity have primarily been studied cross-sectionally among older, overweight/obese populations and yielded inconsistent results. Little is known about the relationship between diet or body composition and TL among younger, low- to normal-weight populations. It also remains unclear how cumulative exposure to a specific diet or body composition during the years of growth and development, when telomere attrition is most rapid, may be related to TL in adulthood. METHODS: In a sample of 1459 young adult Filipinos, we assessed the relationship between blood TL at ages 20.8-22.5 and measures of BMI z-score, waist circumference, and diet collected between the ages of 8.5 and 22.5. TL was measured using monochrome multiplex quantitative PCR, and diet was measured using multiple 24-h recalls. RESULTS: We found no associations between blood TL and any of the measures of adiposity or between blood TL and the seven dietary factors examined: processed meats, fried/grilled meats and fish, non-fried fish, coconut oil, fruits and vegetables, bread and bread products, and sugar-sweetened beverages. CONCLUSIONS: Considering the inconsistencies in the literature and our null results, small differences in body composition and consumption of any single pro- or anti-inflammatory dietary component may not by themselves have a meaningful impact on telomere integrity, or the impact may differ across distinct ecological circumstances.

Further validation of a cigarette purchase task for assessing the relative reinforcing efficacy of nicotine in college smokers.

The authors sought to further validate a cigarette purchase task (CPT), a self-report analogue of a progressive-ratio operant schedule, for the assessment of the relative reinforcing efficacy (RRE) of nicotine in smokers. The measure was assessed in terms of its correspondence to typically observed operant behavior, convergent validity, and divergent validity. Participants were 33 individuals (58% male, age M = 19.30 years) who smoked at least weekly (M = 5.31 cigarettes/day) and underwent a single assessment session. Data from the CPT exhibited the predicted inverse relationship between consumption and price, the predicted relationship between consumption and expenditure, and a heterogeneous pattern of interrelationships among the indices of reinforcement. In addition, 2 indices from the measure, intensity of demand and maximum expenditure for cigarettes, exhibited robust convergent and divergent validity. Although this is an incipient research area and the current study used a relatively small sample, these findings support the validity of a CPT as a time- and cost-efficient method for assessing nicotine reinforcement. Theoretical implications of the findings, limitations, and future directions are also discussed.