if you smoke or are obese you are most likely biologically older than other slim non-smoking individuals, according to an article published online today (tuesday june 14, 2005) by the lancet.
obesity and smoking are important risk factors for many age-related diseases. tim spector (st. thomas' hospital, uk) and colleagues in the usa looked for evidence of ageing at a molecular level in smokers and obese individuals. they analysed telomeres, which cap the ends of the chromosomes in our cells and protect them from damage. every time a cell divides, and as people age, their telomeres get shorter.
the investigators recruited 1122 women from the uk aged 18-76 years onto the study. 119 of the women were obese, with a body mass index (bmi) greater than 30, and 85 women had a bmi under 20. 531 women had never smoked, 369 were ex-smokers, and 203 were current smokers.
the participants were asked to complete a questionnaire on smoking history. their exposure to smoking was measured as pack-years (number of cigarette packs smoked per day_number of years smoking).
the investigators measured the concentrations of a body fat regulator called leptin and telomere length in blood samples from the women. they found that telomere length decreased steadily with age and the telomeres of obese women and smokers were much shorter that those of lean women and never-smokers.
obesity and smoking are important risk factors for many age-related diseases. tim spector (st. thomas' hospital, uk) and colleagues in the usa looked for evidence of ageing at a molecular level in smokers and obese individuals. they analysed telomeres, which cap the ends of the chromosomes in our cells and protect them from damage. every time a cell divides, and as people age, their telomeres get shorter.
the investigators recruited 1122 women from the uk aged 18-76 years onto the study. 119 of the women were obese, with a body mass index (bmi) greater than 30, and 85 women had a bmi under 20. 531 women had never smoked, 369 were ex-smokers, and 203 were current smokers.
the participants were asked to complete a questionnaire on smoking history. their exposure to smoking was measured as pack-years (number of cigarette packs smoked per day_number of years smoking).
the investigators measured the concentrations of a body fat regulator called leptin and telomere length in blood samples from the women. they found that telomere length decreased steadily with age and the telomeres of obese women and smokers were much shorter that those of lean women and never-smokers.