Implications of obesity in exceptional longevity

Abstract

Except for the world's poorest regions, it is estimated that global obesity [body mass index (BMI) >30 kg/m 2 ] prevalence will reach 18% (men) and >21% (women) by 2025 (1). Recent nationally representative surveys in the US for the 2013-2014 period indicate age-adjusted obesity prevalence of 35.0% and 40.4% among adult men and women, respectively (2) and of 17.0% for children and adolescents aged 2-19 years (3). On the other hand, because healthy life expectancy also shows global improvement, the world is becoming apparently heavier and healthier (4). This finding is paradoxical given the association of obesity, and especially severe/morbid obesity, and/or its metabolic consequences with all-cause mortality as well as with a broad range of diseases and health complaints (5). In fact, recent data suggest that life expectancy will start to decline in the US over this century. Accordingly, we could be approaching a tipping point where technological and medical care advances might no longer compensate for our poor lifestyle habits (6).Centenarians show exceptional longevity (~20+ years more than the average Westerner) and most have postponed, and some even escaped major diseases despite their advanced age. The latter represents the paradigm of extended healthy life expectancy that any individual would dream of reaching.We assessed BMI in three independent centenarians' cohorts of both sexes that we have studied extensively (7): n=81 from Northern Italy (Lombardy, Piedmont); n=84 from Spain (central area); and n=467 from Japan [participants in the Tokyo Centenarians and semi-supercentenarians (SS) study] (7). The Italian centenarians were free of major agerelated diseases (cancer, CVD, dementia). (7). We compared BMI mean values and categories across cohorts with one-group ANOVA and χ 2 tests, respectively. We obtained approval from the local ethics committees [European University of Madrid (Spain), 2E Science (Italy), and Keio University (Japan)]. The study followed the tenets of the Declaration of Helsinki for Human Research. Results are shown in Table 1. Aside from some geographic-specific differences (Japanese centenarians had the lowest BMI and a high prevalence of underweightwhich is concurrent with the typical profile of this country compared with most Western societies), a main result is that the percentage of obese centenarians was well below the estimated current values for adults [age-standardized obesity of 10.8% (95% CI: 9.7-12.0) in men and 14.9% (95% CI: 13.6-16.1) in women] (1). Notably, we found no obese male centenarians in any of the cohorts. Italy has one of the world's highest percentages of obese people [ranked number 9 (men) and 14 (women) in 2014] (1). And yet there were no obese disease-free centenarians in the Italian cohort.According to our results, obese people do not show healthy life expectancy. Compared to other hominoids, humans show an evolved predisposition to deposit fat.