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International Journal of Population Studies

RESEARCH PAPER

Earlier and more rapid ageing: Does nutri-

tion contribute?

1*
2
Giambattista Salinari and Gustavo De Santis
1 Department of Economics and Business, University of Sassari, Via Muroni 25, 07100 Sassari
SS, Italy
2 Department of Statistics, Informatics, Applications “Giuseppe Parenti”, University of Flor-
ence, Viale Morgagni 59, 50134 Florence, Italy

Abstract: This paper estimated three parameters related to demographic ageing, i.e., the acce-
leration in mortality rates as people get older. These parameters are: (i) the age when the
process begins (onset), (ii) the rate of ageing in a (simple) Gompertz model and (iii) the rate of
ageing in a (more elaborate) Gamma-Gompertz model. These three indicators were estimated
on the basis of female cohorts born in seven European countries between 1890 and 1919. Our
results indicated a progressively earlier onset and a steeper rise in the rate of ageing in recent
cohorts, i.e., ageing seems to have accelerated over time. The reasons for these shifts are still
unknown, but due to their similarity with the results of a vast body of experiments of calorie
restriction on lab animals, we suggested here that the changed dietary regime of humans since
the end of the 19th century may have played a part in the evolution of their mortality schedule.
Keywords: ageing, nutrition, Gamma-Gompertz, calorie restriction, ageing onset

*Correspondence to: Giambattista Salinari, Department of Economics and Business, University of Sassari, Via
Muroni 25, 07100 Sassari SS, Italy; Email: gbsalinari@gmail.com

Received: June 3, 2015; Accepted: July 29, 2015; Published Online: August 8, 2015
Citation: Salinari G and De Santis G. (2015). Earlier and more rapid ageing: Does nutrition contribute?
International Journal of Population Studies, vol.1(1): 42–59.
http://dx.doi.org/10.18063/IJPS.2015.01.005.
1. Introduction

Modern individuals living in advanced societies are well fed and enjoy the warmth of their
houses and the protection of antibiotics and vaccines. They suffer from later and slower
“ageing” than their predecessors, if ageing means an increase in the risk of death con-
nected to becoming older. The chances of survival have rapidly improved almost every-
where in the past 200 years or so. Anecdotally, one may note that in France for example, a

Copyright: © 2015 Giambattista Sali- forty-year old woman in 2005 had exactly the same life expectancy as a thirty-year old

nari and Gustavo De Santis. This is an woman in 1952 (Sanderson and Scherbov, 2008; 2013). More systematic statistical infor-
Open Access article distributed under mation can be found almost everywhere, for instance in the HMD (Human Mortality Da-
the terms of the Creative Commons
Attribution-NonCommercial 4.0 Interna- tabase), which also happens to be the source of data for our analysis. However, the con-
tional License (http://creativecommons. nection between longevity and physiological ageing is elusive and the two concepts are
org/licenses/by-nc/4.0/), permitting all not synonymous (Baudisch, 2011; Baudisch and Vaupel, 2012). Biologists and gerontolo-
non-commercial use, distribution, and
reproduction in any medium, provided gists interpret ageing (or senescence) as the process by which molecular damage increases
the original work is properly cited. at the cellular level (Rattan, 2006; 2008). This of course affects the probability of death but

International Journal of Population Studies |2015, Volume 1, Issue 1 42