A re-analysis of the long-term effects on life expectancy of the Great Finnish Famine of 1866–68

Abstract

The results of studies exploring the long-term consequences of famine during foetal or infant development are inconsistent. We tested the hypothesis that selection forces occurring during a famine change the distribution of frailty in the affected cohorts, possibly hiding negative long-term effects. Using mortality data for Finland, gathered from the Human Mortality Database, we explored the effect of being born during the Great Finnish Famine of 1866–68 by comparing mortality at age 60 and over for the 1850–89 births, taking into account unobserved cohort heterogeneity. Contemporaneous Swedish cohorts, unexposed to the famine, were used as an additional control group. When cohort heterogeneity is accounted for, a lower life expectancy at age 60 for male cohorts in Finland born during the famine is observed. The results for females are less conclusive. No substantial changes are seen in the Swedish cohorts. In order to provide consistent estimates of the long-run effects of famines, selection forces need to be considered.

Influence of early-life nutrition on mortality and reproductive success during a subsequent famine in a preindustrial population

“…Our findings suggest that, rather than inducing the adaptive development of a phenotype suited to maximizing fitness in poor nutritional conditions in later life, poor nutritional conditions during development may limit future survival and reproduction. As such, they provide the most definitive test yet of one of the strongest predictions that can be derived from the PAR hypothesis, adding to the evidence that poor early nutrition constrains development to compromise individual fitness (21,28,30,31). Our results do not support the hypothesis that developmental changes resulting from poor early nutrition are due to evolved PARs that increase individual prospects in nutrient-poor environments.…”

“…These associations may have resulted from indirect effects on maternal condition and direct effects on the availability of gruel fed to infants (37). An alternative is selection effects: cohorts suffering high mortality in their first year are subsequently comprised of only a subset of the original individuals (30), which have shown greater survival and which may be more "robust" and not representative of the original cohort. However, greater resilience of these individuals means that it is unlikely that such selection effects would have caused spurious positive associations between early-life food availability and survival.…”

Prenatal loss of father during World War One is predictive of a reduced lifespan in adulthood

“…A striking example is the Finnish famine, when selection induced by the immediate threefold increase in mortality was strong enough to mask a 1-y decrease in adult life expectancy (28,29). Had preferential mortality been present among WWI OS, occupation score (Methods).…”

“…Few studies have investigated the mortality consequences of early-life conditions, including caloric deprivation during gestation (28,29), economic conditions at birth (30), and season of birth (31). For instance, males born at the height of the Finnish famine lost ∼1 y of life expectancy at age 40 y (29).…”

Early-life conditions and adult mortality decline in Dutch cohorts born 1812–1921

“…One possible explanation for the conflicting evidence of the long-term effect of famines on survival is that selection during famine altered the distribution of frailty across the population. Hence, Doblhammer et al (2013) re-analyzed the Finnish data used by Kannisto et al (1997). Simultaneously modeling the frailty distributions of cohorts, they showed that cohorts born during the Great Finnish Famine had a lowered life expectancy.…”