A severe economic crisis in Cuba in 1991-1995 that caused extreme food and fuel shortages was associated with a population-wide loss of 4-5 kg in weight, accompanied by dramatic reductions in diabetes and cardiovascular mortality, according to a report published online April 9 in the BMJ.
As the crisis resolved, the population’s rebound in body weight was associated with a rise in diabetes incidence and mortality, and a leveling off of the decline in CV mortality, said Dr. Manuel Franco of the social and cardiovascular epidemiology research group, University of Alcala, Madrid, and his associates.
"The Cuban experience shows that within a relatively short period, modest weight loss in the whole population can have a profound effect on the overall burden of diabetes," as well as CV disease and all-cause mortality." These data are a notable illustration of the potential health benefits of reversing the global obesity epidemic," the investigators said.
Dr. Franco and his colleagues studied population-wide changes in body weight over time using data from several annual cross-sectional health surveys performed in the province of Cienfuegos, Cuba, from 1980 to 2010. Each year’s surveys involved 1,000-2,000 respondents aged 15 years and older who self-reported their physical activity levels. Population data regarding energy intake, smoking, diabetes, and mortality were derived from other surveys.
During the economic crisis, food was scarce and motorized transportation came to a virtual standstill in Cuba. The consequent increase in walking and biking, together with reduced caloric intake, "put the entire population in a negative energy balance," they said.
Urban agriculture was encouraged, giving more people access to fresh produce. Public health campaigns emphasized community gardening and improved nutrition, and more than 1 million bicycles were distributed to the population.
The Cuban economy began recovering in 1996 and has shown sustained growth since 2000.
Several health issues reflected this time trend.
The average daily intake of energy per capita decreased to a nadir in the mid-1990s, then rebounded to pre-crisis levels in the mid-2000s and has since increased further. There was a concomitant population-wide decrease of 5.5 kg across all categories of body mass index in the mid-1990s, a rebound to pre-crisis levels in the mid-2000s, and a striking rise in more recent years.
The proportion of the population who were at normal weight was highest, at 56%, in 1995, the final year of the economic crisis. This decreased to 42% in 2010. Concomitantly, the proportion of the population who were overweight or obese rose from a low of 33% to a high of 53%.
Similarly, the incidence of diabetes was stable at roughly 1.5-1.8/1,000 population before the economic crisis. It fell to 1.2/1,000 during the crisis and remained low for a few years, then sharply increased beginning in the year 2000. The incidence of diabetes exceeded pre-crisis levels, at 2.2/1,000, in 2002, and rose again to 2.4/1,000 in 2009.
Thus, the overall incidence of diabetes decreased by 53% during and immediately after the economic crisis, then rose by 140% during the subsequent economic recovery, the researchers wrote (BMJ 2013;346:f1515[doi:10.1136/bmj.f1515]).
Diabetes mortality followed a similar pattern, decreasing by 50% during and immediately after the crisis, rebounding by 49% by 2002, and returning to pre-crisis levels by 2010.
Trends in mortality from coronary heart disease also followed suit, falling markedly by 34% during and immediately following the economic crisis, then rebounding to pre-crisis levels. Stroke mortality also followed this pattern. Cancer mortality did not.
"Our study presents the first observation of a population-wide event of this magnitude and its subsequent effects on public health," said Dr. Franco, who is also in the department of epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, and his associates.
In contrast, studies of the effectiveness of preventive lifestyle strategies "have either not produced a beneficial effect on cardiovascular mortality or diabetes control and mortality, or have been unsuccessful in reducing risk to a sufficient degree to warrant a conclusion," the investigators said.
This study was limited in that it could not account for the effects of a concomitant decrease in both the prevalence and the amount of cigarette smoking in Cuba during the economic crisis, they added.
No financial conflicts of interest were reported.