Observational study: Less sugar, healthier heart

For 13 years – from 1940 to 1953 – people in the United Kingdom (UK) could only buy very little sugar. They received approximately 230g per person per week in exchange for a ration ticket. This government measure was designed to ensure food supplies during and after World War II. Sugary convenience foods such as chocolate were also very scarce. When sugar rationing was lifted, the UK experienced a veritable sugar boom, and per capita consumption roughly doubled within a year.

Researchers took advantage of this fact to compare the incidence of cardiovascular disease in people born during and shortly after sugar rationing. This indirectly investigated the relationship between sugar consumption in the womb and during the early years of life and cardiovascular health in adulthood.

For their observational study, which was recently published in the journal »The BMJ« , the team led by Jiazhen Zheng from the Hong Kong University of Science and Technology in Guangzhou, China, used the health data of 63,433 people from the UK Biobank who were born in the UK between October 1951 and March 1956. 40,063 of them were exposed to sugar rationing as unborn babies and up to two years after birth, while the remaining 23,370 were never exposed. Since the main recruitment for the UK Biobank ran from 2006 to 2010, the observed people were on average 55 years old at the time of inclusion.

Only data from people who had no heart disease prior to the start of the study were analyzed. The follow-up period was up to 17 years. The primary endpoint was the occurrence of cardiovascular disease or serious cardiovascular events such as heart attack, stroke, or cardiovascular death. The researchers statistically adjusted for genetic, environmental, and lifestyle-related confounding factors.

To ensure that the impacts on heart health were due to sugar rationing and not to other factors such as general birth year or time trends, external validation was conducted with control groups born around 1953 who had not experienced sugar rationing. These included approximately 2,600 UK Biobank participants born outside the UK, as well as approximately 1,700 participants each from two large aging studies from the US and England (HRS and ELSA studies).