Babies born in Britain during the final years of postwar sugar rationing grew into adults with markedly lower rates of several cancers and signs of slower biological ageing, according to a major new study.
Study findings
Researchers examined data from more than 64,000 people born between 1951 and 1956, using the UK Biobank. Those who spent more of their first 1,000 days – from conception to their second birthday – under sugar rationing faced substantially lower lifetime risks of breast, prostate, liver, rectal and lung cancers.
The strongest effect was seen in liver cancer, with rates around 69% lower. Breast cancer incidence was still 36% lower. The differences only emerged decades after rationing ended in September 1953, when sugar consumption nearly doubled almost overnight.
Expert comment
Weilong Zhang, Associate Professor of Economics at the University of Cambridge and co-author of the research, said the end of rationing created a rare natural experiment. He explained: “Children born just a few months apart had very different levels of sugar exposure both in the womb and during early childhood.”
“This is a critical stage because the body is developing very rapidly. Organs are growing, metabolism is taking shape, and the immune system is maturing.”
Biological markers
The team also found biological markers of slower ageing. People exposed to longer periods of rationing had longer telomeres – the protective caps on chromosomes that shorten with age – equivalent to roughly 2.2 years of slower biological ageing. Levels of granzyme B, a protein linked to chronic immune activation, were also lower.
Perhaps most strikingly, the early dietary environment appeared to shape lifelong habits. Prof Zhang said: “What is most surprising, however, is not the cancer results or the biological markers of ageing. It’s how early-life sugar exposure continued to affect people’s diets even 50 years later.”
“We found that people who experienced sugar rationing early in life still consumed less sugar in adulthood, around age 50. They also ate less overall, and their diets were healthier and more diverse.”
Mechanisms and implications
Prof Zhang and colleagues point to two mechanisms. One is biological: early nutrition may programme metabolism, organs and the immune system. The other is behavioural: a taste for less sweetness, formed before the age of two, appears to stick for life.
The findings sit alongside earlier research using the same historical shift, which has linked greater early exposure to rationing with lower risks of type 2 diabetes, hypertension, dementia, Alzheimer’s disease, heart disease and stroke.
Prof Zhang was careful to stress the limits of the evidence, adding: “This does not mean that children should not eat sugar at all, and it certainly does not mean that postwar sugar rationing is a desirable policy.”
“What this historical evidence shows is that, during a critical period of development, even relatively small differences in sugar exposure over a short period may leave effects that are still observable half a century later.”
Children may forget what they ate before their second birthday, he noted, “but their later health, their bodies and even their taste preferences may still carry the imprint of those very early-life experiences”.
