Limiting sugar consumption during the first 1,000 days of life may be linked to slower biological aging and lower rates of several cancers up to five decades later, according to new research. That period stretches from conception through a child’s second birthday.

The study, published in the Proceedings of the National Academy of Sciences, examined data from over 64,000 UK Biobank participants born between 1951 and 1956. Researchers investigated whether sugar exposure early in life was associated with health differences in adulthood.

To explore that question, the researchers used a natural experiment created by sugar rationing in Britain. The policy ended abruptly in September 1953, allowing them to compare people exposed to different sugar conditions during their earliest years.

After rationing ended, average daily sugar consumption across the U.K. nearly doubled from about 41 grams to 80 grams. Consumption of other major foods remained stable, according to historical National Food Survey data cited in the study.

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Researchers compared people who experienced sugar rationing during their first 1,000 days with those conceived after the restrictions ended. They then examined cancer outcomes recorded about five decades later.

People who spent more of their earliest days under sugar rationing had lower rates of liver, rectal, lung, prostate and breast cancers in adulthood. The findings suggest that sugar exposure during pregnancy and the first years of life may be associated with health decades later.

Participants exposed to the early sugar limits also had longer leukocyte telomeres, the protective caps on chromosomes that tend to shorten with age. The difference was equivalent to about two fewer years of biological aging.

Those participants also had lower levels of Granzyme B, a protein associated with long term immune activation and inflammation. Researchers identified a biological imprint and a persistent behavioral habit as two possible pathways behind the results.

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Five decades after rationing ended, people exposed to the restrictions during their earliest days were still eating less sugar. They also maintained healthier and more varied diets, according to the research.

"What surprised me most was how persistent the effects were," study author Weilong Zhang of the University of Cambridge told Fox News Digital. The results indicated that early differences remained visible in both diet and biological markers.

"We might expect childhood diet to matter for health, but differences in sugar exposure during just the first 1,000 days were still reflected in people's diets and biological markers roughly five decades later."

Zhang said early life may be particularly important for biological development and for establishing food preferences that continue over time. However, experts said more research is needed to confirm the connection between early sugar consumption and later cancer risk.

Dr. Brian Slomovitz, deputy director of the Sylvester Comprehensive Cancer Center at Mount Sinai Medical Center in Miami Beach, described the research as useful for generating hypotheses. Slomovitz was not involved in the study.

Dr. Marc Siegel, senior medical analyst for Fox News, said high sugar intake has been linked to metabolic disruption, insulin resistance and chronic inflammation, which may contribute to disease risk. He said the lower cancer rates were consistent with the possibility that less early sugar exposure and healthier diets later in life played a role.

However, Slomovitz raised concerns about the age and size of the data. "We're talking about the 1950s, so clearly there are some biases in data collection," he said, while also noting that most of the cancers had fewer than 100 cases.

Slomovitz also pointed to the reduced lung cancer risk, since that cancer is traditionally connected to external factors such as smoking rather than dietary sugar. Meanwhile, the researchers acknowledged that a natural experiment cannot rule out every other postwar factor.

The UK Biobank is not fully representative of the broader British population. Researchers also could not determine how much of the association reflected biological changes in early life and how much came from healthier diets maintained into adulthood.

Zhang cautioned against treating the findings as a reason to adopt extreme restrictions. "I would not interpret our study as saying that parents should eliminate sugar completely," he said.

"Rather, our findings support existing recommendations to limit added sugar, particularly during pregnancy and early childhood." The researchers and outside experts stressed that the findings require further study.