Could access to sugar during the first years of life influence brain health decades later? A historical shift in Britain’s food supply has given researchers an unusual way to explore that question.
People who were exposed to sugar rationing before birth and during their first one or two years of life were less likely to be diagnosed with dementia than those born after rationing ended, according to a study published in the journal Neurology. Dementia also was diagnosed later among those exposed to rationing.
The findings do not prove that limiting sugar during pregnancy or infancy prevents dementia. Researchers did not know how much sugar individual families consumed, and rationing occurred alongside other economic, dietary and social changes that could have affected long-term health.
Still, the study adds to growing interest in whether nutrition during pregnancy and early childhood may shape health well into adulthood.
“Our findings suggest that limiting sugar during the earliest stages of life may have lasting benefits for brain health,” said study author Jiazhen Zheng of The Hong Kong University of Science and Technology in Guangzhou, China. “These results highlight the potential importance of early-life nutrition in reducing the risk of dementia decades later.”
Researchers examined information from 64,737 people born before and after Britain ended sugar rationing in September 1953. Sugar had been rationed during World War II and remained restricted for several years after the war.
The timing created what researchers call a natural experiment. Instead of assigning families to eat different amounts of sugar, they compared people whose earliest years occurred under different national food policies.
Participants were divided into groups based on whether rationing was in place before their birth and through their first year, before birth and through their first two years, or not during either period.
Researchers began tracking participants through medical records when they were an average age of 55. They followed them for up to 15 years to identify dementia diagnoses.
After accounting for age, sex and health factors including high blood pressure and diabetes, people exposed to sugar rationing before birth and through their first year had a 21% lower risk of dementia than those born after rationing ended.
Those exposed before birth and through their first two years had a 23% lower risk. Dementia was diagnosed an average of 2.6 years later among participants with early-life rationing exposure.
A smaller group of participants underwent brain imaging. Those exposed to rationing had more gray matter overall and fewer white matter hyperintensities, areas that can indicate damage to the brain’s small blood vessels and surrounding tissue.
The imaging findings offer possible biological support for the association, but they do not explain whether sugar itself was responsible.
The study could not measure what individual mothers, infants or toddlers ate. Researchers instead used a person’s birth date and the national rationing schedule to estimate early-life sugar exposure.
Families living under rationing also may have differed from those living after it ended in ways that are difficult to fully capture. Their overall diets, living conditions, health care, income and exposure to childhood illness may not have been the same. Sugar and sweets were not the only foods affected by wartime and postwar conditions.
The study also was observational. Although the end of rationing provided a clear historical dividing point, the researchers could not randomly assign sugar intake or rule out every other explanation for the results.
The findings therefore should not be interpreted as evidence that a specific amount of sugar during pregnancy or infancy determines whether someone will develop dementia.
They also should not be used to discourage foods containing naturally occurring sugars, such as fruit or unsweetened milk. The rationing policy primarily restricted table sugar and sweets, while current nutrition recommendations focus on avoiding or limiting sugars added to foods and drinks.
U.S. dietary guidance already recommends that children younger than 2 avoid added sugars because they need nutrient-dense foods to support rapid growth and development. The new study does not establish a separate dementia-prevention recommendation, but it raises questions about whether early nutrition could have consequences that are not apparent until much later in life.
“Limiting added sugars during pregnancy and infancy may be one beneficial step that families and communities can take, but further research is needed to better understand how these early exposures influence dementia risk and to guide public health strategies,” Zheng said.
The authors reported receiving no targeted funding for the study.